JP2003027222A - Vacuum deposition system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum deposition system which is capable of forming a dense and high-quality film to a large area on a base material. SOLUTION: A cluster evaporation source 3 is used as an evaporation source for evaporating the raw material of the film. Electric power is supplied into a chamber 2 through a base material holder 5 for holding the base material 15 from a rear surface side, by which the clusters spouted from the cluster evaporation source 3 are cluster ionized and the film is formed on the base material 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum film forming apparatus having a cluster evaporation source as an evaporation source for evaporating a film raw material.

[0002]

2. Description of the Related Art A film forming method using a cluster ion beam has been conventionally known. FIG. 4 is a diagram schematically showing a vacuum film forming apparatus 20 capable of forming a film by the cluster ion beam.

In the vacuum film forming apparatus 20 shown in FIG. 4, a base material 25 on which a film is to be formed is held by a base material holder 21 in an upper part of a vacuum chamber 22, and a base material holder is provided in a lower part of the vacuum chamber 22. The cluster evaporation sources 23 are arranged so as to face each other.

The cluster evaporation source 23 evaporates the raw material of the film stored in the crucible 26 and ejects clusters, which are agglomerates of atoms or molecules of the raw material of the film, toward the upper side where the base material 25 is arranged. Let And
The cluster 29 ejected from the cluster evaporation source 23 is ionized by passing through the region where the ionization electrode 27 is arranged, and cluster ions are generated.

The above-mentioned cluster ions are added to the base material 2
5 is accelerated toward the base material 25 by the electric field applied through the accelerating electrode 28 arranged on the front side with respect to 5, and hits the base material. As a result, a film is formed on the base material 25 using the cluster ions.

When a film is formed by using such a cluster ion beam, surface diffusion of atoms or molecules of the raw material of the film on the base material 25 is promoted and a high quality film can be formed.

[0007]

However, when a film is formed by the above cluster ion beam, the vacuum chamber 2 is used in the apparatus for forming the film as described above.
It was necessary to dispose the ionization electrode 27 and the acceleration electrode 28 in the space between the base material 25 and the cluster evaporation source 23 in 2. Therefore, it is necessary to secure a space for providing the ionization electrode 27 and the acceleration electrode 28 between the evaporation source 23 and the base material 25 in the vacuum chamber 22 which is spatially restricted.

When these electrodes 27, 28 are arranged at required positions, the electrodes 27, 28 with respect to the base material 25 are arranged.
Due to the positional relationship, the area where the film can be formed on the base material 25 is limited.

On the other hand, in recent years, it has been desired that a large-area film can be formed on a base material for various devices and the like from the viewpoint of increasing its functionality.

Therefore, the present invention uses the cluster evaporation source as an evaporation source for evaporating the raw material of the film, and
The ionization electrode 27 and the acceleration electrode 2 are placed in the vacuum chamber.
Without being restricted by the space associated with the provision of 8,
An object of the present invention is to provide a vacuum film forming apparatus capable of forming a large area film on a substrate 25.

[0011]

In order to solve the above-mentioned problems, the present invention provides a vacuum chamber in which a base material on which a film is formed is placed in an internal space, and the base material for forming a film on the base material. A substrate holder that holds the substrate from the back side with respect to the surface that is to be formed, and cluster evaporation that is arranged in the vacuum chamber so as to face the substrate and that ejects clusters, which are clusters of atoms or molecules of the raw material of the film. A power supply unit, a power supply electrode arranged on the back side of the substrate in the vacuum chamber, and a power supply unit for supplying at least high-frequency power into the vacuum chamber via the power supply electrode, The electric power output from the unit is supplied into the vacuum chamber to ionize the clusters ejected from the cluster evaporation source to form cluster ions, and A vacuum film forming apparatus that is configured to deposited by applying to a substrate a Taion (claim 1).

According to the vacuum film forming apparatus of the present invention, since the film is formed by the cluster ions, it is possible to reduce the damage to the base material and to obtain the densely formed high quality film. In order to obtain such a film, it is not necessary to dispose an ionization electrode or an acceleration electrode between the cluster evaporation source and the base material in order to generate cluster ions. There is no restriction on the possible area,
It is possible to form a film in a large area.

Further, in generating the cluster ions to act on the base material, since electric power is supplied through the power supply electrode arranged on the back side of the base material, the conditions for obtaining the required cluster ions must be adjusted. You can easily.

Here, the above-mentioned cluster is a group in which hundreds to thousands of atoms or molecules of the raw material of the film are weakly bonded by intermolecular force or the like.

The cluster ions are those that are ionized and positively charged by applying a certain energy to the clusters.

Further, in the vacuum film forming apparatus, the base material holder may be formed of a conductive material, and the base material holder may be formed so as to function also as an electrode for power supply (claim 2). . As a result, the base material holder is also used as the power supply electrode, so that the structure in the vacuum chamber can be made more compact. Also,
Since electric power for generating cluster ions that act on the base material can be supplied by the base material holder that holds the base material from the back side, it is possible to further easily adjust the conditions for obtaining the required cluster ions.

Further, in the above vacuum film forming apparatus, the power supply unit can also be configured to be able to supply DC power (claim 3). As a result, the cluster ions can be more effectively accelerated toward the base material, and a denser film can be formed, and the film quality can be improved.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the vacuum film forming apparatus of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a vacuum film forming apparatus 1 according to an embodiment of the present invention, and shows a schematic structure of the film forming apparatus 1. The vacuum film forming apparatus 1 includes a vacuum chamber 2 in which a substrate 15 on which a film is formed is arranged in an internal space. The space inside the vacuum chamber 2 is evacuated through a gas exhaust port 14 by a vacuum pump (not shown) to create a required vacuum atmosphere for film formation.

The vacuum chamber 2 is also provided with a first gas supply port 13a and a second gas supply port 13b.
Then, an inert gas such as argon can be supplied into the chamber 2 through the first gas supply port 13a, and a reactive gas such as oxygen or nitrogen can be supplied through the second gas supply port 13b. It can be supplied into the chamber 2. The first gas supply port 13a and the second gas supply port 13b are each supplied with the above-mentioned gas at a required pressure by a gas cylinder (not shown).

The inert gas supplied through the first gas supply port 13a is used as a medium for generating plasma in the vacuum chamber 2, and the reaction is supplied through the second gas supply port 13b. The characteristic gas is used as a raw material for the film.

The vacuum atmosphere in the vacuum chamber 2 is preferably maintained so that the mean free path in the chamber 2 becomes a pressure longer than the distance between the evaporation source and the substrate. This is because when the pressure in the chamber 2 becomes higher than that, the number of collisions between clusters described later and between clusters and another gas medium increases, so that the number of cluster ions effectively incident on the base material 15 decreases. .

A cluster evaporation source 3 is arranged in the lower part of the vacuum chamber 2. The cluster evaporation source 3 includes a crucible 6 and a bombarded filament 7 arranged in a coil shape along the outer circumference of the crucible 6.

The crucible 6 has a structure capable of holding the raw material of the film inside. The crucible 6 can be formed of carbon (carbon C) or the like so that it can be heated to a high temperature. Further, a nozzle 6a formed by a small hole is provided in the center on the upper end surface of the crucible 6, so that the vapor filled in the crucible 6 can be ejected from the nozzle 6a into a vacuum atmosphere as described later. Has been done.

The bombarded filament 7 is electrically connected to a heating power source (not shown), and when heated by being supplied with power from the heating power source, the crucible 6 inside is heated.
It is designed to be able to emit electrons toward.

Next, the principle of discharging the clusters 12 from the cluster evaporation source 3 will be described with reference to FIG. As described above, the bombarded filament 7
When is heated, electrons (e-) are emitted from the bombarded filament 7, and the electrons collide with the crucible 6 to heat the crucible 6.

When the crucible 6 is heated, the raw material of the film held in the crucible 6 is heated and starts to evaporate. Then, the vaporized raw material of the film stays in the limited space above the crucible 6 to form high-pressure vapor.
When this high-pressure steam exceeds a certain pressure, the nozzle 6 of the crucible 6
Eject from a into a vacuum atmosphere.

When the vaporized raw material of the film is ejected from the nozzle 6a into the vacuum atmosphere, it is cooled in the adiabatic expansion process, and several hundred to several thousand atoms or molecules of the raw material of the film are converted into molecules. A cluster 12 is formed, which is a group that is weakly coupled by an inter-force or the like.

A substrate holder 5 for holding the substrate 15 on which a film is to be formed from the back side of the surface of the substrate 15 on which the film is to be formed is arranged in the upper part of the vacuum chamber 2. . In addition, in this example, the base material holder 5 is formed of a conductive material, and is formed so as to also function as a power supply electrode for supplying power to the vacuum chamber 2 through the base material holder 5.

Further, the base material holder 5 is provided with a rotary shaft that is rotationally driven so that a film can be formed while rotating the base material 15. That is, the base material holder 5 is rotatably driven about the axis of the rotation shaft by a rotation driving means such as a motor (not shown).

The base material holder 5 is adapted to be capable of supplying electric power from a power supply unit 10 described later through a mechanism capable of transmitting electric power while being in contact with its rotating shaft.

The power supply unit 10 ionizes the clusters 12 ejected above the cluster evaporation source 3 into cluster ions and supplies electric power for accelerating the cluster ions toward the base material 15 by an electric field. To do.

The power supply unit 10 includes a high frequency power supply (RF) 8 which outputs high frequency power and a direct current power supply (DC) 9 which outputs direct current power. The high frequency power supply 8 is electrically connected to the base material holder 5 so as to transmit electric power to the base material holder 5 via a matching box (MB) 11 and a DC blocking capacitor (not shown). The DC power supply 9 is electrically connected to the base material holder 5 via a choke coil (not shown).

The matching box 11 performs a matching operation to match the impedance of the high frequency power source 8 and the impedance of the chamber 2 side. The circuit in this matching box 11 is, as shown in FIG.
For example, variable capacitors C1 and C2 and choke coil L
1 is a well-known one.

When the high frequency power source 8 and the direct current power source 9 are connected to the chamber 2 side, the chamber 2 made of a conductive material is grounded, and the output terminal of the high frequency power source 8 is closer to the substrate holder 5 side. The other side to is grounded. The DC power supply 9 is connected such that the base material holder 5 side is a negative electrode and the other side is grounded.

Regarding the structure for supplying electric power from the power supply unit 10 while rotating the base material holder 5 by the rotating means, various publicly known devices used in the conventional vacuum film forming apparatus based on ion pre-plating. (For example, see Japanese Patent Publication No. 1-48347) can be applied.

When the power source unit 10 is operated to supply high frequency power and DC power into the vacuum chamber 2 while the cluster is being ejected from the cluster evaporation source 3, the cluster is ionized and the cluster ion is generated. Can be applied to the base material 15 to form a film.

That is, when high-frequency power is supplied to the vacuum chamber 2, the high-frequency electric field excites the clusters or turns them into plasma, and cluster ions can be generated.

Then, the generated cluster ions are accelerated toward the base material 15 by the DC electric field accompanying the supply of DC power. The cluster ions incident on the base material 15 are decomposed into constituent atoms or molecules of clusters on the base material 15 and diffused, and a film is formed on the base material 15.

Further, in the film forming apparatus 1, the following can be carried out when generating cluster ions. That is, the inert gas having the required gas pressure is supplied from the first gas supply port 13a. Then, the power supply unit 10 is operated to generate plasma using the inert gas as a medium in the chamber 2.

Then, when the plasma of the inert gas is generated in the chamber 2 and the clusters are ejected from the cluster evaporation source 3, cluster ions made of the raw material of the film can be generated.

Further, in this film forming apparatus 1, it is possible to generate the cluster ions while supplying the reaction gas from the second gas supply port 13b. That is, while ejecting the cluster from the cluster evaporation source 3, the reaction gas at a required pressure is supplied from the second gas supply port 13b to operate the power supply unit 10.

As a result, the reaction gas can be turned into plasma or excited, and the reaction gas that has been turned into plasma can be used to ionize the clusters to generate cluster ions. When the reaction gas is thus supplied, the raw material of the film that has become the cluster ions is deposited on the base material 15 to form a film, and the elements contained in the reaction gas are also added to the base material. A film is formed by depositing on 15.

As described above, when plasma such as an inert gas or a reaction gas is generated in the vacuum chamber 2 and the plasma excites the clusters,
Cluster ions can be efficiently generated.

With respect to the power supply unit 10 described above, it is sufficient that at least high frequency power can be output when the cluster ions are generated and the film is formed, and the DC power supply 9 is not always necessary.

That is, when high-frequency power is supplied into the chamber 2 to generate positively charged cluster ions, the cluster ions can be accelerated toward the base material 15, so that a film can be formed. Because it is.
This is because, when positively charged cluster ions are present in the high frequency electric field, a direct current electric field is formed due to so-called self-bias, and can be accelerated toward the base material 15.

However, if DC power is also supplied from the DC power supply 9, the cluster ions are added to the base material 15.
It is possible to accelerate more effectively toward, and it becomes possible to form a denser film, and the quality of the film can be improved.

When the film is formed by the above-described film forming apparatus 1, the following meanings can be achieved. According to the vacuum film forming apparatus 1, since the cluster ions are used for making the charged particulate matter incident on the base material 15 to form a film, damage to the base material 15 can be reduced and the base material 15 can be formed densely. A high quality film can be obtained.

That is, when a film is formed by using the cluster ion by the vacuum film forming apparatus 1, the electric charge is held in the cluster unit when the cluster ion is generated, and therefore, the energy held by each particle constituting the cluster is The size can be reduced, and the impact when cluster ions are incident on the base material 15 can be reduced to reduce damage to the base material 15.

Further, the atoms or molecules forming the clusters are easily diffused on the base material 15, so that a dense film can be formed and the film quality can be improved.

On the other hand, in a conventional vacuum film forming apparatus based on ion plating in which charged particles are incident on a base material to form a film, plasma of a raw material of the film is generated in a vacuum chamber, and Then, a film is formed by injecting into the base material in units of atoms or molecules constituting plasma. Then, in the conventional vacuum film forming apparatus based on ion plating, when plasma is generated, it is generated so as to hold electric charges mainly in units of atoms or molecules that form the raw material of the film.

Therefore, in the conventional vacuum film-forming apparatus based on ion plating, individual high-energy particles generated so as to hold charges in atomic units or molecular units are incident on the substrate to form a film. Will be done. Therefore, the energy per particle entering the base material is higher than that in the case of using the cluster evaporation source, the impact given to the base material is large, and the base material is easily damaged. Also,
If the energy of the particles is large, it is difficult to diffuse them on the substrate,
It is difficult to increase the film compactness.

When the cluster ions are made to act on the base material 15 to form a film as in the vacuum film forming apparatus 1 of the present invention, the energy of particles per atomic unit or molecular unit can be made relatively low. Thereby, as described above, damage to the base material 15 can be reduced and the quality of the obtained film can be improved.

Further, according to the vacuum film forming apparatus 1 of the present invention,
When the above-described cluster ions are generated to form a film, an ionization electrode for ionizing the clusters and an acceleration electrode for accelerating the cluster ions toward the base material are provided between the base material and the cluster evaporation source. There is no need to specially install it. That is, the vacuum film forming apparatus 1 of the present invention
According to the above, by supplying electric power into the vacuum chamber 2 through the base material holder 5, cluster ions can be generated and a film can be formed by the cluster ions.

As a result, there is no need to specially provide an ionization electrode or an acceleration electrode between the cluster evaporation source and the base material, and there is no restriction on the film formation area due to the provision of these electrodes. A large area can be formed on the substrate.

According to the vacuum film forming apparatus 1 of the present invention,
When generating the cluster ions that act toward the base material 15, electric power is supplied through the base material holder 5 that holds the base material 15 from the back side, so that it is easy to adjust the conditions for obtaining the required cluster ions. You can

In the above description, an example in which the base material holder 5 also serves as an electric power supply electrode for supplying electric power for generating cluster ions in the vacuum chamber has been described. The supply electrode may be provided separately.

Even in the case where the power supply electrode is provided separately from the base material holder, the power supply electrode does not spatially interfere with the base material holder on the back surface side of the base material in the vacuum chamber, and the power supply electrode is vacuumized. It is provided so that the required electric power can be supplied to the chamber.

As described above, even when the power supply electrode is provided separately from the base material holder, it is not necessary to provide an ionization electrode or an acceleration electrode between the base material and the cluster evaporation source. It is possible to take a large area for forming a film on top.

Even when the power supply electrode is provided separately from the base material holder, the power supply electrode arranged on the back side of the base material is used to generate the cluster ions to act on the base material. Since electric power is supplied through the electrodes, it is possible to easily adjust the conditions for obtaining the required cluster ions.

[0061]

As described above, according to the vacuum film forming apparatus of the present invention, it is possible to obtain a dense and high-quality film by using cluster ions and to form a large film on the substrate. This has the effect of forming a film in an area.

Further, in generating the cluster ions to act on the base material, since electric power is supplied through the power supply electrode arranged on the back side of the base material, the conditions for obtaining the required cluster ions must be adjusted. There is also an effect that it can be easily done.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an outline of a configuration of a vacuum film forming apparatus of the present invention.

FIG. 2 is a diagram showing in detail a cluster evaporation source.

FIG. 3 is a circuit diagram showing an example of a circuit in a matching box.

FIG. 4 is a diagram showing a vacuum film forming apparatus using a conventional cluster evaporation source.

[Explanation of symbols] 1 Vacuum film forming equipment 2 vacuum chamber 3 Cluster evaporation source 5 Base material holder 6 crucibles 6a nozzle 7 bombarded filament 8 high frequency power supply 9 DC power supply 10 power supply unit 11 Matching Box 12 clusters 13a First supply port 13b Second supply port 14 exhaust port 15 Base material 20 Conventional vacuum film forming apparatus 21 Substrate holder 22 Vacuum chamber 23 Cluster evaporation source 25 base material 26 crucibles 27 Ionization electrode 28 Accelerating electrode 29 clusters

Claims (3)

[Claims] 1. A vacuum chamber in which a base material on which a film is formed is arranged in an internal space, a base material holder for holding the base material from a back side of a surface of the base material on which a film is to be formed, A cluster evaporation source which is arranged in the vacuum chamber so as to face the base material and ejects a cluster that is an agglomerate of atoms or molecules of the raw material of the film, and a cluster evaporation source on the back side of the base material in the vacuum chamber. The power supply electrode is arranged, and a power supply unit for supplying at least high-frequency power into the vacuum chamber via the power supply electrode, the power output from the power supply unit is supplied into the vacuum chamber The cluster ejected from the cluster evaporation source is ionized into cluster ions,
A vacuum film forming apparatus configured to cause the cluster ions to act on a substrate to form a film. 2. The vacuum film forming apparatus according to claim 1, wherein the base material holder is formed of a conductive material, and the base material holder is formed so as to also function as an electrode for power supply. . 3. The vacuum film forming apparatus according to claim 1, wherein the power supply unit is also configured to supply DC power.