JP2000290771A - Production of thin film and thin film producing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for accelerating ionized material grains to the surface of a base material without being restricted by the shape and electrical conductivity of the base material and a holding method in the conventional thin film forming technique. SOLUTION: As to the method for producing a thin film, plasma 42 is generated in the space between a material feeding part 2 and a base material 31 in a vessel 1 capable of being evacuated to vacuum, and, while the electric potential of plasma is controlled by the electric potential of an electrode installed in the space the same as that of the plasma, film formation is executed. Moreover, as to the thin film producing device, the inside of the vessel 1 capable of evacuation is provided with the material feeding part 2 and the base material holding part 3 respectively one by one, moreover, the space between the material feeding part and the base material holding part is provided with a plasma generating means 4, and, furthermore, the space same as that of the plasma 42 generated by the plasma generating means is provided with an electrode 5 for controlling the plasma potential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film manufacturing method and a thin film manufacturing apparatus suitable for realizing the method.

[0002]

2. Description of the Related Art Conventionally, in a thin film forming process such as sputtering or plasma-assisted deposition, a technique of accelerating ionized material particles to a substrate surface using an electric field to improve adhesion and film quality has been known as bias sputtering (Hosokawa, Kobayashi). : "Introduction to Thin Film Technology for Components and Devices", Sogo Denshi Publishing, 1st edition, 1992, p108) and ion plating (Hosokawa and Kobayashi: "Introduction to Thin Film Technology for Components and Devices", Sogo Denshi Publishing 1st edition, 1992, p112)
It is widely known by the name. As a method for accelerating the ionized material particles to the surface of the substrate, (1) a method of applying a voltage to the substrate, (2) a method of arranging an electrode to which a voltage is applied behind the substrate, and (3) A method of arranging a mesh-like grid electrode to which a voltage is applied between a base material and a material supply unit is known.

[0003]

However, the conventional methods for accelerating ionized material particles to the surface of a substrate have the following problems.

First, the method (1) of applying a voltage to a substrate is limited in application to film formation on a conductive material. In the method (2) of disposing an electrode to which a voltage is applied behind a substrate, it is difficult to apply the method to film formation on a substrate having a three-dimensional shape. In both of the methods (1) and (2), when the base material is held by a conductive member, it is necessary to insulate the base material from the device housing. The holding mechanism includes a mechanism such as rotation, cooling, and heating. Make it difficult to add. Further, in the method (3) of disposing the grid electrode to which a voltage is applied between the base material and the material supply unit, the grid electrode hinders the course of the material to be attached to the base material, thereby impairing the uniformity of the film. Sometimes. In addition, since the material adheres to the mesh grid electrode and causes clogging, it is extremely difficult to apply the method to industrial long-time film formation.

Accordingly, the present invention solves the above-mentioned problems,
It is an object of the present invention to industrially realize a method for accelerating ionized material particles to the surface of a substrate without being limited by the shape, conductivity, and holding method of the substrate.

[0006]

In order to achieve the above object, the present invention comprises the following constitution. That is, [1] a plasma is generated between a material supply unit and a substrate in a container that can be evacuated to a vacuum, and the potential of the plasma is controlled by the potential of an electrode installed in the same space as the plasma. A method for producing a thin film, comprising forming a film.

As a method of generating plasma between the material supply unit and the base material, a method of installing an electrode between the material supply unit and the base material and applying a voltage, or a method of using a micrometer without using an electrode. Although a method of inputting an electromagnetic wave such as a wave may be mentioned, any method may be used in the present invention. In addition, the electrodes installed in the same space as the plasma may be installed separately from those for generating or supporting the generation of plasma. Further, the control of the potential of the plasma can be performed by connecting a power supply to an electrode provided in the same space as the plasma. Note that the potential for controlling the potential of the plasma is preferably about -300 to +300. −300
If the voltage is less than V, the electrode is worn by being hit by ions, and +3
If it exceeds 00V, the energy of the accelerated material ion
Tend to be too large to increase the possibility of damaging the membrane.

[2] The method for producing a thin film according to [1], wherein the film is formed while controlling the material supply amount, the plasma density and the plasma potential independently.

When the material supply amount or the plasma density is changed, the plasma potential may be affected. However, the plasma potential is controlled to a desired value by the potential of an electrode provided in the same space as the plasma. The desired value of the plasma potential varies depending on the process, but a range of + several V to +200 V is preferable because it is effective and sufficient.

According to the present invention, the kinetic energy at which the film-forming material ions in the plasma are incident on the substrate can be controlled by controlling the potential of the plasma. It becomes possible. Specifically, carbides such as diamond and diamond-like carbon and tungsten, silicon, titanium, nitrides,
Suitable for making oxides or borides. It is also suitable for manufacturing a transparent conductive film using indium oxide and / or zinc oxide whose film properties are sensitive to the crystallinity of the film.

[3] The sheet resistance of the surface is 10/8 Ω / □
The method for producing a thin film according to the above [1] or [2], wherein a thin film is formed on the above substrate.

An example of a substrate having a surface sheet resistance of 10 @ 8 .OMEGA ./. Quadrature. Or more is made of a material such as an oxide or a polymer, and is not particularly devised to impart conductivity. Applicable. Specific examples include glass, paper, polyethylene terephthalate, polypropylene, and polyimide. In addition, the shape and size of the base material are not particularly limited,
Any of plate, band, fiber and powder may be used. In the present invention, since the accelerating electric field of the material ions is controlled by the potential of the plasma, it is not necessary to apply a voltage to the substrate, and the sheet resistance of the surface is 10%.
Suitable for film formation on a substrate of ↑ 8Ω / □ or more.

The sheet resistance is defined by JIS K-6911, and is a value measured using a four-point probe method.

[4] The method for producing a thin film according to any one of [1] to [3], wherein the thin film is formed on a substrate whose surface is at least partially made of an organic substance.

Examples of the organic substance include polyethylene terephthalate, polypropylene and polyimide. In the present invention, since the accelerating electric field of material ions is controlled by the potential of the plasma, the present invention is suitable for forming a thin film on the surface of an organic material in which it is difficult to secure adhesion to the thin film.

[5] At least one material supply section and at least one substrate holding section are provided in a container capable of being evacuated to a vacuum, and plasma generating means is provided in a space between the material supply section and the substrate holding section. And a plasma potential controlling electrode is provided in the same space as the plasma generated by the plasma generating means.

As means for generating plasma between the material supply unit and the base material (plasma generation means), an electrode for applying a voltage between the material supply unit and the base material is provided,
Means for injecting electromagnetic waves such as microwaves into the space between the material supply unit and the base material may be mentioned, but any method may be used in the present invention. In addition, the electrodes installed in the same space as the plasma may be installed separately from those for generating or supporting the generation of plasma. In addition, a power supply can be connected to an electrode installed in the same space as the plasma in order to control the potential of the plasma.

[6] The electrode according to [5], wherein the plasma potential control electrodes are arranged so as not to hinder the course of the material supplied from the material supply unit until the material adheres to the substrate surface. The thin film manufacturing apparatus according to the above.

As the arrangement of the plasma potential control electrode which does not hinder the course of the material supplied from the material supply section, if a ring-shaped electrode surrounding the contour of the film formation region on the surface of the substrate is arranged, the plasma potential can be made uniform. It is preferable because it is easy to control.

[7] The material supply unit includes resistance heating, induction heating, electron beam heating, plasma beam heating, and laser beam heating.
The thin film manufacturing apparatus according to the above [5] or [6], further comprising at least one type of evaporation source of the abrasion.

Resistance heating is a method in which a current is passed through a heater such as tungsten to heat the material, and the heat is used to heat the material. Electron beam heating is a method of heating a material surface on which an electron beam is to be evaporated by accelerating, converging, and irradiating the material surface with a magnetic field or an electric field. Plasma beam heating is a method of heating by accelerating, focusing, and irradiating the surface of a material from which ions and / or electrons of plasma are to be evaporated with a magnetic field or an electric field.

Laser abrasion is means for breaking the atomic bonds of a solid by the energy of the laser and heating the material to evaporate the material.

[8] The thin film producing apparatus according to [5] or [6], wherein the material supply unit is provided with a DC cathode sputter source or an AC cathode sputter source.

The DC cathode sputter source applies only a DC voltage to the cathode, and the AC cathode sputter source applies an AC or DC superimposed AC voltage to the cathode.

The AC cathode sputtering source referred to here includes:
Also includes a superposition of a direct current on an alternating current applied to a cathode holding a material.

[9] The apparatus for producing a thin film according to the above [5] or [6], wherein a gas nozzle is provided as the material supply section.

The gas nozzle is a mechanism for introducing a gas into a container that can be evacuated to a vacuum.

[10] The above-mentioned [5] to [5], wherein the base material holding section is provided with a transport mechanism for a continuous sheet body.
The apparatus for producing a thin film according to any one of [9].

An example of a continuous sheet conveying mechanism is a winding mechanism. It is preferable to provide a reciprocating transport mechanism in the transport mechanism for the continuous sheet body, since a multilayer film or the like can be easily formed.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of a preferred embodiment of the present invention will be described with reference to the drawings. The embodiment of the present invention is not limited to this.

FIG. 1 is a conceptual diagram for explaining an example of a thin film manufacturing method and a thin film manufacturing apparatus according to the present invention. FIG.
In the container 1, the material 21 is evacuated to a vacuum.
, A material holding unit 3 on which a base material 31 is set, a plasma generation unit 4 including a plasma generation unit 4 for generating a plasma 42 and a plasma generation power supply 41, and a plasma potential A control electrode 5 is provided. Further, a DC power supply 6 for sputtering is connected to the material supply unit 2.

A cathode power supply 6 is connected to the material 21, and a negative voltage is applied. As a result, positive ions (eg, argon ions) in the plasma are accelerated toward the material 21, and particles are sputtered from the material 21 (sputtering) to generate a material vapor 22. Although plasma for sputtering a material can be generated without using the plasma generating means 4, the plasma generating means 4 has a role of ionizing the material vapor 22 in addition to supporting the plasma for sputtering. The potential of the plasma 42 containing the ionized material vapor 22 is controlled by a plasma potential control power supply 51 via the plasma potential control electrode 5. A potential difference is formed between the substrate surface and the plasma 4 due to the ion sheath, and the ionized material vapor 22 is accelerated toward the substrate surface by the potential difference. At this time, it is preferable to dispose a conductor having a ground potential behind the base material, because it is easy to stably and uniformly form a potential difference with the plasma 4.

[0033]

EXAMPLE A quadrupole mass spectrometer equipped with an energy analyzer was installed at the center of the region where the material vapor 22 of FIG. Kinetic energy was measured. The quadrupole mass spectrometer equipped with an energy analyzer was set to the ground potential.

The procedure of the measurement is as follows. First, after evacuating the inside of the container 1 that can be evacuated to a vacuum once to 10 ° -5 Pa or less, an argon gas is introduced up to 0.3, and a current of 0.3 A is supplied to the material supply unit 2 from the DC power supply 6 for sputtering. As a result, a plasma 42 was generated. Then, a power of 200 W at 13.56 MHz is applied to the plasma generation means (electrode) 4, and +30, 50, 7 are applied to the plasma potential control electrode 5.
0, 80, and 120 V applied, and the number of masses 4 incident on a quadrupole mass spectrometer with an energy analyzer per unit time
The number of titanium positive ions of 8 was measured.

FIG. 2 shows the measurement results at this time. The vertical axis represents the logarithm of the count number of titanium ions having a mass number of 48 per unit, and the horizontal axis represents the kinetic energy of the ion as e.
It is represented by V (electron volt). Thus, as the potential applied to the plasma potential control electrode 5 is increased from +30, 50, 70, 80, and 120 V from FIG. 2, the kinetic energy of the titanium ions becomes higher.
You can see that it has shifted to the side. That is, FIG. 2 shows that the potential of the plasma 42 is controlled by the plasma potential control electrode 5 so that the kinetic energy of the ions incident on the base material 31 is reduced.
Can be controlled.

COMPARATIVE EXAMPLE FIG. 2 shows the distribution of kinetic energy of titanium ions when the plasma potential control electrode 5 is removed from the plasma potential control power supply 51 to make it a floating potential and other conditions are the same as in the embodiment. Is shown by a broken line. Thus, FIG. 2 shows that the peak energy of titanium ions is about 25 eV, which is lower than any of the conditions of the embodiment, and the kinetic energy of the material particles is insufficient at the time of forming a film that is difficult to crystallize. This indicates that the possibility that the film quality is deteriorated is large.

[0037]

According to the present invention, a method for industrially accelerating ionized material particles to the surface of a substrate without being restricted by the shape, conductivity and holding method of the substrate in the conventional thin film forming technology is realized. can do.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram for explaining an example of a thin film manufacturing method and a thin film manufacturing apparatus of the present invention.

FIG. 2 is a diagram showing the results of measuring the number of titanium positive ions in Examples and Comparative Examples.

[Explanation of symbols]

 1: Container that can be evacuated to vacuum 2: Material supply unit 21: Material 22: Material vapor 3: Substrate holding unit 31: Substrate 4: Plasma generation means 41: Power supply for plasma generation 42: Plasma 5: For plasma potential control Electrode 51: Power supply for plasma potential control 6: DC power supply for sputtering

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K029 AA11 DA02 DB18 DB19 DB20 DC28 DC34 DC35 EA00 JA01 JA10 KA03

Claims (10)

[Claims] 1. A plasma is generated between a material supply unit and a substrate in a container that can be evacuated to a vacuum, and the potential of the plasma is controlled by the potential of an electrode provided in the same space as the plasma. A method for producing a thin film, comprising forming a film. 2. The method for producing a thin film according to claim 1, wherein the film is formed while controlling a material supply amount, a plasma density and a plasma potential independently. 3. The method for producing a thin film according to claim 1, wherein the thin film is formed on a base material having a surface sheet resistance of 10 @ 8 .OMEGA ./. Quadrature. Or more. 4. The method for producing a thin film according to claim 1, wherein the thin film is formed on a substrate whose surface is at least partially made of an organic substance. 5. A container that can be evacuated to a vacuum, has at least one material supply unit and at least one substrate holding unit, and has a plasma generating unit in a space between the material supply unit and the substrate holding unit. And a plasma potential control electrode in the same space as the plasma generated by the plasma generating means. 6. The plasma potential controlling electrode is arranged so as not to hinder the course of the material supplied from the material supply unit until it adheres to the substrate surface.
The thin film manufacturing apparatus according to the above. 7. A material supply unit comprising an evaporation source of at least one of resistance heating, induction heating, electron beam heating, plasma beam heating, and laser abrasion. The thin film manufacturing apparatus according to claim 5 or 6, wherein 8. The thin film manufacturing apparatus according to claim 5, wherein a DC cathode sputtering source or an AC cathode sputtering source is provided as the material supply unit. 9. The thin-film manufacturing apparatus according to claim 5, wherein a gas nozzle is provided as the material supply unit. 10. The thin-film manufacturing apparatus according to claim 5, wherein the substrate holding section includes a continuous sheet conveying mechanism.