JP2003268555A - Thin film deposition system and thin film deposition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film deposition system and a thin film deposition method by which a uniform thin film free from unevenness and stripes can be deposited on a base material even if the base material has a large area. <P>SOLUTION: In the system 50, a voltage is applied to the space between electrodes 20 and 30 disposed to face oppositely under an atmospheric pressure or the pressure close to atmospheric pressure to cause discharge, by which a reactive gas is made into a plasma state, and a base material F arranged on the space between the electrodes 20 and 30 is exposed to the reactive gas in a plasma state, so that a thin film is deposited on the surface of the base material F. The system 50 is provided with an introduction system 12 composed so that the reactive gas to form into the raw material for depositing a thin film can be introduced into the space between the electrodes 20 and 30, and an exhaust systems 13a and 13b for exhausting the reactive gas. The electrodes 20 and 30 are composed so that the field intensity between the electrodes 20 and 30 disposed to face oppositely is increased from the side of the introduction system 12 toward the side of the exhaust systems 13a and 13b of the reactive gas. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes a reactive gas into a plasma state by discharging under atmospheric pressure or a pressure in the vicinity of atmospheric pressure to form a thin film derived from the reactive gas on a substrate arranged between electrodes. The present invention relates to a thin film forming apparatus and a thin film forming method.

[0002]

2. Description of the Related Art Conventionally, as an example of a thin film forming method, there is a method of forming a thin film derived from the reactive gas on the surface of a base material or the like placed between electrodes by discharging under a vacuum to bring the reactive gas into a plasma state. Known (hereinafter referred to as vacuum plasma method). However, in the vacuum plasma method, since a closed tank and a vacuum pump are required and the processing apparatus becomes large-scale,
It has been difficult to form a film on a large-area base material or continuously perform a film forming process on the base material. Further, since the plasma density of the reactive gas generated by the discharge is low, the treatment efficiency is low and the productivity is also low. In order to solve these problems, in recent years, a method of forming a thin film on the surface of a substrate by placing a reactive gas in a plasma state under atmospheric pressure or a pressure near the atmospheric pressure (hereinafter referred to as atmospheric pressure plasma method) has been proposed. Proposed. In the atmospheric pressure plasma method, a vacuum device is unnecessary, so that the device can be simplified. Further, since it is not necessary to evacuate each time the treatment is performed, it is possible to continuously perform the film forming treatment on the substrate,
It is possible to improve processing efficiency and productivity.

[0003]

By the way, in order to form a good quality film on a substrate in the atmospheric pressure plasma method, the voltage applied between the electrodes facing each other and the power supplied are made large and introduced between the electrodes. It is necessary to increase the plasma density of the reactive gas to be generated. However, if the voltage applied between both electrodes or the supplied power is large, the discharge may be unevenly distributed between the electrodes, for example, the discharge may be concentrated at the corners of the electrodes. Therefore, the plasma density derived from the reactive gas between the electrodes becomes uneven, and as a result, unevenness or streaks may occur in the film formed on the substrate. Therefore, it has been difficult to form a uniform film without unevenness or streaks on a large-area substrate. An object of the present invention is a thin film forming apparatus capable of forming a uniform thin film having no unevenness or streaks even on a large area substrate,
A thin film forming method using the thin film forming apparatus is provided.

[0004]

In order to solve the above-mentioned problems, the invention according to claim 1 applies a voltage between opposing electrodes under an atmospheric pressure or a pressure in the vicinity of the atmospheric pressure to apply a voltage between both electrodes. By making the reactive gas into a plasma state by discharging,
A device for forming a thin film on the surface of the base material by exposing the base material arranged between the electrodes to the reactive gas in the plasma state, and electrodes arranged to face each other,
An introduction system configured to introduce a reactive gas, which is a raw material for forming a thin film, between the electrodes is provided, and an exhaust system for exhausting the reactive gas is provided, and the opposed electrodes are reactive to the electric field strength between the electrodes. It is characterized in that it is configured to increase from the gas introduction system side toward the exhaust system side.

According to a seventh aspect of the present invention, under the atmospheric pressure or a pressure in the vicinity of the atmospheric pressure, a voltage is applied between the electrodes facing each other to cause a discharge between both electrodes to make the reactive gas into a plasma state, and the substrate is In the thin film forming method of forming a thin film on the surface of the base material by exposing to the reactive gas in the plasma state, the reactive gas is introduced and exhausted between the opposing electrodes to make the electric field strength between the electrodes reactive. It is characterized in that it is increased from the gas introduction side to the reactive gas exhaust side.

According to the first or seventh aspect of the invention, the opposing electrodes are configured to increase the electric field strength between the electrodes from the reactive gas introduction side toward the exhaust side.
When the reactive gas is introduced between the electrodes, it is weakly discharged on the introduction side and strongly discharged on the exhaust side. Therefore, it is possible to prevent the density of plasma from the reactive gas from becoming uneven due to the concentration of the discharge on the side where the reactive gas is introduced, resulting in unevenness or streaks in the film formed on the substrate. Therefore, a uniform film can be formed. That is, a uniform film can be formed even when forming a film on a large-area base material. Further, since it is possible to suppress the generation of streaks and unevenness as described above, it is possible to increase the plasma density by setting the voltage applied between the electrodes to a high frequency and increasing the power supplied to each electrode. Therefore, a high quality film can be efficiently formed on the substrate.

According to a second aspect of the present invention, in the thin film forming apparatus according to the first aspect, at least one of the electrodes facing each other is provided with a plurality of electrodes. According to a third aspect of the present invention, in the thin film forming apparatus according to the first or second aspect, the facing surfaces of the facing electrodes are configured to be closer to each other from the reactive gas introduction system side toward the exhaust system side. It is characterized by being

The invention according to claim 4 is the invention according to claim 1 or 2.
In the thin film forming apparatus described above, the facing surfaces of the facing electrodes are arranged in parallel to each other, and at least one facing surface of the one electrode facing the other electrode is coated with a dielectric, It is characterized in that the thickness is reduced from the reactive gas introduction system side toward the exhaust system side.

According to a fifth aspect of the present invention, in the thin film forming apparatus according to the third aspect, at least one of the facing electrodes, which faces the other electrode, is covered with a dielectric. The thickness of the dielectric is made thinner from the reactive gas introduction system side toward the exhaust system side. The invention according to claim 6 is
The thin film forming apparatus according to any one of claims 1 to 5, wherein at least one of the electrodes facing each other has an arc-shaped cross section.

According to an eighth aspect of the present invention, in the thin film forming method according to the seventh aspect, substantially the same voltage is applied between the electrodes facing each other. The invention according to claim 9 is the method for forming a thin film according to claim 7 or 8, wherein the frequency of the voltage applied between the electrodes is 1
It is characterized in that the frequency is 00 kHz or higher.

According to a tenth aspect of the present invention, in the thin film forming method according to any of the seventh to ninth aspects, the power supplied to each electrode when applying a voltage between the electrodes is 1 W.
/ Cm ² or more.

The invention according to claim 11 is the invention according to claims 7 to 10.
In the method for forming a thin film as described in any one of 1, the reactive gas is an organic fluorine compound, an organic silicon compound, an organic titanium compound, an organic tin compound, an organic zinc compound, an organic indium compound, an organic aluminum compound, an orbital compound, an organic compound. It is characterized by containing any of the silver compounds.

The invention according to claim 12 is the invention according to claims 7 to 11.
In the thin film forming method as described in any one of 1 to 3, a mixed gas containing the reactive gas and an inert gas is introduced between opposing electrodes, and the mixed gas is an inert gas in a volume ratio of 9%.
It is characterized by containing 0.0 to 99.9%.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a thin film forming apparatus and a thin film forming method of the present invention will be described in detail below with reference to the drawings. [First Embodiment] A first embodiment will be described with reference to FIGS. As shown in FIG. 1, a thin film forming apparatus 100 includes a plasma discharge processing container 10 including electrodes 20, 30 and the like, and a gas generator 51 for introducing a reactive gas, which is a material for forming a thin film, into the plasma discharge processing container 10.
And a power source 53 that applies a voltage to the electrodes 20 and 30 to supply electric power, and an electrode cooling unit 55 that cools the electrodes 20 and 30.
And so on.

The plasma discharge processing container 10, which is the main part of the thin film forming apparatus 100, will be described with reference to FIG. The plasma discharge processing container 10 discharges the gas introduced into the plasma discharge processing container 10, the electrodes 20 and 30 arranged to face each other, the air supply port 12 (introduction system) connected to the gas generator 51. The exhaust ports 13a and 13b (exhaust system) are provided. Further, both ends of the plasma processing container 10 are opened, and a carry-in port 10a for carrying the substrate F disposed between the electrodes 20 and 30 into the plasma processing container 10 and a carry-out port 10b for carrying it out. Has become. The plasma processing container 10 is provided with rollers for transporting the base material F into the plasma processing container 10.

A substrate F is placed in the plasma discharge treatment container 10.
Is loaded and placed between the electrodes 20 and 30, and a plasma discharge process is performed to form a thin film on the base material F. In the following, a series of treatments in which a voltage is applied between the electrodes 20 and 30 facing each other to bring the reactive gas into a plasma state is referred to as plasma discharge treatment, and the plasma discharge treatment is performed under atmospheric pressure or a pressure near atmospheric pressure. The method of forming a thin film on a substrate is called atmospheric pressure plasma method.

The plasma discharge treatment container 10 is preferably made of Pyrex (R) glass, but may be made of metal as long as it can be insulated from the electrodes 20 and 30. For example, a polyimide resin or the like may be attached to the inner surface of an aluminum or stainless steel frame, and the metal frame may be sprayed with ceramics to have an insulating property.

The supply port 12 is connected to the gas generator 51 as described above, and a predetermined amount of the reactive gas is supplied to the supply port 12.
Is introduced between the electrodes 20 and 30. In addition, the exhaust port 13
The reactive gas introduced between the electrodes 20 and 30 is exhausted from a and 13b. The pressure inside the plasma discharge treatment container 10 is not particularly adjusted, and is maintained at atmospheric pressure or a pressure near atmospheric pressure even after the reactive gas is introduced from the air supply port 12.
Here, the pressure near atmospheric pressure is 20 kPa to 110 k
Indicates a pressure of Pa, more preferably 93 kPa to 10
Indicates 4 kPa.

Of the electrodes 20 and 30 provided in the plasma discharge processing container 10, one electrode 20 functions as an application electrode, and the other electrode 30 functions as a ground electrode which is grounded. One electrode 20 has a hollow prismatic shape, and a plurality of electrodes 20 are provided so as to face the other electrode 30. Further, the respective electrodes 20 are electrically connected as shown in FIG. 3, and a voltage of the same frequency is collectively applied by a power source 53. The other electrode 30 has a hollow cylindrical shape and is rotatably mounted in the plasma discharge treatment container 10 from the air supply port 12 side toward the exhaust port 13b side by a drive mechanism (not shown). The base material F is transported in a state where one surface is in contact with the other electrode 30.

These electrodes 20 and 30 are constructed by coating a conductive metal base material with a dielectric. As the metal base material, metals such as silver, platinum, stainless steel, aluminum and iron can be used, but stainless steel is preferable from the viewpoint of processing.

The dielectric material is preferably an inorganic material having a relative dielectric constant of 6 to 45. To coat the surface of the metal base material with the dielectric material, an inorganic material as a lining material is lined on the metal base material. Alternatively, or by spraying the ceramics onto the metal base material and then performing a pore-sealing treatment with an inorganic substance, this can be achieved. As the lining material, silicate glass, borate glass, phosphate glass, germanate glass, tellurite glass,
Aluminate glass, vanadate glass and the like can be used. Among these, borate glass is easy to process.

As the ceramic material used for thermal spraying, for example, alumina-based, zirconia-based, silicon nitride-based, and silicon carbide-based materials can be used, but alumina is preferably used because it is easy to process. Further, for example, it is more preferable to perform a pore-sealing treatment with a silicon compound using a sol-gel reaction after spraying alumina ceramics on the metal base material. To accelerate the sol-gel reaction, heat curing or UV curing is good, and further, by diluting the sealing liquid and repeating coating and curing several times successively, the mineralization is further improved, and a dense electrode without deterioration can be formed.

The thickness of the dielectric covering the surfaces of the electrodes 20 and 30 facing each other is determined in consideration of the voltage applied between the electrodes 20 and 30, the power supplied, the amount of reactive gas supplied, and the like. Good.

Also, as shown in FIG.
The facing surface 20a facing the other electrode 30 is closer to the facing surface 30a facing the one electrode 20 of the other electrode 30 from the air supply port 12 side toward the exhaust ports 13a, 13b side. It is arranged. By arranging the one electrode 20 with respect to the other electrode 30 in this way, when a voltage is applied between the electrodes 20 and 30 facing each other, the reactive gas between the electrodes 20 and 30 is introduced into the air supply port 12. On the side, the discharge is weaker than that on the side of the exhaust ports 13a and 13b, and becomes stronger as the facing surfaces 20a and 30a of the electrodes 20 and 30 approach each other. That is, the electrodes 20 and 30 are configured so that the electric field strength between the electrodes 20 and 30 increases from the reactive gas supply port 12 side toward the exhaust port 13a, 13b side. In addition,
Regarding the one electrode 25 (see FIG. 2) located between the air supply port 12 and the air exhaust port 13a, the air supply port 12 and the air exhaust port 13 are
It is configured such that the electric field strength increases in the direction opposite to that of the one electrode 20 located between b and b.

Here, the facing surface 20a of one electrode 20 of the facing electrodes 20, 30 is opposed to the facing surface 30a of the other electrode 30 from the reactive gas supply port 12 side to the exhaust port 1.
The degree of inclination (inclination angle θ) when approaching to the side of 3a, 13b may be determined in consideration of the voltage applied between the electrodes 20, 30, the power supplied, the supply amount of the reactive gas, and the like. . The shortest distance L between the electrodes 20 and 30 is 0.5 m.
m to 20 mm, particularly preferably 1 mm ± 0.
It is 5 mm. The shortest distance L between the electrodes 20 and 30 is
It may be determined in consideration of the thickness of the dielectric material covering the electrodes 20 and 30, the magnitude of the applied voltage, the supply amount of the reactive gas, and the like.

The power source 53 applies a substantially same voltage to the plurality of electrodes 20 and the other electrode 30 at once, and supplies a predetermined electric power to each of the electrodes 20 and 30. Also,
In order to obtain a high plasma density and increase the film formation rate on the base material F, a power source 53 is used between the electrodes 20, 30.
It is preferable to supply a certain amount of electric power with a high frequency voltage.

Specifically, 100 kHz or more and 150 MH
It is preferable to apply a high frequency voltage of z or less between the electrodes 20 and 30, and more preferably 200 kHz or more. The lower limit value of the electric power supplied between the electrodes 20 and 30 is preferably 1 W / cm ² or more and 50 W / cm ² or less, and more preferably ² W / cm ² or more. The voltage application area (/ cm ² ) at the electrodes 20 and 30 refers to the area in the range where discharge occurs. Further, the high-frequency voltage applied between the electrodes 20 and 30 may be an intermittent pulse wave or a continuous sine wave, but it is a sine wave because the film forming speed increases. preferable.

The electrode cooling means 55 comprises a tank 56 containing a coolant, a pump 57, the other electrode 30 and one electrode 2.
It is composed of water channels 58 and 59 connected to 0 and 0 respectively. The water channels 58, 59 are connected to the electrodes 20, 30 facing each other.
Is introduced into the hollow part formed in each of the. An insulating material such as distilled water or oil can be used as the coolant. By appropriately operating the pump 57 and circulating the coolant in the tank 56 through the water passages 58 and 59 in the hollow portions of the electrodes 20 and 30, these electrodes 20 and 30 can be cooled.

The gas generator 51 is means for supplying a predetermined amount of a mixed gas containing an inert gas and a reactive gas into the plasma discharge treatment container 10. An inert gas is mixed with a reactive gas into the plasma discharge treatment container 10 with a predetermined composition and introduced through an air supply port 12.

Examples of the inert gas include atoms of Group 18 of the periodic table, specifically, helium, neon, argon, krypton, xenon, radon, etc. In order to obtain the cost and the effect of the present invention. In addition, helium and argon are preferably used. In particular, it is most preferable to use argon for forming a dense and highly accurate thin film. It is estimated that high density plasma is easily generated when argon is used. Further, these inert gases may be used alone or in combination of two or more kinds. The volume of the inert gas is 90.0% to the whole mixed gas.
It is preferable to contain 99.9%.

As the reactive gas, an organic fluorine compound,
It is preferable to contain any one of an organic silicon compound, an organic titanium compound, an organic tin compound, an organic zinc compound, an organic indium compound, an organic aluminum compound, an organic copper compound, and an organic silver compound. Among these, the organometallic compound other than the organofluorine compound may be a metal hydrogen compound, a metal halogen compound, or a metal alkoxide. The volume of the reactive gas is 0.01% to 1 with respect to the entire mixed gas.
It is preferable to contain 0%.

It is preferable that these compounds are compounds that can be supplied into the plasma discharge treatment container 10 in the form of gas or mist. "Can be supplied in the form of gas or mist" means that it can be supplied as it is at room temperature and atmospheric pressure,
When it is a liquid or a solid at normal pressure, it may be vaporized by a method such as heating, reduced pressure, ultrasonic irradiation, or dissolved in an appropriate solvent. Since the solvent at the time of dilution is decomposed in plasma at the molecular level and the atomic level, the influence on the thin film formation on the substrate can be almost ignored.

Specifically, as reactive gas, zinc acetylacetonate, triethylindium, trimethylindium, diethylzinc, dimethylzinc, tetraethyltin, tetramethyltin, di-n-butyltin diacetate, tetrabutyltin, tetraoctyltin, etc. Using a reactive gas containing at least one organometallic compound selected from
A metal oxide film may be formed on the base material F to form a conductive film, an antistatic film, an antireflection film, or the like.

For the purpose of forming a water repellent film, propylene hexafluoride and cyclobutane octafluoride can be used as the organic fluorine compound. Furthermore, when forming the antireflection film from an organic fluorine compound, a fluorocarbon gas, a fluorohydrocarbon gas, or the like is preferably used. Examples of the carbon fluoride gas include carbon tetrafluoride and carbon hexafluoride, specifically, tetrafluoromethane, tetrafluoroethylene, hexafluoropropylene, octafluorocyclobutane, and the like. Examples of the fluorohydrocarbon gas include difluoromethane, tetrafluoroethane, propylene tetrafluoride, propylene trifluoride, and the like.

Further, as the organic fluorine compound, a halide of a fluorohydrocarbon compound such as trifluoromethane trichloride, monochlorodifluoromethane, dichlorotetrafluoromethane, or tetrafluorocyclobutane, or an organic compound such as an alcohol, an acid or a ketone is used. Fluorine substitutes can be used, but are not limited thereto. Further, these compounds may have an ethylenically unsaturated group in the molecule. The above compounds may be used alone or in combination. When the organic fluorine compound described above is used in the mixed gas, the content of the organic fluorine compound in the mixed gas is 0.1 to 10 vol% from the viewpoint of forming a uniform thin film on the substrate F by plasma discharge treatment.
Is preferred, and more preferably 0.1-5 vo
1%.

In addition to the above, by appropriately selecting the substance and composition contained in the reactive gas, the electrode film, the dielectric protective film,
Semiconductor film, transparent conductive film, electrochromic film, fluorescent film, superconducting film, dielectric film, solar cell film, abrasion resistant film, optical interference film, reflective film, antistatic film, antifouling film, hard coat film, Subbing film, barrier film, electromagnetic wave shielding film, infrared shielding film, ultraviolet absorbing film, lubricating film, shape memory film, magnetic recording film,
Various thin films such as a light emitting device film, a biocompatible film, a corrosion resistant film, a catalyst film, a gas sensor film, and a decorative film can be formed.

The base material F carried into the plasma discharge treatment container 10 is a long film-like base material F, which is wound around the film winding body FF so as to be drawn out, and also inside the plasma discharge treatment container 10. It is wound around the peripheral surface of the other electrode 30 while being pressed by the nip rollers 14 provided near the left and right sides of the other electrode 30.

A rotatable guide roller 15 is attached to the outside of the plasma discharge treatment container 10, and the base material F is a film winding body F as the other electrode 30 rotates.
Unrolled from F, guide roller 15, nip roller 1
4 is carried into the plasma discharge processing container 10 from the carry-in port 10a, and is conveyed along the peripheral surface of the other electrode 30 while facing the one electrode 20. The processed substrate F is further processed by the nip roller 14 and the guide roller 15.
Guided by, the carry-out port 10b is carried out in the direction of the arrow P. The conveyance direction P of the base material F is substantially the same as the direction from the air supply port 12 side of the reactive gas toward the exhaust port 13b side.

As the base material F, the film-shaped base material F wound around the winding body FF is shown in FIGS. 1 and 2, but the shape of the base material F is not limited to the film shape. The shape is not limited to the above, and may be any shape such as a fiber shape or a bulk shape that can form a thin film on the surface thereof. Further, the material thereof is not limited at all, but the thin film forming apparatus 100 and the thin film forming method of the present invention are atmospheric pressure plasma methods, and since the film formation is performed under low temperature glow discharge, a resin is particularly preferably used. be able to.

Specific examples of the resin include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate phthalate, cellulose triacetate. Cellulose esters such as cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, ethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone,
Polyimide, polyether sulfone, polysulfone,
Polyetherketone imide, polyamide, fluororesin,
Nylon, polymethylmethacrylate, acrylic or polyacrylates can be mentioned. These materials may be used alone or in an appropriate mixture. Furthermore, a film made of these materials as a support and coated with a functional film such as a surface protective layer or an antistatic layer can be used as the substrate F.

Further, the base material F of the plasma discharge treatment container 10
Partition plates 16 are arranged in the carry-in entrance 10a and the carry-out exit 10b in the vicinity of the nip roller 14. The partition plate 16 is for suppressing the air entrained when the base material F is transported into the plasma discharge processing container 10 from entering the plasma discharge processing container 10. The air entrained in the base material F by the partition plate 16 is 1% in volume ratio with respect to the total volume of the gas in the plasma discharge processing container 10.
It is preferably suppressed to the following, and more preferably 0.1% or less.

Next, a procedure for forming a thin film on the base material F by the above-mentioned thin film forming apparatus 100 will be described. First, the flow rate of the mixed gas generated by the gas generator 51 is controlled, and the mixed gas is supplied from the air supply port 12 so that the space between the electrodes 20, 30
The mixed gas is introduced into. At this time, unnecessary parts are exhausted from the exhaust ports 13a and 13b.

Next, the base material F is unwound from the film roll FF, and the base material F is passed through the guide roller 15 into the plasma discharge treatment container 10 between the electrodes 20 and 30 and to the other electrode 30. Transport with one side in contact. The base material F
Prior to undergoing the thin film forming treatment, it is preferable to carry out a charge eliminating treatment for preventing electrification and a dust removing treatment.

Then, a voltage is applied to one of the electrodes 20 by the power source 53 to carry out plasma discharge treatment to form a thin film on the substrate. At this time, the other electrode 30 is grounded. Further, in order to suppress the adverse effect of the high temperature at the time of discharge, the temperature of the base material F is set at room temperature (15 to 25 degrees) to 200.
If necessary, it is cooled by the electrode cooling means 55 so that the temperature can be suppressed to less than 100 ° C., more preferably within room temperature to 100 ° C.

The base material F is conveyed between the electrodes 20 and 30 at a predetermined speed as the other electrode 30 rotates, and a thin film is continuously formed on the surface of the base material F which is not in contact with the other electrode 30. . Since one electrode 20 is provided in plurality, a thin film is laminated on the base material F when the base material F is transported under each electrode 20. After that, the base material F is conveyed to the next step via the guide roller 15. A thin film derived from the reactive gas is formed only on the surface of the base material F which is not in contact with the other electrode 30.

According to the first embodiment, of the electrodes 20 and 30 arranged so as to face each other, the facing surface 20a of one electrode 20 is reactive with the facing surface 30a of the other electrode 30. It is configured to be closer to each other from the air supply port 12 side toward the exhaust port 13a, 13b side. By configuring the electrodes 20 and 30 in this way, the electric field strength between the electrodes 20 and 30 is increased from the reactive gas supply port 12 side toward the exhaust ports 13a and 13b side.
Therefore, when the reactive gas is introduced between the electrodes 20 and 30, the side on which the reactive gas is introduced between the electrodes 20 and 30 is weakly discharged as compared with the side to be discarded, and the reactive gas is discharged to the electrode. On the side exhausted from between 20 and 30, strong discharge occurs. That is, it is possible to prevent the unevenness of the plasma density due to the concentration of the discharge on the side where the reactive gas is introduced, and to prevent the unevenness and streaks from occurring on the film forming surface.

Further, since the corner portion 20b of the one electrode 20 is formed in an arcuate cross section, even if a high frequency voltage is applied between the electrodes 20 and 30, the discharge concentrates on the corner 20b of the electrode 20. It is possible to prevent the occurrence of unevenness in the plasma density derived from the reactive gas on the base material F disposed between the electrodes 20 and 30.

Further, one electrode 20 is provided in plural with respect to the other electrode 30, and the reactive gas is introduced between the electrodes 20 and 30 and the substrate F is transported.
Therefore, a thin film is repeatedly formed on the base material F every time it passes under one of the electrodes 20 while moving between the electrodes 20 and 30. By laminating a number of layers on the base material F in this way, a more dense and uniform film can be formed.

Since the generation of streaks and unevenness can be suppressed as described above, the voltage applied between the electrodes 20 and 30 is set to a high frequency, and the power supplied to each of the electrodes 20 and 30 is set to a large value to generate plasma. Since the density can be increased, a high quality film can be efficiently formed on the base material F. Further, since no unevenness or stripes are generated, it is possible to form a uniform film on the base material F having a large area.
Further, when performing plasma discharge processing on the base material F, it is not necessary to make the plasma discharge processing container 10 a vacuum, so that a thin film can be continuously formed on the base material F.

Further, since the electrodes 20 on one side are electrically connected to each other and the voltage of the same frequency is applied collectively,
The thin film forming apparatus 100 does not need to be provided with a plurality of power supplies for applying a voltage to each electrode 20 or to wire the electrodes. Therefore, the structure of the thin film forming apparatus 100 can be simplified.

Further, according to the thin film forming apparatus 100, it is not necessary to evacuate the inside of the plasma discharge processing container 10, and it is not necessary to particularly adjust the pressure even after the reactive gas is introduced. Therefore, it is not necessary to provide a vacuum device in order to evacuate the inside of the plasma discharge processing container 10 or adjust the pressure, and the structure of the thin film forming apparatus can be simplified.

The present invention is not limited to the above-mentioned first embodiment, and it goes without saying that it can be modified as appropriate without departing from the spirit of the present invention. For example,
The opposing surface 20a of one electrode 20 of the opposing electrodes 20, 30 is configured to be closer to the opposing surface 30a of the other electrode 30 from the air supply port 12 side toward the exhaust ports 13a, 13b side. Accordingly, the electric field strength between the electrodes 20 and 30 facing each other can be changed from the reactive gas supply port 12 side to the exhaust port 13
The number is increased to the a and 13b sides, but the invention is not limited to this. The facing surface 20a of the other electrode 30 may be arranged closer to the facing surface 20a of the one electrode 20 from the reactive gas supply port 12 side toward the exhaust ports 13a, 13b side. Opposing surface 2 of one electrode 20
0a and the opposite surface 30a of the other electrode 30 may be configured to be close to each other from the reactive gas supply port 12 side toward the exhaust ports 13a, 13b side.

Further, one electrode 20 has a prism shape and the other electrode 30 has a cylindrical shape and is rotatably attached to the plasma discharge treatment container 10, but the present invention is not limited to this. Each electrode 2
The shapes of 0 and 30 may be a parallel plate type, a coaxial cylinder type, a cylinder facing flat plate type, a sphere facing flat plate type, or a hyperboloid facing type, in which the electrodes are arranged facing each other and the electric field strength between the electrodes is reactive. It may have any shape as long as it can be configured to increase from the gas supply port 12 side to the exhaust ports 13a, 13b side.

Further, one electrode 20 and the other electrode 3
Although the surface of 0 is covered with a dielectric, the present invention is not limited to this, and only one of the electrodes may be covered with a dielectric. It does not have to be covered with. However, since the discharge is performed under the atmospheric pressure or a pressure near the atmospheric pressure, it is desirable that the metal base materials of the electrodes 20 and 30 do not directly face each other in order to avoid occurrence of arc discharge in which the discharge is localized. It is preferable that at least one of the electrodes 20 facing the other electrode 30 of the one electrode 20 is covered with a dielectric. Further, it is more preferable to coat the surfaces of both electrodes 20, 30 with a dielectric as in the present embodiment.

[Second Embodiment] Next, a second embodiment of the thin film forming apparatus and the thin film forming method according to the present invention will be described with reference to FIG. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. Of the electrodes 21, 30 arranged to face each other in the plasma discharge processing container 10, the facing surface 21a of one electrode 21 is provided from the reactive gas supply port 12 side to the exhaust port 13
As it goes toward the a and 13b sides, it gradually approaches the facing surface 30a of the other electrode 30. The facing surface 21a of the one electrode 21 is covered with the dielectric 61, and the thickness W of the dielectric 61 covering the facing surface 21a is W.
Is from the reactive gas supply port 12 side to the exhaust ports 13a, 13b
It is configured to be thinner toward the side. By configuring the opposing electrodes 21 and 30 in this manner, the electric field strength between the opposing electrodes 21 and 30 can be increased from the reactive gas supply port 12 side to the exhaust ports 13a and 13b side.

In the second embodiment, the facing surface 21a of one electrode 21 and the facing surface 30 of the other electrode 30 are opposite to each other.
The degree of inclination (inclination angle θ) when approaching a is the same as in the first embodiment, the voltage applied between the electrodes 21 and 30, the power supplied, the amount of reactive gas supplied, and one electrode 2
It may be determined in consideration of the thickness of the dielectric 61 covering the first facing surface 21a and the like. Further, also in the second embodiment, it is preferable to cover the surface of the other electrode 30 with a dielectric material, as in the first embodiment. The thickness of the dielectric covering the surface of the other electrode 30 is the voltage applied between the electrodes 21 and 30, the power supplied, the amount of reactive gas supplied, and the dielectric 61 covering the facing surface 21 a of the one electrode 21. It may be appropriately determined according to the thickness of the.

In the second embodiment, the electrodes 21 and 30 facing each other are arranged so as to be closer to each other from the reactive gas supply port 12 side toward the exhaust port 13a, 13b side. The thickness W of the dielectric 61 that covers the facing surface 21a of 21 is made thinner from the reactive gas supply port 12 side toward the exhaust ports 13a, 13b side, but the thickness W of the dielectric 61 is adjusted. Only by doing so, the electric field strength between the electrodes 21 and 30 may be increased from the reactive gas supply port 12 side to the exhaust port 13a, 13b side. That is, the facing surface 2 of the electrode 21
1a is arranged parallel to the other electrode 30, and the electrode 21
Between the electrodes 21 and 30 facing each other only by decreasing the thickness W of the dielectric 61 covering the facing surface 21a of the same from the air supply port 12 side of the reactive gas toward the exhaust ports 13a, 13b side. The electric field strength may be increased from the reactive gas supply port 12 side to the exhaust port 13a, 13b side. At this time, it is desirable to appropriately adjust the thickness W of the dielectric 61 so that the distance L between the electrodes 21 and 30 is appropriate.

[Third Embodiment] Next, a third embodiment of the thin film forming apparatus and the thin film forming method of the present invention will be described with reference to FIG. The same components as those in the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted. The electrode 23 and the electrode 24 are arranged so as to face the earth electrode 31 provided in the plasma discharge processing container 10. Both corners 23a, 23b of the electrode 23 and both corners 24a, 24 of the electrode 24
Each b is formed in an arcuate cross section. Curvature R of corners 23a and 23b and corners 24a and 24b at this time
May be appropriately determined according to the sizes of the electrodes 23 and 24, the voltage applied between the electrodes 23 and 31, and the voltage applied between the electrodes 24 and 31, and the amount of current supplied.

The reactive gas supply port (not shown) is the electrode 23.
The reactive gas is introduced from the gap d formed by the electrode 24 and the electrode 24 in the direction of the arrow Q shown in the figure. The reactive gas exhaust port (not shown) splits the reactive gas introduced from the gap d formed by the electrode 23 and the electrode 24 and moves from the corner 23a side to the corner 23b side of the electrode 23. The electrode 23 passes in the direction P2 between the electrodes 23 and 31, and the electrode 24 passes in the direction P1 from the corner 24a side toward the corner 24b side in the direction P2.
Is exhausted from the corner 23b side and the electrode 24 corner 24b side.

The facing surface 23c of the electrode 23 facing the ground electrode 31 and the facing surface 24c of the electrode 24 facing the ground electrode 31 are arranged in a V shape in a sectional view. That is, the facing surface 23c of the electrode 23
Is arranged so as to approach the ground electrode 31 from the side 23a where the reactive gas is introduced to the side 23b where the reactive gas is exhausted, and the facing surface 24c of the electrode 24 is
It is arranged so as to approach the ground electrode 31 from the side 24a where the reactive gas is introduced to the side 24b where the reactive gas is exhausted.

The base material F is placed with one surface in contact with the ground electrode 31, and is conveyed by a driving mechanism (not shown) so as to pass between the electrodes 23 and 31 and between the electrodes 24 and 31 at a predetermined speed. . At this time, the base material F may be transported only in the direction P1 from the electrode 23 to the electrode 24, or may be transported only in the opposite direction, that is, in the direction P2 from the electrode 24 to the electrode 23. Alternatively, the base material F is reciprocated a plurality of times by carrying the base material F a predetermined distance in the direction P1 from the electrode 23 toward the electrode 24 and then carrying it a predetermined distance in the opposite direction P2. You may do it. When the base material F is reciprocated in this way, the base material F moves between the electrodes 23 and 31 and between the electrodes 24 and 3.
Since it will pass between 1 times many times, a dense and uniform thin film can be formed on the upper surface of the base material F each time.

In the third embodiment, the electrode 2
The degree of inclination when the opposing surface 23c of No. 3 is close to the ground electrode 31 (inclination angle θ2) and the degree of inclination when the opposing surface 24c of the electrode 24 is close to the earth electrode 31 (inclination angle θ1) are equal. The values of the tilt angle θ1 and the tilt angle θ2 are determined between the electrodes 23 and 31 and between the electrodes 2 and 31.
It may be determined in consideration of the voltage applied between Nos. 4 and 31, the supplied power, the supply amount of the reactive gas, the thickness of the dielectric covering the electrodes 23 and 24, and the like.

Also in the third embodiment, it is desirable that the metal members of the electrodes 23 and 24 and the metal base material of the ground electrode 31 do not directly face each other, as in the first embodiment. It is preferable that the facing surfaces 23c and 24c of the electrodes 23 and 24 facing the ground electrode 31 are covered with a dielectric material, and it is more preferable that the surface of the ground electrode 31 is also covered with a dielectric material.

[0064]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

In this example, a FSnO ₂ film was formed on the surface of a polyethylene terephthalate film as the base material F, and the thin film forming apparatus 100 described in the first embodiment (FIG. 1) was used.
(See FIG. 3), a film was formed, and the number of streaks formed on the film surface was visually compared with the comparative example described later.

The electric field strength between one electrode and the other electrode facing each other is adjusted from the gas supply port 12 side of the mixed gas to the exhaust port 13a.
It is designed to increase to the 13b side. Specifically, as shown in FIG. 3, each of the one electrodes 20 is connected to the other electrode 30.
To the exhaust port 13a from the air supply port 12 side of the reactive gas,
Provided so as to gradually approach toward the 13b side, the facing surface 20a of one electrode 20 and the facing surface 30a of the other electrode 30.
And the shortest distance L between them is 1 mm. In addition, one electrode 20
Has an inclination angle θ of 5 degrees with respect to the other electrode 30.

Between the other electrode 30 and the electrodes 20 and 30 provided so as to face the other electrode 30, a mixed gas composed of a reactive gas having an after-mentioned composition and an inert gas is supplied from a gas generator 51. A predetermined amount is supplied through the air outlet 12, the mixed gas is passed between the electrodes 20 and 30, and then the exhaust outlet 1
It was made to be discharged from 3a and 13b.

The power source 53 used for the plasma discharge treatment is a high frequency power source 53CF-50 manufactured by Pearl Industrial Co., Ltd.
000-13M and a frequency of 13.
A voltage of 56 MHz was applied, and the power supplied per discharge unit area was 30 W / cm ² . Further, the speed of forming the thin film on the base material F is set to 10 m / min,
The other electrode 30 was rotated by a driving mechanism at a speed of min to convey the base material F to continuously form a thin film on the base material F.

From the air supply port 12 to the plasma discharge treatment container 10
The composition of the mixed gas introduced into the inside is as follows. Inert gas: Argon Reactive gas 1: Oxygen gas (0.5% by volume of the mixed gas) Reactive gas 2: Dibutyltin diacetate (0.1% by volume of the mixed gas) (Mixed with Argon gas by Lintec vaporizer) Reactive gas 3: Fluorinated methane (100 p for reaction gas)
pm)

As a comparative example of the above embodiment, the electric field strength between the opposing electrodes was made uniform, one electrode was arranged so as to face the peripheral surface of the other electrode, and the other conditions were the same as those of the above embodiment. Film formation was performed under the same conditions.

Table 1 shows the number of lines generated on the film surface in Examples and Comparative Examples. As is clear from Table 1, in the example, the number of membranous streaks was zero, whereas in the comparative example, 54 streaks were visually confirmed in a membranous form. That is, the opposing electrodes 2 as in the embodiment
A high frequency voltage of 13.56 MHz is applied between 0 and 30, and 30 W / cm ² is applied to the electrodes 20 and 30.
Even if a large amount of electric power is supplied
It is formed on the base material F by constructing the electric field strength between 0s from the air supply port 12 side of the reactive gas toward the exhaust ports 13a, 13b side, and further by providing a plurality of electrodes 20 on one side. It has been revealed that the film can be made uniform and free from unevenness and streaks.

[Table 1]

[0072]

According to the present invention, the electric field strength between the electrodes arranged facing each other is increased from the reactive gas introduction system side to the exhaust system side, so that the reactive gas is introduced between the electrodes. In this case, the introduction system side discharges weakly, and the exhaust system side discharges strongly. Therefore, it is possible to prevent the density of plasma from the reactive gas from becoming uneven due to the concentration of the discharge on the side where the reactive gas is introduced, resulting in unevenness or streaks in the film formed on the substrate. ,
A uniform film can be formed. That is, a uniform film can be formed even when forming a film on a large-area base material. Further, since it is possible to suppress the generation of streaks and unevenness as described above, it is possible to increase the plasma density by setting the voltage applied between the electrodes to a high frequency and increasing the power supplied to each electrode. Therefore, a high quality film can be efficiently formed on the substrate.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a thin film forming apparatus of the present invention.

FIG. 2 is a schematic view showing a discharge plasma processing container which is a main part configuration of the thin film forming apparatus shown in FIG.

FIG. 3 is a schematic view showing an example of electrodes provided to face the thin film forming apparatus of the present invention.

FIG. 4 is a schematic view showing another example of electrodes provided facing the thin film forming apparatus of the present invention.

FIG. 5 is a schematic view showing still another example of electrodes provided to face the thin film forming apparatus of the present invention.

[Explanation of reference numerals] 12 introduction system (air supply port) 13a, 13b exhaust system (exhaust port) 20, 21, 23, 24 electrode (one electrode) 20b, 23a, 23b, 24a, 24b (of electrode)
Corner 30, 31 Electrode (other electrode) 50 Thin film forming device 61 Dielectric F base material

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kiyoshi Oishi             Konica Stock, 1 Sakura-cho, Hino City, Tokyo             In the company (72) Inventor Yoshikazu Kondo             Konica Stock, 1 Sakura-cho, Hino City, Tokyo             In the company (72) Inventor Yoshiro Toda             Konica Stock, 1 Sakura-cho, Hino City, Tokyo             In the company (72) Inventor Akira Nishiwaki             Konica Stock, 1 Sakura-cho, Hino City, Tokyo             In the company F-term (reference) 4K030 AA11 FA03 JA06 JA14 JA16                       JA18 KA15 KA16 KA47

Claims (12)

[Claims] 1. A base material disposed between electrodes by applying a voltage between opposing electrodes under an atmospheric pressure or a pressure in the vicinity of the atmospheric pressure to cause a discharge between both electrodes to bring a reactive gas into a plasma state. Is a device for forming a thin film on the surface of the base material by exposing the substrate to the reactive gas in the plasma state, the electrode being opposed to each other, and the reactivity being a raw material for forming the thin film between the electrodes. An introduction system configured to be able to introduce gas and an exhaust system for exhausting the reactive gas are provided, and the opposing electrodes direct electric field strength between the electrodes from the reactive gas introduction system side toward the exhaust system side. A thin film forming apparatus characterized by being configured to increase. 2. The thin film forming apparatus according to claim 1, wherein a plurality of at least one of the electrodes facing each other is provided. 3. The thin film forming apparatus according to claim 1, wherein the facing surfaces of the facing electrodes are configured to be closer to each other from the reactive gas introduction system side toward the exhaust system side. Characteristic thin film forming apparatus. 4. The thin film forming apparatus according to claim 1, wherein the facing surfaces of the facing electrodes are arranged in parallel with each other, and at least the facing surface of the one electrode facing the other electrode is made of a dielectric material. The thin film forming apparatus is characterized in that the thickness of the dielectric is reduced from the reactive gas introduction system side toward the exhaust system side. 5. The thin film forming apparatus according to claim 3, wherein at least one electrode of the facing electrodes facing the other electrode is covered with a dielectric, and the dielectric has a thickness. Is thinned from the reactive gas introduction system side toward the exhaust system side. 6. The thin film forming apparatus according to claim 1, wherein at least one of the electrodes facing each other has an arc-shaped cross section. 7. A reactive gas is brought into a plasma state by applying a voltage between opposing electrodes under an atmospheric pressure or a pressure in the vicinity of the atmospheric pressure to make a reactive gas into a plasma state, and the substrate is made to have a reactivity in the plasma state. In the thin film forming method of forming a thin film on the surface of the base material by exposing to a gas, a reactive gas is introduced and exhausted between opposed electrodes, and the electric field strength between the electrodes is changed from the reactive gas introduction side to the reaction gas. A method for forming a thin film, which comprises increasing the amount of a volatile gas toward the exhaust side. 8. The thin film forming method according to claim 7, wherein substantially the same voltage is applied between the electrodes facing each other. 9. The thin film forming method according to claim 7, wherein the frequency of the voltage applied between the electrodes is 100 kHz or more. 10. The thin film forming method according to claim 7, wherein the power supplied to each electrode when a voltage is applied between the electrodes is 1 W / cm ² or more. A method for forming a thin film. 11. The thin film forming method according to claim 7, wherein the reactive gas is an organic fluorine compound, an organic silicon compound, an organic titanium compound, an organic tin compound, an organic zinc compound, an organic indium compound. A method for forming a thin film, containing any of an organic aluminum compound, an orbital compound, and an organic silver compound. 12. The thin film forming method according to claim 7, wherein a mixed gas containing the reactive gas and an inert gas is introduced between opposing electrodes, and the mixed gas is A thin film forming method, characterized in that the active gas is contained in an amount of 90.0 to 99.9% by volume.