JP2003268553A - Thin film deposition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film deposition method using an atmospheric pressure plasma process by which a high-quality film can be obtained with high productivity and which is applicable even to a substrate composed of a resin weak against heat. <P>SOLUTION: Electric discharge gas containing reactant gas is supplied under atmospheric pressure or under a pressure in the vicinity of atmospheric pressure, and high-frequency voltage is impressed between opposed electrodes to carry out electric discharge, by which the electric discharge gas is formed into a plasma state. Then the substrate is exposed to the reactant gas in the plasma state to deposit a thin film onto the surface of the substrate. In this thin film deposition method, the electric discharge gas is supplied at a temperature not lower than 100°C and not higher than the deposition temperature of the reactant gas, preferably at ≥150°C. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming method for forming a thin film on a surface of a base material by bringing a reaction gas into a plasma state under atmospheric pressure or a pressure near atmospheric pressure.

[0002]

2. Description of the Related Art Conventionally, discharge plasma is generated under a reduced pressure of about 0.01 to 10 Torr and plasma CVD (ch
A film forming method is known in which a film is formed on the surface of a base material by emical vapor deposition). However, this method requires a vacuum device and cannot perform a plurality of steps before and after film formation in succession, resulting in poor work efficiency, and since the plasma density is low, the film formation rate is low, resulting in low productivity. Therefore, in recent years, an atmospheric pressure plasma method has been developed in which plasma is generated at or near atmospheric pressure to form a film.

[0003]

By the way, in order to efficiently form a film by the atmospheric pressure plasma method, it is necessary to add sufficient energy to decompose (ionize) the reaction gas that is the raw material of the film. Specifically, there is a method of increasing the voltage applied to the electrodes to increase the discharge output, but if the output is increased too much, the discharge space is greatly expanded. If it spreads to such a large extent, the reaction gas decomposes even at a position distant from the surface of the base material on which the thin film is to be formed, and the same binding reaction as in the case of forming the thin film occurs there. It adheres to the surface and the film becomes cloudy, resulting in a defective product. Further, as can be seen from the above, in the film forming method using plasma, it is preferable that the reaction proceeds on the surface of the base material as much as possible in order to form a high quality film, and it is also known that the base material is heated for that purpose. ing. However, since the base material may have to be heated at a high temperature of 500 ° C. or higher in order to form the inorganic thin film, it cannot be applied to a base material made of a resin which is weak against heat.

An object of the present invention is to provide a thin film forming method utilizing an atmospheric pressure plasma method, which can obtain a high quality film, achieve high productivity as much as possible, and can be applied to a substrate made of a resin which is weak against heat. To do.

[0005]

According to a first aspect of the present invention, a discharge gas containing a reaction gas is supplied under atmospheric pressure or a pressure near the atmospheric pressure, and a high frequency wave is applied between opposing electrodes. In the thin film forming method for forming a thin film on the surface of the base material by exposing the base material to the reaction gas in the plasma state by applying a voltage and causing the discharge gas to be in a plasma state, the discharge gas is used. Is supplied at a temperature not lower than 100 ° C. and not higher than the decomposition temperature of the reaction gas.

According to a second aspect of the present invention, in the thin film forming method according to the first aspect, the discharge gas is supplied at a temperature of 150 ° C. or higher.

According to a third aspect of the present invention, in the thin film forming method according to the first or second aspect, the discharge gas is
The reaction gas and the inert gas are included, and the reaction gas is contained in an amount of 0.1 to 10% by volume.

The invention according to claim 4 is the method for forming a thin film according to any one of claims 1 to 3, wherein the reaction gas is a fluorine compound, a silicon compound, a titanium compound, a tin compound, a zinc compound, an indium compound. , An aluminum compound, a copper compound, and a silver compound.

According to a fifth aspect of the present invention, in the thin film forming method according to the fourth aspect, the organic fluorine compound is fluorocarbon or fluorohydrocarbon.

According to a sixth aspect of the present invention, in the thin film forming method according to the fourth aspect, a silicon compound, a titanium compound,
The tin compound, the zinc compound, the indium compound, and the aluminum compound are characterized by being an organic metal compound, a metal hydrogen compound, a metal halogen compound, or a metal alkoxide.

According to a seventh aspect of the present invention, in the thin film forming method according to any one of the first to sixth aspects, the frequency of the voltage applied between the opposing electrodes is 100 kHz or more.

The invention according to claim 8 is the method for forming a thin film according to any one of claims 1 to 7, characterized in that the electric power of the voltage applied between the opposing electrodes is 1 W / cm ² or more. To do.

The present invention will be described in detail below. The present invention supplies a discharge gas containing a reactive gas under atmospheric pressure or a pressure near the atmospheric pressure, and applies a high-frequency voltage between opposing electrodes to discharge the discharge gas to bring the discharge gas into a plasma state. In a thin film forming method of forming a thin film on the surface of the base material by exposing the base material to the reaction gas in the plasma state, the discharge gas is 100 ° C. or higher,
Further, it is characterized in that the gas is supplied at a temperature not higher than the decomposition temperature of the reaction gas. Here, the atmospheric pressure or a pressure near the atmospheric pressure is a pressure of 20 kPa to 110 kPa, and more preferably 93 kPa to 104 kPa.

By supplying the discharge gas containing the reaction gas at 100 ° C. or higher, the discharge gas is more activated, that is, easily separated into ions as compared with the case of supplying the discharge gas to the plasma space at room temperature. It will be supplied in the state. The discharge gas thus activated is easily turned into plasma when it enters the discharge space. Conversely, even if the frequency and power of the voltage applied between the electrodes are suppressed to such an extent that only the surface of the substrate on which the film is formed is in a discharged state, the discharge gas containing the reactive gas that has flowed in the vicinity of It can be surely turned into plasma, and a film can be formed by causing the reaction on or near the surface of the substrate. In other words, it becomes possible to reliably generate a plasma reaction without reacting at a place away from the surface of the base material, so that particles after the reaction do not fall from the space, A good quality film can be formed on the surface. Of course, the fact that the reaction gas is easily turned into plasma increases the film formation rate and increases the production efficiency.

When the decomposition temperature of the reaction gas is exceeded, the reaction gas is not decomposed by the discharge phenomenon but is decomposed by heat and is supplied to the discharge space and is supplied to the discharge space. Immediately after that, a reaction for producing particles occurs, and the particles fall on the film, resulting in poor film quality. Therefore, the supply temperature must be lower than the decomposition temperature of the reaction gas. The specific value depends on the type of the reaction gas, but when the above-mentioned compounds are used as the reaction gas, the temperature is 400 ° C.
The temperature is preferably 350 ° C or lower.

As the discharge gas used in the present invention, it is preferable to use a mixed gas consisting mainly of a reaction gas which is a raw material of the thin film on the surface of the substrate and an inert gas. Examples of the inert gas include elements belonging to Group 18 of the periodic table, specifically, helium, neon, argon, krypton, xenon, radon, etc. To obtain the effect described in the present invention, helium, Argon is preferably used. Argon is most preferably used to form a dense and highly accurate thin film. It is considered that high density plasma is easily generated when argon is used. The proportion of the inert gas is 90 to 99.9% by volume in the discharge gas. In the present invention, the discharge gas is supplied to the discharge space at a high temperature of 100 ° C. However, since the inert gas such as argon and helium, which occupies most of the discharge gas, has a small heat capacity, even if the temperature is raised to some extent, Only the temperature of the extreme surface of the material rises, but the temperature does not rise to the inside of the base material.

As the reaction gas used in the present invention, for example, a metal compound is preferably used, and a silicon compound, a titanium compound, a tin compound, a zinc compound, an indium compound,
It is possible to use one or more compounds selected from aluminum compounds, copper compounds, and silver compounds. Among these, as a silicon compound, a titanium compound, a tin compound, a zinc compound, an indium compound, and an aluminum compound,
A compound of any of an organometallic compound, a metal hydrogen compound, a metal halogen compound and a metal alkoxide can be preferably used.

Specific examples include diethylzinc, dimethylzinc, zinc acetylacetonate, triethylindium, trimethylindium, tetraethyltin, tetramethyltin, dibutyltin diacetate, tetrabutyltin and tetraoctyltin. Examples of the silicon compound include organic metal compounds such as dimethylsilane and tetramethylsilane, metal hydrogen compounds such as monosilane and disilane, metal halogen compounds such as silane dichloride and silane trichloride, tetramethoxysilane and tetraethoxy. A metal alkoxide such as silane or dimethyldiethoxysilane can be used. Titanium compounds include organometallic compounds such as tetradimethylaminotitanium, metal hydrogen compounds such as monotitanium and dititanium, metal halogen compounds such as titanium dichloride, titanium trichloride and titanium tetrachloride, tetraethoxytitanium and tetraisopropoxytitanium. A metal alkoxide such as tetrabutoxytitanium can be used.

Further, not only the metal compound but also various reaction gases can be contained in the discharge gas for the purpose of controlling the physical properties of the thin film. For example, a halogen compound, especially a fluorine compound can be used for the purpose of increasing the conductivity. As the fluorine compound, fluorocarbon or fluorohydrocarbon is particularly preferable. Examples of the carbon fluoride include methane tetrafluoride, propylene hexafluoride, and cyclobutane octafluoride. Examples of the fluorohydrocarbon gas include methane difluoride, tetrafluoroethane, propylene tetrafluoride, propylene trifluoride, and the like.

The compounds used for these reaction gases include
A compound that can be supplied in the form of gas or mist into the plasma space is particularly preferable. "Can be supplied in the form of gas or mist" may be supplied as it is at normal temperature and pressure,
When it is liquid or fixed at room temperature and atmospheric pressure, it may be vaporized by a method such as heating, reduced pressure, ultrasonic irradiation, or dissolved in a suitable 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 formation of the metal film can be almost ignored. The above reaction gas is preferably contained in the discharge gas in an amount of 0.1 to 10% by volume.

The reaction is promoted by adding 0.01 to 5% by volume of a component selected from oxygen, ozone, hydrogen peroxide, carbon dioxide, carbon monoxide, hydrogen and nitrogen in the discharge gas. In addition, a dense and high-quality thin film can be formed.

In the present invention, the substrate on which the thin film is formed is not particularly limited as long as it has a shape capable of forming a film on its surface, such as a film, fiber or bulk. Further, the material thereof is not limited at all, and metal, glass, resin or the like can be used. Since the thin film forming method of the present invention is an atmospheric pressure plasma method and is a film formation under low temperature glow discharge, and as described above, the discharge gas is supplied at a high temperature to secure sufficient reactivity. A resin can be particularly preferably used since it is not necessary to actively heat the substrate.

As the resin mainly constituting the above-mentioned base material,
Specifically, polyethylene terephthalate, polyester film such as polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film, cellulose acetate phthalate film, cellulose triacetate, Films made of cellulose esters such as cellulose nitrate or derivatives thereof, polyvinylidene chloride films, polyvinyl alcohol films, ethylene vinyl alcohol films, syndiotactic polystyrene films,
Polycarbonate film, norbornene resin film, polymethylpentene film, polyetherketone film, polyimide film, polyethersulfone film, polysulfone film, polyetherketoneimide film, polyamide film, fluororesin film, nylon film, polymethylmethacrylate film An acrylic film or a polyarylate film can be used. These materials may be used alone or in an appropriate mixture. Further, it is also possible to use, as a substrate, those films having these films as a support and coated with a functional film such as a protective layer or an antistatic layer on the surface thereof.

The thin film formed on the surface of the substrate by the forming method of the present invention is used as an electrode film, a dielectric protective film, a semiconductor film, a transparent conductive film, an electrochromic film, a fluorescent film, a superconducting film, a dielectric. Film, solar cell film, antireflection film, abrasion resistant film, optical interference film, reflection film, antistatic film, conductive film such as wiring, antifouling film, hard coat film, undercoat film, barrier film, electromagnetic wave shielding film , Infrared shielding film, ultraviolet absorption film, lubricating film, shape memory film, magnetic recording film, light emitting device film, biocompatible film, corrosion resistant film, catalyst film, gas sensor film, decorative film, heat resistant film, abrasion resistant film, etc. Can be mentioned. The film thickness of the formed thin film is in the range of 0.1 nm to 1000 nm.

A plasma discharge treatment apparatus used in the thin film forming method of the present invention will be described with reference to FIGS. 1 and 2. In FIGS. 1 and 2, the symbol F is a long film as an example of the base material. It is preferable that the film F is subjected to a static elimination treatment for preventing electrification or a dust removal treatment before being subjected to the plasma treatment. FIG. 1 shows a plasma discharge processing chamber 30 provided in the plasma discharge processing apparatus. In FIG. 1, a film-shaped substrate F is transported while being wound around a roll electrode 25 that rotates in a transport direction (clockwise in the figure). The plurality of fixed electrodes 36 fixed around the roll electrode 25 are each formed of a rectangular tube.
It is installed opposite to 5. The discharge vessel 11 that constitutes the plasma discharge processing chamber 30 is preferably a Pyrex (registered trademark) glass processing vessel or the like, but may be made of metal as long as it is insulated from the electrodes. 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 base material F wound around the roll electrode 25 is pressed by the nip rollers 15, 15, 16 and is regulated by the guide roller 24 to be transported to the discharge processing space secured inside the discharge vessel 11 to discharge plasma. It is processed and then conveyed to the next step via the guide roller 27. In the present invention, since the film is formed not under a vacuum system but under a pressure close to the atmospheric pressure, such a continuous process is possible, and high productivity can be improved. The amount of air entering the base material F as it is conveyed is preferably 1% by volume or less, and more preferably 0.1% by volume or less, based on the total volume of the gas in the discharge vessel 11. This can be achieved by means of the nip rollers 15 and 16. The discharge gas used for the discharge plasma treatment is introduced into the discharge vessel 11 through the air supply port 12, and the treated gas is the exhaust port 1.
Exhausted from 3, 13.

The roll electrode 25 serves as a ground electrode, discharges between the fixed electrodes 36, 36 ... Which are application electrodes, and introduces the heated discharge gas between the electrodes to form a plasma state. By exposing the base material F wound around the roll electrode 25 to the reaction gas in the plasma state, a film derived from the reaction gas is formed. In order to obtain a high plasma density and increase the film formation rate, it is preferable to supply a certain amount of high-frequency electric power between the electrodes. Specifically, it is preferable to apply a high frequency voltage of 100 kHz or more and 150 MHz or less, and 200 kH
It is even more preferable if it is z or more. The lower limit of the power supplied between the electrodes 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 electrode is the area in which discharge occurs. Further, the high-frequency voltage applied between the electrodes may be an intermittent pulse wave or a continuous sine wave, but a sine wave is preferable because the film forming speed increases.

The electrode is preferably a metal base material coated with a dielectric. At least fixed electrode 3
6 or the roll electrode 25 is coated with a dielectric, and preferably both are coated with a dielectric. The dielectric material is preferably an inorganic material having a relative dielectric constant of 6 to 45. In either case, the shortest distance between the solid dielectric and the electrode when the solid dielectric is installed on one of the electrodes 25 and 36, and the distance between the solid dielectrics when the solid dielectric is installed on both of the electrodes From the viewpoint of performing uniform discharge, 0.5 mm to 20 mm is preferable, and 1 mm ± 0.5 mm is particularly preferable. The distance between the electrodes is determined in consideration of the thickness of the dielectric around the electrodes, the magnitude of the applied voltage, and the like. Further, the edges of both corners of each solid electrode 36 facing the roll electrode 25 may be rounded to have roundness. By forming the radius in this way, it becomes difficult for the discharge to concentrate on the corners, and it is possible to prevent deterioration of the film quality such as streaking on the film due to the discharge concentration.

Further, the surface of the dielectric is further polished so that the surface roughness Rmax (JIS B0601) of the electrode is 10 μm.
By setting the thickness to m or less, the thickness of the dielectric and the gap between the electrodes can be kept constant, and the discharge state can be stabilized.
In addition, it is possible to greatly improve durability by eliminating distortion and cracking due to the difference in thermal contraction of the dielectric material and residual stress and by coating with a highly accurate inorganic dielectric material having no porosity.

In the dielectric coating of the metal base material, it is necessary to polish and finish the dielectric material as described above and to minimize the difference in thermal expansion between the metal base material and the dielectric material of the electrode. It is preferable to line the inorganic material on the surface of the base material by controlling the amount of bubbles mixed as a layer capable of absorbing stress. In particular, the material is preferably glass obtained by the melting method known as enamel, etc., and the amount of bubbles mixed in the lowermost layer in contact with the conductive metal base material is 2
By setting 0 to 30 vol% and 5 vol% or less from the next layer onward, a good electrode that is dense and does not cause cracks or the like can be formed.

As another method for coating the dielectric material on the base material of the electrode, ceramics thermal spraying is applied with a porosity of 10 vol%.
It can be mentioned that the treatment is performed up to the following densely, and the sealing treatment is further performed with an inorganic material that is cured by a sol-gel reaction. Here, for curing the sol-gel reaction, heat curing or UV curing is good, and further diluting the sealing liquid and repeating coating and curing several times in order to further improve the mineralization and prevent deterioration of the dense electrode. Can be done.

Specifically, for example, the roll electrode 25 is composed of a combination of a conductive base material such as a metal sprayed with ceramics, and then a ceramics-coated dielectric material obtained by sealing a pore with an inorganic material. There is something. Alumina, silicon nitride and the like are preferably used as the ceramic material used for the thermal spraying. Among them, alumina is more preferably used because it is easy to process. Alternatively, the roll electrode 25 may be composed of a combination of a conductive base material such as metal coated with a lining-treated dielectric material provided with an inorganic material by lining. As the lining material, silicate glass, borate glass, phosphate glass,
Germanate glass, tellurite glass, aluminate glass, vanadate glass and the like are preferably used, but among them, borate glass is easy to process,
More preferably used. Examples of the conductive base material such as metal include metals such as silver, platinum, stainless steel, aluminum and iron, and stainless steel is preferable from the viewpoint of processing. In addition, in the examples described later, the roll electrode 2
As the base material of No. 5, a stainless steel jacket roll base material is used so that it can be cooled by cooling water. Further, the roll electrode 25 is configured to be rotationally driven by a drive mechanism (not shown).

The fixed electrodes 36, 36, ... Are also formed by coating a metal base material with a dielectric material similarly to the roll electrode 25 described above. As with the roll electrode 25, the method of forming the dielectric may be either a ceramic coating-treated dielectric or a lining-treated dielectric. In the examples described below, a hollow stainless steel pipe is coated with a dielectric material so that cooling can be performed with cooling water during discharge. In addition, the number of the fixed electrodes 36 is set to 9 along the circumference of the roll electrode 25 in FIG. 1, but the specific number can be appropriately changed. Further, the fixed electrode is not limited to the prismatic shape, but may be a cylindrical shape or the like.

FIG. 2 shows the plasma discharge processing chamber 30 of FIG.
The plasma discharge treatment apparatus 50 provided with is shown. Figure 2
In addition, in addition to the plasma discharge processing chamber 30, a gas generator 51, a power supply 41, an electrode cooling unit 55, etc. are arranged as a device configuration. The electrode cooling unit 55 includes a tank 57 containing a coolant and a pump 56. An insulating material such as distilled water or oil is used as the coolant.

Gas generator 51 or gas flow path 51a
In the above, the discharge gas to be supplied can be heated to a predetermined temperature. On the other hand, a temperature detector (not shown) is attached near the outlet of the air supply port 12 on the side of the discharge container 11, The temperature of the discharge gas supplied to the can be monitored. Furthermore, the discharge vessel 1
The temperature of the base material surface during film formation is detected by a method such as attaching a temperature detection sticker whose color changes when a predetermined temperature is reached on the surface of the base material F through which the thin film is formed. May be. In the present invention, the discharge gas is supplied at 100 ° C. or higher as described above, but this increases the temperature only in the vicinity of the surface of the substrate during film formation, and the reaction for forming the film Be promoted.

When forming a film, first, a voltage is applied to the fixed electrodes 36, 36 ... By the power supply 41, and the roll electrode 25 is grounded to the ground to bring it into a discharged state. Then, the discharge gas generated by the gas generator 51 and heated to a temperature of 100 ° C. or higher is supplied from the air supply port 12 while controlling the flow rate, the processing container 11 is filled with the gas, and the unnecessary gas is exhausted. 1
Evacuate from 3. Next, the base material F supplied from the roll-shaped original winding base material FF through the rollers 54, 54, 54.
Is guided by the guide roller 24 and is conveyed between the electrodes in the plasma discharge processing chamber 30 while being in one-side contact with the roll electrode 25. At this time, a film is formed on the surface of the base material F by the discharge plasma, and thereafter, it is conveyed to the next step via the guide roller 27. Here, the base material F has a film formed only on the surface that is not in contact with the roll electrode 25. In addition, during this time, in order to suppress the adverse effect on the entire base material due to the high temperature at the time of discharge, the electrode cooling unit 55 controls the roll electrode 25 as necessary so that the temperature of the entire base material can be suppressed within the range of room temperature to 100 ° C. Cool to about 50-60 ° C.

The plasma discharge processing apparatus 50 shown in FIG. 2 is merely an example, and the plasma discharge processing apparatus used in the present invention may have other configurations. For example, the electrodes facing each other may be of a parallel plate type, and even in that case, one side may be composed of a plurality of small electrodes similarly to the fixed electrodes 36, 36 ... In FIGS.

[0038]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples. A film was formed as follows using the plasma discharge treatment apparatus 50 shown in FIG. Here, both the roll electrode 25 and the fixed electrodes 36, 36 ... Are coated with a dielectric by 1 mm by ceramic spraying. The roll electrode 25 was made of a stainless steel jacket roll as a base material, had a diameter of 200φ including the dielectric, was connected to the ground side, and was rotated by the drive mechanism. The discharge length W (see FIG. 1) of each of the fixed electrodes 36, 36 ... Was set to 20 mm, and both corners facing the roll electrode 25 were rounded so that the curvature radius of the cross-sectional shape was 5 mm. In addition, although the fixed electrode 36 is 9 in FIG. 2, 20 electrodes are installed in this embodiment. During the discharge treatment, the roll electrode 25, the fixed electrode 36, 3
6 ... In both cases, the medium was circulated as described above to continue cooling.

Next, the power supply 41 is turned on, and the roll electrode 25
Between the fixed electrode 36 and each fixed electrode 36 at a frequency of 13.56 MHz
A voltage of V (voltage difference between positive and negative peaks when the voltage was applied in a sine waveform) was applied. Here, as the power supply 41, high frequency power supply CF-10000-13M manufactured by Pearl Industrial Co., Ltd.
It was used. Next, a discharge gas was supplied from the gas supply port 12 to form a film. Discharge power density is 10 W / cm ²
Met.

As the discharge gas, one containing the following four kinds of gas was used to form the FSnO ₂ film. Inert gas: Argon Reaction gas: Oxygen gas (0.5% of the total mixed gas) Reaction gas: Dibutyltin diacetate 0.1% Steam (mixed with Argon gas by Lintec vaporizer) Reaction gas : Fluorinated methane (100p for the whole reaction gas)
pm) Fluorinated methane was added to increase the conductivity. A heating device was provided in the middle of the gas flow path 51a, the discharge gas was heated by the heating device, and film formation was performed while monitoring the temperature in the vicinity of the processing chamber 11 of the air supply port 12. The thickness of each obtained film was about 60 nm. The speed at which the film was formed was 5 m / min. Met. The surface specific resistance (reciprocal of conductivity) of the obtained film was measured, plotted against the gas temperature at the time of supply, and graphed as shown in FIG.

As can be clearly seen from FIG. 3, when the gas supply temperature is lower than 100 ° C., the surface resistivity is slightly high. It is considered that this is because the reaction is insufficient and the film quality is not good. When the temperature is 100 ° C. or higher, the surface resistivity is obviously decreased, and it is the lowest at 150 to 200 ° C. Since the film this time is one in which fluorinated methane is added to form a film having a low surface specific resistance value, it is 100 ° C. or higher, and further 15
It can be seen that if the temperature is 0 ° C., a desired high-quality film can be formed. When the temperature further rises to near 350 ° C., the surface resistivity suddenly rises. It is considered that this is because the reaction gas is decomposed by heating and supplied to the discharge space, reacts in the plasma space, and the particles after the reaction are contained in the film. Visually, the film having a gas temperature of 100 to 200 ° C. was a uniform and good film, but at a temperature of less than 100 ° C., a slightly yellowed film was obtained, and at a temperature of 300 ° C. or higher, it was clearly opaque. It was a poor quality film.

[0042]

According to the thin film forming method using the atmospheric pressure plasma method of the present invention, the discharge gas containing the reactive gas is added to 10
By supplying at a temperature of 0 ° C. or higher and at a temperature not higher than the decomposition temperature of the reaction gas, the discharge gas is supplied in a more activated state, that is, in a state of being easily separated into ions and the like.
Therefore, even if the frequency and power of the voltage applied between the electrodes are suppressed to the extent that the discharge space does not spread too much, the discharge gas containing the reaction gas that has flowed near the surface of the base material is reliably turned into plasma, Alternatively, a film can be formed by reacting in the vicinity thereof. In other words, it becomes possible to reliably generate a plasma reaction without reacting at a place away from the surface of the base material, so that particles after the reaction do not fall from the space, A high quality film can be formed on the surface at high speed. Further, the thin film forming method of the present invention is an atmospheric pressure plasma method and is a film formation under low temperature glow discharge, and as described above, a discharge gas is supplied at a high temperature to secure sufficient reactivity. Therefore, it is not necessary to actively heat the base material, and a resin base material can be particularly preferably used. In the present invention, since the film formation is performed not under a vacuum system but under a pressure close to the atmospheric pressure, continuous processes are possible, and high productivity can be achieved in this respect as well.

[Brief description of drawings]

FIG. 1 is a diagram showing a plasma discharge processing chamber used in a thin film forming method of the present invention.

FIG. 2 is a diagram showing a plasma discharge processing apparatus provided with the plasma discharge processing chamber of FIG.

FIG. 3 is a graph showing the surface specific resistance value of the thin film with respect to the temperature of the discharge gas.

[Explanation of symbols]

12 Air supply port 13, 13 exhaust port 25 roller electrode 36, 36 ... Fixed electrode 30 Plasma discharge chamber 41 power supply 50 Plasma discharge treatment device 51 gas generator 51a channel F film (base material)

Continued front page    (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 Wataru Mizuno             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 AA04 AA05 AA11 CA17 FA03                       JA06 JA09 JA10 JA16 JA18                       KA25

Claims (8)

[Claims] 1. A discharge gas containing a reaction gas is supplied under atmospheric pressure or a pressure near the atmospheric pressure, and a high-frequency voltage is applied between opposing electrodes to discharge the discharge gas. In the thin film forming method of forming a thin film on the surface of the base material by exposing the base material to the reaction gas in the plasma state, the discharge gas is at a temperature of 100 ° C. or higher and the decomposition temperature of the reaction gas or lower. The method of forming a thin film, characterized in that 2. The thin film forming method according to claim 1, wherein the discharge gas is supplied at a temperature of 150 ° C. or higher. 3. The discharge gas contains the reaction gas and an inert gas, and contains the reaction gas in an amount of 0.1 to 10% by volume. Thin film forming method. 4. The reaction gas is selected from a fluorine compound, a silicon compound, a titanium compound, a tin compound, a zinc compound, an indium compound, an aluminum compound, a copper compound and a silver compound. The method for forming a thin film according to any one of 1. 5. The method of forming a thin film according to claim 4, wherein the fluorine compound is fluorocarbon or fluorohydrocarbon. 6. A silicon compound, a titanium compound, a tin compound,
The thin film forming method according to claim 4, wherein the zinc compound, the indium compound, and the aluminum compound are organic metal compounds, metal hydrogen compounds, metal halogen compounds, or metal alkoxides. 7. The frequency of the voltage applied between the opposing electrodes is 100 kHz or more.
7. The method for forming a thin film according to any one of to 6. 8. The power of the voltage applied between the opposing electrodes is
It is 1 W / cm ² or more, 1 to 7 characterized by the above-mentioned.
5. The thin film forming method described in any one of 1.