JP2010031303A - Metal oxide thin film and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal oxide thin film having high film density and high film hardness, and a manufacturing method thereof with high film deposition rate. <P>SOLUTION: In the manufacturing method of the metal oxide thin film, the metal oxide thin film is formed on a base material when reactive gas becomes in a plasma state by applying the high frequency voltage between two electrodes facing each other and executing the discharge in a reactive space under the atmospheric pressure or under the pressure in a vicinity of the atmospheric pressure, and a base material is exposed to reactive gas in the plasma state. Acid having the acid dissociation constant pKa of ≤3.5 is introduced in the reactive space. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a metal oxide thin film and a manufacturing method thereof.

  Various products such as LSIs, semiconductors, display devices, magnetic recording devices, photoelectric conversion devices, Josephson devices, solar cells, photothermal conversion devices, touch panels, etc. have materials with a high-performance metal oxide thin film on a substrate. Many are used. These highly functional metal oxide thin films include, for example, antireflection films, gas barrier films, antifouling films, transparent conductive films, dielectric protective films, semiconductor films, transparent conductive films, electrochromic films, fluorescent films, and superconducting films. , Dielectric film, solar cell film, abrasion-resistant film, optical interference film, reflective film, antistatic film, conductive film, hard coat film, undercoat film, barrier film, electromagnetic wave shielding film, infrared shielding film, ultraviolet absorbing film A lubricating film, a shape memory film, a magnetic recording film, a light emitting element film, a biocompatible film, a corrosion resistant film, a catalyst film, a gas sensor film, a decorative film, and the like.

  Conventionally, in order to obtain such a highly functional thin film, there are a wet coating method and a dry film forming method (physical vapor deposition method, chemical vapor deposition method).

  The wet coating method is useful in terms of high productivity. However, since the material constituting the thin film must be used as a coating solution dissolved or dispersed in a solvent, the solvent remains in the thin film or the film thickness is uniform. It cannot be said that it is suitable for forming a high-performance thin film because it is difficult to maintain the properties. Moreover, in the drying process after application | coating, the problem that solvents, such as an organic solvent evaporated from the coating liquid, gives load to an environment is also included.

  The sol-gel method, which is one of the wet coating methods, is a method for obtaining a thin film by hydrolyzing an organometallic compound dissolved in a solvent, applying the solution onto a substrate, and then drying. However, the film density is low due to the formation of micro voids through which the evaporating solvent passes, and in order to eliminate such micro voids, it is necessary to sinter at a high temperature, and the film density is high on the plastic substrate. It is difficult to obtain a film.

  On the other hand, a dry film forming method using vacuum is a preferable method for forming a highly functional thin film because a highly accurate thin film can be formed.

  A physical vapor deposition method (PVD method) which is one of dry film forming methods can be further divided into a vacuum deposition method, a sputtering method, an ion plating method and the like. The vacuum deposition method is a method in which a thin film material is heated under high vacuum by a method such as electron beam irradiation, resistance heating, induction heating, and the like, and a cluster of volatile thin film materials is deposited on a substrate. The sputtering method is a technique in which ions of a rare gas such as argon are incident on a thin film material target at a high speed under high vacuum, and fine thin film material clusters ejected by elastic collision are deposited on the substrate. The ion plating method is a method in which minute clusters of a thin film material charged under a high vacuum are generated and deposited on a substrate charged to a reverse charge. All of these PVD methods require high vacuum conditions, and the materials that make up the thin film come linearly from the thin film material target, resulting in poor coverage and deposition regularity on the film, resulting in cracks. There is a problem that the film is likely to occur.

  The chemical vapor deposition method (CVD method), which is another dry film forming method, volatilizes the compound containing the raw material constituting the thin film in the vicinity of the base material, and then chemistry by heat, light, plasma, etc. This is a technique of inducing a reaction and depositing the produced ceramics on a substrate. Depending on the method of applying energy that causes a chemical reaction to the raw material compound, it is classified into thermal CVD, photo CVD, plasma CVD, etc., respectively.

  In thermal CVD, a temperature of 500 ° C. or higher is usually required, and since it is difficult to design a raw material compound in photo-CVD, film formation on a plastic substrate is mostly performed by plasma CVD.

  In the CVD method, a chemically active compound such as a radical is generated, so that the adhesion to the substrate is high, and a chemical reaction occurs due to collision between molecules, so there is no direction to the material constituting the thin film. Thus, a film with high coverage can be obtained.

  However, the vacuum apparatus used in the dry film-forming method becomes very large and expensive when the substrate to be processed becomes large. In addition to the huge amount of time required for vacuum exhaust, productivity cannot be increased. The disadvantage is large.

  Therefore, the methods capable of forming a highly functional thin film on a substrate are practically limited to the PVD method and the plasma CVD method. Furthermore, the plasma CVD method is the most preferable means in consideration of the obtained film quality.

  As a method of overcoming the above disadvantages that it is difficult to obtain a high-performance thin film by coating and the disadvantage of low productivity due to the use of a vacuum apparatus, the reactive gas is discharged under atmospheric pressure or a pressure near atmospheric pressure, and the reactive gas is plasma. Methods for exciting and forming a thin film on a substrate are described in JP-A-11-133205, JP-A-2000-185362, JP-A-11-61406, JP-A-2000-147209, 2000-121804, and the like. (Hereinafter also referred to as atmospheric pressure plasma method).

However, the atmospheric pressure plasma method has a problem that the film forming speed is slower than the wet coating method. On the other hand, in Patent Document 1, a high-frequency voltage exceeding 100 kHz is supplied between opposed electrodes and power of 1 W / cm ² or more is supplied to excite reactive gas to generate plasma, and such a high voltage is generated. It is described that a high-functional thin film can be obtained at a high film-forming speed by applying a power electric field. In Patent Document 2, a plurality of discharge processing units are provided on both sides of the source gas introduction unit to increase the film forming speed. In Patent Document 3, two discharge sections are provided, and the source gas is decomposed in the two discharge sections. Further, it is described that by promoting the decomposition of the raw material gas, the film forming speed is increased and the film forming yield (ratio of the film forming amount to the consumption amount of the raw material compound) is improved.

Although these techniques have improved the film-forming speed, there is a problem that the film density and the film hardness decrease as the film-forming speed increases, and the metal oxide thin film having a high film density and film hardness and the film-forming speed are increased. A fast manufacturing method has been desired.
International Publication No. 02/048428 Pamphlet JP 2005-150474 A JP 2005-200710 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a metal oxide thin film having a high film density and film hardness and a manufacturing method having a high film forming speed.

  The above object of the present invention is achieved by the following configurations.

  1. Under a pressure of atmospheric pressure or near atmospheric pressure, a reactive gas is made into a plasma state by applying a high-frequency voltage between two opposing electrodes to discharge the reaction space, and the substrate is reacted in the plasma state. In the method for producing a metal oxide thin film, wherein the metal oxide thin film is formed on the substrate by exposing to a gas, an acid having an acid dissociation constant pKa of 3.5 or less is introduced into the reaction space. Thin film manufacturing method.

  2. 2. The method for producing a metal oxide thin film according to 1 above, wherein 1 to 15% by volume of water is introduced into the reaction space.

  3. 3. The method for producing a metal oxide thin film according to 1 or 2, wherein the acid is introduced into the reaction space by volatilizing the aqueous solution of the acid.

  4). 3. The method for producing a metal oxide thin film as described in 1 or 2 above, wherein the acid is introduced into the reaction space by spraying the aqueous solution of the acid.

  5. 5. The metal oxidation according to any one of 1 to 4, wherein the acid is an acid selected from nitric acid, nitrous acid, hydrochloric acid, chloric acid, chlorous acid, sulfuric acid, sulfurous acid, and phosphoric acid. Thin film manufacturing method.

  6). 6. The method for producing a metal oxide thin film according to any one of 1 to 5, wherein the discharge gas is nitrogen.

7). 7. The method for producing a metal oxide thin film according to any one of 1 to 6, wherein the frequency of the high-frequency voltage is 1 kHz to 2500 MHz and the supplied power is 1 to 50 W / cm ² .

  8). 8. The method for producing a metal oxide thin film as described in 7 above, wherein the high-frequency voltage is a superposition of a high-frequency voltage of 1 kHz to 1 MHz and a high-frequency voltage of 1 MHz to 2500 MHz.

  9. 9. The method for producing a metal oxide thin film according to any one of 1 to 8, wherein the substrate temperature when exposed to the reactive gas in the plasma state is 80 to 200 ° C.

  10. 10. The method for producing a metal oxide thin film according to any one of 1 to 9, wherein an oxidizing gas is introduced into the reaction space.

  11. 11. The method for producing a metal oxide thin film as described in 10 above, wherein the oxidizing gas is 1 to 20% by volume of oxygen.

  12 A metal oxide thin film obtained by the method for producing a metal oxide thin film according to any one of 1 to 11 above.

  13. The metal oxide thin film includes a metal selected from Al, Si, Ti, V, Fe, Ni, Cu, Zn, Y, Nb, Mo, In, Ta, Ir, Sn, and W. 12. The metal oxide thin film according to 12.

  According to the present invention, it is possible to provide a metal oxide thin film having a high film density and film hardness and a manufacturing method having a high film forming speed.

  As a result of intensive studies in view of the above problems, the inventor applied a high-frequency voltage between two opposing electrodes under atmospheric pressure or a pressure in the vicinity of atmospheric pressure to discharge the reaction space. In the method for producing a metal oxide thin film in which a reactive gas is made into a plasma state and the substrate is exposed to the reactive gas in the plasma state to form a metal oxide thin film on the substrate, an acid dissociation constant pKa is present in the reaction space. It has been found that a metal oxide thin film having a high density and film hardness can be obtained at high speed by a method for producing a metal oxide thin film in which an acid of 3.5 or less is introduced, and the present invention has been achieved.

  Such an effect is considered as follows.

  When tetraethoxysilane (TEOS) is used as a reactive gas source gas and a film is formed without using an acid (conventional method), the vicinity (inside) of the formed silicon oxide film surface is subjected to photoelectron spectroscopy (ESCA), Auger When composite surface analysis was performed using electron spectroscopy (Auger), secondary ion mass spectrometry (SIMS), diffuse reflection FI-IR, or the like, OH groups were confirmed in the vicinity (inside) of the silicon oxide surface. Refer to FIG.

  On the other hand, when tetraethoxysilane (TEOS) is used as a reactive gas source gas and a film is formed using an acid having an acid dissociation constant pKa of 3.5 or less (the present invention), the vicinity of the formed silicon oxide surface (internal ) In the same manner, almost no OH group was detected near (inside) the surface of the silicon oxide film. See (B-2) in FIG.

In the conventional method, the dehydration condensation rate of silanol groups is slower than the deposition rate on the base material or deposited silicon oxide, so that OH groups remain in the silicon oxide film, which causes a decrease in film density and film hardness. Inferred to be the cause. In the case of the present invention, the acid introduced into the reaction space generates H ⁺ (H ₃ O ⁺ ), which acts as a catalyst to promote the dehydration condensation reaction on the film surface. It is presumed that no OH group remains in the silicon oxide film. See (B-1) in FIG.

Moreover, when the gas discharged from the plasma discharge treatment apparatus was collected and analyzed by TOF-SIMS, in the conventional method, many components having groups such as undecomposed Si—OCH ₂ CH ₃ remained, In the case of the invention, a result suggesting that this is small was obtained. These results are presumed that in the case of the present invention, the acid introduced into the reaction space promotes the decomposition of the source gas and contributes to the improvement of the deposition rate (film formation rate).

  Hereinafter, the present invention will be described in detail.

<< Acid with pKa of 3.5 or less >>
The present invention is characterized in that an acid having an acid dissociation constant pKa of 3.5 or less is introduced into the reaction space. As the pKa is smaller, protons are more likely to be generated in the reaction space. In addition, the addition of hydrogen gas only generates radicals and does not promote the dehydration condensation reaction.

The pK value is a numerical value defined by pK = −log 10K, where K is the equilibrium constant. At this time, p means power, and the smaller the pK value, the stronger the acid. For example, in the case of dissociation of acid and base, when the ionization constant of the base is Kb and the ionization constant of the conjugate acid is Ka, and the ion product of water is Kw, it is expressed as Kb = Kw / Ka, and at 25 ° C. as Kw = 1 × ^{10 14,} the pKb = 14-pKa.

  One of the characteristics of the acid used in the present invention is that the pKa is 3.5 or less (strong acid), preferably the pKa is 3.0 to -10.0, more preferably 2.0 to-. 8.5 strong acid.

  Examples of acids (strong acids) having a pKa of 3.5 or less according to the present invention include “selection of buffering agents and applied hydrogen ions and metal ions” (DD Perrin, B. Dempsey, Keiichi Tsuji, Kodansha Scientific) FIC) and "Lange's Chemistry Handbook" (Lamge's Handbook of Chemistry, 11th Edition Edited byJOIN A. Dean. McCRAW HILL BOON COMPANY, 1973) “Dissociation constants of weak acids, weak bases and ampholytes” described on pages 1054-1058 of “Basic Manual of Chemistry” (Chemical Society of Japan, Maruzen) It can be appropriately selected from those described in.

  For example, an acid selected from nitric acid, nitrous acid, hydrochloric acid, chloric acid, chlorous acid, sulfuric acid, sulfurous acid and phosphoric acid is preferable, and nitric acid is particularly preferable. Since these acids have a large dissociation constant and do not contain carbon, a metal oxide thin film (hereinafter also simply referred to as a thin film) is not contaminated with carbon. If carbon remains in the thin film, dangling bonds may be formed and the film density may decrease.

When water is introduced into the reaction space, the acid is preferably liberated in the form of H ₃ O ⁺ . The amount of water is preferably not less than the same volume as the acid, or 1 to 15% by volume of the reaction space.

  In order to introduce an acid into the reaction space, it is preferable to introduce the acid into the reaction space by volatilizing the aqueous acid solution or by spraying the aqueous acid solution. In this method, water can be introduced into the reaction space simultaneously with the acid.

  FIG. 2 is a schematic view of an ultrasonic sprayer used when a liquid containing acid is supplied as droplets to the reaction space. Thereby, a micro droplet (droplet) can be formed. In FIG. 2, 1 is an ultrasonic atomizer, 2 is an introduction tube for introducing nitrogen gas, 3 is a liquid storage unit for storing a liquid containing acid as a droplet material, 4 is an ultrasonic generator, and 5 is an ultrasonic wave. A power source 6 connected to the generating unit 4 is a discharge tube that discharges the generated droplets. When nitrogen gas is introduced from the introduction pipe 2 into the liquid storage unit 3 and the ultrasonic power is generated by turning on the power source 5, droplets are generated. The droplets generated in this manner are discharged out of the ultrasonic sprayer 1 through the discharge tube 6 and introduced into a reaction space of an atmospheric pressure plasma apparatus (not shown).

<Atmospheric pressure plasma method>
Next, the atmospheric pressure plasma method according to the present invention will be described.

  An atmospheric pressure plasma method is used to form an antireflection film and a barrier film made of a metal oxide thin film according to the present invention, and a laminate thereof.

  The atmospheric pressure plasma method is described in, for example, Japanese Patent Application Laid-Open No. 10-154598, Japanese Patent Application Laid-Open No. 2003-49272, International Publication No. 02/048428, and the like. The described thin film forming method is preferable for forming a metal oxide thin film having high film density and film hardness. Moreover, a web-shaped base material can be drawn out from a roll-shaped original winding to continuously form metal oxide thin films having different compositions.

  The above atmospheric pressure plasma method according to the present invention is a plasma CVD method performed under atmospheric pressure or a pressure in the vicinity thereof, and the atmospheric pressure or the pressure in the vicinity thereof is about 20 to 110 kPa, and is described in the present invention. In order to obtain a good effect, 93 to 104 kPa is preferable.

The discharge conditions in the present invention are preferably such that the frequency of the high-frequency voltage is 1 kHz to 2500 MHz and the supplied power is 1 to 50 W / cm ² . More preferably, the frequency is 50 kHz or more and the supplied power is 5 W / cm ² or more. The higher the frequency and the higher the supplied power, the more the raw material is decomposed, and a metal oxide thin film having a higher film density and film hardness can be obtained. As the decomposition of the raw material proceeds, the components having OH groups increase in the reaction space, and the effect of introducing an acid can be obtained more effectively. In addition, when a component having a group such as undecomposed Si—OCH ₂ CH ₃ remains, carbon may be contaminated in the thin film to form dangling bonds and the film density may be reduced.

  The discharge condition in the present invention is more preferably that two or more electric fields having different frequencies are applied to the discharge space and superimposed. Thereby, the plasma density is increased, and a metal oxide thin film having a high film density and film hardness is obtained. The two electric fields preferably have a high frequency voltage superposed of a high frequency voltage of 1 kHz to 1 MHz and a high frequency voltage of 1 MHz to 2500 MHz.

  High frequency refers to one having a frequency of at least 0.5 kHz.

  In the present invention, the strength of the electric field at which discharge starts is the lowest electric field intensity that can cause discharge in the discharge space (electrode configuration, etc.) and reaction conditions (gas conditions, etc.) used in the actual thin film formation method. Point to. The discharge start electric field strength varies somewhat depending on the gas type supplied to the discharge space, the dielectric type of the electrode, the distance between the electrodes, and the like, but is controlled by the discharge start electric field strength of the discharge gas in the same discharge space.

  By applying a high-frequency electric field as described above to the discharge space, it is presumed that a discharge capable of forming a thin film is caused and high-density plasma necessary for forming a high-quality thin film can be generated.

  Although the superposition of continuous waves such as sine waves has been described above, the present invention is not limited to this, and both pulse waves may be used, one of them may be a continuous wave and the other may be a pulse wave. Further, it may have a third electric field having a different frequency.

  Moreover, it is preferable to connect a 1st filter to either a 1st electrode, a 1st power supply, or them, and a 2nd filter to a 2nd electrode, a 2nd power supply, or any between them.

  Further, by increasing the output density of the first high-frequency electric field, it is possible to generate further uniform and high-density plasma, and it is possible to improve both the film forming speed and the film quality.

  The atmospheric pressure plasma discharge treatment apparatus includes a gas supply means for supplying a discharge gas and a thin film forming gas between the counter electrodes, and an acid introduction means for the reaction space. Furthermore, it is preferable to have an electrode temperature control means for controlling the temperature of the electrode.

  The atmospheric pressure plasma discharge treatment apparatus used in the present invention, as described above, discharges between the counter electrodes, puts the gas and acid introduced between the counter electrodes into a plasma state, and is placed between the counter electrodes or the electrodes A thin film is formed on the substrate by exposing the substrate to be transferred between the substrates to the plasma state gas. As another method, the atmospheric pressure plasma discharge treatment apparatus discharges between the counter electrodes similar to the above, excites the gas introduced between the counter electrodes or puts it in a plasma state, and forms a jet together with the acid outside the counter electrode. Jet type apparatus for forming a thin film on a substrate by blowing out excited or plasma gas and exposing a substrate (which may be stationary or transferred) in the vicinity of the counter electrode There is.

  FIG. 3 is a schematic view showing an example of a jet-type atmospheric pressure plasma discharge treatment apparatus useful for the present invention.

  In addition to the plasma discharge processing apparatus and the electric field applying means having two power sources, the jet type atmospheric pressure plasma discharge processing apparatus is not shown in FIG. The apparatus has means, acid introduction means, and electrode temperature adjusting means.

  The plasma discharge processing apparatus 10 has a counter electrode composed of a first electrode 11 and a second electrode 12, and the first electrode 11 has a frequency ω1 from the first power source 21 between the counter electrodes. A high frequency electric field is applied, and a high frequency electric field having a frequency ω2 from the second power source 22 is applied from the second electrode 12.

  The above-described thin film forming gas G is introduced from the gas supply means as shown in FIG. 4 described later into the space (discharge space) 13 between the opposing electrodes of the first electrode 11 and the second electrode 12, and the first power source 21. The second power source 22 applies the above-described high-frequency electric field between the first electrode 11 and the second electrode 12 to generate a discharge, and the thin film forming gas G described above is brought into a plasma state while the lower side of the counter electrode (below the paper surface). The processing space formed by the lower surface of the counter electrode and the base material F is filled with a gas G ° in a plasma state, and is unwound from a base winding (unwinder) (not shown). A thin film is formed in the vicinity of the processing position 14 on the base material F that is transported or transported from the previous process. Although the acid introduction means is not shown, it may be mixed with the thin film forming gas G in advance, or may be directly supplied to the space between the first and second electrodes and the substrate. During the thin film formation, the medium heats or cools the electrode through the pipe from the electrode temperature adjusting means as shown in FIG. Depending on the temperature of the base material during the plasma discharge treatment, the properties, composition, etc. of the thin film obtained may change, and it is desirable to appropriately control this. As the temperature control medium, an insulating material such as distilled water or oil is preferably used. During the plasma discharge treatment, it is desirable to uniformly adjust the temperature inside the electrode so that temperature unevenness in the width direction or longitudinal direction of the substrate does not occur as much as possible.

  By arranging a plurality of jet-type atmospheric pressure plasma discharge treatment apparatuses in parallel with the transport direction of the base material F and simultaneously discharging gas in the same plasma state, it becomes possible to form a plurality of thin films at the same position, and for a short time. Thus, a desired film thickness can be formed. If a plurality of units are arranged in parallel with the transport direction of the base material F, different thin film forming gases are supplied to each apparatus and different plasma states of the gas are jetted, it is possible to form laminated thin films having different layers.

  FIG. 4 is a schematic view showing an example of an atmospheric pressure plasma discharge treatment apparatus of a system for treating a substrate between counter electrodes useful for the present invention.

  The atmospheric pressure plasma discharge treatment apparatus of the present invention includes at least a plasma discharge treatment apparatus 30, an electric field application means 40 having two power supplies, a gas supply means 50, an electrode temperature adjustment means 60, and an acid introduction means 70. It is.

  A thin film is formed by subjecting the base material F to plasma discharge treatment between the opposing electrodes 32 of the roll rotating electrode (first electrode) 35 and the fixed electrode group (second electrode) 36 (hereinafter also referred to as the discharge space 32). To form.

  In the discharge space 32 formed between the roll rotating electrode 35 and the fixed electrode group 36, the roll rotating electrode 35 receives a high-frequency electric field having a frequency ω1 from the first power source 41, and the fixed electrode group 36 has a second power source 42. A high frequency electric field having a frequency ω2 is applied.

  In the present invention, the roll rotation electrode 35 may be the second electrode, and the fixed electrode group 36 may be the first electrode.

  The thin film forming gas G generated by the gas generator 51 of the gas supply means 50 is introduced into the plasma discharge processing vessel 31 from the air supply port 52 while the flow rate is controlled by a gas flow rate adjusting means (not shown). The acid is supplied from the acid introduction means 70.

  The substrate F is unwound from the original winding (not shown) and conveyed, or is conveyed in the direction of the arrow from the previous process and is accompanied by the nip roll 65 through the guide roll 64 and the substrate. Etc., and is transferred to the fixed electrode group 36 while being wound while being in contact with the roll rotating electrode 35.

  An electric field is applied from both the roll rotating electrode 35 and the fixed electrode group 36 during the transfer, and discharge plasma is generated between the counter electrodes (discharge space) 32. The base material F forms a thin film with a gas in a plasma state while being wound while being in contact with the roll rotating electrode 35.

  A plurality of fixed electrodes are installed along a circumference larger than the circumference of the roll electrode, and the discharge area of the electrodes is a roll of all the fixed electrodes facing the roll rotating electrode 35. It is represented by the sum of the areas of the surfaces facing the rotating electrode 35.

  The base material F passes through the nip roll 66 and the guide roll 67 and is wound up by a winder (not shown) or transferred to the next process.

  Discharged treated exhaust gas G ′ is discharged from the exhaust port 53.

  During the thin film formation, in order to heat or cool the roll rotating electrode 35 and the fixed electrode group 36, the medium whose temperature is adjusted by the electrode temperature adjusting means 60 is sent to both electrodes via the pipe 61 by the liquid feed pump P, and inside the electrodes Adjust the temperature from Reference numerals 68 and 69 denote partition plates that partition the plasma discharge processing vessel 31 from the outside.

  FIG. 5 is a perspective view showing an example of the structure of the conductive metallic base material of the roll rotating electrode shown in FIG. 4 and the dielectric material coated thereon.

  In FIG. 5, a roll electrode 35a is formed by covering a conductive metallic base material 35A and a dielectric 35B thereon. In order to control the electrode surface temperature during the plasma discharge treatment and to keep the surface temperature of the substrate F at a predetermined value, a temperature adjusting medium (such as water or silicon oil) can be circulated.

  FIG. 6 is a perspective view showing an example of the structure of the conductive metallic base material of the fixed electrode and the dielectric material coated thereon.

  In FIG. 6, the fixed electrode 36a has a coating of a dielectric 36B similar to that shown in FIG. 4 on the conductive metallic base material 36A.

  The fixed electrode 36a shown in FIG. 6 is not particularly limited, and may be a cylindrical electrode or a rectangular tube electrode.

  5 and 6, a roll electrode 35a and a fixed electrode 36a are obtained by thermal spraying ceramics as dielectrics 35B and 36B on conductive metallic base materials 35A and 36A, respectively. The ceramic dielectric may be covered by about 1 mm with a single wall. As the ceramic material used for thermal spraying, alumina, silicon nitride, or the like is preferably used. Among these, alumina is particularly preferable because it is easily processed. The dielectric layer may be a lining-processed dielectric provided with an inorganic material by lining.

  Examples of the conductive metal base materials 35A and 36A include titanium metal or titanium alloy, metal such as silver, platinum, stainless steel, aluminum, and iron, a composite material of iron and ceramics, or a composite material of aluminum and ceramics. Can be mentioned.

  The distance between the opposing first electrode and second electrode is the shortest distance between the surface of the dielectric and the surface of the conductive metallic base material of the other electrode when a dielectric is provided on one of the electrodes. Say that. When a dielectric is provided on both electrodes, it means the shortest distance between the dielectric surfaces. The distance between the electrodes is determined in consideration of the thickness of the dielectric provided on the conductive metallic base material, the magnitude of the applied electric field strength, the purpose of using the plasma, etc. From the viewpoint of performing 0.15 mm, 0.1 to 20 mm is preferable, and 0.5 to 2 mm is particularly preferable.

  The plasma discharge treatment vessel 31 is preferably a treatment vessel made of Pyrex (registered trademark) glass or the like, but can be made of metal as long as it can be insulated from the electrodes. For example, polyimide resin or the like may be attached to the inner surface of an aluminum or stainless steel frame, and ceramic spraying may be performed on the metal frame to achieve insulation. In FIG. 3, it is preferable to cover both side surfaces (up to the vicinity of the substrate surface) of both parallel electrodes with an object made of the above-described material.

  As the first power source (high frequency power source) installed in the atmospheric pressure plasma discharge treatment apparatus of the present invention, SPG5-4500 (5 kHz) manufactured by Shinko Electric Co., Ltd., AGI-023 (15 kHz) manufactured by Kasuga Electric Co., Ltd., and PHF-6k manufactured by HEIDEN Laboratory. (100 kHz *) and commercially available products such as CF-2000-200k (200 kHz) manufactured by Pearl Industry, and any of them can be used.

  As the second power source (high frequency power source), commercially available products such as CF-2000-800k (800 kHz), CF-5000-13M (13.56 MHz), CF-2000-150M (150 MHz) manufactured by Pearl Industries, Ltd. Any of these can be preferably used.

  Of the above power supplies, * indicates a HEIDEN Laboratory impulse high-frequency power supply (100 kHz in continuous mode). Other than that, it is a high-frequency power source that can apply only a continuous sine wave.

  In the present invention, it is preferable to employ an electrode capable of maintaining a uniform and stable discharge state by applying such an electric field in an atmospheric pressure plasma discharge treatment apparatus.

In the present invention, the power applied between the electrodes facing each other is such that power (power density) of 1 W / cm ² or more is supplied to the second electrode (second high-frequency electric field) to excite the discharge gas to generate plasma. The energy is applied to the thin film forming gas to form a thin film. The upper limit value of the power supplied to the second electrode is preferably 50 W / cm ² , more preferably 20 W / cm ² . The lower limit is preferably 1.2 W / cm ² . The discharge area (cm ² ) refers to an area in a range where discharge occurs between the electrodes.

Further, by supplying power (output density) of 1 W / cm ² or more to the first electrode (first high frequency electric field), the output density is improved while maintaining the uniformity of the second high frequency electric field. be able to. Thereby, a further uniform high-density plasma can be generated, and a further improvement in film forming speed and an improvement in film quality can be achieved. Preferably it is 5 W / cm ² or more. The upper limit value of the power supplied to the first electrode is preferably 50 W / cm ² .

  Here, the waveform of the high-frequency electric field is not particularly limited. There are a continuous sine wave continuous oscillation mode called a continuous mode, an intermittent oscillation mode called ON / OFF intermittently called a pulse mode, and either of them may be adopted, but at least the second electrode side (second The high-frequency electric field is preferably a continuous sine wave because a denser and better quality film can be obtained.

《Metal oxide thin film forming material》
Next, a preferable raw material gas for obtaining a metal oxide thin film will be described.

  The raw material for the metal oxide thin film may be in a gas, liquid, or solid state at normal temperature and pressure. In the case of gas, it can be introduced into the discharge space as it is, but in the case of liquid or solid, it is used after being vaporized by means such as heating, bubbling, decompression, ultrasonic irradiation, vaporizer or the like. Moreover, you may dilute and use by a solvent and organic solvents, such as methanol, ethanol, n-hexane, and these mixed solvents can be used for a solvent. Since these diluted solvents are decomposed into molecular and atomic forms during the plasma discharge treatment, the influence can be almost ignored.

  However, it is preferably an organometallic compound having a vapor pressure in a temperature range of 0 to 250 ° C. under atmospheric pressure, and more preferably an organometallic compound exhibiting a liquid state in a temperature range of 0 to 250 ° C. This is because the plasma deposition chamber is at a pressure close to atmospheric pressure, and it is difficult to send gas into the plasma deposition chamber unless it can be vaporized under atmospheric pressure. This is because the amount of the raw material compound that is fed into the plasma film forming chamber can be accurately controlled. In particular, when the raw material compound is a liquid, a vaporizer can be used. The vaporizer can directly vaporize from the liquid, and the amount of vaporization can be managed with an accuracy of ± 1%. In addition, when the heat resistance of the base material which forms a metal oxide thin film is 270 degrees C or less, it is preferable that it is a compound which has vapor pressure from the base-material heat resistance temperature to 20 degrees C or less.

  Examples of such organometallic compounds include silicon-containing compounds such as silane, tetramethoxysilane, tetraethoxysilane, tetra n-propoxy silane, tetraisopropoxy silane, tetra n-butoxy silane, and tetra t-butoxy silane. , Dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, phenyltriethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, hexamethyl Disiloxane, bis (dimethylamino) dimethylsilane, bis (dimethylamino) methylvinylsilane, bis (ethylamino) dimethylsilane, N, O-bis (trimethylsilyl) acetamide, bis Trimethylsilyl) carbodiimide, diethylaminotrimethylsilane, dimethylaminodimethylsilane, hexamethyldisilazane, hexamethylcyclotrisilazane, heptamethyldisilazane, nonamethyltrisilazane, octamethylcyclotetrasilazane, tetrakisdimethylaminosilane, tetraisocyanatosilane, tetra Methyldisilazane, tris (dimethylamino) silane, triethoxyfluorosilane, allyldimethylsilane, allyltrimethylsilane, benzyltrimethylsilane, bis (trimethylsilyl) acetylene, 1,4-bistrimethylsilyl-1,3-butadiyne, di-t -Butylsilane, 1,3-disilabutane, bis (trimethylsilyl) methane, cyclopentadienyltrimethylsilane, phenyldimethyl Examples include silane, phenyltrimethylsilane, propargyltrimethylsilane, tetramethylsilane, trimethylsilylacetylene, 1- (trimethylsilyl) -1-propyne, tris (trimethylsilyl) methane, tris (trimethylsilyl) silane, vinyltrimethylsilane, hexamethyldisilane, and the like. .

  Examples of the compound containing titanium include titanium methoxide, titanium ethoxide, titanium isopropoxide, titanium n-butoxide, titanium diisopropoxide (bis-2,4-pentanedionate), titanium diiso Examples include propoxide (bis-2,4-ethylacetoacetate), titanium di-n-butoxide (bis-2,4-pentanedionate), titanium acetylacetonate, and butyl titanate dimer.

  Further, zirconium-containing compounds include zirconium n-propoxide, zirconium n-butoxide, zirconium t-butoxide, zirconium tri-n-butoxide acetylacetonate, zirconium di-n-butoxide bisacetylacetonate, zirconium acetylacetate. Nate, zirconium acetate, zirconium hexafluoropentandionate and the like.

  Examples of the compound containing aluminum include aluminum ethoxide, aluminum isopropoxide, aluminum n-butoxide, aluminum s-butoxide, aluminum t-butoxide, and aluminum acetylacetonate.

  Examples of the boron-containing compound include diborane, tetraborane, boron fluoride, boron chloride, boron bromide, borane-diethyl ether complex, borane-THF complex, borane-dimethyl sulfide complex, boron trifluoride diethyl ether complex, Examples include triethylborane, trimethoxyborane, triethoxyborane, tri (isopropoxy) borane, borazole, trimethylborazole, triethylborazole, triisopropylborazole and the like.

  Compounds containing tin include tetraethyltin, tetramethyltin, di-n-butyltin diacetate, tetrabutyltin, tetraoctyltin, tetraethoxytin, methyltriethoxytin, diethyldiethoxytin, triisopropylethoxytin, Diethyltin, dimethyltin, diisopropyltin, dibutyltin, diethoxytin, dimethoxytin, diisopropoxytin, dibutoxytin, tin dibutyrate, tin diacetoacetonate, ethyltin acetoacetonate, ethoxytin acetoacetonate, dimethyltin di Examples of tin halides such as acetoacetonate and tin hydrogen compounds include tin dichloride and tin tetrachloride.

  Examples of other organic compounds composed of metals include antimony ethoxide, arsenic triethoxide, barium 2,2,6,6-tetramethylheptanedionate, beryllium acetylacetonate, bismuth hexafluoropentanedionate, dimethylcadmium. , Calcium 2,2,6,6-tetramethylheptanedionate, chromium trifluoropentanedionate, cobalt acetylacetonate, copper ethylacetoacetate, copper hexafluoropentanedionate, magnesium acetate, magnesium trifluoroacetate, magnesium tri Fluoropentanedionate, magnesium hexafluoropentanedionate, magnesium hexafluoropentanedionate-dimethyl ether complex, gallium ethoxide, tetra Toxigermane, tetramethoxygermane, hafnium t-butoxide, hafnium ethoxide, indium acetylacetonate, indium 2,6-dimethylaminoheptanedionate, ferrocene, lanthanum isopropoxide, lead acetate, tetraethyllead, neodymium acetylacetonate, Platinum hexafluoropentanedionate, trimethylcyclopentadienylplatinum, rhodium dicarbonylacetylacetonate, strontium 2,2,6,6-tetramethylheptanedionate, tantalum methoxide, tantalum trifluoroethoxide, tellurium ethoxide, Examples include tungsten ethoxide, vanadium triisopropoxide oxide, zinc acetylacetonate, and diethylzinc.

  The metal oxide thin film according to the present invention preferably contains a metal selected from Al, Si, Ti, V, Fe, Ni, Cu, Zn, Y, Nb, Mo, In, Ta, Ir, Sn and W. More preferably, it contains a metal selected from Al, Si, Ti, Nb, In, Ta, Ir, Sn and W, and most preferably contains Si.

Various high-functional thin films can be obtained by appropriately selecting the source gas and using it in the thin film forming method of the present invention. One example is shown below, but the present invention is not limited to this.
Dielectric protective film _{SiO 2, SiO, Al 2 O} 3, Al 2 O 3, Y 2 O 3
Transparent conductive film In ₂ O ₃ , SnO ₂
Electrochromic film WO ₃ , IrO ₂ , MoO ₃ , V ₂ O ₅
Magnetic recording film γ-Fe ₂ O ₃ , Fe ₃ O ₄ , SiO ₂ , AlO ₃
Selective permeable membrane In ₂ O ₃ , SnO ₂
Antireflection film SiO ₂ , TiO ₂ , SnO ₂
For the source gas, compounds containing these metals are preferably used. Of these metal compounds, organosilicon compounds are most preferred. This is because the organosilicon compound has high volatility, is inexpensive compared with other metal compounds, and the silicon oxide thin film obtained from the organosilicon compound has high density and transparency.

  Decomposing gases for decomposing these source gases to obtain metal oxide thin films include reducing gases that generate hydrogen atoms such as hydrogen, water, ammonia, methane, hydrogen sulfide, oxygen, ozone, and sub-oxidation. Examples thereof include oxidizing gases that generate oxygen atoms, such as nitrogen, nitrogen monoxide, nitrogen dioxide, carbon monoxide, carbon dioxide, and sulfur dioxide. As the decomposition gas, either a reducing gas or an oxidizing gas can be used, but carbon or nitrogen deposited on the substrate, for example, forming dangling bonds in the silicon oxide film can be removed by the oxidizing gas. In the present invention, it is preferable to use an oxidizing gas. In oxidizing gas, 1-20 volume%, Preferably 5-20 volume% of oxygen is preferable. When oxygen is used, the raw material gas is decomposed well and the effect of introducing an acid is obtained, so that a metal oxide thin film having high film density and film hardness can be obtained.

  In the atmospheric pressure plasma method, these reactive gases are diluted with a discharge gas that tends to be in a plasma state mainly to maintain the plasma discharge, and are introduced into the plasma discharge space (reaction space). As such a discharge gas, nitrogen gas and / or an 18th group atom of the periodic table, specifically helium, neon, argon, krypton, xenon, radon, etc., particularly helium and argon are preferably used. Among these, nitrogen, helium, and argon are preferable, and nitrogen is more preferable.

  As described above, the film formation is performed by mixing the raw material gas, the decomposition gas, and the discharge gas and supplying the mixed gas to the plasma discharge space. Although the ratio of the discharge gas and the raw material gas varies depending on the properties of the film to be obtained, the reactive gas is supplied with the ratio of the discharge gas being 90.0 to 99.9% with respect to the entire mixed gas. Although the ratio of the discharge gas and the reactive gas varies depending on the properties of the film to be obtained, the reactive gas is supplied with the ratio of the discharge gas being 50% or more with respect to the entire mixed gas.

  The substrate temperature when exposed to the reactive gas in the plasma state is preferably 80 to 200 ° C. In order to promote the dehydration condensation reaction, the substrate temperature is 80 ° C. or higher, preferably 100 ° C. or higher. When the substrate is made of resin, it is preferable to adjust the temperature of the substrate to 200 ° C. or less, and more preferably to 100 ° C. or less, in order to minimize the influence on the substrate during the plasma discharge treatment. Is to adjust. In order to adjust to the above temperature range, the electrode and the substrate are subjected to plasma discharge treatment while being cooled by a cooling means as necessary.

"Base material"
Next, the base material that can be used in the present invention will be described.

  The base material that can be used in the present invention is not particularly limited as long as a thin film can be formed on the surface thereof, such as a film-like material or a three-dimensional material such as a lens shape. If the substrate can be placed between the electrodes, it can be placed between the electrodes, and if the substrate cannot be placed between the electrodes, the generated plasma can be blown against the substrate to blow the thin film. What is necessary is just to form.

  The material constituting the substrate is not particularly limited, but a resin can be preferably used because it is under atmospheric pressure or a pressure near atmospheric pressure and low-temperature glow discharge.

  For example, when the thin film according to the present invention is an antireflection film, the substrate is preferably a cellulose ester such as a cellulose triacetate film, polyester, polycarbonate, polystyrene, and further gelatin, polyvinyl alcohol (PVA), acrylic on these. Resins, polyester resins, cellulose-based resins and the like can be used. Moreover, these base materials can use what coated the anti-glare layer and the clear hard-coat layer on the support body, and coated the back-coat layer and the antistatic layer.

  As the above support (also used as a base material), specifically, polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate butyrate film, Cellulose acetate propionate film, cellulose acetate phthalate film, cellulose triacetate, cellulose ester film such as cellulose nitrate, or derivatives thereof, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene series Film, polycarbonate film, norbornene resin film, polymethylpen Film, polyetherketone film, polyimide film, polyethersulfone film, polysulfone film, polyetherketoneimide film, polyamide film, fluororesin film, nylon film, polymethylmethacrylate film, acrylic film or polyarylate film Can be mentioned.

  These materials can be used alone or in combination as appropriate. Among these, commercially available products such as ZEONEX (manufactured by Nippon Zeon Co., Ltd.) and ARTON (manufactured by Nippon Synthetic Rubber Co., Ltd.) can be preferably used. Furthermore, even for materials having a large intrinsic birefringence such as polycarbonate, polyarylate, polysulfone, and polyether sulfone, conditions such as solution casting and melt extrusion, and further, stretching conditions in the longitudinal and lateral directions are appropriately set. Can be obtained. Moreover, the support body which concerns on this invention is not limited to said description. A film thickness of 10 to 1000 μm is preferably used.

  In the present invention, when the thin film provided on the base material is a thin film for optical use such as an antireflection film, it is preferable to use a cellulose ester film as the base material because a laminate having a low reflectance can be obtained. From the viewpoint of preferably obtaining the effects described in the present invention, as the cellulose ester, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate are preferable, and among these, cellulose acetate butyrate and cellulose acetate propionate are preferably used.

  In the present invention, when the cellulose ester film is used as a substrate, the cellulose ester film preferably contains a plasticizer.

  The plasticizer is not particularly limited, but is a phosphate ester plasticizer, a phthalate ester plasticizer, a trimellitic ester plasticizer, a pyromellitic acid plasticizer, a glycolate plasticizer, or a citrate ester plasticizer. An agent, a polyester plasticizer, or the like can be preferably used. For phosphate esters, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc.For phthalate esters, diethyl phthalate, dimethoxyethyl phthalate, dimethyl Trimellitic plasticizers such as phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, etc. Tributyl trimellitate, triphenyl trimellitate, triethyl trimellitate, pyromellitic acid ester Examples of plasticizers include tetrabutyl pyromellitate, tetraphenyl pyromellitate, tetraethyl pyromellitate, In acid ester type, triacetin, tributyrin, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, etc., citrate ester plasticizers such as triethyl citrate, tri-n-butyl citrate Acetyl triethyl citrate, acetyl tri-n-butyl citrate, acetyl tri-n- (2-ethylhexyl) citrate and the like can be preferably used.

  Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.

  As the polyester plasticizer, a copolymer of a dibasic acid such as an aliphatic dibasic acid, an alicyclic dibasic acid, or an aromatic dibasic acid and a glycol can be used. The aliphatic dibasic acid is not particularly limited, and adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4-cyclohexyl dicarboxylic acid, and the like can be used. As glycol, ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol and the like can be used. These dibasic acids and glycols may be used alone or in combination of two or more.

  It is preferable that the usage-amount of these plasticizers is 1-20 mass% with respect to a cellulose ester at points, such as film performance and workability.

  In the present invention, when the thin film is an antireflection film, an ultraviolet absorber is preferably used as the base material (which may be a support alone) from the viewpoint of preventing deterioration of liquid crystals and the like.

  As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having a small absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Specific examples of preferably used ultraviolet absorbers include, but are not limited to, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. Not. Further, a polymer ultraviolet absorber described in JP-A-6-148430 is also preferably used.

  In addition, the ultraviolet absorber that can be used for the support includes an ultraviolet absorber having a distribution coefficient of 9.2 or more described in Japanese Patent Application No. 11-295209, so that there is little contamination in the plasma treatment process. Moreover, since it is excellent also in the applicability | paintability of various application layers, it is preferable to use the ultraviolet absorber with a distribution coefficient of 10.1 or more especially.

  When cellulose ester films containing plasticizers and UV absorber absorbers are used as the base material, they may contaminate the process by attaching to the plasma processing part due to bleeding out, etc., and this may adhere to the film Can be considered. In order to solve this problem, it is preferable to use a support having a cellulose ester and a plasticizer and having a mass change of less than ± 2% by mass before and after the time treatment at 80 ° C. and 90% RH. (Holding). As such a cellulose ester film, a cellulose ester film described in Japanese Patent Application No. 2000-338883 is preferably used. For this purpose, a polymeric ultraviolet absorber (or ultraviolet absorbing polymer) described in JP-A-6-148430 can be preferably used. As a polymer ultraviolet absorber, PUVA-30M (manufactured by Otsuka Chemical Co., Ltd.) and the like are commercially available. The polymer ultraviolet absorbers described in the general formula (1) or general formula (2) of JP-A-6-148430 or the general formulas (3), (6) and (7) of Japanese Patent Application No. 2000-156039 are particularly preferably used.

  In the present invention, when the thin film is an antireflective film, the in-plane retardation R0 is preferably 0 to 1000 nm and the thickness direction retardation Rt is 0 to 300 nm. Is preferably used depending on the application. Further, as wavelength dispersion characteristics, R0 (600) / R0 (450) is preferably 0.7 to 1.3, and particularly preferably 1.0 to 1.3.

  Here, R0 (450) represents in-plane retardation based on three-dimensional refractive index measurement using light with a wavelength of 450 nm, and R0 (600) represents in-plane retardation based on three-dimensional refractive index measurement using light with a wavelength of 600 nm. .

  In the present invention, when the thin film is an antireflection film, a component containing one or more ethylenically unsaturated monomers is polymerized from the viewpoint of improving the adhesion between the substrate and the thin film formed by the discharge plasma treatment. The formed layer is preferably formed by performing the above-described discharge plasma treatment, and in particular, the layer formed by polymerizing the component containing the ethylenically unsaturated monomer was treated with a solution having a pH of 10 or more. It is preferable to perform discharge plasma treatment later because the adhesion is further improved. As a solution having a pH of 10 or more, a 0.1 to 3 mol / L sodium hydroxide or potassium hydroxide aqueous solution is preferably used.

  As the resin layer formed by polymerizing a component containing an ethylenically unsaturated monomer, a layer containing an actinic ray curable resin or a thermosetting resin as a constituent component is preferably used, but an actinic ray curable resin is particularly preferably used. Is a layer.

  Here, the actinic radiation curable resin layer refers to a layer mainly composed of a resin that cures through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams. Typical examples of the actinic radiation curable resin include an ultraviolet curable resin, an electron beam curable resin, and the like, but a resin that is cured by irradiation with active rays other than ultraviolet rays and electron beams may also be used. Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. be able to.

  UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylate) in products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. It can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate (for example, see JP-A-59-151110).

  The UV curable polyester acrylate resin can be easily obtained by reacting a polyester polyol with a 2-hydroxyethyl acrylate or 2-hydroxy acrylate monomer (see, for example, JP-A-59-151112). .

  Specific examples of ultraviolet curable epoxy acrylate resins include those obtained by reacting epoxy acrylate with an oligomer, a reactive diluent and a photoreaction initiator added thereto (for example, JP-A-1- No. 105738). As the photoreaction initiator, one or more kinds selected from benzoin derivatives, oxime ketone derivatives, benzophenone derivatives, thioxanthone derivatives and the like can be selected and used.

  Specific examples of ultraviolet curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate. Etc.

  These resins are usually used together with known photosensitizers. Moreover, the said photoinitiator can also be used as a photosensitizer. Specific examples include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and the like. In addition, when using an epoxy acrylate photoreactive agent, a sensitizer such as n-butylamine, triethylamine, tri-n-butylphosphine can be used. The photoreaction initiator or photosensitizer contained in the ultraviolet curable resin composition excluding the solvent component that volatilizes after coating and drying is preferably 2.5 to 6% by mass of the composition.

  Examples of the resin monomer include common monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, vinyl acetate, benzyl acrylate, cyclohexyl acrylate, and styrene as monomers having one unsaturated double bond. In addition, monomers having two or more unsaturated double bonds include ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyl adiacrylate, and the above trimethylolpropane. Examples thereof include triacrylate and pentaerythritol tetraacryl ester.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example << Preparation of Sample >>
[Preparation of Sample 1]
Using the atmospheric pressure plasma discharge treatment apparatus shown in FIG. 4 on a roll-shaped polyethylene terephthalate film having a thickness of 100 μm as a base material, a silicon oxide thin film having a thickness of 200 nm was formed under the following film-forming conditions. Sample 1 was prepared.

(Film forming conditions)
Discharge gas: Nitrogen gas 94.9% by volume
Source gas: Tetraethoxysilane (mixed with nitrogen gas and vaporized by a Lintec vaporizer) 0.1% by volume
Reaction gas: Oxygen gas 5.0% by volume
Film forming speed: 30 nm / sec
First power supply side: frequency 80 kHz, power (power density) 5 W / cm ²
Second power supply side: frequency 13.56 MkHz, power (power density) 5 W / cm ²
Substrate temperature: 100 ° C
[Preparation of Sample 2]
Sample 2 was prepared in the same manner as Sample 1 except that 5% by volume of nitric acid and 13% by volume of water vapor were introduced into the reaction space by volatilization of an aqueous nitric acid solution.

[Preparation of Samples 3 and 5-12]
Samples 3 and 5-12 were prepared in the same manner as in the preparation of Sample 2, except that the type of acid, the amount introduced, the introduction method, the amount of oxidizing gas introduced, and the substrate temperature were changed as shown in Table 1. did.

[Preparation of Sample 4]
Sample 4 was prepared in the same manner as in Preparation of Sample 2, except that the acid type and introduction method were changed as shown in Table 1 and water vapor was not introduced.

《Sample evaluation》
The following evaluation was performed about the produced sample.

(Evaluation of film density)
It measured by the X-ray reflectivity measuring method. As the measuring apparatus, MXP21 manufactured by Mac Science Co., Ltd. was used, copper was used as the target of the X-ray source, and it was operated at 42 kV and 500 mA. A multilayer parabolic mirror was used for the incident monochromator. The entrance slit is 0.05 mm x 5 mm, the light receiving slit is 0.03 mm x 20 mm, and the 2θ / θ scan method is used to measure from 0 to 5 ° by the FT method with a step width of 0.005 ° and a step of 10 seconds. It was. With respect to the obtained reflectance curve, Reflectivity Analysis Program Ver. Curve fitting was performed using No. 1, each parameter was determined so that the residual sum of squares of the actual measurement value and the footing curve was minimized, and the film density was determined from each parameter. The film density was evaluated according to the following criteria.

◎: film density 2.15 g / cm ³ or more ○: film density 2.05~2.15g / cm ³ less ×: film density is less than 2.05 g / cm ³ (film hardness rating)
About the thin film formation surface of the produced said sample, the hardness of the thin film was measured with the pencil scratch test method based on JISK5400. As for the rank of hardness, 6B is the softest and 9H is the hardest in the order of (soft) 6B to B, HB, F, H to 9H (hard).

  The evaluation results are shown in Table 1.

  From the table, it can be seen that the sample of the present invention has higher film density and film hardness than the comparative example. Moreover, water (steam) is introduced into the reaction space, the substrate temperature is a high temperature of 80 to 200 ° C. (100 ° C.), the high frequency voltage is 1 kHz to 1 MHz high frequency voltage (80 kHz), and 1 MHz to It can be seen that the sample on which the high frequency voltage of 2500 MHz (13.56 MHz) is superimposed has improved film density and film hardness.

It is a schematic diagram which shows the internal structure of the metal oxide thin film formed with the conventional method and the method of this invention. It is the schematic which shows an example of an ultrasonic atomizer. It is the schematic which shows an example of a jet-type atmospheric pressure plasma discharge processing apparatus. It is the schematic which shows an example of the atmospheric pressure plasma discharge processing apparatus of the system which processes a base material between counter electrodes. It is a perspective view which shows an example of the structure of the electroconductive metal base material of a roll rotating electrode, and the dielectric material coat | covered on it. It is a perspective view which shows an example of the structure of the electroconductive metal base material of a fixed electrode, and the dielectric material coat | covered on it.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic sprayer 2 Introducing pipe 3 Liquid storage part 4 Ultrasonic wave generation part 5 Power supply 6 Emission pipe 10 Plasma discharge processing apparatus 11 1st electrode 12 2nd electrode 21 1st power supply 23,43 1st filter 24,44 2nd filter DESCRIPTION OF SYMBOLS 30 Plasma discharge processing apparatus 32 Discharge space 35 Roll rotation electrode 35a Roll electrode 35A Metal base material 35B Dielectric 36a Fixed electrode 36A Metal base material 36B Dielectric 40 Electric field application means 41 1st power supply 42 2nd power supply 50 Gas supply means 51 Gas Generator 52 Air Supply Port 53 Exhaust Port 60 Electrode Temperature Control Unit 70 Acid Introduction Unit G Thin Film Forming Gas G ° Plasma State Gas G ′ Treatment Exhaust Gas

Claims (13)

Under a pressure of atmospheric pressure or near atmospheric pressure, a reactive gas is made into a plasma state by applying a high-frequency voltage between two opposing electrodes to discharge the reaction space, and the substrate is reacted in the plasma state. In the method for producing a metal oxide thin film, wherein the metal oxide thin film is formed on the substrate by exposing to a gas, an acid having an acid dissociation constant pKa of 3.5 or less is introduced into the reaction space. Thin film manufacturing method. The method for producing a metal oxide thin film according to claim 1, wherein 1 to 15% by volume of water is introduced into the reaction space. The method for producing a metal oxide thin film according to claim 1, wherein the acid is introduced into the reaction space by volatilizing the aqueous solution of the acid. The method for producing a metal oxide thin film according to claim 1, wherein the acid is introduced into the reaction space by spraying the aqueous solution of the acid. The metal according to any one of claims 1 to 4, wherein the acid is an acid selected from nitric acid, nitrous acid, hydrochloric acid, chloric acid, chlorous acid, sulfuric acid, sulfurous acid, and phosphoric acid. Manufacturing method of oxide thin film. The method for producing a metal oxide thin film according to any one of claims 1 to 5, wherein the discharge gas is nitrogen. Wherein the frequency of the high frequency voltage 1KHz～2500MHz, and method for producing a metal oxide thin film according to any one of claims 1 to 6, the supply power is characterized by a 1~50W / cm ^2. The method for producing a metal oxide thin film according to claim 7, wherein the high-frequency voltage is a superposition of a high-frequency voltage of 1 kHz to 1 MHz and a high-frequency voltage of 1 MHz to 2500 MHz. The method for producing a metal oxide thin film according to any one of claims 1 to 8, wherein the substrate temperature when exposed to the reactive gas in the plasma state is 80 to 200 ° C. The method for producing a metal oxide thin film according to claim 1, wherein an oxidizing gas is introduced into the reaction space. The method for producing a metal oxide thin film according to claim 10, wherein the oxidizing gas is 1 to 20% by volume of oxygen. A metal oxide thin film obtained by the method for producing a metal oxide thin film according to claim 1. The metal oxide thin film contains a metal selected from Al, Si, Ti, V, Fe, Ni, Cu, Zn, Y, Nb, Mo, In, Ta, Ir, Sn, and W. Item 13. The metal oxide thin film according to Item 12.

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