WO2005035824A1

WO2005035824A1 - Amorphous boron nitride thin film and method for producing same, multilayer film, transparent plastic film, and organic el device

Info

Publication number: WO2005035824A1
Application number: PCT/JP2004/014676
Authority: WO
Inventors: Yasushi Okubo
Original assignee: Konica Minolta Holdings, Inc.
Priority date: 2003-10-07
Filing date: 2004-09-29
Publication date: 2005-04-21
Also published as: JPWO2005035824A1; JP4946049B2

Abstract

A method for producing an amorphous boron nitride thin film is characterized in that a thin film having a composition represented by the general formula (1) below is formed by supplying a reactive gas between opposing electrodes, applying a high-frequency voltage thereto for exciting the reactive gas, and exposing a base to the excited reactive gas at or near atmospheric pressure. General formula (1) BNxCy:H (In the formula, x and y satisfy: 0.7 ≤ x ≤ 1.3, 0 ≤ y ≤ 1.5.)

Description

Description Amorphous boron nitride thin film and its manufacturing method, and laminated film, transparent plastic film, and organic EL device

The present invention relates to an amorphous boron nitride thin film and a method for producing the same, and more particularly, to an amorphous boron nitride film having high transparency, excellent steam barrier properties, high surface hardness and high flatness, and a method for producing the same. In addition, the present invention relates to an amorphous boron nitride film having high adhesion to a plastic substrate or a laminated film thereof, a transparent plastic film and an organic EL device using the same. Background art

Conventionally, substrates for electronic display devices such as liquid crystal display devices, organic EL display devices, plasma displays, and electronic paper, or substrates for electro-optical devices such as CCD and CMOS sensors, or substrates for solar cells, have thermal stability, Glass has been used because of its high transparency and low water vapor permeability. However, with the recent spread of mobile phones and portable information terminals, there has been a demand for a flexible, hard-to-break, lightweight substrate for glass that is easily broken and relatively heavy.

A plastic substrate is advantageous as such a substrate. Since a plastic substrate has gas permeability, it breaks down due to the presence of moisture and oxygen, as in an organic electroluminescence display device, and its performance is reduced. It was difficult to apply to the application, and how to seal it became a problem. In order to suppress the permeation of water vapor and oxygen, it is known to provide a layer (gas barrier film) for suppressing the permeation of various gases through the plastic substrate. Such a layer includes a silicon oxide film and a nitride film. Known are a silicon film, a silicon oxynitride film, a silicon carbide film, an aluminum oxide film, an aluminum oxynitride film, an titanium oxynitride film, an oxyzirconium oxide film, a boron nitride film, a carbon nitride film, and a diamond-like carbon film. Have been. Also, a gas barrier film in which an inorganic thin film having high gas barrier properties and a flexible organic thin film are laminated is known (for example, see Patent Document 1).

Among these ceramic films, cubic boron nitride (c-BN) films high hardness (5 400 k gZmm ^2), high transparency (Bandogiyappu about 8 e V), because of its high chemical stability, It is expected as a surface protective film such as a plastic film. As a method of forming such a c-BN thin film, a sputtering method, a plasma CVD method, and the like are known.

For example, in JP-A-1 1- 1 2 7 1 7, 1 X 1 0- 7 T orr by sputtering (about 1. 3 X ¹ 0 -. 1 atmosphere), c one BN at a substrate temperature of 6 0 0 ° C (Cubic boron nitride) A film is formed. Further, in JP-200 3-25476, a plasma CVD method therefore 5T orr (about 6. 6 X 1 0- ³ atmosphere) to form a c _ BN film at a substrate temperature of 500 ° C.

As described above, a high temperature was required to generate c-BN, and it was practically impossible to form a film on a plastic substrate.

However, besides cubic, the crystal structure of boron nitride is known to be rhombohedral (r-BN), hexagonal (h-BN) and wurtzite (w-BN). (Amorphous) boron nitride (a-BN) is also known. These boron nitrides cannot provide a high-performance thin film such as c-BN, but depending on the application, a thin film with sufficient performance can be obtained. Rukoto can. - most easily obtained it is able is _a _BN, plasma CVD method has been known as a method capable of film formation at Among these substrate temperatures low.

For example, in Patent Document 2, a film is formed at 150 ° C. under 0.036 Pa (3.6 × 10 ⁷ atm). In Patent Document ^{3, 5 X 1 0- 6 To} rr (6. 6 X 1 0- s pressure) under the following 200 ° C, Patent Document 4, 2To rr (2. 6 X 10 3 atmosphere), The film is formed at 150 ° C.

As described above, although these methods achieve a low temperature for the formation of the boron nitride film, they still require a high degree of vacuum, are complicated and large-scale, have low productivity, and have a low productivity. The grant was expensive.

The purpose of forming the boron nitride film in the above-mentioned patent documents is to form a heat-resistant semiconductor, a transparent good heat conductor, a wear-resistant film, an oxidation-resistant protective film, and a heat-resistant low dielectric constant film. Has no notes. There is no description about laminating amorphous boron nitride films having different compositions.

[Patent Document 1] International Publication Patent WO00 ノ 36665 pamphlet

[Patent Document 2] Japanese Patent Application Laid-Open No. 5-239648

[Patent Document 3] JP-A-8-41633

[Patent Document 4] Japanese Patent Application Laid-Open No. 2001-15496 Disclosure of the Invention

An object of the present invention is to provide an amorphous boron nitride thin film having a transparent and high gas barrier property by a method with high productivity without using a vacuum process and a method for producing the same, and to provide a high adhesion to a plastic substrate. Amorphous boron nitride film or And a transparent plastic film and an organic EL device using the same.

The object of the present invention is to supply a reactive gas between opposing electrodes under atmospheric pressure or a pressure close to atmospheric pressure and apply a high-frequency voltage to bring the reactive gas into an excited state, This is achieved by a method for producing a thin film of amorphous boron nitride, which comprises exposing a substrate to a reactive gas. Brief Description of Drawings

FIG. 1 is a diagram showing an example of a plasma discharge processing chamber.

FIG. 2 (a) FIG. 2 (b) is a diagram showing an example of a roll electrode. FIG. 3 (a) and FIG. 3 (b) are schematic perspective views of the fixed electrode.

FIG. 4 is a diagram showing a plasma discharge processing chamber in which a rectangular fixed electrode is disposed around a roll electrode 25.

FIG. 5 is a diagram showing a plasma film forming apparatus provided with a plasma discharge processing chamber.

FIG. 6 is a view showing another example of a plasma film forming apparatus.

FIG. 7 is a cross-sectional view showing the structure of the organic EL display device thus manufactured. BEST MODE FOR CARRYING OUT THE INVENTION

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

(1) A reactive gas is supplied between opposing electrodes under an atmospheric pressure or a pressure close to the atmospheric pressure, and a high-frequency voltage is applied to bring the reactive gas into an excited state, based on the reactive gas in the excited state. By exposing the material, a thin film having the composition represented by the following general formula (1) is formed. A method for producing an amorphous boron nitride thin film.

General formula (1) BN _x C _y : H

(Where x and y represent 0.7≤x≤l.3 and 0≤y≤1.5)

(2) the high frequency voltage is 1 in a range of KHz～2500MHz, and serial mounting of amorphous to above, wherein the test feed force is in the range of ^{lW / cm 2 ~5 OW / cm} 2 A method for producing a boron nitride thin film.

(3) The high-frequency voltage according to the above-described item 1 or 2, wherein an AC voltage having a frequency in a range of 1 kHz to 1 MHz and an AC voltage having a frequency of 1 MHz to 2500 MHz are superimposed. A method for producing an amorphous boron nitride thin film.

(4) The amorphous boron nitride thin film as described in any one of (1) to (3) above, wherein the reactive gas contains a substituted or unsubstituted borazole represented by the following general formula (2). Manufacturing method.

General formula (2)

(Ι ^ ~Ι ₃ represents a hydrogen atom, a halogen atom, an alkyl group or Ariru group)

(5) A thin film produced by the method for producing an amorphous boron nitride thin film according to any one of the above items 1 to 4, wherein the moisture permeability of the thin film is 1.0 g / m ² Zd or less. Characterized by a thin film.

(6) The thin film according to the above (5), wherein the surface of the thin film has a pencil hardness of 4 H or more.

(7) thin film according to the 5 or ^6, wherein the average surface roughness of the film surface 1. is 0 nm or less. (8) The thin film produced by the method for producing an amorphous boron nitride thin film according to any one of the above 1 to 4 or the thin film according to any one of the above 5 to 7 is formed on a transparent plastic film. A transparent plastic film characterized by being made.

(9) A reactive gas is supplied between opposing electrodes under an atmospheric pressure or a pressure close to the atmospheric pressure, and a high-frequency voltage is applied to bring the reactive gas into an excited state, based on the reactive gas in the excited state. in the laminated film formed by exposing the timber, at least a first § mode Rufasu boron nitride thin film, a second amorphous boron nitride thin films are stacked, the first amorphous boron nitride films BN _x C _y: H (. y> 0 3) , the second Amoru Fast boron nitride films _{_{BN x C y: H (.}} y≤0 3) laminated film, which is a.

(10) A transparent plastic film, wherein the laminated film according to (9) is formed on a transparent plastic film.

(11) A transparent plastic film, wherein the glass transition temperature of the transparent plastic film according to the above item 8 or 10 is at least 180 ° C.

(12) A transparent plastic finolem characterized in that the transparent plastic film according to any one of (8), (10) and (11) is mainly composed of cellulose ester.

(13) An organic EL device, wherein the laminated film according to (9) is formed on the organic EL device.

Hereinafter, the present invention is not limited to the power S for describing the best mode for carrying out the present invention in detail, and the present invention is not limited thereto.

The present inventor has conducted intensive studies on the above-mentioned problems and found that under certain conditions, it is possible to form an amorphous silicon nitride film by a plasma CVD method under atmospheric pressure. The amorphous boron nitride film formed by the plasma CVD method under the atmospheric pressure described above has a high gas barrier property, and also has a good surface hardness and flatness, and the film forming speed is reduced by the plasma under vacuum. The inventors have found that the film formation speed is higher than that of the CVD method, and have completed the present invention.

In recent years, liquid crystal or organic electroluminescence (EL) display devices, electro-optical devices, and the like have adopted plastic substrates such as plastic films because they are more flexible, have higher flexibility, are less likely to break, and are lighter than glass that is easily broken and heavy. Are being considered.

In general, plastic substrates that are usually produced have relatively high permeability to moisture and oxygen, and contain moisture inside.For example, this was used in organic electroluminescence display devices. In such a case, there is a problem that the moisture gradually diffuses into the display device, and the durability of the display device or the like decreases due to the influence of the diffused moisture. In order to avoid this, attempts have been made to obtain a substrate that can cope with the above-mentioned various electronic devices by performing a certain processing on the plastic base material to lower the moisture permeability and lowering the water content. I have. For example, on a plastic film, for example, glass, silicon oxide film, silicon nitride film, silicon oxynitride film, silicon carbide film, aluminum oxide film, aluminum oxynitride film, titanium oxide film, titanium oxide film, silicon oxide film having low water vapor permeability Attempts have been made to obtain a composite material in which a thin film such as a boron nitride film, a carbon nitride film, or a diamond-like carbon film has been formed, and among them, a silicon oxide film is often used. On the other hand, plastic films for display devices are required to have not only gas barrier properties but also solvent resistance and surface hardness. ·

By providing a silicon oxide film, the plastic film has a surface hardness and a chemical resistance to N-methylpyrrolidone, which is a solvent for the liquid crystal alignment film precursor, and the like. The silicon oxide film has insufficient chemical resistance to hydrogen fluoride and hydrogen fluoride. In particular, low resistance to alkalinity is an issue because the film is exposed to an aqueous solution of resist in the resist stripping step after patterning of a transparent conductive film (indium monotin oxide, ITO). On the other hand, boron nitride Bmo is known to have high chemical resistance and high surface height. However, boron nitride is a hard-to-sinter ceramic, and the production of boron nitride, which is a target for vapor deposition and sputtering, requires sintering at high temperature and high pressure, and the boron nitride film obtained by vapor deposition and sputtering is brittle and easily peels off. ! / It was a membrane.

Attempts have been made to form boron nitride films by plasma CVD, but few reports have been made at temperatures at which they can be formed on plastic substrates. In JP-A-5 _ 239648 Gazette, 0. 036 P a (3. 6 X 10- 7 atm) under which a film was formed by a 0.99 ° C. JP 8- 41633 No. 5 X 10 in publication ^{"6 T orr (6. 6 X} 10- 9 atm) under, 2 00 ° and a film was formed by a C or less. JP 2001- 1 In 5496 JP 2 the To rr (2. 6 X 10- ³ atm) under, 1 50 ° is to form a film of boron nitride film C. However, boron nitride obtained by these film method all amorphous boron nitride (a- BN) It is not a cubic boron nitride (c_BN) having one of the leading surface hardnesses among the ceramics.However, according to JP-A-8-41633, even amorphous boron nitride has a surface hardness of 9 to 11 GPa. (About 53 GPa for cubic boron nitride), which has a practically sufficient surface hardness, however, there is no mention of gas barrier properties in these publications.

As a result of intensive studies by the present inventors, they have found that an amorphous boron nitride film produced under specific conditions exhibits a high gas barrier property, and have just solved the problem.

In the present invention, the amorphous boron nitride film represented by the general formula (1) is gas-buffered. Used as a film.

A thin film composed of boron, nitrogen, hydrogen, and carbon and represented by the general formula (1) and having some structural defects and not being crystallized is defined as amorphous boron nitride (a-BN or a— BN: C: H) Thin film. : C and: H indicate that C or H is present as a trace contaminant in the boron nitride film.

The ratio of nitrogen atoms and carbon atoms to the boron atoms in the amorphous boron nitride film can be determined by X-ray photoelectron spectroscopy (also called ESCA or XPS), X-ray microphone-mouth spectroscopy, large- ヱ electron spectroscopy, Razahod backscattering, etc. Analyze and decide. Although these methods cannot measure the proportion of hydrogen atoms, it is assumed that hydrogen atoms are present in the film in a certain proportion except for the boron nitride film where x = 1.0 and y = 0. You.

In the general formula (1), X is close to 1 and the smaller the value of y, the smaller the number of structural defects in boron nitride. If x == l.0 and y = 0, complete (no hydrogen atoms) boron nitride However, in the case of complete boron nitride, the coefficient of linear expansion is low, and the difference from the plastic film (10 to 100 ppm / ° C) as the support is too large. It is not preferable because cracks may occur due to the difference in the rates.

Therefore, the boron nitride film containing a certain amount of impurities has a larger coefficient of linear expansion and the difference in the coefficient of linear expansion from the plastic film is smaller. Membrane is preferred.

However, if the amount of impurities in the boron nitride film increases and deviates from the range of 0.7 ≤ x ≤ l.3 and 0 ≤ y ≤ 1.5, the network structure of the boron nitride film becomes coarse and the gas-parrier property decreases. Not preferred.

The surface hardness of the silicon nitride film depends on the impurity mixing ratio of the amorphous boron nitride film. Is affected. In the general formula (1), the surface hardness increases as X is closer to 1 and as y is smaller. Conversely, the surface hardness decreases as the shutoff value of X-1 increases and y increases. A film with high surface hardness and high hardness (small y) is a film that is brittle and fragile against bending and the like, and a film with low surface hardness and soft (large y) is strong against bending.

Therefore, x and y can be selected from the above-mentioned ranges depending on the physical properties required for the amorphous boron nitride film.

Although the surface hardness can be controlled in this manner, the pencil hardness of the surface of the amorphous boron nitride film according to the present invention is preferably 4 H or more.

Further, it is not necessary to achieve each physical property with a single layer of the amorphous boron nitride film, and an amorphous boron nitride thin film having the desired performance may be obtained by laminating a plurality of the amorphous boron nitride thin films having different properties. .

In particular, since the soft layer also acts as a stress relieving layer, a layered structure of a hard layer and a soft layer allows cracks to occur in all layers even if the plastic film as a support is bent. This is a preferable gas barrier laminated thin film because it has an effect of preventing the occurrence of gas generation and preventing a decrease in gas barrier properties.

As a preferable example of laminating such a gas-parallel amorphous boron nitride film, for example, a layer in contact with the base material has a soft structure in order to have adhesion, and then has a hard structure in order to have a gas barrier property in the base material. Further, the laminated film has a soft layer as a stress relaxation layer and a hard structure as a gas barrier layer and a hard coat layer.

That is, in the case where the second amorphous boron nitride thin film is laminated on the first amorphous boron nitride thin film in the laminated film, the first amorphous boron nitride thin film is formed from the substrate surface side. The elemental thin film is BN _x C _y : H (y> 0.3), and then the second amorphous boron nitride thin film is a laminate of an amorphous boron nitride thin film of BN _x C _y : H ( _y ≤ 0.3). Is preferred.

The amorphous boron nitride film may be a single layer or a laminate of two or more layers, but the total thickness of the entire film is preferably 10 m or less from the viewpoint of maintaining flexibility and resistance to bending.

The thickness of each layer is preferably 500 nm or less, and more preferably 500 nm or less, because when the thickness is large, stress cannot be relieved when bending stress is applied and cracks occur. Is less than 200 nm. On the other hand, if the thickness is less than 5 nm, it is difficult to form a uniform film, which is not preferable.

Next, a method of forming the amorphous boron nitride film will be described.

Methods for obtaining boron nitride films include physical vapor deposition (PVD) such as evaporation, sputtering, and ion plating, and chemical vapor deposition (CVD) such as plasma CVD. It has been known.

However, as mentioned above, the film formation method that can freely change the physical properties of the amorphous boron nitride film without changing the material for film formation is limited to chemical vapor deposition (CV D). In the physical vapor deposition (PVD) method such as evaporation method, sputtering method, and ion plating method, in order to stack films with different properties in the same chamber, the target which is the raw material must be changed. It is difficult to change the layer structure. Further, these are not preferable because the productivity is low because they are vacuum processes. Therefore, a plasma CVD method is preferable as a film forming method for producing a laminated film. In the plasma CVD method, the properties of the boron nitride film to be formed can be changed depending on the temperature of the substrate to be formed, the power supplied to the plasma, and the frequency. The higher the temperature, the higher the film The higher the electric field of electric power and high frequency, the harder the film becomes and the higher the gas barrier property. The more the film is formed at low temperature, or the lower the electric field of electric power and the lower frequency, the softer the film and the larger the coefficient of linear expansion.

^However , ordinary plasma CVD is a vacuum process and is not preferred. As described above, in Japanese Laid-5-2 3 9 6 48 JP, 0. 0 3 6 P a ( 3. 6 X 1 0 - 7 atm) under the Patent 8-4 1 6 3 3 No. ^{5 X 1 0- 6 T orr (} 6. 6 X 1 0 one ⁹ atm) under Patent 20 0 1 1 54 9 6 discloses a 2T orr (2. 6 X 1 0- 3 atmospheric pressure) under The film is being formed.

However, as a result of the study by the present inventors, it has been found that under specific conditions, it is possible to form a boron nitride film by plasma CVD even at atmospheric pressure or a gas pressure near atmospheric pressure. Compared to the plasma CVD method under vacuum, the plasma CVD method near atmospheric pressure not only does not require pressure reduction and has high productivity, but also has the effect of high film density and high film formation speed due to the high plasma density. It was found that this method was superior to the plasma CVD method under vacuum.

In addition, a boron nitride film obtained by plasma CVD under atmospheric pressure has a smaller center line average surface roughness (Ra) than a boron nitride film obtained by plasma CVD under vacuum. The effect that should be said became clear. The details are unknown. It is speculated that this is because the plasma density is high, high energy is applied, and the collision frequency between the particles grown in the vapor phase is high (the mean free path is short).

The center line average surface roughness (R a) of the surface of the amorphous boron nitride film according to the present invention is preferably 1.0 mm or less.

The center line average roughness of the amorphous boron nitride film is small. For example, when a transparent conductive film is applied on this layer, a transparent conductive film having a uniform film thickness can be formed, and the transparent film having a low sheet resistance can be formed. A bright conductive film can be formed. Further, the uniformity of gas barrier properties of the film is improved.

Hereinafter, an apparatus for forming a film made of amorphous boron nitride using a plasma CVD method at atmospheric pressure or near atmospheric pressure will be described in detail.

A plasma film forming apparatus used in the method for forming an amorphous boron nitride film of the present invention will be described with reference to FIGS. In the figure, the symbol F is a long length as an example of the substrate. The discharge plasma treatment preferably used in the present invention is performed at or near atmospheric pressure. The vicinity of the atmospheric pressure indicates a pressure of 20 kPa to 110 kPa, and more preferably 93 kPa to 104 kPa.

FIG. 1 shows an example of a plasma discharge processing chamber provided in a plasma film forming apparatus. In the plasma discharge processing chamber 10 shown in FIG. 1, the film-shaped substrate F is transported while being wound around the roll electrode 25 rotating in the transport direction (clockwise in the figure). The plurality of fixed electrodes 26 fixed around the roll electrode 25 are each formed of a cylinder, and are installed so as to face the hole electrode 25.

As the discharge vessel 11 constituting the plasma discharge processing chamber 10, a metal vessel can be used as long as insulation from a force electrode, which is preferably a Pyrex (R) glass processing vessel, can be obtained. 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 obtain insulation.

The substrate F wound around the roll electrode 25 is pressed by the nip rollers 15, 15, and 16, transported to the discharge processing space secured inside the discharge vessel 11 by being regulated by the guide rollers 24. And discharge plasma treatment, then nip roller 16 and guide roller 2 It is conveyed to the next process via 7. In the present invention, since a film can be formed by a discharge treatment under a pressure close to the atmospheric pressure instead of a vacuum system, such a continuous process can be performed, and high productivity can be increased.

The partition plates 14 and 14 are arranged close to the top rollers 15, 15 and 16, and suppress the air accompanying the substrate F from entering the discharge vessel 11. This entrained air is preferably suppressed to 1% by volume or less, more preferably 0.1% by volume or less, based on the total volume of the gas in the discharge vessel 11. It is possible to achieve this with the help of rollers 15 and 16.

The mixed gas used for the discharge plasma treatment is introduced into the discharge vessel 11 from the air supply port 12, and the gas after the treatment is exhausted from the exhaust port 13.

The roll electrode 25 is a ground electrode, is discharged between a plurality of fixed electrodes 26 serving as application electrodes, and the above-described reactive gas is introduced between the electrodes to form a plasma state. The film derived from the reactive gas is formed by exposing the long film-shaped substrate wound in 5 to the reactive gas in the plasma state.

To obtain a high plasma density between the electrodes and increase the film forming speed and to control the carbon content within a predetermined ratio, it is preferable to supply a certain amount of high power with a high frequency voltage. Specifically, it is preferable to apply a high-frequency voltage of 1 kHz to 250 MHz, and a voltage of any frequency between 1 kHz and 1 MHz, It is more preferable to superimpose and apply a voltage of any frequency between 150 and 250 MHz.

The lower limit of the power supplied between the electrodes is preferably 1 WZ cm ² or more, and more preferably 5 W / cm ² or more in order to obtain a boron nitride film having high gas barrier properties. but to be a discharge is unstable arc discharge at 5 OW / cm ² or more Yes, the uniformity of the resulting boron nitride film may be reduced, so that it is preferably 50 WZcm ² or less. Also, when superimposing a voltage with a frequency of 1 MHz and a voltage with a frequency of 1ΜΗζ to 2500 MHz, the voltage of 1 MHz to 250 OMHz should be smaller than the voltage of 1 kHz to 1 MHz. Preferably, the voltage is 20% to 80% of the voltage of 1 kHz to 1 MHz. Note that the voltage application area (cm ² ) of the electrode is the area in which discharge occurs.

The high-frequency voltage applied between the electrodes may be an intermittent pulse wave or a continuous sine wave, but is preferably a sine wave because the film forming speed is increased.

Such an electrode is preferably a metal base material coated with a dielectric. At least one of the fixed electrode 26 and the roll electrode 25 is coated with a dielectric, and preferably both are coated with a dielectric. The dielectric is preferably an inorganic substance having a non-electrical conductivity of 6 to 45.

The minimum distance between the solid dielectric and the electrode when a solid dielectric is placed on one of the electrodes 25 and .26, and the distance between the solid dielectrics when the solid dielectric is placed on both of the electrodes, In this case, from the viewpoint of uniform discharge, the thickness is preferably 0.3 mm to 20 mm, and particularly preferably lmm ± 0.5 mm. The distance between the electrodes is determined in consideration of the thickness of the dielectric around the electrodes and the magnitude of the applied voltage.

When the substrate is placed between the electrodes or transported between the electrodes and exposed to plasma, not only is the roll electrode specification capable of transporting the substrate in contact with one of the electrodes, but also the surface of the return material is further improved. By polishing and reducing the electrode surface roughness Rmax (JISB0601) to 10 μm or less, the thickness of the dielectric and the gap between the electrodes can be kept constant, and the discharge state can be stabilized. Furthermore, distortion and cracking due to the difference in thermal contraction of the dielectric and residual stress In addition, the durability can be greatly improved by coating with a non-porous high-precision inorganic dielectric.

In addition, in manufacturing an electrode by coating a metal base material with a dielectric, as described above, the dielectric is polished and finished, and the difference in thermal expansion between the metal base material and the dielectric of the electrode is made as small as possible. Therefore, it is preferable that the surface of the base material is lined with an inorganic material as a layer capable of absorbing stress by controlling the amount of foam mixed therein. In particular, the material is preferably glass obtained by a melting method known as an enamel, and the amount of bubbles mixed in the lowermost layer in contact with the conductive metal base material is set to 20 to 30% by volume. By setting the content to 5% by volume or less, a good electrode that is dense and free from cracks can be obtained.

'Also, as another method of coating the dielectric material on the base material of the electrode, the ceramics is sprayed densely to a porosity of 10 Vo 1% or less, and then an inorganic material that is cured by a sol-gel reaction. Performing a sealing treatment may be mentioned. In order to promote the sol-gel reaction, thermal hardening and UV curing are good.If the sealing liquid is further diluted and coating and curing are repeated several times in succession, the mineralization is further improved and the density without deterioration is improved. Electrode.

2 (a) and 2 (b) show roll electrodes 25c and 25C as an example of roll electrode 25. FIG.

As shown in Fig. 2 (a), the roll electrode 25c, which is a ground electrode, is formed by spraying ceramic onto a conductive base material 25a such as a metal, and then sealing it with an inorganic material. It is composed of a combination in which a dielectric coating 25b is coated. Cover the dielectric with 1 mm of ceramic coating, make it to a diameter of 200 mm after coating, and connect to earth. As a ceramic material used for thermal spraying, aluminum nitride silicon nitride or the like is preferably used. Among them, alumina is more preferably used because it is easy to process. ' Alternatively, as in the case of a roll electrode 25C shown in FIG. 2 (b), a conductive base material 25A of metal or the like is coated with a lined dielectric 25B provided with an inorganic material by lining. May be. As the lining material, silicate glass, borate glass, silicate glass, germanate glass, tellurite glass, aluminate glass, and vanadate glass are preferably used. Of these, borate glass is more preferably used because it is easy to process.

Examples of the conductive base materials 25a and 25A such as metals 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 present embodiment, the base material of the roll electrode is a stainless steel jacket roll base material having cooling means with cooling water (not shown).

Further, the roll electrodes 25c and 25C (same for the roll electrodes 25) are configured to be driven to rotate about the shaft portions 25d and 25D by a drive mechanism (not shown).

FIG. 3 (a) is a schematic perspective view of the fixed electrode 26. Further, the fixed electrode is not limited to a cylindrical shape, and may be a prismatic type like the fixed electrode 36 in FIG. 3 (b). Compared with the columnar electrode 26, the prismatic electrode has the effect of expanding the discharge range, and is therefore preferably used depending on the properties of the film to be formed.

The fixed electrodes 26 and 36 V have the same structure as the above-described portal electrodes 25 c and 25 C even if they are shifted. That is, the surroundings of the hollow stainless steel pipes 26a and 36a are covered with dielectrics 26b and 36b in the same manner as the roll electrodes 25 (25c and 25C). Cooling water Cooling can be performed. The dielectrics 26 b and 36 b may be either a ceramic-coated dielectric or a lining-treated dielectric.

The fixed electrode is manufactured so as to have a diameter of 12 φ or 15 mm after coating with a dielectric. For example, 14 electrodes are provided along the circumference of the roll electrode.

FIG. 4 shows a plasma discharge processing chamber 30 in which the rectangular fixed electrode 3′6 of FIG. 3 (b) is arranged around the roll electrode 25. In FIG. 4, the same members as those in FIG.

FIG. 5 shows a plasma film forming apparatus 50 provided with the plasma discharge processing chamber 30 of FIG. In FIG. 5, in addition to the plasma discharge processing chamber 30, a gas generator 51, a power supply 41, an electrode cooling cut 55, and the like are arranged as a device configuration. The electrode cooling unit 55 includes a tank 57 containing a coolant and a pump 56. As a cooling agent, an insulating material such as distilled water or oil is used.

The gap between the electrodes in the plasma discharge processing chamber 30 shown in FIGS. 5 and 4 is set to, for example, about 1 mm.

A nozzle electrode 25 and a fixed electrode 36 are arranged at predetermined positions in the plasma discharge processing chamber 30, and the mixed gas generated by the gas generator 51 is controlled in flow rate and supplied from the air supply port 12. Then, the inside of the discharge vessel 11 is filled with the mixed gas used for the plasma processing, and unnecessary portions are exhausted from the exhaust port.

Next, a voltage is applied to the fixed electrode 36 by the power supply 41, and the roll electrode 25 is grounded to generate discharge plasma. Here, the base material is supplied from the roll-shaped base material FF through the rolls 54, 54, 54, and the gap between the electrodes in the plasma discharge processing chamber 30 is fed through the guide roll 24. It is transported in a state of contacting the single-sided electrode 25 on one side. At this time, the surface of the base material F is subjected to a discharge treatment by the discharge plasma, and then is conveyed to the next step via the guide roller 27. Here, the discharge treatment is performed only on the surface of the substrate F that is not in contact with the roll electrode 25.

In addition, in order to suppress the adverse effects of high temperature during discharge, the temperature of the base (25 ° C) to less than 250 ° C, more preferably at room temperature to 200 ° C, if necessary, by cooling with an electrode cooling unit 55.

FIG. 6 shows a plasma film forming apparatus 60 that can be used in the film forming method of the present invention. The film forming apparatus 60 has a property that cannot be placed between electrodes, for example, forming a film on a thick base material 61. In this case, a reactive gas in a plasma state is sprayed onto the base material to form a thin film. Such a film formation method using a plasma jet method is also preferable when the film is formed on a non-planar base material such as a lenticular lens, a Fresnel lens, and a cylinder.

In the plasma film forming apparatus shown in FIG. 6, 35a is a dielectric, 35b is a metal base material, and 65 is a power supply. A mixed gas consisting of an inert gas and a reactive gas is introduced from above into a slit-shaped discharge space in which a dielectric material 35a is coated on a metal base material 35b, and a high-frequency voltage is applied by a power supply 65. The reactive gas is turned into a plasma state, and the reactive gas in the plasma state is sprayed onto the substrate 61 to form a film on the surface of the substrate 61.

The power source of the plasma film forming apparatus used for forming the film of the present invention such as the power source 41 in FIG. 5 and the power source 65 in FIG. 6 is not particularly limited, but a high frequency power source (3 kHz) manufactured by Shinko Electric Co., Ltd. Shinko Electric high frequency power supply (5 kHz), Shinko Electric high frequency power supply (15 kHz), Shinko Electric high frequency power supply (50 kHz), Heiden Laboratory high frequency power supply (continuous mode, 100 kHz) , Pearl Industrial high frequency power supply (200 kHz), Pearl Industrial high frequency power supply (800 kHz), Pearl Industrial high frequency power supply (2 MHz), JEOL high frequency power supply (1 3.56 MHz), Pearl Industrial high frequency power supply (27 MHz), a high frequency power supply (150 MHz) manufactured by Pearl Industries, etc. can be used. Also 40 MHz, 54 MHz, 6 OM Hz, 80 MHz, 433 MHz, 800 MHz, 1.3 GHz, 1.5 GHz, 1.9 GHz, 2.45 GHz, 5.2 GHz, 10 GHz Using a power supply that oscillates May be. Also, two or more frequencies may be superimposed and used. As a preferable combination at that time, it is preferable to superimpose a power supply of 1 kHz to: 1 MHz and a power supply of 1 MHz to 250 OMHz.

Next, preferable raw materials for obtaining an amorphous boron nitride film will be described. As a raw material of the amorphous boron nitride film, there are a method using a mixture of a compound containing boron and a compound containing nitrogen, and a method using a compound containing both nitrogen and boron.

The boron source, diborane (B ₂ H _6), tetraborane _{_{(B 4 H 1 ())}} , boron fluoride (BF _3), boron chloride (BC 1 _3), boron bromide (BB r _3), Boran Examples include getyl ether complex, borane-THF complex, borane-dimethylsulfide complex, boron trifluoride getyl ether complex, triethylborane, trimethoxyborane, triethoxyborane, and tri (isopropoxy) borane.

Nitrogen sources include nitrogen gas (N ₂ ), ammonia (NH ₃ ), methylamine, dimethylamine, trimethinoleamine, ethylmethinoleamine, and acetonitrile. However, diporane and boron chloride are dangerous and difficult to handle, and it is difficult to match them with nitrogen. Therefore, it is preferable to form a boron nitride film from a compound containing boron and nitrogen in a ratio of 1: 1.

Examples of such a compound containing an equivalent amount of boron and nitrogen include a borane-dimethylamine complex, a borane-triethylamine complex, a borane-dimethylaline complex, a borane-pyridine complex, borazole, trimethylporazole, triethylborazole, and triethylamine. isopropyl Bora tetrazole, Bora zone naphthalene _{_{_{(B 5 N 5 H 8)}}} , and the like Borazobifueniru _(Be Ν ₆ Η αο).

Of these, substituted or unsubstituted borazoles represented by the above general formula (2), in which nitrogen and boron are already trimerized, are preferably used. These borazoles are at normal temperature to 100 under atmospheric pressure. Since it has a sufficient vapor pressure in the range of C, it is a raw material compound suitable for atmospheric pressure plasma CVD.

Examples of such porazoles include borazole, trimethyl borazole, triethyl porazole, tree _n -propyl porazole, triisopropyl borazole, tri 1 n-butyl porazole, triisobutyl porazole, and tree t-butylporazole, triphenylporazole, and the like. The 1 ^ to 1 ₃ may be a different vorazole derivatives, for example, methyl mullet tetrazole, dimethyl polariton tetrazole, main Chino milled by wet Chino repos la zone Honoré, dimethylcarbamoyl Honoré ethyl Honoré polariton zone Honoré, methylcarbamoyl Bruno Leger Chino les Bora Eaux Honoré, Echiruborazoru , Getylborazole, dimethylisopropylporazole, methylethylphenylborazole, and the like.

Of these borazoles, preferred are porazole and trimethylborazole.

These compounds may be in a gas, liquid, or solid state at normal temperature and normal pressure.In the case of gas, they can be directly introduced into the discharge space, but in the case of liquid or solid, heating and bubbling It is used after being vaporized by means such as decompression and ultrasonic irradiation. Further, the solvent may be used after being diluted with a solvent. As the solvent, an organic solvent such as methanol, ethanol, n-hexane or a mixed solvent thereof can be used. In addition, these diluting solvents are decomposed into molecules and atoms during the plasma discharge treatment, so that the influence can be almost ignored.

Further, a hydrogen gas or the like may be mixed in the mixed gas as described above in order to adjust the content of carbon and hydrogen in the film, and a nitrogen gas and / or a periodic table may be mixed with these reactive gases. Group 18 atoms of, specifically, helium, neon, argon, krypton, xenon, radon, etc., especially helium and argon are preferably used, Are mixed and supplied to a plasma discharge generator (plasma generator) as a mixed gas to form a film. The ratio of the inert gas to the reactive gas differs depending on the properties of the film to be obtained. The ratio of the inert gas is set to 90.0 to 99.9% with respect to the entire mixed gas. Supply.

The thickness of the amorphous boron nitride film according to the present invention can be adjusted by increasing the plasma treatment time, increasing the number of treatments, or increasing the partial pressure of the raw material compound in the mixed gas.

As a method of laminating amorphous boron nitride films having different carbon and hydrogen contents by the atmospheric pressure plasma CVD method, for example, a substrate is transported through a plasma discharge treatment chamber shown in FIG. A method in which a boron film is provided and wound up, and then the film formation is repeated as many times as necessary by changing the conditions of the plasma discharge treatment apparatus. A plurality of plasma discharge treatment chambers shown in FIG. 1 are prepared. A method in which a plurality of layers are provided, one layer each time a substrate is transported and passes through each substrate, the base material is passed through a plurality of plasma discharge processing devices, the head and tail of the substrate are connected, and the substrate is transported. A method in which the layer is provided a plurality of times is exemplified.

The transparent plastic substrate on which the amorphous boron nitride thin film of the present invention is formed is not particularly limited as long as it is substantially transparent. Specifically, polyester such as polyethylene terephthalate and polyethylene naphthalate, polyethylene, polypropylene, and polyethylene Mouth fans, cellulose esters such as cenorellose diacetate, cellulose triacetate, cellulose acetate butylate, cenorellose acetate propionate, cenorellose acetate phthalate, cellulose nitrate and derivatives thereof, Poly Shiridani vinylidene, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, Polymethylpentene, Polyetherketone, Polyimide, Polyethersulfone, Polysulfones, Polyetherketoneimide, Polyamide, Fluororesin, Nippon, Polymethylmethacrylate, Acryl or Polyarylate, or these resins Organic-inorganic hybrid resins with silica or the like can be mentioned.

However, the amorphous boron nitride film formed by the atmospheric pressure plasma CVD method has a higher gas barrier property as the film formation temperature is higher, and undergoes various heating processes such as formation of a transparent conductive film as a transparent support for a display. Therefore, it is preferable that the resin forming the amorphous boron nitride film has high heat resistance.

As for heat resistance, the glass transition temperature is preferably 180 ° C. or higher. Plastic substrates satisfying such conditions include some polycarbonates, some cycloolefin polymers, polythenoresolephone, polytheneolethene ketones, polyimides, fluororesins, diacetyl cellulose, Examples include triacetyl cellulose, and organic-inorganic hybrid resins of these resins and silica.

As a method of measuring the glass transition temperature of the resin substrate, it can be measured by DSC (differential scanning calorimetry), TMA (thermal stress strain measurement), DMA (dynamic viscoelasticity measurement), or the like.

Of these, diacetyl cellulose and triacetyl cellulose, which have high transparency, low birefringence, and positive birefringence wavelength dispersion characteristics, and organic and inorganic hybrid resins of these and silica are preferred.

An organic-inorganic hybrid resin or an organic-inorganic polymer composite) is a material obtained by combining an organic polymer and an inorganic compound and imparting both properties. It is formed by using a method (called sol-gel method) to synthesize an inorganic substance to be mixed with an organic polymer from a liquid state such as a metal alkoxide. Inorganic particles can be dispersed in organic materials on a nanoscale below the wavelength of visible light (up to about 750 nm), and materials that are optically transparent and have high heat resistance can be obtained. Like that.

The transparent plastic substrate is originally a substrate having moisture permeability. By forming the amorphous boron nitride film according to the present invention on a plastic substrate, the moisture permeability of the substrate surface is greatly reduced. In the present invention, the moisture permeability of the amorphous boron nitride film is preferably not more than 1.0 g / m ² Zd in consideration of application to an organic EL device described later.

In the present invention, since the plastic substrate is directly exposed to a plasma atmosphere, it may have an undercoat layer on one or both sides as a plasma etching layer or a hard coat layer. And an organic layer formed by application of a polymer or the like. The organic layer includes, for example, a film obtained by subjecting an organic material film having a polymerizable group to post-treatment by means such as ultraviolet irradiation or heating.

In addition, the amorphous boron nitride film according to the present invention has high gas barrier properties, high surface hardness, and high flatness. Therefore, the amorphous boron nitride film is manufactured for articles requiring these characteristics in addition to transparent plastic films for displays. By providing a film, such performance can be provided.

An organic electroluminescence (EL) device is required to have a high gas barrier property. Organic EL devices need to be sealed because they are sensitive to moisture. The amorphous boron nitride film of the present invention can be used as a film for sealing these elements.

Note that an organic electroluminescent element (also referred to as an organic EL element) has a structure in which a light emitting layer is sandwiched between a pair of electrodes of a cathode and a cathode. Specifically, the cathode and the positive A layer containing an organic compound that emits light when a current is applied to an electrode consisting of electrodes. Since the cathode and the light-emitting layer are sensitive to moisture, after forming the organic EL device, the cathode side is sealed as a sealing film on the cathode side or sealed with an epoxy resin, etc. By forming an amorphous boron nitride film, the permeation of moisture is suppressed, the moisture resistance of the organic EL display device is further improved, and the generation and growth of dark spots can be suppressed. Can be obtained.

【Example】

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

Synthesis Example 1 <Synthesis of borazole>

After replacing the inside of a 1 L three-necked flask system with a magnetic stirrer, gas inlet, dropping funnel and a reflux condenser connected to a trap cooled to 196 ° C with nitrogen gas, 41.1 parts by mass of sodium hydride and 53.5 parts by mass of sodium chloride ammonium were added. About 500 parts by weight of triethylene glycol dimethyl ether was dropped by a dropping funnel within 10 minutes. The reaction began with intense heat and hydrogen evolution. Then after 30 minutes the reaction mixture was heated with a heating device and boiled at reflux for 6 hours. Strong bubbling was observed. Components boiling at 50-60 ° C. were fractionated from the crude product.

Yield: 9.5 parts by mass (35.3% of theory)

nD20 measured value: 1.3 8 2 2 ■

n D 2 0 Literature value: 1.3 8 2 1

Synthesis Example 2 <Synthesis of trimethylporazole>

Nitrogen gas in a 1 L three-necked flask system with a magnetic stirrer, gas inlet, dropping funnel and reflux condenser connected to a trap cooled to 196 ° C. After that, 41.1 parts by weight of sodium borohydride and 67.5 parts by weight of sodium salt methylammonium were added. About 500 parts by mass of triethylene glycol dimethyl ether was added dropwise within 10 minutes by a dropping funnel. The reaction began with intense heat and hydrogen evolution. Then, after 30 minutes, the reaction mixture was heated with a heating device and boiled at reflux for 6 hours. Strong foaming was observed. Components boiling at 125-135 ° C were fractionated from the crude product. Yield: 19.9 parts by mass (48.7% of theory)

nD 20 found: 1.4375

n D 20 Literature value: 1. 4375

(Refractive index at 20 ° C is excerpted from J. Am. Chem. Soc. Vol. 77 (1955), p. 864)

Example 1

An 80 m-thick diacetyl cellulose film was formed, a hard coat layer was formed thereon, and an amorphous boron nitride film was further formed thereon under the conditions shown in Table 1, and the following evaluation was performed. .

60 parts by mass of ethanol, 685 parts by mass of methylene chloride, and 100 parts by mass of diacetyl cellulose were charged into a mixing tank, and dissolved by stirring at 80 ° C. while heating.

The obtained dope (solution) was cast using a band casting machine. When the residual solvent amount became 50%, the dope was stripped off from the band, immediately transferred to a tenter, and then 30% in the TD direction, and then After stretching in the MD by 30%, the film was dried at 120 ° C. to obtain a acetylcellulose film. Note that the film thickness was adjusted so as to be finally 80 μπι. In addition, the glass transition temperature of the obtained diacetyl cellulose film was ΤΜΑ (thermal stress). Was 203 ° C. The average coefficient of linear expansion from 30 ° C to 180 ° C was 27 ppm / ° C.

The resulting diacetyl cellulose film was coated with the following hard coat layer coating composition by an extrusion coater so as to have a thickness of 3 μπι, and then dried for 1 minute in a drying section set at 80 ° C. It was formed by ultraviolet irradiation intensity 1 20 mW / cm dose 1 00 m JZ cm ^2.

The diacetyl cellulose film provided with the clear hard coat layer had a moisture permeability of 840 gZm ² Zd.

<Tari-go hard coat layer coating composition>

Dipentaerythritol hexaacrylate monomer 60 mass parts Dipentaerythritol hexaatalylate dimer 20 mass parts Dipentaerythritol hexaatalylate trimer or higher component 20 mass parts Dimethoxybenzophenone 4 mass parts Ethyl acetate 50 mass parts Parts Methyl ethyl ketone 50 parts by mass Isopropyl alcohol 50 parts by mass

Each of the amorphous boron nitride films was formed by the atmospheric pressure plasma CVD in the plasma discharge processing chamber 30 shown in FIG. 4, and the plasma was generated by a high frequency power source J RF-1 00 manufactured by JEOL Ltd. 0 or a high-frequency power source DHF-2K manufactured by Heiden Laboratory, and the borazole synthesized in Synthesis Example 1 was used as a raw material for the amorphous boron nitride film. At 0 ° C. And the film formation was performed. Table 1 shows the types of discharge gas and other discharge conditions. In each condition, first, a calibration curve of the film formation time and the film thickness was prepared, the film formation speed was calculated, and the film was formed again so that the film thickness became l O Onm. The film thickness was measured using FE3000 manufactured by Otsuka Electronics. '

Discharge gas: helium, argon or nitrogen 99.3 volume ^_0/0 cracked gas: hydrogen 0.5 volume ^_0/0 material gas: vorazole 0.2 vol% addition, deposition conditions H of the comparative example, JP-A-5 — Referring to Example 4 of 239648, the pressure in the plasma discharge treatment chamber was reduced using a vacuum pump, and then a gas having the following composition was sent into the discharge space at 25 ° C to a gas pressure of 36 mPa. OMHz microwaves were applied between the electrodes to perform vacuum ECR plasma CVD film formation.

Discharge gas: Argon 75.0 volume ^_0/0 decomposed gases: hydrogen 18.0 vol ^_0/0 material gas: vorazole 7.0 vol% <Composition Analysis>

The ratio of boron, nitrogen, and carbon was measured using an X-ray photoelectron spectrometer (ESCA) manufactured by VG Scientific.

Based on JISK 7129, it was measured with a Mode 17000 made by Illinois Instrumentsne clay. (Unit g / m ² / d)

The measurement limit of this device is 0.005 g / m ² / d.

The surface hardness was measured according to the pencil hardness test described in JISK5400. Evaluation Is the hardness of the pencil lead, expressed as 9H to 2B.

<Measurement of center line average surface roughness> ''

Scanning electron micrographs were taken of the surface of the boron nitride film using JSM 6100 manufactured by JEOL Ltd., and the center line average surface roughness: Ra was calculated.

table 1

As is clear from Table 1, it can be seen that the deposition rate of the boron nitride film varies more depending on the conditions of the discharge gas than the applied voltage and applied frequency. The deposition conditions A to D using a rare gas at atmospheric pressure as the discharge gas were 3 to 4 times faster than the deposition speed H under reduced pressure. This is presumed to be due to the higher plasma density under atmospheric pressure plasma conditions. Furthermore, it can be seen that the film formation conditions E to G using nitrogen gas as the discharge gas species are even faster (about 5 to 7 times faster than He discharge under reduced pressure). In particular, the conditions of F and G in which voltages of two frequencies of 100 kHz and 13.56 MHz were superimposed were the earliest. This is presumed to be due to the fact that the energy and generation density of ions and radicals in the plasma differ depending on the discharge gas, and that in the case of nitrogen gas, the force is not because nitrogen gas also serves as the nitrogen source for the boron nitride film. You.

On the other hand, the moisture permeability of the film to be formed depends on the applied voltage and the film forming temperature. It is recognized from the comparison of In ESC A, it is not possible to confirm the element ratio of hydrogen because it cannot be measured, but it is speculated that high-voltage, high-frequency, and high-temperature film formation conditions may cause hydrogen to hardly remain in the film.

Regarding the surface hardness, the force of obtaining a film with a high surface hardness was obtained.The surface roughness was determined by comparing the film forming conditions A to G of the present invention and the film forming condition H under reduced pressure of the comparative example. It can be seen that the film formation conditions under the atmospheric pressure of the invention clearly produce a film with higher smoothness.

As described above, according to the discharge conditions of the present invention, it is possible to obtain an effect that a film having high gas barrier properties, high surface hardness, and high surface smoothness can be obtained at a high film forming rate. Example 2

A— BN: C: H film formation> As in Example 1, trimethylborazole synthesized in Synthesis Example 2 was used as a raw material for the amorphous boron nitride film, and a gas having the following composition was pumped into the discharge space at 20 s 1 m at 40 ° C. Was formed. Table 2 shows the discharge gas types and other discharge conditions.

In each condition, first, a calibration curve of the film forming time and the film thickness was prepared, the film forming speed was calculated, and the film was formed again so that the film thickness became 100 nm. The film thickness was measured using FE3000 manufactured by Otsuka Electronics.

Discharge gas: helium, argon or nitrogen 99.3 volume ^_0/0 cracked gas: hydrogen 0.5% by volume of the raw material gas: trimethyl polariton tetrazole 0.2 volume ^_0/0 Note that film forming conditions N in the comparative example, JP Referring to Example 4 of Kaihei 5-239648, the pressure in the plasma discharge treatment chamber was reduced by using a vacuum pump,

The gas was sent into the discharge space at a gas pressure of 36 mPa at 5 ° C, and a microwave of 245 OMHz was applied between the electrodes to perform vacuum ECR plasma CVD film formation.

Cracked gas: argon 75.0 volume ^_0/0 source gas: trimethyl Bora tetrazole 25.0 volume ^_0/0

Table 2

Unlike Example 1 in which porazole was used as a raw material for the boron nitride film, it was found that carbon was also mixed into the film when trimethylborazole was used. As a result, a soft film with low surface hardness is obtained, and the moisture permeability is slightly reduced. As for the surface roughness, as in Example 1, the film formed by the plasma CVD method under the atmospheric pressure was superior.

The film formation rate also showed the same tendency as in Example 1, that is, plasma CVD under atmospheric pressure was 2 to 6 times faster than plasma CVD under vacuum, and productivity was higher. .

Example 3

The condition G for obtaining a hard film in Example 1 and the condition J for obtaining a soft film in Example 2 were alternately and continuously formed on a base film with a film thickness as shown in Table 3, Amorphous boron nitride laminated films 301 to 303 having a total thickness of about 200 nm were produced.

In addition, a transparent laminated film 307 of a comparative example was produced in accordance with the broth of WO 00/36665.

<Transparent laminated film of Comparative Example 3 07)

A clear hard coat layer having a thickness of 3 μm was formed on a diacetyl cellulose film having a thickness of 80 μππ according to the above-described method, and WO 00/366 665 was formed on the clear hard coat layer. The gas barrier layer was formed according to the method described in (1).

The polymethyl methacrylate oligomer was introduced into the vacuum evaporation apparatus from the introduction nozzle, and was vapor-deposited. After that, the polymethyl methacrylate oligomer was removed from the vacuum evaporation apparatus, and irradiated with ultraviolet light under a dry nitrogen stream to polymerize, thereby forming a film. Ρ The thickness of the film was adjusted to 50 nm. RF sputtering using silicon oxide as a sputtering target A silicon oxide film was formed to a thickness of 50 nm by using a sputtering method (frequency: 13.56 MHz). Further, the PMMA film and the silicon oxide film were each formed with a thickness of 50 nm to form a laminated film of four layers (200 nm thick), which was a transparent laminated film 307 of Comparative Example.

The obtained transparent laminated films 301 to 307 were subjected to moisture permeability measurement and a grid test. <Water vapor permeability test: moisture permeability>

Based on JIS K 7129, the measurement was carried out with a Model 170000 manufactured by Illinois' Instrument. In addition, measurements were performed after 10 consecutive cooling / heating cycles of heating at 180 ° C for 1 hour and then cooling at room temperature for 1 hour.

<Go-go test>

A grid test in accordance with JIS K5400 was performed. A single-blade force razor blade was cut into the surface of the formed thin film at a 90-degree angle to the surface at intervals of 1 mm, one by one, to make 100 lmm squares. On top of this, a cellophane tape sold in the market was fortune-telled, and one end was peeled off vertically by hand, and the ratio of the area where the thin film was peeled to the area of the tape pasted from the score line was evaluated according to the following ranks. .

A: Not at all

B: Peeled area ratio was less than 10%

C: Peeled area ratio was 10% or more

[Table 3]

First, when the films under the conditions J and G are compared between Example 1 (100 nm thick) and Example 2 (200 nm thick), almost no improvement in gas barrier properties is observed even when the film thickness is increased. It can be seen that simply increasing the film thickness does not lower the moisture permeability, but that the effect of lowering the moisture permeability reaches a plateau when the film thickness exceeds a certain level.

On the other hand, when the total number of layers was increased to 1, 2, 4, 6, and 8 with the total film thickness kept constant (about 200 nm), the more layers, the lower the moisture permeability, and the more effective the layer. It was a gasparia layer. The results were more effective after the thermal cycling, and the effect of the thermal cycling was smaller as the number of layers increased. This is presumably because the difference in the coefficient of linear expansion between the gas barrier layer and the support is due to the soft amorphous boron nitride film acting as a stress relaxation layer.

On the other hand, in the transparent laminated film 307 of the comparative example, the moisture permeability after the cooling / heating cycle is significantly deteriorated. This is presumed to be due not only to the support but also to the low heat resistance of the stress relaxation layer PMMA and the high linear expansion coefficient.

The adhesiveness of the film was the same as that of the transparent laminated film 307 of the comparative example. (Transparent laminated film 301 of the present invention) was a film having poor adhesion, but films 302 to 306 of the present invention had good adhesion.

Example 4

Organic EL elements were produced on the transparent laminated films 301 to 306 of the present invention produced in Example 3 and the transparent laminated film 307 of Comparative Example.

FIG. 7 is a cross-sectional view illustrating the structure of the organic EL display device manufactured. First, using the transparent laminated films 301 to 307 prepared in Example 3 as the transparent substrate 1, a mixture of indium oxide and zinc oxide (atomic ratio of In) was formed as a sputtering target on the side having the amorphous boron nitride film. Using a sintered body made of In / (Ίη + Ζη) = 0.80), an IZO (Indium Zinc Oxide) film as a transparent conductive film was formed by DC magnetron sputtering. That is, pressure in the vacuum evaporation apparatus was reduced to a sputtering apparatus to less than 1 X 10- ³ P a, at a volume ratio of argon gas and oxygen gas 1000: 2. the vacuum apparatus a mixed gas of 8 1 X 10- ' After introducing the film into the vacuum chamber until Ρa was reached, an IZO film, which was a transparent conductive film, was formed to a thickness of 250 nm by a DC magnetron method at a target applied voltage of 420 V and a substrate temperature of 60 ° C. The IZO film was patterned to form an anode (anode) 2, and then the transparent support substrate provided with the transparent conductive film was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and dried with UV nitrogen. Washing was performed for 5 minutes.

The α-NPD layer (25 nm thick), CBP and Ir (ppy) were formed on the resulting transparent conductive film as the organic EL layer 3 in FIG. 7 by vacuum evaporation through a square hole mask. Co-deposited layers (thickness 35 nm) and BC layers (thickness 1 Onm), _three layers of Alq (thickness of 40 nm), and a layer of lithium fluoride (thickness of 0.5 nm) were sequentially stacked (not shown in detail in FIG. 7). A 100-nm-thick aluminum force sword (cathode) 4 was formed through the mask.

CBP BC

ir (py) 3

The transparent laminate films 301 to 307 as described above as the substrate 5 in FIG. 7 are brought into close contact with the thus obtained laminate so that the amorphous boron nitride film side is in contact with the substrate 5 in FIG. The resultant was sealed with an agent (Lux Track LC0629 B manufactured by Toagosei Co., Ltd.) to obtain organic EL display devices OLED 401 to 407. Although not shown in FIG. 7, the transparent electrode and the aluminum cathode were each taken out as a terminal.

The following evaluations were performed on the light emitting portions of these organic EL devices.

Immediately after encapsulation, a 50x magnified photograph was taken. After storage at 80 ° C for 300 hours, a 50-fold enlarged photograph was taken and the area increase rate of the observed dark spot was evaluated.

Immediately after encapsulation, a 50x magnified photograph was taken. After repeating the bending test of bending the element to 45 ° and returning it to the original state 1000 times, the same storage test as in evaluation item 1 was performed to evaluate the increase rate of the dark spot area.

The area increase rate was evaluated according to the following criteria for both evaluation items 1 and 2.

When the increase rate of the dark spot exceeds the O LED 407 XX The increase rate of the dark spot is 80% or more and 100% or less of the OL ED407 X The increase rate of the dark spot is 50% or more and less than 80% of the OLED 407 △ The increase rate of the dark spot is O 30% or more of LED407 and less than 50% △ 〇 Dark spot increase rate is 15% or more and less than 30% of O LED407 〇 Dark spot increase rate is less than 15% of O LED407 ◎ [Table 4]

From these results, it can be seen that the organic EL display device in which the number of layers in which the soft amorphous boron nitride film and the hard amorphous boron nitride film are alternately laminated can be increased, the dark spot area increase rate can be suppressed lower.

Also, in consideration of the results of the evaluation of the adhesion of the film of Example 3, the better the adhesion between the layers of a single-layer film or a laminated film is, the lower the rate of increase in the area of dark spots is reduced. You can do it.

In this example, materials that adsorb moisture or react with moisture (for example, barium oxide) were not sealed in the device, but this does not prevent sealing of these materials in the device.

From the above, amorphous boron nitride film with high transparency, excellent steam barrier property, high surface hardness, small surface center line average roughness, excellent adhesion to plastic substrates, etc., and high film formation speed Could be provided.

Further, the transparent laminated finolem using the amorphous boron nitride film of the present invention as a gas barrier layer is a substrate having high gas barrier durability and useful as a substrate for an electronic display. An element was obtained. . Industrial Applicability According to the present invention, it is possible to provide an amorphous boron nitride thin film having high transparency and a high gas-dispersing property by a method with high productivity without using a vacuum process, and a method for producing the same.

Further, it is possible to provide an amorphous boron nitride film having high adhesion to a plastic substrate or a laminated film thereof, a transparent plastic film and an organic EL device using the same.

Claims

The scope of the claims

1. A reactive gas is supplied between opposing electrodes under atmospheric pressure or a pressure close to atmospheric pressure, and a high-frequency voltage is applied to make the reactive gas into an excited state. Forming a thin film having a composition represented by the following general formula (1) by exposing the thin film to an amorphous boron nitride thin film.

General formula (1) BN _x C _y : H.

(Where x and y represent 0.7≤x≤l.3 and 0≤y≤1.5)

2. The method according to claim 1, wherein the high-frequency voltage is in a range of 1 kHz to 2500 MHz, and a supply power is in a range of 1 W / cm ^{2 to} 5 OWZcm ^2. A method for producing an amorphous boron nitride thin film.

3. The high frequency voltage according to claim 1, wherein an AC voltage having a frequency in a range of 1 kHz to 1 MHz and an AC voltage having a frequency in a range of 1 MHz to 2500 MHz are superposed. A method for producing an amorphous boron nitride thin film.

4. The method for producing an amorphous boron nitride thin film according to claim 1, wherein the reactive gas contains a substituted or unsubstituted borazole represented by the following general formula (2).

General formula (2)

H

Ft | N NR ₃

HB, .BH

R ₂ (! ^ ~! ^ Represents a hydrogen atom, a halogen atom, an alkyl group, or an aryl group)

5-A thin film manufactured by the method for producing an amorphous boron nitride thin film according to claim 1, wherein the thin film has a moisture permeability of 1.0 gZm ² Zd or less. .

6. The thin film according to claim 5, wherein the thin film surface has a pencil hardness of 4 H or more.

7. The thin film according to claim 5, wherein the average surface roughness of the thin film surface is 1.0 nm or less.

8. A transparent plastic film / rem, wherein the thin film produced by the method for producing an amorphous boron nitride thin film according to claim 1 is formed on a transparent plastic film.

9. A reactive gas is supplied between opposing electrodes under atmospheric pressure or a pressure close to atmospheric pressure, and a high-frequency voltage is applied to make the reactive gas into an excited state. A second amorphous boron nitride thin film is laminated on at least the first amorphous boron nitride thin film, and

1 of amorphous boron nitride thin _{_{BN x C y: H (.}} Y> 0 3), the second Amoru Fast boron nitride films BN _x C _y: and Toku徵that the H (y≤0 3.) Laminated film.

10. The laminated film according to claim 9, wherein the laminated film is formed by:

1 1. The transparent plastic transition temperature described in claim 8 is 180 ° C or higher.

1 2. The transparent plastic film according to claim 8, wherein the transparent plastic film is mainly composed of a cellulose ester.

1 3. An organic EL device, wherein the laminated film according to claim 9 is formed on an organic EL device.