JP2014001444A - Film deposition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film deposition method capable of sufficiently increasing a film deposition speed.SOLUTION: In a method, a laminate is manufactured using a plasma CVD film deposition device comprising: a vacuum chamber; a pair of film deposition rolls parallely or almost parallely opposed to each other and having magnetic field generation members inside; and a plasma power source whose polarity is inverted. While a long substrate is conveyed under a condition that the substrate is wound around the film deposition rolls so that a first portion on a surface of the substrate is opposed to a second portion on the surface of the substrate in the vacuum chamber, film deposition gas containing organosilicon compound gas and oxygen gas is supplied to a film deposition space between the film deposition rolls. A magnetic field is generated in the film deposition space by the magnetic field generation members, and discharge plasma is generated between the film deposition rolls by the plasma power source, so as to continuously form a thin film layer on the substrate. A frequency of the plasma power source is 1000 kHz to 5800 MHz.

Description

The present invention relates to a film forming method.

The gas barrier film can be suitably used as a container suitable for packaging articles such as foods and drinks, cosmetics, and detergents. In recent years, a gas barrier film formed by forming a thin film layer of silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide or the like on one surface of a base film such as a plastic film has been proposed.

As a method for forming a thin film layer on the surface of a plastic substrate, physical vapor deposition (PVD) such as vacuum deposition, sputtering, ion plating, vacuum chemical vapor deposition, plasma, etc. Chemical vapor deposition (CVD) such as chemical vapor deposition is known.

As a plasma CVD method, there is a method of forming a film using various types of film forming apparatuses. As a method of forming a film while winding a film on a film forming roll, for example, Patent Document 1 discloses a pair of film forming rolls. And a film forming apparatus including a magnetic field generating member and a plasma power source whose polarity is reversed, the frequency of the plasma power source is set to 1 kHz or more, and plasma is generated in the facing space between the rolls to form a film. Have been described.

Japanese Patent No. 4268195

However, in the film forming method described in Patent Document 1, it is difficult to increase the film forming speed, which is not always sufficient in terms of productivity.

The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a film forming method capable of sufficiently increasing the film forming speed.

As a result of intensive studies to achieve the above object, the present inventors have completed the present invention.

That is, according to the present invention, the following is provided.
[1] A vacuum chamber, a pair of film forming rolls arranged in parallel or substantially parallel to each other and provided with a magnetic field generating member therein, and a plasma power source for alternately reversing the polarities of the pair of film forming rolls A film forming method performed using a film forming apparatus comprising:
In the vacuum chamber, the substrate is wound around the film forming roll so that the first portion of the surface of the long substrate and the second portion of the surface of the substrate face each other. While transporting the substrate, a film forming gas containing an organosilicon compound gas and oxygen gas is supplied to the film forming space between the film forming rolls, and a magnetic field is generated in the film forming space by the magnetic field generating member. The discharge plasma is generated by the plasma power source between the film forming rolls, thereby continuously forming a thin film layer on the substrate.
The plasma power source has a frequency of 1000 kHz to 5800 MHz.
[2] The film forming method according to [1], wherein the plasma power source has a frequency of 13.56 MHz to 2450 MHz.
[3] The film forming method according to [1] or [2], wherein the plasma power source has a frequency of 27.12 MHz to 60 MHz.
[4] The gas flow rate of the organosilicon compound according to any one of [1] to [3], wherein the flow rate of the organic silicon compound is 100 to 300 sccm based on an area velocity of 1 m ² / min of the substrate at 0 ° C. and 1 atm. Film forming method.
[5] The flow rate ratio of the organic silicon compound gas to the oxygen gas (flow rate of oxygen gas) / (flow rate of the organic silicon compound gas) of the film forming gas is not more than twice the molar ratio for completely oxidizing the organosilicon compound. The film forming method according to any one of [1] to [4].
[6] The flow rate ratio of the organic silicon compound gas to the oxygen gas (flow rate of oxygen gas) / (flow rate of the organosilicon compound gas) of the film forming gas is equal to or less than the molar ratio for completely oxidizing the organosilicon compound. The film forming method according to any one of [1] to [5].
[7] The organic silicon compound of the film forming gas is hexamethyldisiloxane (HMDSO), and the flow ratio of HMDSO and oxygen gas (oxygen gas flow rate) / (flow rate of HMDSO gas) is 24 or less. -The film-forming method in any one of [6].
[8] The organic silicon compound of the film forming gas is hexamethyldisiloxane (HMDSO), and the flow ratio of HMDSO and oxygen gas (oxygen gas flow rate) / (flow rate of HMDSO gas) is 12 or less. -The film-forming method in any one of [7].

According to the film forming method of the present invention, the film forming speed can be increased, and the production amount per unit time of a laminated film having gas barrier properties can be increased.

It is a schematic diagram which shows an example of a preferable manufacturing apparatus for manufacturing a laminated | multilayer film using the method of invention.

(Definition)
Hereinafter, definitions of main terms relating to the present invention will be described.
A “vacuum chamber” is a container for evacuating the interior. Normally, a vacuum environment is created in the chamber by operating a vacuum pump attached to the chamber.
“Wrap” means that a bendable object such as a film is brought into contact with a cylindrical object such as a roll so as to cover the cylindrical object.
“Long” means that the length in the length direction is longer than the length in the width direction, like a film wound in a roll shape.
The “substrate” is an object that becomes a support for the film when the film is formed.
The “film-forming roll” is a roll for forming a film on the surface of the substrate wound around it, and is usually made of metal and also serves as an electrode for discharge.
The “film formation space” is a space between a pair of film formation rolls and where plasma for film formation is generated.
An “organosilicon compound” is an organic compound containing silicon as a constituent element.
“Film-forming gas” is a gas containing a raw material gas that is a raw material of a film as an essential element, and if necessary, a reactive gas that reacts with the raw material gas to form a compound, or is included in the formed film In some cases, it may further contain an auxiliary gas that contributes to plasma generation and film quality improvement.
The “source gas” is a gas that is a supply source of a material that is a main component of the film. For example, in the case of forming a SiOx film, a gas containing Si such as HMDSO, TEOS, or silane is a source gas.
The “reactive gas” is a gas that reacts with the source gas and is taken into the formed film. For example, oxygen (O ₂ ) corresponds to this when forming a SiOx film.
The “magnetic field generating member” is a magnetic field generating mechanism composed of a permanent magnet, for example, a member composed of a long central magnet, an outer peripheral magnet surrounding the central magnet, and a magnetic field short-circuiting member connecting them. .
The “plasma power source” is a power source that is connected to a pair of film forming rolls that are electrodes and generates plasma between the film forming rolls.
“Plasma power source for reversing the polarity of a pair of film forming rolls” is a plasma power source as defined above, and when the polarity of one film forming roll is positive, the polarity of the other film forming roll is negative. This is a plasma power source whose polarity is reversed.
“Discharge plasma” is plasma generated by discharge.
The “plasma CVD method” is a type of CVD film forming method for forming a film using a chemical reaction of a gaseous substance, and is a CVD film forming method for promoting a chemical reaction using a plasma discharge.
“Area speed” is an area in which a substrate advances in a certain time in a roll-to-roll film forming method or the like. Between the linear velocity of the substrate and the width of the substrate, there is a relationship of (area velocity) = (linear velocity) × (substrate width).
“On the basis of 0 ° C. and 1 atm” means that the amount of the displayed gas is the volume of the gas at 0 ° C. and 1 atm.
“To completely oxidize an organosilicon compound” means that an organosilicon compound contains Si, C and H contained in the compound, Si becomes SiO ₂ , C becomes CO ₂ , and H becomes H ₂ O. Means to be oxidized.
Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

The film forming method of the present invention includes a pair of film forming rolls disposed in parallel or substantially parallel to the vacuum chamber and having a magnetic field generating member therein, and the polarity of the pair of film forming rolls is reversed. A film forming method performed using a film forming apparatus including a plasma power source, wherein a first portion of a surface of a long base material and a second portion of the surface of the base material in the vacuum chamber The film formation space between the film formation rolls containing the organic silicon compound gas and the oxygen gas is conveyed while the substrate is transported in a state where the substrate is wound around the film formation roll so as to face each other. A film gas is supplied, a magnetic field is generated in the film forming space by the magnetic field generating member, and discharge plasma is generated by the plasma power source between the film forming rolls, whereby a thin film layer is continuously formed on the substrate. A plasma power source Frequency is the 1000kHz~5800MHz.

Examples of the long base material used in the film forming method of the present invention include a film or sheet made of a resin. Examples of the resin used for such a substrate include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefin resins such as polyethylene (PE), polypropylene (PP), and cyclic polyolefin; polyamide Polycarbonate resin; Polystyrene resin; Polyvinyl alcohol resin; Saponified ethylene-vinyl acetate copolymer; Polyacrylonitrile resin; Acetal resin; Polyimide resin. Among these resins, polyester resins and polyolefin resins are preferred, and PET and PEN are particularly preferred from the viewpoints of high heat resistance and linear expansion coefficient and low production cost. Moreover, these resin can be used individually by 1 type or in combination of 2 or more types.

The thickness of the long base material can be appropriately set in consideration of the stability when producing a laminated film. The thickness of the substrate is preferably in the range of 5 to 500 μm, more preferably in the range of 50 to 200 μm, and more preferably in the range of 50 to 100 μm from the viewpoint that the film can be conveyed even in vacuum. A range is particularly preferred.

Moreover, it is preferable to perform the surface activation process for cleaning the surface of a base material to the said base material from an adhesive viewpoint with a thin film layer. Examples of such surface activation treatment include corona treatment, plasma treatment, and flame treatment.

In the present invention, an inter-roll discharge plasma CVD method is used as a method for forming a thin film layer as a barrier film on a resin film. Thereby, even if it bends, the laminated | multilayer film which a barrier property cannot fall easily can be obtained. In the conventional laminated film, if it is bent, the barrier film is likely to crack, and the barrier property is likely to be lowered. However, according to the present invention, even if bent, the barrier film is hardly cracked and the barrier property is not easily lowered. A film can be obtained.

Here, the plasma CVD method is a film forming method in which a source material is radicalized and / or ionized by gasifying the gas containing the source material with alternating current, and the source material is deposited on a substrate such as a resin film. is there. Furthermore, in the present invention, a low-pressure plasma CVD method is used in order to obtain a laminated film having excellent gas barrier properties and bending resistance.
The low pressure is 0.1 Pa to 6 Pa, preferably 1 to 3 Pa.
When the pressure in the vacuum chamber is 0.1 Pa or more, it is not difficult to generate a discharge in a region where a magnetic field exists. When the pressure is 6 Pa or less, a reaction occurs in the gas phase, and a thin film is formed on or in the thin film layer. Formation of particles having the same or similar chemical composition as the layer can be prevented. The particles reduce the gas barrier property of the thin film layer. However, if the particle is within the above range, the formation of the particles is well suppressed, and a thin film layer having a high barrier property can be formed.

An organic silicon compound containing silicon is used as a source gas in the film forming gas used for forming such a thin film layer. Examples of such organosilicon compounds include hexamethyldisiloxane, 1,1,3,3-tetramethyldisiloxane, vinyltrimethylsilane, methyltrimethylsilane, hexamethyldisilane, methylsilane, dimethylsilane, trimethylsilane, diethyl Examples thereof include silane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, and octamethylcyclotetrasiloxane. Among these organosilicon compounds, hexamethyldisiloxane and 1,1,3,3-tetramethyldisiloxane are preferable from the viewpoints of properties such as handling of the compound and gas barrier properties of the obtained thin film layer. Moreover, these organosilicon compounds can be used individually by 1 type or in combination of 2 or more types.
Further, as the source gas, monosilane may be contained in addition to the above-described organosilicon compound, and used as a silicon source for the barrier film to be formed.

In the film forming method of the present invention, the gas flow rate of the organosilicon compound is 100 to 300 sccm (Standard Cubic Centimeter per Minute) at 0 ° C. and 1 atm based on the substrate area velocity of 1 m ² / min, preferably Is 140-290 sccm. When it is 100 sccm or more, the thin film layer is not porous and sufficient gas barrier properties are obtained. When it is 300 sccm or less, pressure control is not hindered due to insufficient exhaust capacity.

In the film forming method of the present invention, the flow rate of the organosilicon compound gas is 10 to 300 sccm, preferably 20 to 200 sccm. Such a numerical value is a value when the width of the film forming roll is not limited.

In addition to the source gas, a reactive gas is used as the film forming gas. As such a reactive gas, oxygen gas is used to react with the raw material gas to form an oxide.

As the film forming gas, a carrier gas may be used as necessary to supply the source gas into the vacuum chamber. Further, as the film forming gas, a discharge gas may be used as necessary in order to generate plasma discharge. As such carrier gas and discharge gas, known ones can be used as appropriate, for example, rare gases such as helium, argon, neon, xenon, etc .; hydrogen can be used.

In the inter-roll discharge plasma CVD method, plasma discharge is generated in the space between the film forming rolls. In a typical example, two water-cooled rotating drums containing non-rotating magnets are installed between film forming rolls at intervals of 4 to 5 cm, a magnetic field is formed between the rolls, and power is supplied to the film forming roll pair by a plasma power source. Supply.
When gas is introduced, a very bright high density plasma is formed between the rolls. Electrons are confined in the vicinity of the center of the gap between rolls by the magnetic field and electric field between the rolls, and a high-density plasma is formed.

This plasma source can operate at a low pressure of several Pa, the temperature of neutral particles and ions is low, and it is close to room temperature. On the other hand, since the electron temperature is high, many radicals and ions are generated. Further, high temperature secondary electrons are prevented from flowing into the resin film by the action of the magnetic field, and high power can be input while keeping the temperature of the resin film low, thereby achieving high-speed film formation. Film deposition mainly occurs only on the surface of the resin film, and since the electrode is covered with the resin film and is not easily soiled, stable film formation can be performed for a long time.

FIG. 1 is a schematic view showing an example of a production apparatus preferable for producing a laminated film using the method of the present invention. In the following description and drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

1 includes a feed roll 11, transport rolls 21, 22, 23, 24, film forming rolls 31, 32, a gas supply pipe 41, a plasma generating power supply 51, a film forming roll 31, and 32 includes magnetic field generators 61 and 62 installed inside 32, and a winding roll 71. In such a manufacturing apparatus, at least the film forming rolls 31, 32, the gas supply pipe 41, the plasma generating power source 51, and the magnetic field generating apparatuses 61, 62 are arranged in a vacuum chamber (not shown). ing. Further, in such a manufacturing apparatus, the vacuum chamber is connected to a vacuum pump (not shown), and the pressure in the vacuum chamber can be appropriately adjusted by the vacuum pump.

In such a manufacturing apparatus, each film-forming roll has a plasma generation power source so that the pair of film-forming rolls (film-forming roll 31 and film-forming roll 32) can function as a pair of counter electrodes. 51 is connected. Therefore, in such a manufacturing apparatus, it is possible to discharge into the space between the film forming roll 31 and the film forming roll 32 by supplying power from the plasma generating power source 51, thereby forming the film. Plasma can be generated in the space between the roll 31 and the film forming roll 32. Further, in such a manufacturing apparatus, the pair of film forming rolls (film forming rolls 31 and 32) are arranged to face each other in parallel or substantially in parallel. Thus, by arranging a pair of film forming rolls (film forming rolls 31 and 32), the film forming rate can be doubled and a film having the same structure can be formed.
According to such a manufacturing apparatus, it is possible to form a thin film layer on the surface of the film 100 by a CVD method. A film component can be deposited on the surface of the film 100 also on the film roll 32. Therefore, the thin film layer can be efficiently formed on the surface of the film 100.

Further, inside the film forming roll 31 and the film forming roll 32, magnetic field generators 61 and 62 fixed so as not to rotate in conjunction with the rotation of the film forming roll are provided, respectively.

As the film forming roll 31 and the film forming roll 32, known rolls can be appropriately used.
As such film forming rolls 31 and 32, those having the same diameter are preferably used from the viewpoint of forming a thin film layer more efficiently. Further, the diameter of the film forming rolls 31 and 32 is preferably in the range of 5 to 100 cm from the viewpoint of discharge conditions, chamber space, and the like.

Moreover, in such a manufacturing apparatus, a pair of film-forming rolls (film-forming roll 31 and film-forming roll 32) are arranged so that the first part and the second part on the surface of the film 100 face each other. A film 100 is wound around. By disposing the film 100 in this way, when the plasma is generated by discharging between the film forming roll 31 and the film forming roll 32, the surface of the film 100 existing between the pair of film forming rolls is changed. It is possible to form a film on the first part and the second part simultaneously. That is, according to such a manufacturing apparatus, as described above, the film component is deposited on the surface of the film 100 on the film forming roll 31 by the CVD method, and the film component is further deposited on the film forming roll 32. Since the film can be deposited, the thin film layer can be efficiently formed on the surface of the film 100. In addition, the first part and the second part of the film 100 do not indicate a fixed part of the surface of the film, but “a part located in the film formation space on the surface of the film”. Is defined.

Further, as the feed roll 11 and the transport rolls 21, 22, 23, and 24 used in such a manufacturing apparatus, known rolls can be appropriately used. Further, the winding roll 71 is not particularly limited as long as it can wind the film 100 on which the thin film layer is formed, and a known roll can be appropriately used.

Further, as the gas supply pipe 41, a pipe capable of supplying or discharging the source gas or the like at a predetermined speed can be appropriately used. Furthermore, as the plasma generating power source 51, a known power source for a plasma generating apparatus can be used as appropriate. Such a power source 51 for generating plasma supplies power to the film forming roll 31 and the film forming roll 32 connected to the power source 51 and makes it possible to use them as a counter electrode for discharging. As such a plasma generation power source 51, an AC power source capable of alternately reversing the polarities of the pair of film forming rolls is used because plasma CVD can be performed more efficiently. Moreover, as such a plasma generation power supply 51, since it becomes possible to implement plasma CVD more efficiently, it is preferable that the applied power can be set to 100 W to 10 kW. The frequency of the power source is 1000 kHz to 5800 MHz. The frequency is preferably 13.56 MHz to 2450 MHz, and more preferably 27.12 MHz to 60 MHz. As the magnetic field generators 61 and 62, known magnetic field generators can be used as appropriate. Furthermore, as the film 100, a film in which a thin film layer is formed in advance can be used. Thus, by using a film 100 in which a thin film layer is formed in advance, the thickness of the thin film layer can be increased.

The reason why the deposition rate increases when the frequency is set in the above range is not necessarily clear, but the present inventors presume as follows. When the frequency of the power source is increased, the discharge starting voltage decreases. In general, in an AC electric circuit, the impedance of a capacitive component (such as a capacitor) decreases as the frequency increases. When power is controlled (the power supply output is adjusted so that the power is constant) and film formation is performed, the current value increases as the impedance decreases, and the plasma reaction is promoted. Thereby, the film-forming speed increases. When trying to obtain a thin film having the same film thickness, the line speed can be increased, so that productivity is increased and production cost is reduced.

Further, when the frequency is increased, an impedance matching device (also referred to as a matching box) may be used.

Thus, the laminated film excellent in gas barrier property and bending resistance can be manufactured using the manufacturing apparatus shown in FIG. Further, for example, the power of the electrode drum of the plasma generator, the diameter of the film forming roll, and the film conveyance speed may be adjusted as appropriate. That is, by using the manufacturing apparatus shown in FIG. 1 to generate a discharge between a pair of film forming rolls (film forming rolls 31 and 32) while supplying a film forming gas (such as a raw material gas) into the vacuum chamber. The film forming gas (raw material gas or the like) is decomposed by plasma, and the thin film layer is formed on the surface of the film 100 on the film forming roll 31 and on the surface of the film 100 on the film forming roll 32 by the plasma CVD method. Is done. In such film formation, the long film 100 is conveyed by the delivery roll 11, the film formation roll 31, and the like, respectively, so that the film 100 is subjected to a roll-to-roll continuous film formation process. The thin film layer is formed on the surface.

The film-forming gas contains the organosilicon compound and oxygen, and the ratio of the organosilicon compound that is the source gas and oxygen that is the reaction gas is to completely react the source gas and the reaction gas. It is preferable that the ratio of the reaction gas is not excessively larger than the ratio of the amount of the reaction gas that is theoretically required. If the ratio of the reaction gas is excessive, a laminated film having excellent gas barrier properties and bending resistance cannot be obtained. Therefore, it is preferable that the oxygen gas is less than or equal to the theoretical oxygen amount necessary to completely oxidize the entire amount of the organosilicon compound in the film forming gas.

In the actual reaction in the plasma CVD chamber, the organic silicon compound gas of the film formation gas and the oxygen of the reaction gas are supplied from the gas supply unit to the film formation region to react and form a film. Even if the ratio of the flow rate of the organic silicon compound gas to the oxygen gas (flow rate of oxygen gas) / (flow rate of the gas of the organosilicon compound) is a molar ratio that completely oxidizes the organic silicon compound as a raw material, The reaction cannot proceed completely, and it is considered that the reaction is completed only when the oxygen content is supplied in a large excess compared to the stoichiometric ratio.
Therefore, the flow rate ratio between the organic silicon compound gas and the oxygen gas in the film forming gas is preferably not more than twice the molar ratio for completely oxidizing the organosilicon compound, and not more than the molar ratio for completely oxidizing the organosilicon compound. More preferably.

Hereinafter, as the film forming gas, a gas containing hexamethyldisiloxane (organosilicon compound: HMDSO: (CH ₃ ) ₆ Si ₂ O :) as a source gas and oxygen (O ₂ ) as a reaction gas is used. Taking a case of producing a silicon-oxygen-based thin film as an example, a suitable ratio of the source gas and the reactive gas in the film forming gas will be described in more detail.

A film-forming gas containing hexamethyldisiloxane (HMDSO, (CH ₃ ) ₆ Si ₂ O) as a source gas and oxygen (O ₂ ) as a reaction gas is reacted by plasma CVD to form a silicon-oxygen-based material. When producing a thin film, the following reaction formula (1) is given by the film-forming gas:
(CH ₃ ) ₆ Si ₂ O + 12O ₂ → 6CO ₂ + 9H ₂ O + 2SiO ₂ (1)
The reaction as described in 1 takes place to produce silicon dioxide. In such a reaction, the amount of oxygen required to completely oxidize 1 mol of hexamethyldisiloxane is 12 mol. Therefore, when the film forming gas contains 12 moles or more of oxygen with respect to 1 mole of hexamethyldisiloxane and is completely reacted, a uniform silicon dioxide film is formed. It becomes impossible to obtain a laminated film excellent in flexibility. Therefore, when forming the thin film layer, the oxygen amount is less than the stoichiometric ratio of 12 moles per mole of hexamethyldisiloxane so that the reaction of the above formula (1) does not proceed completely. There is a need to.
Note that, as described above, in the actual reaction in the plasma CVD chamber, the raw material hexamethyldisiloxane and the reaction gas oxygen are supplied from the gas supply unit to the film formation region and reacted to form a film. Therefore, even if the molar amount (flow rate) of oxygen in the reaction gas is 12 times the molar amount (flow rate) of hexamethyldisiloxane as a raw material, the reaction can actually proceed completely. It is considered that the reaction is completed only when the oxygen content is supplied in a large excess compared to the stoichiometric ratio.
Therefore, the molar amount (flow rate) of oxygen with respect to the molar amount (flow rate) of hexamethyldisiloxane as a raw material is preferably a stoichiometric ratio of 24 times or less, and 12 times or less. More preferred.
By containing hexamethyldisiloxane and oxygen in such a ratio, carbon atoms and hydrogen atoms in hexamethyldisiloxane that have not been completely oxidized are taken into the thin film layer, and an excellent barrier to the resulting laminated film And exhibiting flexibility.
If the molar amount (flow rate) of oxygen relative to the molar amount (flow rate) of hexamethyldisiloxane in the film forming gas is too small, unoxidized carbon atoms and hydrogen atoms are excessively taken into the thin film layer. In this case, the transparency of the barrier film decreases, and the barrier film cannot be used for a flexible substrate for a device that requires transparency such as an organic EL device or an organic thin film solar cell. From such a viewpoint, the lower limit of the molar amount (flow rate) of oxygen relative to the molar amount (flow rate) of hexamethyldisiloxane in the film forming gas is more than 0.1 times the molar amount (flow rate) of hexamethyldisiloxane. Preferably, the amount is more than 0.5 times.

In such a plasma CVD method, in order to discharge between the film forming rolls 31 and 32, an electrode drum connected to the plasma generating power source 51 (in this embodiment, the film is installed on the film forming rolls 31 and 32). The electric power to be applied can be adjusted as appropriate according to the type of the source gas, the pressure in the vacuum chamber, etc., and cannot be generally stated, but may be in the range of 0.1 to 10 kW. preferable. If this applied power is less than the lower limit, particles tend to be generated.On the other hand, if the upper limit is exceeded, the amount of heat generated during film formation increases, and the temperature of the substrate surface during film formation increases. There is a possibility that the substrate loses heat and wrinkles occur during film formation. In severe cases, the film melts due to heat, and a large current discharge occurs between the bare film formation rolls. May cause damage.

The conveyance speed (line speed) of the film 100 can be appropriately adjusted according to the type of raw material gas, the pressure in the vacuum chamber, etc., but is preferably in the range of 0.1 to 100 m / min. A range of 5 to 20 m / min is more preferable. If the line speed is less than the lower limit, wrinkles due to heat tend to occur in the film. On the other hand, if the upper limit is exceeded, the thickness of the formed thin film layer tends to be thin.

Hereinafter, based on an Example, this invention is demonstrated more concretely.

[Measurement of water vapor permeability]
(I) Using a water vapor permeability measuring machine (GTR Tech Co., model name “GTR Tech-3000”) under the conditions of a temperature of 40 ° C., a humidity of 0% RH on the low humidity side, and a humidity of 90% RH on the high humidity side. Then, the water vapor permeability of the laminated film is measured.
(Ii) For a laminated film having a water vapor permeability exceeding the detection limit of the method (i), the water vapor permeability is measured by a Ca corrosion method (a method described in JP-A-2005-283561).

Example 1
A laminated film is manufactured using the manufacturing apparatus shown in FIG. That is, a biaxially stretched polyethylene naphthalate film (PEN film, thickness: 100 μm, width: 350 mm to 700 mm, manufactured by Teijin DuPont Films Ltd., trade name “Teonex Q65FA”) is used as a base material (film 100). Mount on the delivery roll 11. And while applying a magnetic field between the film-forming roll 31 and the film-forming roll 32 and supplying electric power to the film-forming roll 31 and the film-forming roll 32, respectively, Plasma is generated by discharging, and a film forming gas (mixed gas of hexamethyldisiloxane (HMDSO) as a source gas and oxygen gas (also functioning as a discharge gas) as a reaction gas) is supplied to such a discharge region. Then, a thin film is formed by the plasma CVD method under the following conditions to obtain a laminated film.

<Film formation conditions>
Frequency of power source for plasma generation: 27.12 MHz to 60 MHz
Deposition gas mixture ratio (oxygen / hexamethyldisiloxane) = 10
Degree of vacuum in the vacuum chamber: 0.1-10 Pa
Power supplied from the power source for plasma generation: 0.5 to 2.5 kW
Width: 350mm to 700mm
Substrate conveyance speed: 0.5 to 10 m / min Substrate area velocity 1 m ² / min gas flow rate of organosilicon compound: 100 to 300 sccm
(0 ° C, 1 atmosphere standard)

(Example 2)
In Example 1, film formation is performed by changing only the frequency of the power source for plasma generation under the film formation conditions to the following values.

<Film formation conditions>
Frequency of power source for plasma generation: 13.56 MHz or more and less than 27.12 MHz

(Example 3)
In Example 1, film formation is performed by changing only the frequency of the power source for plasma generation under the film formation conditions to the following values.

<Film formation conditions>
Power supply frequency for plasma generation: greater than 60 MHz and less than 2450 MHz

Example 4
In Example 1, film formation is performed by changing only the frequency of the power source for plasma generation under the film formation conditions to the following values.

<Film formation conditions>
Frequency of power source for plasma generation: 1000 kHz or more and less than 13.56 MHz

(Example 5)
In Example 1, film formation is performed by changing only the frequency of the power source for plasma generation under the film formation conditions to the following values.

<Film formation conditions>
Frequency of power source for plasma generation: greater than 2450 MHz and less than 5800 MHz

  The film formation in Examples 1 to 5 is carried out under conditions of a frequency of 1000 kHz to 5800 MHz, and the plasma reaction is promoted. As a result, when the film forming speed is increased and a thin film having the same film thickness is to be obtained, the line speed can be increased, so that the productivity is increased and the production cost is decreased.

DESCRIPTION OF SYMBOLS 11 ... Sending roll, 21, 22, 23, 24 ... Conveyance roll, 31, 32 ... Film-forming roll, 41 ... Gas supply pipe, 51 ... Power source for plasma generation, 61, 62 ... Magnetic field generator, 71 ... Winding roll , 100 ... Film

Claims (8)

A vacuum chamber, a pair of film forming rolls arranged in parallel or substantially parallel to each other and having a magnetic field generating member therein, and a plasma power source that alternately reverses the polarity of the pair of film forming rolls. A film forming method performed using a film apparatus,
In the vacuum chamber, the substrate is wound around the film forming roll so that the first portion of the surface of the long substrate and the second portion of the surface of the substrate face each other. While transporting the substrate, a film forming gas containing an organosilicon compound gas and oxygen gas is supplied to the film forming space between the film forming rolls, and a magnetic field is generated in the film forming space by the magnetic field generating member. The discharge plasma is generated by the plasma power source between the film forming rolls, thereby continuously forming a thin film layer on the substrate.
The plasma power source has a frequency of 1000 kHz to 5800 MHz. The film forming method according to claim 1, wherein a frequency of the plasma power source is 13.56 MHz to 2450 MHz. The film forming method according to claim 1, wherein a frequency of the plasma power source is 27.12 MHz to 60 MHz. The film forming method according to any one of claims 1 to 3, wherein a flow rate of the gas of the organosilicon compound is 100 to 300 sccm based on an atmospheric velocity of 1 m ² / min of the substrate at 0 ° C and 1 atm. 2. The flow rate ratio of the organic silicon compound gas to the oxygen gas (the flow rate of oxygen gas / the flow rate of the organic silicon compound gas) of the film forming gas is not more than twice the molar ratio for completely oxidizing the organosilicon compound. The film-forming method as described in any one of -4. The flow rate ratio of the gas and the oxygen gas to the organic silicon compound of the film forming gas (the flow rate of oxygen gas / the flow rate of the gas of the organosilicon compound) is equal to or less than the molar ratio for completely oxidizing the organosilicon compound. The film-forming method as described in any one of these. The organic silicon compound of the film forming gas is hexamethyldisiloxane (HMDSO), and a flow rate ratio of oxygen gas to HMDSO (oxygen gas flow rate / HMDSO gas flow rate) is 24 or less. The film forming method according to one item. The organic silicon compound of the film forming gas is hexamethyldisiloxane (HMDSO), and the flow rate ratio of oxygen gas to HMDSO (oxygen gas flow rate / HMDSO gas flow rate) is 12 or less. The film forming method according to one item.

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