JP2009024205A - Plasma cvd system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma CVD system using an inexpensive shading base material capable of suitably preventing deposition of ineffective deposits on an exposed part of an electrode drum in the roll-to-roll type plasma CVD method, and having excellent heat resistance and excellent durability and electric characteristics. <P>SOLUTION: In order to solve the above-described problem, the invention according to Claim 1 of the present invention relates to a roll-to-roll type plasma CVD system capable of depositing ineffective deposits on a conductive sheet by forming the shielding base material on an exposed part of a drum electrode except a part at which the drum electrode is abutted on a base material for vapor deposition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention introduces a predetermined gas into a reaction chamber and applies an alternating voltage between at least two electrodes to bring the reactive gas into a plasma state, thereby forming a substance contained in the gas on the electrode. The present invention relates to a film forming plasma CVD apparatus.

  Typical film forming methods for forming a thin film on a substrate to be deposited include heating methods such as an electron beam method, induction heating method and resistance heating method, sputtering method, ion plating method, plasma CVD method, etc. Various film forming methods are used, and a thin film can be formed by appropriately using a method suitable for various properties such as a melting point and a vapor pressure of a substance to be deposited.

  However, in any of the above-described vapor deposition methods, the vaporized material is scattered, so that there is a problem that invalid vaporized material is deposited in the reaction chamber. In particular, if the evaporant deposits and adheres to the movable part of the vapor deposition apparatus, the operation of the apparatus may be disturbed, and therefore, it is necessary to remove the ineffective evaporant adhering to the apparatus. In order to solve such a problem, generally, a shielding plate or the like that prevents scattering of ineffective evaporates is appropriately disposed in the reaction vessel. (For example, Patent Document 1 and Patent Document 2)

  In particular, the plasma CVD method is a film forming method in which a product is deposited on a vapor deposition substrate by introducing a reactive gas into an electric field generated by applying a voltage between two electrodes. Therefore, it is suitably used as a vapor deposition method on a vapor deposition substrate having poor heat resistance.

  And as an example of the method of forming a thin film on the substrate to be vapor-deposited using the plasma CVD method, generally, a roll-to-roll type plasma CVD apparatus 10 is exemplified, and as shown in FIG. It is possible to continuously form a deposited film on the film 5 by winding the continuously drawn film 5 around the drum-shaped electrode 1 (drum electrode 1) and performing deposition while rotating the film 5 ( For example, Patent Document 3).

  However, in such a roll-to-roll type plasma CVD apparatus 10, the width of the film 5 that is usually wound around the drum electrode 1 is smaller than the width of the drum electrode 1, so that both end portions 11 of the drum electrode 1 are exposed. In addition, since the electrode of the exposed portion 11 is exposed, there is a drawback that the ineffective vapor deposition material 20 is deposited and fixed on the electrode of the exposed portion 11 as shown in FIG.

  Furthermore, the deposit 20 once fixed on the electrode is difficult to peel off. In particular, when a silicon oxide compound is deposited and fixed, it is firmly fixed to the electrode and is difficult to remove. Further, since the fixed silicon oxide compound is insulative, there is a problem that no voltage is applied to the base material 5 portion located on the electrode 1 on which the silicon oxide compound is deposited, and a film cannot be formed.

  As a method for removing such an ineffective deposit 20 such as a silicon oxide compound, the reaction chamber is returned to the atmospheric state and directly scraped with a scraper or a sander, or a fluoride such as hydrogen fluoride is removed in the reaction chamber. And a method of removing by etching by applying a voltage (for example, Patent Document 4). However, the method of directly scraping the silicon oxide compound not only has a poor working efficiency but also may damage the electrode. On the other hand, the method using fluoride requires careful handling of the fluoride, However, there is a problem that the risk of residual fluoride occurs.

Japanese Patent Application Laid-Open No. 61-213368 Japanese Patent Laid-Open No. 10-287967 Japanese Patent No. 3031551 Japanese Patent No. 1840209

  In view of such problems, the present inventor suitably prevents the deposition of ineffective vapor deposits on the exposed portions of the electrode drum in the roll-to-roll plasma CVD method, and has excellent heat resistance and low cost. Furthermore, it is an object to provide a plasma CVD apparatus using a shielding base material having excellent durability and electrical characteristics.

  That is, in order to solve the above-mentioned problem, the invention according to claim 1 of the present invention introduces a predetermined gas into a low-pressure reaction chamber and applies an AC voltage between the electrodes, thereby bringing the reactive gas into a plasma state. And a plasma CVD apparatus for forming a deposited film on a substrate to be deposited, wherein at least one of the electrodes is a rotating drum-shaped drum electrode, and is wound around the drum electrode and is conveyed by rotation. In a roll-to-roll plasma CVD apparatus for forming a film on the substrate to be deposited, the exposed portion of the drum electrode is exposed to the exposed portion except for the portion where the drum electrode and the substrate to be deposited are in contact with each other. A plasma CVD apparatus characterized in that a shielding base material for preventing the film formation is formed.

Further, the shielding substrate has a heat resistant temperature of 100 ° C. or higher, a volume resistivity of 10 × 10 ¹³ [Ω · m] or higher, and a dielectric breakdown voltage of 10 kV or higher. It is.

  Moreover, it is a plasma CVD apparatus characterized by using mica as the shielding base material.

  According to the first aspect of the present invention, a predetermined gas is introduced into a low-pressure reaction chamber and an alternating voltage is applied between the electrodes to bring the reactive gas into a plasma state, and to the substrate to be deposited. A plasma CVD apparatus for forming a deposited film, wherein at least one of the electrodes is a rotating drum-shaped drum electrode, and is wound around the drum electrode and is rotated and conveyed to the deposition target substrate. In a roll-to-roll plasma CVD apparatus for forming a film, for preventing film formation on the exposed portion of the drum electrode, except for a portion where the drum electrode and the deposition base material are in contact with each other. Since the shielding base material is formed, it is possible to suitably prevent the deposition of ineffective vapor deposits on the exposed portions of the electrode drum, and safely without damaging the film forming apparatus. It is possible to prevent adhesion of invalid deposit to the electrode drum.

In the invention according to claim 2, the shielding base material has a heat resistant temperature of 100 ° C. or higher, a volume resistivity of 10 × 10 ¹³ [Ω · m] or higher, and a dielectric breakdown voltage of 10 kV or higher. Therefore, it is possible to use a shielding base material that has excellent heat resistance and excellent durability and electrical characteristics.

  Further, since the invention according to claim 3 is characterized in that mica is used as the shielding base material, it is excellent in electric insulation properties such as withstand voltage, insulation resistance, corona resistance, arc resistance, It is possible to use a shielding base material that is excellent in heat resistance, compression resistance, water resistance, chemical resistance, and cost performance.

  As an example of the roll-to-roller type plasma CVD apparatus 10 in the plasma CVD apparatus 10 according to the present invention, as shown in FIG. It is continuously drawn out and wound around the rotating metal electrode drum 1 via the reversing roller 3, and after being formed at a location immediately above the counter electrode 2, again through the other reversing roller 3, It is the structure wound around the winding roller 7 which rotates.

  The reaction chamber in which the plasma CVD apparatus 10 is disposed is depressurized to about 10 mTorr by a vacuum pump in advance, and at the same time, a raw material gas having a specified flow rate from a gas introduction port (not shown) to the reaction chamber through a mass flow valve, In addition, an active carrier gas such as nitrogen, hydrogen, carbon dioxide, and carbon monoxide and an inert carrier gas such as helium and argon are supplied, and the reaction chamber is always filled with these gases at a constant pressure.

  A counter electrode 2 is disposed at a position facing the electrode drum 1, and a high frequency voltage is applied between the electrode drum 1 and the counter electrode 2 from an AC power supply G. When a high frequency voltage is applied between the electrode drum 1 and the counter electrode 2, the gas existing between the electrodes is ionized and a discharge 9 (plasma 9) is generated between the electrodes. The ionized gas is in an active radical state in the plasma and adheres to the surface of the deposition target substrate 5 of the electrode drum 1 and is taken into and deposited on the deposition target substrate 5 by a surface reaction. It is possible to form a film on top.

  In this way, it is possible to form a desired thin film on the evaporation target substrate 5 on the electrode drum 1, and the evaporation target substrate 5 after the film formation is further wound up via the reverse roller 3. 7 is sequentially wound up. In such film formation by the plasma CVD apparatus 10, the film pressure of the thin film can be easily controlled by the gas flow rate, the discharge conditions, the delivery speed of the substrate to be deposited, and the like. Further, the substrate 5 to be deposited fed from the feed roller 4 is wound around the reversing roller 3 while being synchronized with the rotation of the electrode drum 1, and the surface temperature of the substrate to be deposited and the surface temperature of the electrode drum are as follows. The surface temperature of the vapor deposition substrate 5 on which the source gas is deposited during film formation, that is, the film formation temperature can be arbitrarily controlled.

  However, in such a roll-to-roll type plasma CVD apparatus, as shown in FIG. 3, there are exposed portions 11 at both end portions of the electrode drum 1 except for the portions where the electrode drum 1 and the substrate 5 to be deposited are in contact with each other. As a result, the vapor deposition 20 (invalid vapor deposition 20) is deposited and fixed on the exposed portion 11 of the electrode drum.

  On the other hand, as shown in FIG. 1B, the plasma CVD apparatus according to the present invention forms a simple shielding base 6 formed by winding a film-like base around the exposed portion of the electrode drum 1. According to the configuration, it is possible to cover the exposed portion of the electrode drum 1 and prevent the ineffective deposit 20 from adhering to the surface of the electrode drum 1.

As the shielding substrate, mica (mica) is preferably used. Mica is a kind of layered silicate mineral, and the main component is composed of SiO ₂ , Al ₂ O ₃ , K ₂ O, or the like. In particular, hard mica (mascobite) mainly composed of KAl ₂ (Si ₃ Al) O ₁₀ (OH) 2 is known to be suitable as an electrical insulating material, and has a density of (2.6 to 3). .2) × 10 ³ (kg / m ³ ), the dielectric breakdown voltage is 18-25 (kV / 0.1 mm), and the tensile strength is 25-30 × 10 ⁷ (Pa). The volume resistivity is 10 ¹⁰ to 10 ¹³ [Ω · m].

  With such mica, it is possible to obtain mica paper (gathered mica) with a purity of approximately 100% by crushing mica raw ore by a special method and making it into paper. Glued mica board (laminated board) that was impregnated with adhesive, dried appropriately, and then pressed into a plate shape by heating and compression. Glued mica bonded with a reinforcing material and adhesive and processed into a tape shape. Mica tape can be used.

In particular, by using the mica as a shielding base material, the heat resistance is remarkably increased from 200 ° C., which is the heat resistance of the polyimide film, to 1000 ° C., which is the heat resistance of mica, as compared to the case where the polyimide film is used. This improves the durability as well as improving the durability.
Furthermore, although general PVD type shielding plates and shielding films have only been considered for heat resistance, the use of mica as a shielding base material has the effect of significantly improving the electrical characteristics (insulating properties) described above. is there.

Below, the shielding base material 6 in the plasma CVD apparatus 10 of this invention is demonstrated.
As described above, in the roll-to-roller type plasma CVD apparatus 10 that sequentially forms a film on the deposition target substrate 5 on the rotating electrode drum 1, the deposition target substrate 5 that rotates together with the electrode drum 1 is an electrode drum. Therefore, there is a problem in that an ineffective deposit is formed on the exposed portion of the drum-like electrode 1 excluding the substrate 5 to be deposited.

  For this reason, as shown in FIG. 2A, the ineffective deposit removal means in the plasma CVD apparatus of the present invention winds a film-shaped shielding base material 6 around the exposed portion of the electrode drum 1, thereby depositing deposits. It is possible to prevent film formation directly on the exposed portion of the electrode drum 1.

  That is, the deposition target substrate 5 wound around the electrode drum 1 is supplied with the new deposition target substrate 5 sequentially to the electrode drum 1 as the electrode drum 1 rotates. The deposition substrate 5 rotates while contacting the constant width of the electrode drum 1 that always rotates.

  And as shown in FIG.2 (b), according to the exposed location formed in the both ends part of an electrode drum except the part which an electrode drum and a to-be-deposited base material contact, the film-form shielding base material 6 is provided. Since the surface of the electrode drum 1 is completely covered with the shielding base material and the substrate to be deposited by being wound around the electrode drum 1, an invalid deposit is directly formed on the surface of the electrode drum 1. Can be prevented.

  At this time, it is desirable to form the shielding base material 6 longer and to form a part 8 (polymerization part 8) that partially overlaps the deposition target substrate 5. Even if this occurs, it is possible to reliably prevent an exposed portion from being generated on the surface of the electrode drum 1.

However, since the shielding base 6 is always exposed to plasma, heat resistance and insulation are required to withstand this, and when the heat resistance temperature of the shielding base 6 is less than 100 ° C., plasma CVD is used. There is a possibility that the shielding base material 6 is deformed during the film formation. Further, when the dielectric breakdown voltage is less than 10 kV, the shielding base material 6 may be destroyed when arc discharge occurs between the electrodes.
And when the partial defect | deletion arises in the shielding base material 6, the electrode 1 of a defect | deletion location will be exposed and plasma will concentrate on this location. As a result, a discharge continuously occurs locally starting from the defective portion, and accordingly, a defective portion is also generated in the evaporation deposition base material. Need to be replaced.

Therefore, it is not possible to use a PET film or the like that is an inexpensive film, and it is necessary to use a polymer film having excellent heat resistance such as a polyimide film, and the shielding base material 6 has a heat resistance temperature of 100 ° C. or higher. In addition, it is desirable that the volume resistivity is 10 × 10 ¹³ [Ω · m] or more and the dielectric breakdown voltage is 10 kV or more. By using such a shielding substrate 6, the deposition of ineffective vapor deposition on the electrode drum 1 is performed. Can be suitably prevented.

  And the result of having performed the film-forming experiment by the roll-to-roll type plasma CVD apparatus using the shielding base material of various materials is shown in a following example.

(Example)
Using the roll-to-roller type plasma CVD apparatus 10, the substrate 5 to be deposited is disposed so as to be in contact with the central portion of the electrode drum 1, and at both end portions of the electrode drum 1 which are exposed portions of the electrode drum 1. The shielding base material 6 was wound and fixed.
As a result, the surface of the electrode drum 1 is completely covered with the deposition base material 5 and the shielding base materials 6 positioned at both ends. In this state, the line speed is 50 m / min, the film formation power is 12 kW, and the film formation is performed. Film formation was performed on a deposition target substrate by a plasma CVD apparatus under a condition of 5000 m long.

  Further, a PET film (made by P60 Toray) having a thickness of 12 μm is used as the substrate 5 to be deposited, and oxygen (5 slm), hexamethyldisiloxane (HMDSO (1.2 slm)), Helium (2.0 slm) was introduced, and film formation by plasma CVD was performed at an equilibrium pressure of 5 mTorr.

  And each example at the time of film-forming using the shielding base material 6 which consists of three types of different materials as the said shielding base material 6, and the comparative example when not using the shielding base material 6, and a 50 micrometer PET film A comparative example in which is used as the shielding substrate 6 is shown below.

Example 1
As the shielding substrate 6, a polyimide film (200 V: manufactured by Toray DuPont Co., Ltd.) having a thickness of 50 μm was used.
(Example 2)
As the shielding base 6, a 100 μm thick mica tape (ZG822HDT: manufactured by Nippon Mica Manufacturing Co., Ltd.) was used.
(Example 3)
As the shielding substrate 6, a Teflon (registered trademark) film (Nitoflon No. 920UL: manufactured by Nitto Denko Corporation) having a thickness of 50 μm was used.
(Comparative Example 1)
Film formation was performed on the deposition target substrate without using the shielding substrate 6.
(Comparative Example 2)
As the shielding substrate 6, a PET film (E5000: manufactured by Toyobo Co., Ltd.) having a thickness of 50 μm was used.

The results for Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1 below. In particular, in Examples 1 to 3, the shielding base material 6 was not deformed even after the film formation of 5000 m, and it was possible to satisfactorily prevent the deposition of ineffective deposits on the electrode drum 1.

  As described above, the plasma CVD apparatus 10 of the present invention introduces a predetermined gas into a low-pressure reaction chamber and applies an alternating voltage between the electrodes, thereby bringing the reactive gas into a plasma state, and depositing the substrate. A plasma CVD apparatus for forming a deposited film on a material 5, wherein at least one of the electrodes is a rotating drum-shaped drum electrode 1, wound around the drum electrode 1 and rotated and conveyed In the roll-to-roll type plasma CVD apparatus 10 for forming a film on the substrate 5 to be deposited, the exposed portion 11 of the drum electrode 1 excluding the portion where the drum electrode 1 and the substrate 5 to be deposited are in contact with each other, With a simple configuration characterized in that the shielding base material 6 for preventing the film formation on the exposed portion 11 is formed, it is preferable that the ineffective vapor deposition deposits on the exposed portion 11 of the electrode drum 1. It is possible to stop, without damage the film forming apparatus 10, it is possible to suitably prevent the adhesion of invalid deposit to the electrode drum 1.

The shielding substrate 6 has a heat resistance temperature of 100 ° C. or higher, a volume resistivity of 10 × 10 ¹³ [Ω · m] or higher, and a dielectric breakdown voltage of 10 kV or higher. It is possible to use the shielding base material 6 that is excellent in durability and excellent in durability and electrical characteristics.

  In particular, by using mica as the shielding base material, it has excellent electric insulation properties such as withstand voltage, insulation resistance, corona resistance, arc resistance, and further, heat resistance, compression resistance, water resistance, chemical resistance. It is possible to use a shielding base material excellent in property and cost performance.

  The shielding substrate is not limited to the above example, and as an example of the shielding substrate 6, in the case of an organic system, polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / ethylene copolymer , Tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, polychlorotrifluoroethylene (trifluoride), polyvinylidene fluoride, polybenzimidazole, polyimide, polyamideimide, polyetheretherketone, polyphenylene sulfide, polyetherimide, etc. Is preferred. Moreover, in an inorganic system, it is possible to use laminated bodies, such as glass fiber, mica, and alumina.

It is a figure which shows an example of the plasma CVD apparatus of the roll-to-roll system which concerns on this invention. (A) It is explanatory drawing which shows the front view of a plasma CVD apparatus. (B) It is explanatory drawing which shows a plasma CVD apparatus. It is a figure which shows an example of the plasma CVD apparatus of the roll-to-roll system which concerns on this invention. (A) It is explanatory drawing which shows a plasma CVD apparatus. (B) It is side view explanatory drawing which shows the electrode drum of a plasma CVD apparatus. (A) (b) It is a figure which shows an example of the conventional plasma CVD apparatus of a roll-to-roll system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrode drum 2 Counter electrode 3 Reversing roller 4 Feeding roller 5 Deposited base material 6 Shielding base material 7 Take-up roller 8 Superposition location 9 Discharge location (plasma)
10 Plasma CVD apparatus 11 Exposed location 20 Invalid deposit

Claims (3)

In this plasma CVD apparatus, a predetermined gas is introduced into a low-pressure reaction chamber and an AC voltage is applied between electrodes to bring the reactive gas into a plasma state and form a deposited film on a deposition target substrate. At least one of the electrodes is a rotating drum-shaped drum electrode, and a roll-to-roll type plasma CVD apparatus for forming a film on the deposition target substrate that is wound around the drum electrode and rotated and conveyed. In
The plasma characterized in that a shielding base material for preventing film formation on the exposed portion is formed at an exposed portion of the drum electrode, excluding a portion where the drum electrode and the substrate to be deposited are in contact with each other. CVD equipment. The shielding base material has a heat resistant temperature of 100 ° C. or higher and a volume resistivity of 10 × 10 ^13.
The plasma CVD apparatus according to claim 1, wherein the resistance is [Ω · m] or more and the dielectric breakdown voltage is 10 kV or more.   3. The plasma CVD apparatus according to claim 1, wherein mica is used as the shielding base material.

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