JP2011058079A - Apparatus and method for forming thin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure sufficient substrate cooling capability while suppressing damage to a substrate in a method for forming film using gas cooling. <P>SOLUTION: An apparatus for forming thin film includes a cooling body 10 which is located near the back side of a substrate 7 in a thin film forming region 9 and a gas introducing means for introducing a gas between the cooling body 10 and the back side of the substrate 7. The cooling body 10 includes a transmission body which is located near the substrate and transmits infrared light and an absorber which is opposed to the substrate through the transmission body. By such a configuration, the radiant light emitted from the substrate is transmitted through the transmission body and absorbed in the absorber having high emissivity which is opposed to the substrate through the transmission body. Therefore, the radiation to the substrate 7 from the cooling body 10 can be suppressed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thin film forming apparatus or a thin film forming method.

  Thin film technology is widely deployed to improve the performance and miniaturization of devices. In addition, the thinning of devices is not only a direct merit for users, but also plays an important role in environmental aspects such as protecting earth resources and reducing power consumption.

  To advance the thin film technology, it is indispensable to meet the demands of industrial use such as high efficiency, stabilization, high productivity and low cost of the thin film manufacturing method. It has been.

  High deposition rate technology is essential for high productivity of thin films, and higher deposition rates are being promoted in thin film manufacturing, including vacuum deposition, sputtering, ion plating, and CVD. ing. Further, as a method of continuously forming a large amount of thin film, a winding type thin film manufacturing method is used. In the winding type thin film manufacturing method, a long substrate wound in a roll is unwound from an unwinding roll, a thin film is formed on the substrate while being transported along the transport system, and then wound on the winding roll. It is a method to take. The roll-up type thin film manufacturing method can form a thin film with high productivity by combining with a high deposition rate film forming source such as a vacuum evaporation source using an electron beam.

  As a factor that determines the success or failure of manufacturing such a continuous winding type thin film, there is a problem of heat load during film formation. For example, in the case of vacuum deposition, thermal radiation from the evaporation source and thermal energy possessed by the evaporated atoms are applied to the substrate, and the temperature of the substrate rises. In particular, when the temperature of the evaporation source is increased to increase the deposition rate, or when the evaporation source and the substrate are brought close to each other, the temperature of the substrate excessively increases. However, if the temperature of the substrate rises too much, the mechanical properties of the substrate are significantly lowered, and the problem is that the substrate is greatly deformed or the substrate is blown out due to the deposited thin film or the thermal expansion of the substrate. In other film formation methods, the heat source is different, but a thermal load is applied to the substrate during film formation, and the same problem occurs.

  In order to prevent such deformation and fusing of the substrate, the substrate is cooled during film formation. For the purpose of cooling the substrate, it is widely performed that the film is formed in a state where the substrate is along a cylindrical can disposed on the path of the transport system. If thermal contact between the substrate and the cylindrical can is ensured by this method, heat can be released to the cooling can with a large heat capacity, preventing an increase in the substrate temperature, or maintaining the substrate temperature at a specific cooling temperature. I can do it.

  As one of methods for ensuring the thermal contact between the substrate and the cylindrical can in a vacuum atmosphere, there is a gas cooling method. The gas cooling system uses a heat transfer of gas by supplying a small amount of cooling gas to this gap while maintaining a slight gap of several mm or less between the substrate and the cylindrical can which is a cooling body. In this method, the thermal contact between the substrate and the cylindrical can is ensured and the substrate is cooled. Patent Document 1 discloses that a cooling gas is introduced between a web and a cylindrical can as a supporting means in an apparatus for forming a thin film on the web as a substrate. According to this, since heat conduction between the web and the supporting means can be ensured, an increase in the temperature of the web can be suppressed.

JP-A-1-152262

  However, as in Patent Document 1, in a vacuum atmosphere in which vapor deposition is performed, the heat conduction due to contact is small, so the rate of heat transfer due to radiant heat transfer increases. However, in the configuration where the web and the can are close to each other, When the can reflects the radiant light from the can, the reflected radiant light is again absorbed by the web, and there is a problem that the radiant heat transfer from the web to the can is hindered. In particular, in the process where the scratches on the web and the transfer of the surface shape of the scan surface to the web are sensitive, when the mirror surface is mirrored, there is a problem that the reflection of the radiant light on the can surface is large.

In order to solve the above problems, a thin film forming apparatus of the present invention is a thin film forming apparatus for forming a thin film on the surface of a belt-like substrate having a front surface and a back surface in a vacuum, and a transport mechanism for transporting the substrate Thin film forming means for forming a thin film in a thin film forming region on the surface of the substrate being transported, a cooling body having a cooling surface close to the back surface in the thin film forming region, and the transport mechanism; A thin film forming means; and a vacuum vessel for housing the cooling body, wherein the cooling body is close to the substrate and transmits infrared light, and an absorber facing the substrate through the transmission body The thin film forming apparatus is characterized in that the emissivity of the transmission body is smaller than the emissivity of the absorber. , Thin film forming method for forming a thin film And a disposing step of disposing a cooling body close to the back surface in the thin film forming region, and a thin film forming step of forming a thin film in the thin film forming region on the front surface of the substrate being transported, The cooling body has a transmissive body that is close to the substrate and transmits infrared light, and an absorber that faces the substrate through the transmissive body, and the emissivity of the transmissive body is smaller than the emissivity of the absorber. A thin film forming method is characterized.

  With the configuration as described above, the radiation emitted from the substrate is transmitted through the transmission body, and the radiation rate facing the substrate is absorbed by the large absorption body through the transmission body, so that radiation from the cooling body to the substrate is prevented. Can be suppressed.

  Therefore, the cooling capacity of the substrate is improved, and damage due to transfer of the can surface shape can be suppressed.

1 is a schematic side view showing a configuration of an entire film forming apparatus according to Embodiment 1 of the present invention. (A) is a front view of the can used for Embodiment 1 of this invention, (B) is AA 'sectional drawing of FIG. 2 (A). (A) is a front view of the can used for Embodiment 1 of this invention, (B) is AA 'sectional drawing of FIG. 3 (A). (A) Front view of can used for Embodiment 1 of this invention, (B) is AA 'sectional drawing of FIG. 4 (A). The schematic side view which shows the structure of the whole film-forming apparatus of Embodiment 2 of this invention. Sectional drawing of the cooling body used for Embodiment 2 of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following embodiments, the same parts are denoted by the same reference numerals, and duplicate descriptions are omitted.

(Embodiment 1)
FIG. 1 is a side view schematically showing the entire configuration of a film forming apparatus when a substrate is transported along a cylindrical can in a thin film forming area, which is Embodiment 1 of the present invention.

  The vacuum vessel 1 is a pressure-resistant container-like member having an internal space. In the internal space, a take-out roller 2, a plurality of transport rollers 3, a thin film forming region 9, a take-up roller 4, a film forming source 5, and a shield. The plate 6 is accommodated. The unwinding roller 2 is a roller-like member provided so as to be rotatable around an axis, and a belt-like and long substrate 7 is wound on the surface thereof, and the substrate 7 is directed toward the closest conveying roller 3. Supply.

  The transport roller 3 is a roller-like member provided so as to be rotatable about its axis, and guides the substrate 7 supplied from the unwinding roller 2 to the thin film forming region 9 and finally guides it to the winding roller 4. When the substrate 7 travels in the thin film formation region 9, the material particles flying from the film forming source 5 react with the source gas introduced from the source gas introduction pipe (not shown) as necessary to react with the surface of the substrate 7. And a thin film is formed. The winding roller 4 is a roller-like member provided so as to be rotationally driven by a driving means (not shown), and winds and stores the substrate 7 having a thin film formed on the surface thereof.

  Various film forming sources can be used as the film forming source 5, for example, an evaporation source by resistance heating, induction heating, electron beam heating, an ion plating source, a sputtering source, a CVD source, or the like. In addition, an ion source or a plasma source can be used in combination as a film formation source. For example, the film formation source 5 is provided in the lower part of the thin film formation region 9 in the vertical direction, and has a container-like member whose upper part in the vertical direction is open, and a film placed on the inside of the container-like member. Including materials. Heating means (not shown) such as an electron gun and an induction coil is provided in the vicinity of the film forming source 5, and the film forming material inside the container-like member is heated and evaporated by these heating means. The vapor of the material moves upward in the vertical direction and adheres to the surface of the substrate 7 in the thin film formation region 9 to form a thin film. The film formation source 5 gives a thermal load to the substrate 7 during film formation.

  The shielding plate 6 limits the region where the material particles flying from the film forming source 5 can come into contact with the substrate 7 to the thin film forming region 9 only.

  The exhaust means 8 is provided outside the vacuum vessel 1 and adjusts the inside of the vacuum vessel 1 to a reduced pressure state suitable for forming a thin film. The exhaust means 8 is constituted by various vacuum exhaust systems using, for example, an oil diffusion pump, a cryopump, a turbo molecular pump, or the like as a main pump.

  In the thin film formation region 9, a cylindrical can cooling body 10 is disposed on the back surface (opposite surface of the surface to be formed) of the substrate 7, and the substrate 7 is transported along the cooling body 10 during thin film formation. ing.

  The cooling body 10 is cooled by the refrigerant. The refrigerant is usually a liquid or gaseous substance, typically water. A cooling medium flow path (not shown) is installed in contact with or embedded in the cooling body 10, and the cooling body 10 is cooled by passing the cooling medium through the flow path. When piping is used as the refrigerant flow path, the material of the piping is not particularly limited, and pipes such as copper and stainless steel can be used. The pipe may be attached to the cooling body 10 by welding or the like.

  A cooling gas is supplied between the cooling body 10 and the substrate 7 by the gas supply mechanism 25. Various gases such as helium and argon can be used as the cooling gas. Examples of the gas supply mechanism include a method in which a gas nozzle having a horizontal flute-like blowing shape is installed in the vicinity of the cooling body 10 and gas is introduced from the nozzle toward the substrate 7 and the cooling body 10.

  As described above, according to the thin film forming apparatus of FIG. 1, the substrate 7 fed from the unwinding roller 2 travels via the transport roller 3, and the vapor that has come from the evaporation source 5 in the thin film forming region 9 and A thin film is formed on the substrate by receiving supply of oxygen, nitrogen or the like as necessary. The substrate 7 is taken up by the take-up roller 4 via another transport roller 3. As a result, a substrate 7 having a thin film formed on the surface is obtained.

  For the substrate 7, various polymer films, various metal foils, composites of polymer films and metal foils, and other long substrates not limited to the above materials can be used. Examples of the polymer film include polyethylene terephthalate, polyethylene naphthalate, polyamide, polyimide, and the like. Examples of the metal foil include aluminum foil, copper foil, nickel foil, titanium foil, and alloy foil such as stainless steel. The width of the substrate is, for example, 50 to 1000 mm, and the desirable thickness of the substrate is, for example, 3 to 150 μm. If the width of the substrate is 100 mm or more, there is a partial difference in the thermal expansion of the substrate due to temperature unevenness, and a part of the substrate is easily lifted from the can, but this does not mean that the present invention cannot be applied. If the thickness of the substrate is less than 3 μm, the heat capacity of the substrate is extremely small, and thus thermal deformation is likely to occur during the thin film formation. If the thickness of the substrate is larger than 150 μm, the substrate hardly stretches even with the tension applied from the unwinding roller 2 or the take-up roller 4. Large gaps are likely to occur between them, and the leakage of cooling gas during gas cooling increases. However, neither indicates that the present invention is not applicable. Although the conveyance speed of a board | substrate changes with the kind of thin film to produce, and film-forming conditions, it is 0.1-500 m / min, for example. The tension applied to the substrate 7 being transported in the transport direction R is appropriately selected depending on the process conditions such as the material and thickness of the substrate and the film forming rate.

  FIG. 2 shows a front view of the cooling body 10 and a cross-sectional view at the substrate passage position.

The cooling body 10 includes a transmissive body 51 that contacts the substrate 7 and an absorber 52 that faces the substrate 7 through the transmissive body.
The transmissive body 51 is in thermal contact with the substrate 7 directly or via a cooling gas, is responsible for cooling the substrate 7 by contact heat conduction, and transmits infrared light emitted by radiation from the substrate 7. The surface of the transparent body 51 is smooth to prevent transfer of the surface shape to the substrate 7 and scratches on the substrate 7. Although the transparent body 51 directly contacts the substrate 7 macroscopically, since the cooling gas is introduced between the substrate 7 and the transparent body, it is not necessary to ensure the contact strictly, and it is sufficient that they are close to each other.

  The upper limit of the thickness of the transmissive body 51 is limited to approximately 10 mm or less because the upper limit is limited by the transmittance of infrared light. The lower limit of the thickness is limited to some extent depending on the mechanical strength, but if the material is not broken by the friction between the substrate 7 and the transmission body or the tension applied to the substrate 7, the absorber surface can be formed by various methods such as vapor deposition and plating. It is also possible to use a thin film of a transparent body. The present invention is not limited by the thickness of the transmission body.

The transmissive body 51 is made of a material that transmits infrared light emitted from the substrate 7.
It is known that the peak wavelength (λm (μm)) of radiation from the substrate is determined by the substrate absolute temperature (T (K)) and follows Formula 1 (Wien's formula).

(Equation 1) λm = 2896 / T Vienna equation In order to effectively transmit the radiation from the substrate 7, it is preferable that the transmission body 51 has a transmittance of 50% or more at the peak wavelength λm with respect to the substrate temperature.

  Although the substrate temperature used in the vapor deposition process varies depending on the material of the substrate and the properties of the thin film, it is roughly about 100 ° C to 500 ° C, and the peak wavelength of the radiated light at this time is about 3 to 8 µm. The transmittance in the region is preferably 50% or more.

  Specifically, silicon, germanium, sapphire, calcium fluoride, barium fluoride, or the like can be used. Further, when the substrate temperature is relatively high and the peak wavelength is short, it is possible to use a material having a low transmittance in a long wavelength region such as quartz glass.

  The absorber 52 faces the substrate 7 through the transmissive body 51 and absorbs radiation light from the substrate 7.

  The absorber 52 has no risk of direct contact with the substrate 7, and there is no risk of damage to the substrate, such as transfer to a surface-shaped substrate. Therefore, the absorber 52 is a conventional cooling body that requires smooth and wear-resistant surface properties. Compared to the surface shape and material, more options can be taken.

  In order to improve the absorption rate of the radiation light of the absorber 52, it is desirable that the absorber surface is made of a material having a high emissivity, and the absorber surface roughness is larger than the transmission surface roughness.

  Specifically, the radiation rate of the surface of the absorber 52 is desirably 0.7 or more, and various metals such as aluminum whose surface has been subjected to electrolytic treatment or oxidation treatment to improve the radiation rate can be used. In addition, it is possible to use a material with a relatively high surface, such as an oxide such as silica or alumina, or graphite, and a high emissivity material that is weak or brittle to wear. When the mechanical strength of the absorbent body 52 is small, it is also possible to compensate the mechanical strength by embedding a core 53 having a high mechanical strength inside the absorbent body as shown in FIG. . Various materials such as aluminum, which is generally used as a material for rollers and cylindrical cans, can be used as the material for the core, and the present invention is not limited to the material and shape of the core 53. Further, when the core 53 is installed, the absorber 52 does not require mechanical strength. Therefore, the thin-film absorber 52 is formed on the core 53 by applying various blackening paints, plating, or vapor deposition. Also good.

  In the case of various metal materials such as aluminum and stainless steel used as the material of the conventional cylindrical can cooling body, the emissivity is a value of about 0.1, but in order to suppress the transfer of the surface shape to the substrate and damage, When the surface of the cooling body is polished, although depending on the degree of polishing, the emissivity is further decreased to about 0.05. In this case, about 95% of the radiated light from the substrate is not absorbed by the cooling body but is reflected by the substrate, and the substrate is again absorbed, so that cooling by radiation is hindered and cooling efficiency is lowered.

  On the other hand, the material used in the present invention can achieve emissivity of 0.8 with anodized aluminum and about 0.9 with graphite material, and about 0.95 when blackening paint is used. Can be achieved. For this reason, since it becomes possible to absorb about 70% to 95% of the radiation light from the substrate, it is possible to greatly reduce the reflection of the radiation light to the substrate, and the substrate cooling by radiation is excellent. Achieved.

  As a method for supplying the cooling gas between the substrate 7 and the cooling body 10, there is a method for supplying the cooling gas from the cooling body 10 itself in addition to the method for supplying the cooling gas using the gas supply mechanism as shown in FIG. 1. It is done.

  FIG. 4 shows an example of the cooling body 10 provided with a mechanism for supplying a cooling gas.

  The cooling body 10 is composed of a transmission body 51 and an absorption body 52. At the position where the substrate on the transmission body passes, pores 53 for circulating a cooling gas are opened, and the transmission body 51 and the cooling body 10 are cooled. A space (manifold) 15 for holding cooling gas is provided between the bodies 52. By introducing the cooling gas into the manifold, the gas can be supplied between the substrate 7 and the transmissive body 51 through the pores 53.

The opening area of the pores 53 on the surface of the transmission body 51 is preferably 0.5 to ²⁰ mm ² per one. If it is less than 0.5 mm ² , pores are easily clogged with film-forming particles, which is not preferable. If it exceeds 20 mm ² , the gas pressure introduced from each pore is likely to vary, and cooling unevenness occurs in the substrate width direction and the substrate longitudinal direction, which is not preferable.

  2A and 2B, a plurality of pores 53 are provided, but the number of pores depends on the required gas pressure or the tension applied to the substrate between the substrate 7 and the cooling body 10. The gas pressure can be appropriately selected so as to be uniform, and the present invention is not limited by the number of pores.

The plurality of pores 53 may be arranged at uniform intervals on the surface of the transmission body 51. However, when there is a lot of gas leakage from between the cooling body and the substrate 7, the gas flow rate in the vicinity of both ends in the substrate width direction is increased by adjusting the arrangement and size of the gas introduction holes. The arrangement of the holes 51 may be adjusted.
As a method of introducing the cooling gas into the manifold 15 between the absorber 52 and the permeator 51, a gas introduction pipe 13 is installed inside the absorber 52, and a pore is also formed in the absorber. In addition, various methods can be used, and the present invention is not limited to the method of introducing the cooling gas.

Further, the cooling body of the present invention can be used not only for the thin film formation region 9 but also for the transport roller 3, the take-up roller 4, and the unwind roller 2 in the substrate transport path.
When the cooling body 10 is used for the transport roller 3, the winding roller 4, and the unwinding roller 2, unlike the thin film formation region 9, the cooling load is not necessarily between the substrate 7 and the cooling body 10 because the thermal load on the substrate 7 is small. There is no need to improve the cooling capacity by introducing gas, and the required cooling capacity is small, or the exhaust pressure is low and introducing the cooling gas increases the internal pressure of the vacuum vessel 1 and interferes with thin film formation. There is no problem even if the cooling body 10 is used without introducing the cooling gas.

(Embodiment 2)
In the present invention, it is also possible to introduce a cooling gas between the substrate 7 and the cooling body by using a plate-like cooling body, bringing the substrate 7 and the cooling body close to each other.

  FIG. 5 is a side view schematically showing a configuration of the entire film forming apparatus when the substrate is conveyed linearly in the thin film forming area, which is Embodiment 2 of the present invention. Here, “the substrate is conveyed in a straight line” is intended to exclude the conveyance of the substrate in a curved state along the cylindrical can as shown in FIG. As shown in FIG. 5, this means that the substrate is transported in a state where tension is applied in the transport direction by a plurality of rollers. However, in the side view as shown in FIG. 5, not only when the substrate is transported on a complete straight line, but also due to slack due to its own weight, injection of cooling gas, source gas, etc. This includes the case where some bends are included in the transport path.

  The vacuum vessel 1 is a pressure-resistant container-like member having an internal space. In the internal space, a take-out roller 2, a plurality of transport rollers 3, a thin film forming region 9, a take-up roller 4, a film forming source 5, and a shield. The plate 6 is accommodated. The unwinding roller 2 is a roller-like member provided so as to be rotatable around an axis, and a belt-like and long substrate 7 is wound on the surface thereof, and the substrate 7 is directed toward the closest conveying roller 3. Supply.

The transport roller 3 is a roller-like member provided so as to be rotatable about its axis, and guides the substrate 7 supplied from the unwinding roller 2 to the thin film forming region 9 and finally guides it to the winding roller 4. When the substrate 7 travels in the thin film formation region 9, the material particles flying from the film forming source 5 react with the source gas introduced from the source gas introduction pipe (not shown) as necessary to react with the surface of the substrate 7. And a thin film is formed. The winding roller 4 is a roller-like member provided so as to be rotationally driven by a driving means (not shown), and winds and stores the substrate 7 having a thin film formed on the surface thereof.

  Various film forming sources can be used as the film forming source 5, for example, an evaporation source by resistance heating, induction heating, electron beam heating, an ion plating source, a sputtering source, a CVD source, or the like. In addition, an ion source or a plasma source can be used in combination as a film formation source. For example, the film formation source 5 is provided in the lower part of the thin film formation region 9 in the vertical direction, and has a container-like member whose upper part in the vertical direction is open, and a film placed on the inside of the container-like member. Including materials. Heating means (not shown) such as an electron gun and an induction coil is provided in the vicinity of the film forming source 5, and the film forming material inside the container-like member is heated and evaporated by these heating means. The vapor of the material moves upward in the vertical direction and adheres to the surface of the substrate 7 in the thin film formation region 9 to form a thin film. The film formation source 5 gives a thermal load to the substrate 7 during film formation.

  The shielding plate 6 limits the region where the material particles flying from the film forming source 5 can come into contact with the substrate 7 to the thin film forming region 9 only.

  The exhaust means 8 is provided outside the vacuum vessel 1 and adjusts the inside of the vacuum vessel 1 to a reduced pressure state suitable for forming a thin film. The exhaust means 8 is constituted by various vacuum exhaust systems using, for example, an oil diffusion pump, a cryopump, a turbo molecular pump, or the like as a main pump.

  In the thin film formation region 9, a cooling body 10 is disposed in the vicinity of the substrate 7 on the back surface (the surface opposite to the surface on which the film is formed) of the substrate 7.

  A pair of auxiliary rollers 11 are arranged in front of and behind the cooling body 10 along the transport path of the substrate 7 and are in contact with the back surface of the substrate 7. Thereby, it becomes easy to adjust the transport path of the substrate 7 in the vicinity of the thin film formation region 9 and finely adjust the distance between the substrate and the cooling body.

  A gas whose introduction amount is controlled by the gas flow controller 12 is introduced from the cooling gas supply means 14 through the gas pipe 13 between the cooling body 10 and the back surface of the substrate. The introduced gas transmits the cooling heat of the cooling body 10 to cool the substrate 7. The cooling gas supply means 14 includes a gas cylinder and a gas generator.

  The cooling body 10 is cooled by the refrigerant. The refrigerant is usually a liquid or gaseous substance, typically water. A cooling medium flow path (not shown) is installed in contact with or embedded in the cooling body 10, and the cooling body 10 is cooled by passing the cooling medium through the flow path. When piping is used as the refrigerant flow path, the material of the piping is not particularly limited, and pipes such as copper and stainless steel can be used. The pipe may be attached to the cooling body 10 by welding or the like. Further, the coolant channel may be formed by directly opening a hole for allowing the coolant to pass through the cooling body 10.

  The cooling capacity of the substrate 7 can be adjusted by changing various conditions. As such conditions, for example, the type, flow rate, or temperature of the coolant that cools the cooling body 10, the flow rate, type, or temperature (gas introduction conditions) of the cooling gas introduced between the cooling body 10 and the back surface of the substrate, auxiliary For example, the distance between the cooling body 10 adjusted by the roller 11 or the like and the substrate 7 may be used. Only one type of these conditions may be adjusted, or two or more types may be combined and adjusted.

As described above, according to the thin film forming apparatus of FIG. 5, the substrate 7 sent out from the unwinding roller 2 travels via the transport roller 3, and the vapor that has come from the evaporation source 5 in the thin film forming region 9 and A thin film is formed on the substrate by receiving supply of oxygen, nitrogen or the like as necessary. The substrate 7 is taken up by the take-up roller 4 via another transport roller 3. As a result, a substrate 7 having a thin film formed on the surface is obtained.

  For the substrate 7, various polymer films, various metal foils, composites of polymer films and metal foils, and other long substrates not limited to the above materials can be used. Examples of the polymer film include polyethylene terephthalate, polyethylene naphthalate, polyamide, polyimide, and the like. Examples of the metal foil include aluminum foil, copper foil, nickel foil, titanium foil, alloy foil such as stainless steel, and the like. The width of the substrate is, for example, 50 to 1000 mm, and the desirable thickness of the substrate is, for example, 3 to 150 μm.

  If the width of the substrate is less than 50 mm, gas leakage during gas cooling is large, but this does not mean that the present invention cannot be applied. If the thickness of the substrate is less than 3 μm, the heat capacity of the substrate is extremely small, and thus thermal deformation is likely to occur. If the thickness of the substrate is larger than 150 μm, the substrate hardly stretches even with the tension applied from the unwinding roller 2 or the take-up roller 4. Large gaps are likely to occur between them, and gas leakage during gas cooling increases. However, neither indicates that the present invention is not applicable. Although the conveyance speed of a board | substrate changes with the kind of thin film to produce, and film-forming conditions, it is 0.1-500 m / min, for example. The tension applied to the substrate 7 being transferred is appropriately selected depending on the process conditions such as the material and thickness of the substrate, or the film formation rate.

  FIG. 6 is an enlarged cross-sectional view of the vicinity of the thin film formation region 9 of the film forming apparatus shown in FIG.

  Like the cooling body described in the first embodiment, the cooling body 10 includes a transmissive body 51 that is close to the substrate 7 and an absorber 52 that faces the substrate through the transmissive body 51.

  Various methods are possible as a method for introducing gas between the cooling body 10 and the substrate 7. As an example, as shown in FIG. 6, a manifold 15 connected to a gas pipe 13 is provided inside the cooling body 10, and a plurality of pores extending from there to the surface of the permeator (the surface opposite to the back surface of the substrate 7). Gas is supplied via 53. As another method, gas can be introduced between the cooling body 10 and the substrate 7 by, for example, a method in which a gas nozzle having a horizontal flute-like blowing shape is embedded in the cooling body and gas is introduced from the nozzle. The gas introduction method is not limited to these, and other methods may be used as long as the gas as the heat transfer medium can be introduced while being controlled between the cooling body and the substrate.

The opening area of the pores 53 in FIG. 6 is preferably 0.5 to ²⁰ mm ² per pore. If it is less than 0.5 mm ² , pores are easily clogged with film-forming particles, which is not preferable. If it exceeds 20 mm ² , the gas pressure introduced from each hole tends to vary, and cooling unevenness occurs in the substrate width direction and the substrate longitudinal direction, which is not preferable.

  The plurality of pores 53 may be arranged at a uniform interval on the surface of the cooling body 10. However, if there is a lot of gas leakage from between the cooling body and the substrate, it is possible to adjust the arrangement and size of the gas introduction holes to increase the gas flow rate near the both ends in the substrate width direction. The arrangement of 53 may be adjusted.

When the plate-like cooling body described in the second embodiment is used, there is a risk that defects such as scratches or substrate breakage may occur when the traveling substrate and the cooling body come into contact with each other. When protruding from the path, the cooling gas introduced between the cooling body and the back surface of the substrate causes a gap between the cooling surface and the back surface of the substrate (that is, the substrate floats from the cooling surface). It is preferable to adjust the pressure of the cooling gas. At this time, the distance between the cooling body and the back surface of the substrate is preferably 0.1 to 5 mm. If it is less than 0.1 mm, there is a possibility that the substrate and the cooling body come into contact with each other due to variations in the shape and travel of the substrate. If it exceeds 5 mm, the gas easily leaks from the gap, so that it is necessary to increase the amount of gas introduced, and further, the cooling efficiency is lowered due to the gap expansion, which is not preferable.

  The pressure of the cooling gas introduced to generate the gap is preferably 20 to 200 Pa. If the pressure is less than 20 Pa, the pressure is too low, and therefore there is a possibility that the substrate may come into contact with the cooling body if there is variation in the shape of the substrate or travel variation. When it exceeds 200 Pa, the gap between the cooling surface and the back surface becomes large, increasing gas leakage and generating an unnecessary load on the vacuum pump.

  Although the embodiments of the present invention have been specifically described above, the present invention is not limited thereto.

  As specific application examples, a battery electrode plate using silicon, a magnetic tape, and the like have been described. However, the present invention is not limited to these, and a capacitor, sensor, solar cell, optical film, moisture proof Needless to say, the present invention can be applied to various devices that require stable film formation, such as a film, a conductive film, and the like.

  In the thin film forming film apparatus and the thin film forming method of the present invention, there is a concern about the contact between the substrate and the cooling body in the gas cooling method, and even in a process where the surface of the cooling body needs to be smoothed, the radiation light from the substrate to the cooling body By suppressing reflection and promoting heat transfer, it is possible to achieve a sufficient cooling effect. As a result, it is possible to realize thin film formation that achieves both high material utilization efficiency and a high film formation rate while preventing deformation and fusing of the substrate.

DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Unwinding roller 3 Conveying roller 4 Take-up roller 5 Film formation source 6 Shielding plate 7 Substrate 8 Exhaust means 9 Thin film formation area 10 Cooling body 11 Auxiliary roller 12 Gas flow controller 13 Gas piping 14 Cooling gas supply means 15 Manifold 16 Gas introduction hole 17 Introduction gas 51 Transmitter 52 Absorber 53 Pore 55 Core

Claims (13)

A thin film forming apparatus for forming a thin film on a surface of a belt-like substrate having a front surface and a back surface in a vacuum,
A transport mechanism for transporting the substrate;
Thin film forming means for forming a thin film in the thin film forming region on the surface of the substrate being conveyed,
A cooling body having a cooling surface close to the back surface in the thin film formation region;
A vacuum vessel that houses the transport mechanism, the thin film forming means, and the cooling body;
The cooling body includes a transmissive body that is close to the substrate and transmits infrared light, and an absorber that faces the substrate through the transmissive body. The emissivity of the transmissive body is greater than the emissivity of the absorber. Is a thin film forming apparatus.   The thin film forming apparatus according to claim 1, further comprising a gas introduction unit configured to introduce a cooling gas between the cooling surface and the back surface to cool the substrate.   It comprises a space for holding a gas between the permeator and the absorber and a pore penetrating the permeator, and a cooling gas is introduced between the substrate and the cooling body from the pore. The thin film forming apparatus according to claim 2 The thin film forming apparatus according to claim 3, wherein an opening area per one of the pores is 0.5 to ²⁰ mm ^2. The cooling body is a rotary cooling body in which the cooling surface has a cylindrical shape,
The thin film forming apparatus according to claim 1, wherein the substrate is conveyed while being curved along the cooling surface in the thin film forming region.   The thin film forming apparatus according to claim 1, wherein the transmitting body transmits infrared light having a wavelength of 3 to 8 μm by 50% or more.   The thin film forming apparatus according to claim 6, wherein an emissivity of the absorber is 0.7 or more.   The thin film forming apparatus according to claim 1, wherein the cooling body is cooled by a refrigerant. A thin film forming method for forming a thin film on the surface of a belt-like substrate having a front surface and a back surface in a vacuum,
An arrangement step of arranging a cooling body close to the back surface in the thin film formation region;
Including a thin film forming step of forming a thin film in the thin film forming region on the surface of the substrate being conveyed;
The cooling body has a transmitting body that is close to the substrate and transmits infrared light, and an absorber that faces the substrate through the transmitting body, and the emissivity of the transmitting body is smaller than the emissivity of the absorbing body. A method for forming a thin film. The thin film forming method according to claim 9, wherein a cooling gas is introduced between the cooling body and the back surface.
  The thin film forming method according to claim 10, wherein in the thin film forming step, the cooling gas is introduced at a pressure adjusted so that a gap is generated between the back surface and the cooling surface.   The method for forming a thin film according to claim 11, wherein a distance between the back surface and the cooling surface is 0.1 to 5 mm.   The thin film forming method according to claim 11 or 12, wherein the pressure is 20 to 200 Pa.