JP4669593B2 - Method and apparatus for forming AlOx film with controlled film characteristics by light transmittance of one wavelength - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming an AlOx film having a controlled film property on a substrate and a vacuum film forming apparatus, and more particularly, the film property is controlled on a substrate using light transmittance of a single wavelength. The present invention relates to a method for forming an AlOx film and a vacuum film forming apparatus.
[0002]
[Prior art]
Conventionally, in order to form an AlOx film with controlled film characteristics, for example, in the case of the electron beam heating type, the film forming conditions of the AlOx film are a constant electron beam output and a constant reaction gas (oxygen gas) introduction amount. Thus, the film formation was performed only by controlling so that the characteristics of the obtained film were controlled. In this case, after film formation, the obtained AlOx film is taken out into the atmosphere and measurement of film properties such as water vapor transmission rate, oxygen transmission rate, total light transmission rate, etc. is performed to determine whether the film properties have been controlled. It was only confirmed that the AlOx film | membrane with which the film | membrane characteristic was controlled was provided.
[0003]
As a simple method for controlling gas barrier characteristics during film formation, there is also a method for controlling film characteristics while keeping the light transmittance at a wavelength in the visible light region (for example, 550 nm) constant.
[0004]
[Problems to be solved by the invention]
In the conventional method of forming a film by managing the film formation conditions as described above, when an AlOx film is formed on a substrate made of a dielectric material such as plastic, a water vapor transmission characteristic that is a film characteristic of the AlOx film as a transparent gas barrier film is used. It was impossible to control the humidity, oxygen transmission rate, and total light transmittance at the same time and in the vacuum film formation chamber during film formation.
[0005]
In addition, in the conventional method for controlling the film characteristics using the light transmittance by the wavelength in the visible light region as described above, in the case of an oxide film with high transparency, the substrate on which the film is formed due to the interference action of the oxide film. The difference in light transmittance between the substrate and the non-deposited substrate could not be recognized, and it was difficult to control the effective film characteristics.
[0006]
In the present invention, while forming an AlOx film on a substrate made of a dielectric material in a vacuum film formation chamber, the film characteristics of the AlOx film as a gas barrier film (water vapor permeability, oxygen permeability, total light transmittance) are simultaneously obtained. It is an object of the present invention to provide a method and apparatus for forming an AlOx film that can be controlled during film formation and whose film characteristics are controlled.
[0007]
[Means for Solving the Problems]
As a result of continual research on the technology for simultaneously controlling the water vapor transmission rate, oxygen transmission rate, and light transmission rate of a film while forming an AlOx film in the same apparatus, the present inventors The inventors have found that the above problems can be solved by controlling the light transmittance at a specific wavelength, and have completed the present invention.
[0008]
The method for forming an AlOx film with controlled film characteristics according to the present invention is a method for forming a transparent gas barrier film on a transparent substrate made of a dielectric material using Al and oxygen gas or oxygen-containing gas as a reactive gas in a vacuum film forming chamber. In the method of forming an AlOx film, the light transmittance of the AlOx film formed on the substrate in the vacuum film forming chamber is determined by using a transparent substrate on which the AlOx film is formed and a transparent film on which the AlOx film is not formed. Measurement is performed at one wavelength selected from a wavelength in the range of 350 to 400 nm where a difference in light transmittance with the substrate is likely to appear , and this measured value is monitored so that the measured light transmittance is 77 to 80%. When the amount of reaction gas introduced is fixed at this stage, the AlOx film is formed so as to keep the light transmittance at 77 to 80%, and the light transmittance changes during the film formation. In By adjusting the amount of evaporated Al, the AlOx film is continuously formed so as to keep the light transmittance at 77 to 80%, and an AlOx film in which water vapor permeability, oxygen transmittance, and total light transmittance are controlled is formed. Consists of. Thereby, an AlOx film in which the water vapor transmission rate, the oxygen transmission rate, and the total light transmission rate are simultaneously controlled during film formation can be obtained.
[0011]
As one wavelength selected from the wavelength in the boundary region between the ultraviolet region and the visible light region and the wavelength in the vicinity of the region, a wavelength in the range of 350 to 400 nm is used. This is because the light transmittance of most dielectric transparent substrates cannot be measured at a wavelength of less than 350 nm , and the difference in light transmittance between the non-film-formed substrate and the film-formed substrate at a wavelength of more than 400 nm. This is because it is difficult to identify and fine adjustment of the light transmittance is difficult.
[0012]
The light transmittance is set to 77-80%. If it is set to less than 77%, the total light transmittance of the resulting film will be low, and if it exceeds 80%, it will be difficult to identify the difference in light transmittance between the non-deposited substrate and the deposited substrate, This is because fine adjustment of the light transmittance is difficult.
[0013]
The substrate may be plastic or glass, and the AlOx film is metal or ceramic. In forming the AlOx film, the film can be formed while fixing or moving the substrate.
[0014]
A vacuum film forming apparatus for forming a film with controlled film characteristics according to the present invention includes a vacuum film forming chamber and a substrate feeding / winding device installed in the film forming chamber. The apparatus comprises a substrate feed roll, a cooling drum, and a take-up roll. The substrate is unwound from the feed roll and sent to the cooling drum, and then continuously moves as the cooling drum rotates. The container is configured to be wound on a winding roll, and a container for storing the evaporated substance is installed below the cooling drum, and the evaporated substance is heated and evaporated to be formed as a film on the substrate. The vacuum film formation chamber is provided with a reaction gas inlet, and the target film is formed on the substrate by introducing the reaction gas from the inlet. And between the cooling drum and the take-up roll, the shape of the target film It has been measured for light transmittance of the substrate at one wavelength selected from 350 to 400 nm, after setting to maintain the light transmittance by monitoring the 77-80%, secure the amount of introduction of the reaction gas at this stage Then, an AlOx film is formed so as to keep the light transmittance at 77 to 80%, and when the light transmittance changes during the film formation, the light transmittance is adjusted by adjusting the amount of Al evaporation. A control device is provided which is configured to keep the ratio at 77-80%. By using this apparatus, it is possible to easily form a target film whose film characteristics such as water vapor transmission rate, oxygen transmission rate, and total light transmittance are controlled at the same time.
[0015]
The substrate is fed out from the feed roll to the cooling drum via a guide roll, and is wound from the cooling drum to the take-up roll via another guide roll. The heating means for the evaporating substance is not particularly limited, but it is preferably performed by irradiation with an electron beam from an electron gun.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0017]
In the present invention, during film formation, the light transmittance of the AlOx film is measured and monitored by a specific single wavelength selected from the wavelength of the boundary region between the ultraviolet region and the visible light region and the wavelength in the vicinity of the region. FIG. 1 shows a configuration of a control apparatus for performing the above, and FIG. 2 shows a vacuum film forming apparatus of the present invention equipped with this control apparatus.
[0018]
1 is transported so that the substrate 1 on which the AlOx film is formed passes between the light projecting side sensor 2 and the light receiving side sensor 3, and the light transmittance when passing between the sensors. Can be measured, and its light transmittance can be monitored. After a light beam having a predetermined wavelength generated by the lamp house 4 passes through the optical fiber cable 5 and the optical fiber introduction flange 6, the light projecting side sensor 2 applies to the substrate 1 on which the AlOx film as the measurement object is formed. The light beam emitted and transmitted through the film is received by the light receiving side sensor 3. Thereafter, the light transmittance is measured by the transmittance monitor body 7 based on the received light.
[0019]
The configuration of the control device as shown in FIG. 1 is almost the same as a conventional light transmittance measuring device for a metal film. In the case of a conventional apparatus using only a wavelength in the visible light region, as described above, the difference in light transmittance between a film-formed substrate and a non-film-formed substrate cannot be recognized, which may cause inconvenience. In the case of the present invention, since one wavelength within the range of 350 nm to 400 nm is used as the wavelength of the light beam used for measurement, the difference in light transmittance can be recognized, and satisfactory measurement can be performed.
[0020]
In FIG. 1, a plurality of light-emitting side sensors 2 and light-receiving side sensors 3 are shown side by side in the width direction of the substrate on which the AlOx film is formed, but the light transmittance of the formed substrate is appropriately measured. The arrangement is not particularly limited as long as it can be monitored. For example, only a single pair of sensors may be provided as sensors, and the sensors may be configured to travel in the width direction of the substrate. It may be configured to be provided.
[0021]
The transparent substrate used for forming the AlOx film by the forming method of the present invention may be a dielectric substrate, for example, a plastic film made of polypropylene, polyester, nylon or the like, or a sheet. Further, it may be a roll-like long substrate or a cut sheet substrate. As a method for forming the AlOx film, a vapor deposition method, a sputtering method, a CVD method such as a plasma CVD method, an ion plating method, or the like can be used .
[0022]
The vacuum film forming apparatus of the present invention shown in FIG. 2 is a take-up vacuum deposition apparatus, and a substrate sending / winding device 12 is provided in the vacuum film forming chamber 11, and this substrate sending / winding device 12 is sent. The substrate 16 includes a roll 13, a cooling drum 14, and a take-up roll 15. The substrate 16 is fed out from the delivery roll 13 and sent to the cooling drum 14 through the guide rolls 17 and 18, and then the substrate is rotated by the cooling drum 14. Along with this, it is configured to continuously move and be taken up by the take-up roll 15 via the other guide rolls 19 and 20. Below the cooling drum 14, an electron beam evaporation container 22 for storing the evaporation substance 21 is installed, and the evaporation substance is heated and evaporated by irradiation of the electron beam 24 from the electron gun 23 to form a film on the substrate. It has come to be. Further, the vacuum film formation chamber 11 is provided with a reaction gas introduction port 25, and a reaction gas such as oxygen gas and oxygen-containing gas introduced from the reaction gas introduction port is arranged in the vicinity of the film formation portion of the substrate. Film formation is performed so as to be guided from the gas introduction nozzle onto the substrate. In FIG. 1, the control device 26 using one wavelength selected from the wavelength of the boundary region between the ultraviolet region and the visible light region and the wavelength in the vicinity of the region, and the control device 27 using one wavelength of the visible light region, It is installed between the guide roll 19 and the take-up roll 15 so that the light transmittance of the film-formed substrate can be measured. However, the control device 27 shown in FIG. 1 is shown for convenience in order to clarify the effect of a specific single wavelength used in the present invention in the following embodiment in comparison with a single wavelength in the visible light region. In the case of the vacuum film forming apparatus of the present invention, only the control device 26 using a specific single wavelength is a constituent element. That is, the control device 27 should be read as a control device that uses a specific single wavelength in the same manner as the control device 26.
[0023]
In the following examples, a wavelength of 350 nm was used as the wavelength of the light used for measuring the light transmittance. However, as described above, any wavelength may be used as long as the wavelength is in the range of 350 to 400 nm. .
[0024]
【Example】
Example 1
In this example, as will be described below, an AlOx film is formed using the winding type vacuum vapor deposition apparatus shown in FIG. 2, and the light transmittance of the obtained film is set to a wavelength of 350 nm in the same apparatus. Film formation was continued by controlling the amount of oxygen gas (or oxygen-containing gas) introduced and the amount of evaporated Al so as to maintain a predetermined light transmittance while measuring and monitoring to obtain a desired AlOx film. Further, the light transmittance of the obtained film was measured using a wavelength of 550 nm instead of a wavelength of 350 nm, and the film formation was continued in the same manner as described above to obtain another AlOx film. Comparison with the membrane was performed.
[0025]
First, a normal winding tension is applied to the long substrate 16 of PET film having a thickness of 12 μm wound around the delivery roll 13, and the guide rolls 17 and 18 are placed inside the film formation chamber 11 of 2 × 10 ⁻⁵ Torr. The substrate is moved to the metal cooling drum 14 at a speed of 200 m / min, and the evaporation material (Al) 21 in the container 22 is heated and evaporated by irradiation of the electron beam 24 from the electron gun 23 with an output of 120 Kw, and the substrate A predetermined thickness (50 to 130 angstroms) of Al was vapor-deposited on 16. Next, when the substrate 16 passes through the cooling drum 14, oxygen gas is introduced from the reaction gas introduction port 25, and this oxygen gas is guided onto the substrate from the gas introduction nozzle installed in the vicinity of the film forming unit, and the AlOx film is formed. Produced. Before the wound AlOx film is wound on the winding roll 15, the light transmittance at each wavelength is measured and monitored by the control device 26 using a wavelength of 350 nm and the control device 27 using a wavelength of 550 nm. did. While monitoring, the oxygen gas introduction amount was adjusted so that the light transmittance measured at a wavelength of 350 nm was a predetermined light transmittance (77 to 80%), and the predetermined light transmittance was maintained. At the stage where the predetermined light transmittance was set, the amount of oxygen gas introduced was fixed, and film formation was continued. In addition, when the film is formed while monitoring the light transmittance, and the light transmittance changes during the film formation and falls outside the predetermined light transmittance range, the output of the electron beam is changed to change the Al The evaporation amount was adjusted so that a predetermined light transmittance was maintained. In this way, the desired film thickness and light transmittance could be managed.
[0026]
The long substrate used had a total light transmittance of 88.3%, gas barrier properties of water vapor permeability of 42 g / m ² · day, and oxygen transmission rate of 137 g / m ² · day · atm. The AlOx film obtained by controlling with the control device 27 using a wavelength of 550 nm has a water vapor permeability of 0.8 g / m ² · day and an oxygen permeability of 1.04 g / m ² · day · atm and has a good gas barrier property. However, the total light transmittance was as low as 83%, the transparency of the film as seen in a perfect Al ₂ O ₃ film was not obtained, and it was unsatisfactory as a gas barrier film. On the other hand, the AlOx film controlled by the control device 26 using a wavelength of 350 nm has good gas barrier properties such as water vapor permeability of 0.8 g / m ² · day and oxygen permeability of 1.04 g / m ² · day · atm. And the total light transmittance was as high as 88%, and it was a favorable transparent gas barrier film.
[0027]
FIG. 3 shows the results of examining the light transmittance at wavelengths from 300 nm to 780 nm of the transparent AlOx gas barrier film formed on the PET film by the method of the present invention. The symbol a in FIG. 3 indicates the light transmittance of the long substrate used, and the symbol b indicates the light transmittance of the long substrate on which the AlOx film is formed. Looking at the light transmittance indicated by symbol b, it can be seen that interference by the AlOx film occurs over a wide wavelength range in the visible light range (wavelength exceeding 400 nm). Further, from the light transmittance indicated by symbols b and a, in the wavelength region of 325 to 400 nm, there is a difference in light transmittance between the film-formed substrate and the non-film-formed substrate as compared with the wavelength region exceeding 400 nm. It turns out that it is easy.
[0028]
The light transmittance of, for example, a PET film used as a substrate in the present invention has almost the same curve tendency as a shown in FIG. 3, but it depends on the PET manufacturer and the type of film. There are some variations in measurable wavelength and light transmittance. However, if the wavelength is about 350 nm or more, the light transmittance can be measured, and a difference in light transmittance between the film-formed substrate and the non-film-formed substrate tends to appear. Therefore, a wavelength in the range of 350 to 400 nm is used to form an AlOx film with controlled film characteristics.
[0029]
【The invention's effect】
According to the formation method of the present invention, when forming an AlOx film as a transparent gas barrier film, a difference in light transmittance between a transparent substrate on which an AlOx film is formed and a transparent substrate on which no AlOx film is formed is likely to appear. The light transmittance of the film at one wavelength selected from wavelengths of 350 to 400 nm is controlled, and when the light transmittance changes during film formation, the light transmittance is adjusted to 77 by adjusting the amount of Al evaporation. By keeping it at ˜80%, film characteristics such as total light transmittance, water vapor permeability, and oxygen permeability can be easily controlled, and satisfactory characteristics as a gas barrier film can be obtained. Moreover, if the vacuum film forming apparatus of the present invention is used, an AlOx film having good film characteristics can be easily obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an example of a control device used for carrying out a method of the present invention.
FIG. 2 is a cut side view schematically showing an example of the configuration of a vacuum film forming apparatus that can be used for carrying out the method of the present invention.
FIG. 3 is a graph showing an example of light transmittance of a PET film substrate on which an AlOx film is formed and a non-deposited PET film substrate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Substrate 2 Light emitting side sensor 3 Light receiving side sensor 4 Lamp house 5 Optical fiber cable 6 Optical fiber introduction flange 7 Transmittance monitor main body 11 Vacuum film forming chamber 12 Substrate delivery / winding device 13 Delivery roll 14 Cooling drum 15 Winding roll 16 Substrate 17, 18, 19, 20 Guide roll 21 Evaporating substance 22 Electron beam evaporation container 23 Electron gun 24 Electron beam 25 Reactive gas inlet 26, 27 Control device

Claims (3)

In a method of forming an AlOx film as a transparent gas barrier film on a transparent substrate made of a dielectric material using Al and oxygen gas or oxygen-containing gas as a reaction gas in a vacuum film formation chamber, The light transmittance of the AlOx film formed on the substrate is in the range of 350 to 400 nm where the difference in light transmittance between the transparent substrate on which the AlOx film is formed and the transparent substrate on which the AlOx film is not formed is likely to appear. After measuring at one wavelength selected from the above wavelengths and monitoring this measured value, the measured light transmittance was set to 77-80%, and then the reaction gas introduction amount was fixed at this stage. When the AlOx film is formed while maintaining the light transmittance at 77 to 80%, and the light transmittance changes during the film formation, the light transmittance is adjusted by adjusting the amount of evaporation of Al. 77 ~ Formation of an AlOx film with controlled film characteristics, characterized by continuing to form an AlOx film while maintaining 80%, and forming an AlOx film with controlled water vapor transmission rate, oxygen transmission rate, and total light transmission rate Method.   2. The method according to claim 1, wherein the film is formed while fixing or moving the substrate. A vacuum film forming chamber and a substrate feeding / winding device installed in the film forming chamber, the feeding / winding device comprising a substrate feeding roll, a cooling drum, and a winding roll; It is configured to be fed out from the feed roll and sent to the cooling drum, and then continuously moved along with the rotation of the cooling drum and taken up by the take-up roll. A container for containing the evaporating substance is installed, the evaporating substance is heated and evaporated, and is formed as a film on the substrate, and a reactive gas inlet is provided in the vacuum film forming chamber. The target gas is formed on the substrate by introducing the reaction gas from the inlet, and the target film is formed between the cooling drum and the winding roll. transparent substrate and the a of the light transmittance of the substrate AlOx film is formed with Ox film is measured at one wavelength where the difference in light transmittance is selected from a range of appear likely 350~400nm the transparent substrate that are not deposited, to keep monitoring the light transmittance from 77 to 80% After setting, the amount of reaction gas introduced is fixed at this stage, the AlOx film is formed so as to keep the light transmittance at 77 to 80%, and the light transmittance changes during the film formation. Is provided with a control device configured to keep the light transmittance at 77 to 80% by adjusting the amount of evaporation of Al, in order to form a film with controlled film characteristics Vacuum deposition equipment.

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