JP4339437B2 - Vacuum deposition system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum film forming apparatus, and more particularly to a vacuum film forming apparatus suitable for forming a film on the surface of a long substrate such as a film.
[0002]
[Prior art]
When a film is formed on the material surface, a vacuum film forming apparatus is usually used. The vacuum film forming apparatus is an apparatus having a function of forming a film on the surface of a substrate in a vacuum environment. Specific film forming methods include vacuum deposition, sputtering, CVD, ion plating, Various methods such as plasma discharge, glow discharge, electron beam irradiation, ultraviolet irradiation, and material spraying are known. In addition, there are a wide variety of base materials for film formation, such as metal plates, glass plates, metal films, plastic films, and paper. In many cases, the process of forming the multilayer structure is performed by repeating the forming process. In the vacuum film forming apparatus, a predetermined film forming method is executed in a state where a base material to be formed is accommodated in a vacuum chamber and the inside of the chamber is evacuated and maintained at a certain degree of vacuum. If necessary, a film forming gas is introduced into the chamber.
[0003]
[Problems to be solved by the invention]
In a vacuum environment, the components of the atmospheric gas are remarkably limited as compared with a general atmospheric environment, so that a high-quality film with few impurities can be formed. For example, when a predetermined amount of a specific film forming gas is introduced while the vacuum chamber is evacuated, the atmosphere in the vacuum chamber theoretically includes the predetermined amount of the film forming gas. Therefore, the film forming process under optimum conditions becomes possible.
[0004]
However, in practice, film formation under such optimum conditions is difficult due to the influence of degassing. Degassing is based on gas directly released from the base material (film formation target) in the vacuum chamber and various devices (heating device, sputtering device, transfer device, etc.) in the vacuum chamber used for film formation processing. It is a general term for gases released by Actually, it is difficult to predict how much gas is released as degassing in the film forming process. Therefore, under the present circumstances, the film forming process is not necessarily performed under the optimum conditions due to the influence of the degassing. In particular, various gases are easily released as degassed from a base material mainly composed of an organic material such as a plastic film. Further, when film formation is performed on a long base material in the form of a film, a delivery roll in which the base material is wound in a roll shape, a winding roll for winding up the processed base material, and these Since a substrate transport system between the rolls is required, degassing that occurs at the time of feeding or winding of each of these rolls or when the transport system and the substrate are in contact with each other cannot be ignored.
[0005]
Accordingly, an object of the present invention is to provide a vacuum film forming apparatus capable of performing a film forming process under optimum conditions even under the influence of degassing.
[0006]
[Means for Solving the Problems]
(1) A first aspect of the present invention is a vacuum film forming apparatus for forming a film on the surface of a long substrate in a vacuum environment.
A vacuum chamber for containing the substrate;
An evacuation device for maintaining a predetermined degree of vacuum in the vacuum chamber;
In order to perform the film formation process by causing particles in an excited state to act on the surface of the substrate, a first gas that is supplied also as degassing and a second gas that is not supplied as degassing are formed. A film forming apparatus for forming a film while introducing it into a vacuum chamber as a film processing gas ;
A delivery roll that winds and holds the substrate in a roll shape, a transport drum that transports the substrate delivered from the delivery roll to a position suitable for the film formation process, and a substrate that has completed the film formation process. A take-up roll wound up into a roll, and a transport device having
A light irradiation device for irradiating light from a white light source to gas particles in the vicinity of the outer periphery of the transport drum;
A spectroscopic analyzer that receives the white irradiation light from the light irradiation device together with light emitted from gas particles excited by the action of the film forming processing apparatus and irradiated with the white irradiation light, and observes its spectrum;
The ratio of the spectral intensity of the first gas near the representative emission wavelength of the first gas and the spectral intensity of the second gas near the representative emission wavelength of the second gas in the spectrum observed by the spectroscopic analyzer. A film formation control apparatus for controlling the amount of the first gas introduced so that the ratio is constant, while maintaining the amount of the second gas introduced constant;
Is provided.
[0007]
(2) A second aspect of the present invention is the vacuum film forming apparatus according to the first aspect described above,
The film forming apparatus introduces oxygen as the first gas and argon as the second gas.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiments. FIG. 1 is a block diagram showing a basic configuration of a vacuum film forming apparatus according to the present invention. This apparatus includes a vacuum chamber 10, an evacuation apparatus 20, a film formation processing apparatus 30, a light irradiation apparatus 41, a spectroscopic analysis apparatus 42, a film formation control apparatus 50, and a transfer apparatus 60. And has a function of forming a film on the surface of the base material B in a vacuum environment. The inside of the vacuum chamber 10 containing the base material B is maintained at a predetermined degree of vacuum by the vacuum exhaust device 20, and in this vacuum environment, the film forming processing on the surface of the base material B is performed by the film forming processing device 30. . The film forming apparatus 30 is an apparatus that performs a film forming process by causing predetermined plasma particles to act on the surface of the base material B. Specifically, sputtering (magnetron sputtering (DC sputtering, high frequency sputtering, etc.)) ), An apparatus having a function of forming a film by a method such as plasma CVD, ion plating, plasma discharge, glow discharge, or the like. Since an apparatus having such a function is already known, a detailed description of the apparatus configuration is omitted here. In addition, the transport device 60 is a device having a function of transporting the base material B to a position suitable for the film forming process by the film forming apparatus 30.
[0012]
On the other hand, the light irradiation device 41, the spectroscopic analysis device 42, and the film formation control device 50 are characteristic components of the vacuum film formation device according to the present invention. That is, the light irradiation device 41 has a function of irradiating light in the vicinity of the plasma particles generated by the film formation processing device 30 and causing the plasma gas particles to emit light. Has a function of observing the emission spectrum. In addition, the film formation control device 50 has a function of controlling the film formation conditions of the film formation processing device 30 based on the emission spectrum observed by the spectroscopic analysis device 42. As already described, in a general vacuum film forming apparatus, degassing is released from the base material B in the film forming process, which causes an obstacle to optimum film forming conditions. This is because it is difficult to predict the amount of degassing that actually occurs.
[0013]
In the apparatus according to the present invention, light is irradiated into the vacuum chamber 10 by the light irradiation device 41, and an emission spectrum from the plasma-like gas particles that have received this light irradiation is observed by the spectroscopic analysis device 42. Information on the degassing generated in 10 can be obtained based on this emission spectrum, and the amount of degassing generated can be detected in real time during the film forming process. In addition, the detection result of the degassing is immediately given to the film formation control device 50. The film formation control device 50 can control the film formation conditions of the film formation processing device 30 based on the detection result. In other words, since the film forming process executed by the film forming processing apparatus 30 is a process reflecting the degassing detection result given in real time, how much degassing occurs from the base material B, the transfer device 60, and the like. Even if it does, it becomes possible to perform the film-forming process on the optimal film-forming conditions in consideration of the actual degassing amount.
[0014]
In the apparatus shown in FIG. 1, as described above, the plasma particles generated by the film forming apparatus 30 adhere to the surface of the base material B, and film formation is performed. Therefore, a plasma space in which a large number of plasma particles are present is formed between the film forming apparatus 30 and the base material B. For this reason, the gas particles existing in the plasma space are also turned into plasma and are in an excited state. When the light beam L is irradiated from the light irradiation device 41 to the gas particles converted into plasma in this way, each gas particle emits light with a specific emission wavelength. Therefore, if the emission spectrum of the gas particles is observed, the gas particles can be specified based on the peak wavelength, and the amount of the gas particles can be specified based on the spectrum intensity at the peak position. In the example shown in FIG. 1, since the spectroscopic analyzer 42 receives the light beam L from the light irradiation device 41 as it is, the spectrum obtained is the light source spectrum of the light irradiation device 41 and the emission of gas particles. It is a superposition of the spectrum. However, since a white light source is used as the light source of the light irradiation device 41, the spectrum of the light source is a gentle spectrum over the entire wavelength range, whereas the emission spectrum of the gas particles is steep near the specific emission wavelength. The spectrum has a peak. For this reason, if attention is paid to the peak in the spectrum observed by the spectroscopic analyzer 42, the type and amount of the gas particles can be recognized.
[0015]
In general, when a long plastic film or the like is used as the base material B, the influence of degassing is significant. This is because various degasses are directly emitted from the organic component of the plastic, and various degasses are also emitted by the interaction between the transport system such as the delivery roll and the take-up roll and the substrate B. FIG. 2 is a configuration diagram showing a specific example of a vacuum film forming apparatus for forming a film on the surface of such a long plastic film (a part is shown in a block diagram). The vacuum chamber 100 is separated into a lower film formation zone 101 and an upper transfer zone 102 by a partition 110, and both zones are exhausted by a vacuum exhaust device 120 and maintained at a predetermined degree of vacuum.
[0016]
A sputtering apparatus 130 is provided in the film formation zone 101, and a film forming process gas (in this example, argon and oxygen) is introduced by a predetermined amount via a flow rate control apparatus 135. The sputtering apparatus 130 and the flow rate control apparatus 135 function as a film forming apparatus in the present invention. In addition, as described above, the light irradiation device 141 is a device that irradiates the light beam L (in this example, a beam having a diameter of about 10 mm) using a white light source. The light beam L emitted from the light irradiation device 141 is irradiated to the inside of the vacuum chamber 100 through the quartz window 103 provided on the wall surface of the vacuum chamber 100 and passes through the quartz window 104 provided on the opposite wall surface. The light is received by the spectroscopic analyzer 142. At this time, plasma emission from degassing particles generated in the film formation zone 101 (which is in a plasma state in the plasma space generated by the sputtering apparatus 130) is generated, and light generated by the plasma emission is also generated by the spectroscopic analysis apparatus 142. Light will be received. As a result, in the spectrum observed by the spectroscopic analyzer 142, a peak appears at the emission wavelength position unique to the degassed particles. Information regarding such spectral peaks is given to the film formation control device 150. The film formation control device 150 has a function of controlling the sputtering device 130 and the flow rate control device 135 based on information on the spectrum peak, in other words, information on observed degassing.
[0017]
On the other hand, various members functioning as a transport device are installed in the transport zone 102. First, the delivery roll 161 is a member that winds and holds a long base material B made of a film in a roll shape, and the base material B sent out from the delivery roll 161 is transport members 162, 163, and 163. The base material B which has been transported to a position suitable for the film forming process through 164 and completed the film forming process is wound up in a roll shape by a winding roll 165. The transport drum 163 is a large drum-shaped member, and the film-like base material B in contact with the peripheral surface thereof is transported to a position directly above the sputtering apparatus 130, and at this position, from the sputtering apparatus 130. The released plasma-like sputtered material (film forming material) adheres to the surface of the substrate B to form a film. The base material B on which film formation has been completed in this way is taken up by the take-up roll 165. The conveyance members 162 and 164 function as guide rollers before and after the conveyance drum 163. A slight gap is formed between the transfer drum 163 and the partition wall 110, and the base material B is transferred from the transfer zone 102 to the film formation zone 101 through the gap, and again from the film formation zone 101 to the transfer zone. To 102.
[0018]
In such a system, outgassing is expected at various points. Specifically, at the stage where the film-like substrate B is delivered from the delivery roll 161, both surfaces of the film come into contact with the vacuum atmosphere, and thus degassing occurs from the substrate B itself. Further, degassing occurs when the film-like base material B comes into contact with the conveying member 162 (guide roller) or the conveying drum 163. Further, degassing occurs when heat generated by the sputtering process by the sputtering apparatus 130 is applied to the base material B, and degassing also occurs during winding by the winding roll 165. Such degassing can be detected based on the spectrum observed by the spectroscopic analyzer 142 as described above. In FIG. 2, the light beam L from the light irradiation device 141 is irradiated to the vicinity of the outer peripheral portion of the transport drum 163. This is because more accurate film formation control can be performed.
[0019]
In the apparatus according to the embodiment shown here, attention is paid particularly to oxygen as degassing, and control is performed so that optimum film forming conditions can be obtained even when oxygen is generated as degassing. Yes. In general, the main component of degassing generated from a film-like substrate is water, and oxygen is generated when this water is plasma-decomposed. Therefore, in the case of handling a film-like substrate, film formation control focusing on oxygen is very effective. As described above, argon and oxygen are introduced into the film formation zone 101 via the flow rate control device 135. These introduced gases are intentionally introduced as film forming gas and are necessary for the film forming process by the sputtering apparatus 130. Here, in order to perform film formation under optimum conditions, it is necessary to control the amount of introduced gas to an optimal value, and it is particularly necessary to perform film formation while maintaining the amount of oxygen at a predetermined value. However, even if the oxygen flow rate by the flow control device 135 is set to a predetermined value, when oxygen is released from the base material B as degassing, excess oxygen is supplied into the vacuum chamber 100, and oxygen is discharged. The optimum condition regarding the quantity is not maintained.
[0020]
Therefore, the film formation control device 150 controls the amount of oxygen introduced via the flow rate control device 135 so that the amount of oxygen detected from the observation spectrum by the spectroscopic analysis device 142 is kept constant. When light is applied to the oxygenated gas, light emission having several peak wavelengths occurs. Here, a peak wavelength of 777 nm is used as the representative emission wavelength. That is, in the spectrum observed by the spectroscopic analyzer 142, the peak existing in the wavelength region near the representative emission wavelength of 777 nm is considered to be the peak caused by emission from oxygen gas, and the spectrum intensity (peak) of this peak is considered. Is treated as a value indicating the concentration of oxygen gas. When oxygen is released from the base material B as degassing and the oxygen in the vacuum chamber 100 becomes excessive, the spectral intensity of a peak existing in the wavelength region near this representative emission wavelength of 777 nm increases. As described above, when excess oxygen is detected, the film formation control device 150 performs control to give an instruction to the flow control device 135 to reduce the amount of oxygen introduced so as to reduce the oxygen in the chamber. It will be. By such feedback control, the amount of oxygen in the chamber can always be maintained at a constant amount (optimal value for film formation).
[0021]
In practice, it is difficult to accurately detect the absolute amount of oxygen, so the amount of two kinds of gases introduced as the film forming gas, that is, both the amount of argon gas and the amount of oxygen gas are detected. The amount of oxygen introduced is controlled so that these ratios are constant. Since argon is not generated as degassing, if the amount of argon introduced is always kept constant, the absolute amount of oxygen can be kept constant simply by controlling the amount of oxygen relative to argon to be constant. Can be maintained. Specifically, since the typical emission wavelength of argon gas is known to be 812 nm, the spectral intensity (oxygen gas) of the peak existing in the wavelength region near 777 nm in the observation spectrum obtained by the spectroscopic analyzer 142 is known. And the amount of oxygen introduced may be controlled so that the ratio of the peak spectral intensity (corresponding to the concentration of argon gas) existing in the wavelength region near 812 nm is constant.
[0022]
Thus, in the vacuum film forming apparatus according to the present invention, the type and amount of degas actually generated in the chamber can be evaluated, and this evaluation result is based on the development of a substrate suitable for various vacuum processes, It can also be used in fields such as examination of laminated structures and design of vacuum process equipment. Moreover, since the degassing species in each process can be recognized, it is possible to investigate the influence of this degassing on the treatment process. In the embodiment of FIG. 2, an example in which film formation is performed on a base material made of a long plastic film is described. However, the base material used in the vacuum film formation apparatus according to the present invention is a metal plate or glass. Any material such as a plate, metal film or paper may be used. Further, it is sufficient that the spectrum to be observed by the spectroscopic analyzer 142 includes a wavelength range necessary for control. For example, in the above-described example, it is only necessary to obtain a peak value of oxygen gas with a typical emission wavelength of 777 nm and a peak value of argon gas with a typical emission wavelength of 812 nm. Therefore, the spectrum observed by the spectroscopic analyzer in this specification is not necessarily a continuous spectrum.
[0023]
The vacuum film forming apparatus according to the present invention has been described above based on the illustrated embodiment. However, the present invention is not limited to this embodiment, and can be implemented in various other forms. For example, in the above-described embodiment, an example in which the present invention is applied to an apparatus for forming a film by causing plasma particles to act on the surface of the base material has been shown. However, the present invention acts on ions, radicals, and other active species. The present invention can also be applied to an apparatus for forming a film. The technical idea of the present invention is to monitor the occurrence of degassing based on the emission spectrum from the degassed particles in an excited state and feedback control the film forming conditions based on the result. Therefore, the present invention can be widely applied to an apparatus for performing a film forming process by causing some excited state particles to act on the surface of the base material. Moreover, in the above-mentioned embodiment, although light irradiation with respect to a degassing particle is performed using a light irradiation apparatus, this light irradiation apparatus is not necessarily an essential component for this invention. This light irradiation functions to efficiently excite the degassed particles. However, sufficient information on the emission spectrum necessary for film formation control is obtained from the degassed particles excited by the action of the film forming apparatus. If possible, the present invention can be implemented without performing light irradiation.
[0024]
【Example】
A commercially available PET film (manufactured by Toray Industries, Inc .: Lumirror T60, roll-shaped having a thickness of 100 μm and a width of 300 mm) is mounted as a delivery roll 161 using the vacuum film forming apparatus shown in FIG. Conveyed. At the same time, a sputtering process by a DC magnetron sputtering method was performed by the sputtering apparatus 130 (input power 3 kW, film formation pressure 3 mTorr), and a low-resistance ITO film was formed on the PET film. At this time, argon gas was introduced as a film forming treatment gas at a fixed flow rate of 100 sccm, and oxygen gas was introduced at a predetermined flow rate. The amount of oxygen gas introduced is such that the spectral intensity of the representative emission wavelength of 777 nm of oxygen gas in the spectrum observed by the spectroscopic analyzer 142 is maintained at 1.4 times the spectral intensity of the representative emission wavelength of 812 nm of argon gas. Feedback control by the membrane controller 150 (control of the amount of oxygen introduced by the flow controller 135) was performed.
[0025]
Thus, the formed sample was taken out into the atmosphere, sampled, and sheet resistance was measured using a four-terminal method (manufactured by Mitsubishi Chemical Corporation: LORESTA). Specifically, for a section having an effective film formation length of 100 m, 10 measurement points are defined at intervals of 10 m on a center line (position 150 mm from the side edge of the film) extending in the longitudinal direction of the film. The resistance value at the measurement point was measured. The result of repeating such measurement three times is shown in the table of FIG. It can be seen that the variation in measured values between the measurement points is quite small, and a substantially uniform high-quality ITO film is formed on the entire surface.
[0026]
On the other hand, without performing feedback control by the film formation control device 150, the oxygen introduction amount of the flow rate control device 135 is fixed to 2.5 sccm, film formation is performed in the same manner, and the measurement results are shown in the table of FIG. Shown in Compared with the table shown in FIG. 3, it can be seen that the variation in the measured values between the respective measurement points is large, and the formed ITO film is non-uniform. This is thought to be because oxygen released as degassing from the PET film destabilized the film formation conditions. From the above results, it can be seen that the present invention is sufficiently effective in maintaining the film forming conditions optimally.
[0027]
【The invention's effect】
As described above, according to the vacuum film forming apparatus of the present invention, the degassing in the vacuum chamber is detected and the film forming conditions are controlled. Therefore, the film forming process is performed under the optimum conditions even under the influence of the degassing. It becomes possible to do.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a basic configuration of a vacuum film forming apparatus according to the present invention.
FIG. 2 is a configuration diagram (partially a block diagram) showing a specific example of a vacuum film forming apparatus for forming a film on the surface of a long substrate.
FIG. 3 is a chart showing film uniformity when an ITO film is formed while feedback control is performed by a vacuum film forming apparatus according to the present invention.
FIG. 4 is a chart showing film uniformity when an ITO film is formed without performing feedback control by the vacuum film forming apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Vacuum chamber 20 ... Vacuum exhaust apparatus 30 ... Film formation processing apparatus 41 ... Light irradiation apparatus 42 ... Spectroscopic analysis apparatus 50 ... Film formation control apparatus 60 ... Transfer apparatus 100 ... Vacuum chamber 101 ... Film formation zone 102 ... Transfer zone 103, 104 ... Quartz window 110 ... Partition 120 ... Vacuum exhaust device 130 ... Sputtering device 135 ... Flow rate control device 141 ... Light irradiation device 142 ... Spectroscopic analysis device 150 ... Film formation control device 161 ... Delivery roll 162 ... Conveying member (guide roll)
163 ... Conveying drum 164 ... Conveying member (guide roll)
165 ... Winding roll B ... Base material L ... Light beam

Claims (2)

A vacuum film forming apparatus for forming a film on the surface of a long substrate in a vacuum environment,
A vacuum chamber for containing the substrate;
An evacuation device that maintains a predetermined degree of vacuum in the vacuum chamber;
In order to perform a film forming process by causing particles in an excited state to act on the surface of the base material, a first gas that is supplied also as degassing and a second gas that is not supplied as degassing A film forming apparatus for forming a film while introducing it into the vacuum chamber as a film forming gas ;
A delivery roll that winds and holds the substrate in a roll shape, a transport drum that transports the substrate delivered from the delivery roll to a position suitable for the film formation process, and a substrate that has completed the film formation process. A take-up roll wound up into a roll, and a transport device having
A light irradiation device for irradiating light particles from a white light source to gas particles in the vicinity of the outer periphery of the transport drum;
A spectroscopic analyzer that receives white light from the light irradiation device together with light emitted from gas particles excited by the action of the film forming processing apparatus and irradiated with the white light, and observes its spectrum; ,
The spectrum intensity of the first gas near the representative emission wavelength of the first gas and the spectrum intensity of the second gas near the representative emission wavelength of the second gas in the spectrum observed by the spectroscopic analyzer A film formation control apparatus that determines the ratio of the first gas, maintains the introduction amount of the second gas constant, and controls the introduction amount of the first gas so that the ratio is constant;
A vacuum film forming apparatus comprising: In the vacuum film-forming apparatus according to claim 1,
A vacuum film forming apparatus, wherein the film forming apparatus introduces oxygen as a first gas and argon as a second gas.

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