JP2009275251A - Film deposition apparatus and film deposition method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film deposition apparatus and a film deposition method capable of depositing a continuous film on a long substrate while maintaining the productivity, and suppressing any abnormal discharge. <P>SOLUTION: The film deposition apparatus deposits a predetermined film on a surface of a substrate by executing the sputtering while conveying a long substrate in the predetermined conveying direction in a film deposition chamber. The film deposition apparatus comprises: an evacuation unit for evacuating the inside of the film deposition chamber into the predetermined degree of vacuum; a plurality of metal targets arranged along the conveying direction; a first power supply unit for applying the negative voltage to each metal target; a second power supply unit for applying the positive voltage to the metal target arranged on the most upstream side in the conveying direction; a sputtering gas feed unit for feeding sputtering gas between a surface of the substrate and each metal target; and a control unit which applies the negative voltage to each metal target for the predetermined time at the predetermined time interval during the film deposition, and applies the positive voltage when any negative voltage is not applied to the metal target arranged on the most upstream side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a film forming apparatus and a film forming method for forming a predetermined film on the surface of a substrate by performing sputtering while transporting a long substrate in a predetermined transport direction, and in particular, maintaining film forming productivity. However, the present invention relates to a film forming apparatus and a film forming method capable of suppressing abnormal discharge.

Currently, when a metal film is formed on the surface of a substrate, a metal target having a composition of the metal film to be formed is used in a vacuum chamber, and a magnet is disposed on the back surface of the metal target.
Further, argon gas (Ar gas) is introduced into the vacuum chamber, an AC voltage is applied to the metal target for discharge, and the ionized argon gas collides with the surface of the metal target to eject metal atoms from the metal target. A method called a magnetron sputtering method is used in which is deposited on the surface of a substrate.

When forming a metal compound film, a method called reactive sputtering is used in which a metal atom is reacted with a reactive gas to obtain a compound to form a metal compound film.
Even in this case, a metal target having a metal composition constituting the metal compound film is used, and a magnet is disposed on the back surface of the metal target. Then, in order to obtain the composition of the metal compound film, an atmosphere containing a reactive gas, for example, an oxygen atmosphere when forming an oxide, an nitrogen atmosphere when forming an oxide, and a vacuum chamber are used. do.
Furthermore, argon gas (Ar gas) is introduced into the vacuum chamber, an AC voltage is applied to the metal target for discharge, and the ionized argon gas collides with the surface of the metal target to eject metal atoms. This is reacted with a reaction gas to obtain a compound, thereby forming a metal compound film.

In the sputtering method, a phenomenon called abnormal discharge occurs during sputtering. Hereinafter, the abnormal discharge will be described.
In magnetron sputtering, a negative potential is applied to a metal target. Of the metal target, a portion having a high magnetic field strength is strongly sputtered, and the portion is deeply cut and erosion is formed.
When the sputtered particles fly to the non-erosion part due to scattering or the like, and a reactive gas such as oxygen gas or nitrogen gas is taken into this, an oxide film or a nitride film is formed as a high resistance film. . During sputtering, when Ar cations collide with the surface of a high-resistance film (oxide film or nitride film), electrons are extracted and secondary electrons are emitted.

On the other hand, since a negative potential is applied to the metal target, a repulsive force acts on the electrons flying due to the scattering, thereby preventing the incident on the metal target. As a result, electrons are emitted from the high-resistance film (oxide film or nitride film), and the film is positively charged.
When the difference between the applied voltage and the positive potential of the coating becomes greater than a certain level, dielectric breakdown occurs. This causes abnormal discharge.

Abnormal discharge often occurs when the metal constituting the metal target has a relatively low resistance and the film (oxide film or nitride film) generated on the surface has a high resistance.
When abnormal discharge occurs, the film quality changes, or pinholes are generated in the film, causing the characteristics of the film to be significantly impaired. Therefore, a method for suppressing the occurrence of abnormal discharge has been proposed (see Patent Document 1).

The barrier film forming method disclosed in Patent Document 1 uses a dual magnetron sputtering method in which a negative voltage is alternately and intermittently applied to each target at a constant period (several tens to several hundreds of times / second). is there. Usually, two targets are set as one set.
In Patent Document 1, the applied side of the two targets is a negative potential, and the non-applied side is a ground potential. This is periodically switched between the two targets. During non-application, the positively charged film portion can attract electrons in the plasma and neutralize the charge-up.
Patent Document 1 describes that the effect of neutralizing a positive potential can be further improved by applying a positive potential during a time when a negative potential is not applied.

JP 2004-137531 A

However, when the barrier film formation method of Patent Document 1 is applied to film formation while transporting a substrate made of an organic substance or a substrate on which an organic layer is formed, the abnormality increases as the input power is increased. There is a problem that the frequency of occurrence of discharge increases.
For this reason, in patent document 1, when the board | substrate comprised by the organic substance or the board | substrate with which the organic layer was formed is used, a favorable film | membrane cannot be formed efficiently.

  The object of the present invention is to eliminate the problems based on the prior art and produce a continuous film formation on a long substrate, particularly a substrate composed of an organic substance or a substrate on which an organic layer is formed. An object of the present invention is to provide a film forming apparatus and a film forming method capable of suppressing abnormal discharge while maintaining the properties.

  In order to achieve the above object, according to a first aspect of the present invention, a long film is transported in a predetermined transport direction in a film forming chamber, and sputtering is performed to form a predetermined film on the surface of the substrate. A film apparatus, a vacuum evacuation unit for setting the inside of the film forming chamber to a predetermined degree of vacuum, a plurality of metal targets opposed to the surface of the substrate and arranged along the transport direction, and the metal targets A first power supply unit that applies a negative voltage to the first power supply unit, a second power supply unit that applies a positive voltage to a metal target arranged on the most upstream side in the transport direction among the metal targets, A sputtering gas supply unit that supplies a sputtering gas between a surface and each metal target, and a negative voltage is applied to each metal target at predetermined time intervals by the first power supply unit during film formation. Together with the above When a negative voltage is not applied from the first power supply unit to the metal target disposed on the flow side, the positive voltage is applied to the metal target disposed on the most upstream side by the second power supply unit. And a control unit that controls the film formation.

In the present invention, it is preferable that a reactive gas supply unit that supplies a reactive gas is further provided between the surface of the substrate and each of the metal targets, and the reactive gas is supplied during the film formation.
In the present invention, each metal target is preferably provided with a magnet.

Furthermore, in the present invention, the film is, for example, a gas barrier film.
In the present invention, the gas barrier film is, for example, an aluminum oxide film.
In the present invention, the first power supply unit is, for example, a pulse power supply or a high-frequency power supply.

  The second aspect of the present invention is a film forming method for forming a predetermined film on the surface of a substrate by performing sputtering while transporting a long substrate in a predetermined transport direction so as to face a plurality of metal targets. A step of supplying a sputtering gas between the substrate and each metal target; and applying a negative voltage to each metal target at a predetermined time interval for a predetermined time, and being disposed on the most upstream side. And a step of applying the positive voltage to the metal target disposed on the most upstream side when a negative voltage is not applied to the metal target.

In the present invention, in the step of supplying a sputtering gas between the substrate and the metal targets, it is preferable to supply a reactive gas between the surface of the substrate and the metal targets.
Moreover, in this invention, when applying a negative voltage to each said metal target, it is preferable that the average value of the power density in each metal target is 5.9 kW / cm < ² > or more.
Furthermore, in the present invention, the film is, for example, a gas barrier film.
Furthermore, in the present invention, the gas barrier film is, for example, an aluminum oxide film.

  A third aspect of the present invention is a film forming apparatus for forming a predetermined film on the surface of a substrate by performing sputtering while transferring a long substrate in a predetermined transfer direction in a film forming chamber. A first transport unit that transports a long substrate in the transport path, and a rotation shaft that is provided in the film forming chamber and has a rotation axis in a direction orthogonal to the transport direction of the substrate, is transported by the first transport unit. A rotatable drum on which a substrate is wound around a predetermined region of the surface, a second transport means for transporting the substrate wound on the drum in a predetermined transport path, and a predetermined interior of the film forming chamber A vacuum evacuation unit having a degree of vacuum, a plurality of metal targets opposed to the surface of the drum and disposed along a rotation direction of the drum, and a first voltage applying a negative voltage to each metal target Of the power supply and the metal target, the A second power supply unit that applies a positive voltage to a metal target disposed on the most upstream side in the feed direction, a sputtering gas supply unit that supplies a sputtering gas between the surface of the substrate and each of the metal targets, At the time of film formation, the first power supply unit applies a negative voltage to the metal targets at predetermined time intervals for a predetermined time, and the metal target disposed on the most upstream side is negatively applied from the first power supply unit. And a control unit that applies the positive voltage to the metal target disposed on the most upstream side by the second power supply unit when the voltage of 2 is not applied. Is.

  According to the film forming apparatus and the film forming method of the present invention, productivity can be maintained by forming a continuous film on a long substrate, particularly a substrate made of an organic material or a substrate on which an organic layer is formed. However, abnormal discharge can be suppressed.

Hereinafter, a film forming apparatus and a film forming method of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
FIG. 1 is a schematic view showing a film forming apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic view showing a main part of a film forming unit of the film forming apparatus shown in FIG.

A film forming apparatus 10 according to the embodiment of the present invention shown in FIG. 1 is a roll to roll type film forming apparatus, and an organic layer is formed on the surface Zf of the substrate Z or the surface Zf of the substrate Z. Is formed, a film having a predetermined function is formed on the surface thereof. For example, the film is used for manufacturing a functional film F such as an optical film or a gas barrier film.
The film forming apparatus 10 is an apparatus that continuously forms a film on a long substrate Z (web-like substrate Z), and basically includes a supply chamber 12 for supplying the long substrate Z, A film forming chamber 14 for forming a film on the substrate Z, a winding chamber 16 for winding the long substrate Z on which the film is formed, a vacuum exhaust unit 32, and a control unit 36 are provided. The operation of each element in the film forming apparatus 10 is controlled by the control unit 36.
In the film forming apparatus 10, the wall 15 a that partitions the supply chamber 12 and the film forming chamber 14 and the wall 15 b that partitions the film forming chamber 14 and the winding chamber 16 are slit-shaped through which the substrate Z passes. The opening 15c is formed.

In the film forming apparatus 10, a vacuum exhaust unit 32 is connected to the supply chamber 12, the film forming chamber 14, and the winding chamber 16 through a pipe 34. The inside of the supply chamber 12, the film formation chamber 14, and the winding chamber 16 is set to a predetermined degree of vacuum by the vacuum exhaust unit 32.
The evacuation unit 32 evacuates the supply chamber 12, the film formation chamber 14, and the take-up chamber 16 to maintain a predetermined degree of vacuum, and includes a vacuum pump such as a dry pump and a turbo molecular pump. The supply chamber 12, the film formation chamber 14, and the winding chamber 16 are each provided with a pressure sensor (not shown) for measuring the internal pressure.
In addition, there is no limitation in the ultimate vacuum degree of the supply chamber 12, the film formation chamber 14, and the winding chamber 16 by the vacuum exhaust part 32, and it should just maintain sufficient vacuum degree according to the film-forming method etc. to implement. . The evacuation unit 32 is controlled by the control unit 36.

The supply chamber 12 is a part that supplies a long substrate Z, and is provided with a substrate roll 20 and a guide roller 21.
The substrate roll 20 continuously feeds out a long substrate Z. For example, the substrate Z is wound counterclockwise.
For example, a motor (not shown) is connected to the substrate roll 20 as a drive source. By this motor, the substrate roll 20 is rotated in the direction r to rewind the substrate Z. In this embodiment, the substrate roll 20 is rotated clockwise and the substrate Z is continuously fed out.

The guide roller 21 guides the substrate Z to the film forming chamber 14 through a predetermined transport path. The guide roller 21 is a known guide roller.
In the film forming apparatus 10 of the present embodiment, the guide roller 21 may be a driving roller or a driven roller. Further, the guide roller 21 may be a roller that acts as a tension roller that adjusts the tension when the substrate Z is transported.

In the film forming apparatus of the present invention, the substrate Z is not particularly limited, and any of various substrates capable of forming a film by reactive sputtering can be used. As the substrate Z, for example, various resin films such as a PET film and a PEN film, or various metal sheets such as an aluminum sheet can be used.
The film forming apparatus of the present invention is particularly effective for forming a film on a substrate on which a resin film containing an organic substance and an organic layer are formed as a substrate.

  As will be described later, the take-up chamber 16 is a portion in which the substrate Z having a film formed on the surface Zf is taken up in the film formation chamber 14, and is provided with a take-up roll 30 and a guide roller 31.

The winding roll 30 is for winding the film-formed substrate Z in a roll shape, for example, clockwise.
For example, a motor (not shown) is connected to the winding roll 30 as a drive source. The take-up roll 30 is rotated by this motor, and the film-formed substrate Z is taken up.
The take-up roll 30 is rotated in the direction R for taking up the substrate Z by a motor. In this embodiment, the take-up roll 30 is rotated clockwise to continuously wind the film-formed substrate Z, for example, clockwise. take.

  The guide roller 31 guides the substrate Z transported from the film forming chamber 14 to the take-up roll 30 through a predetermined transport path. The guide roller 31 is a known guide roller. Similar to the guide roller 21 in the supply chamber 12, the guide roller 31 may be a driving roller or a driven roller. The guide roller 31 may be a roller that acts as a tension roller.

The film forming chamber 14 functions as a vacuum chamber, and is a part for continuously forming a compound film on the surface Zf of the substrate Z by, for example, reactive sputtering while transporting the substrate Z.
The film forming chamber 14 is configured by using materials used in various vacuum chambers such as stainless steel, aluminum, or aluminum alloy.

In the film forming chamber 14, two guide rollers 24 and 28, a drum 26, and a film forming unit 40 are provided.
The guide roller 24 and the guide roller 28 are arranged in parallel so as to face each other at a predetermined interval. The guide roller 24 and the guide roller 28 are arranged with respect to the transport direction D of the substrate Z. The longitudinal directions are arranged orthogonally.

The guide roller 24 transports the substrate Z transported from the guide roller 21 provided in the supply chamber 12 to the drum 26. For example, the guide roller 24 has a rotation shaft in a direction (hereinafter referred to as an axial direction) orthogonal to the conveyance direction D of the substrate Z and is rotatable, and the guide roller 24 has a length in the axial direction. It is longer than the length in the width direction orthogonal to the longitudinal direction of Z (hereinafter referred to as the width of the substrate Z).
The substrate roll 20, the guide roller 21, and the guide roller 24 constitute a first transport unit.

The guide roller 28 conveys the substrate Z wound around the drum 26 to a guide roller 31 provided in the winding chamber 16. For example, the guide roller 28 has a rotation shaft in the axial direction and is rotatable, and the guide roller 28 has an axial length longer than the width of the substrate Z.
The guide roller 28, the guide roller 31, and the take-up roll 30 constitute a second transport unit.
Since the guide roller 24 and the guide roller 28 have the same configuration as the guide roller 21 provided in the supply chamber 12 except for the above configuration, detailed description thereof will be omitted.

The drum 26 is provided below the space H between the guide roller 24 and the guide roller 28. The drum 26 is arranged with its longitudinal direction parallel to the longitudinal directions of the guide roller 24 and the guide roller 28.
The drum 26 has, for example, a cylindrical shape, has a rotating shaft in the axial direction, and can rotate in the rotating direction ω. The length of the drum 26 in the axial direction is longer than the width of the substrate Z.
In the drum 26, the substrate Z is wound around the surface 26a (circumferential surface) and rotated in the rotational direction ω, so that the substrate Z is transported in the transport direction D while being held at a predetermined film formation position. To do.
Note that the traveling direction side of the rotation direction ω of the drum 26, that is, the side on which the substrate Z is transported is the downstream side Dd, and the opposite side of the downstream side Dd is the upstream side Du.

  As shown in FIG. 1, the film forming unit 40 includes a surface Zf of the substrate Z wound around the surface 26 a of the drum 26 while the drum 26 rotates in the rotation direction ω and transports the substrate Z in the transport direction D. A film is formed.

  The film forming unit 40 includes discharge units 42a to 42d, pulse power sources (first power source units) 44a and 44b, a DC power source (second power source unit) 46, detectors 47a and 47b, a sputter gas supply unit 48, a reaction A gas supply unit 49 is provided. The control unit 36 controls the pulse power sources 44 a and 44 b, the direct current power source (DC power source) 46, the sputtering gas supply unit 48, and the reactive gas supply unit 49 of the film forming unit 40.

In the film forming unit 40, the discharge units 42 a to 42 d are disposed along the downstream Dd from the upstream Du side in the rotational direction ω with a gap S of a predetermined distance from the surface 26 a of the drum 26. Yes.
In the film forming apparatus 10, a gap S between the surface 26 a of the drum 26 and the discharge units 42 a to 42 d becomes a space for generating plasma P.
The discharge units 42 a to 42 d are formed in a rectangular shape in plan view, and are arranged such that the longitudinal direction thereof coincides with the axial direction of the drum 26. The discharge units 42 a to 42 d are longer than the length in the width direction of the substrate Z wound around the drum 26.

The discharge units 42a to 42d have basically the same configuration, and the DC power source 46 is connected only to the discharge unit 42a.
Hereinafter, the discharge unit 42a will be described as an example with reference to FIG.
As shown in FIG. 2, the discharge unit 42 a includes an electrode plate 50, a metal target 52, and a magnet 54. A target 52 is provided on the front surface 50a of the electrode plate 50, and a magnet 54 is disposed on the back surface 50b.

  The electrode plate 50 applies a predetermined voltage to the metal target 52 from the pulse power sources 44 a and 44 b or the DC power source 46, and also serves as a target folder that holds the metal target 52. For example, a metal target 52 is fixed to the electrode plate 50 with a bolt or the like.

The metal target 52 is a raw material for the film to be formed, and is formed of a metal corresponding to the composition of the film formed on the surface Zf of the substrate Z. For example, when forming an Al ₂ O ₃ film, aluminum (Al) is used for the metal target 52. Further, when forming a SiO ₂ film or a SiN film, silicon (Si) is used for the metal target 52. This metal target 52 is a general one used for sputtering.

The magnet 54 is provided to maintain plasma discharge at a high density, and generates a certain magnetic force on the surface 52 a of the metal target 52. For example, three magnets 54 are arranged in parallel on the back surface 50b side of the electrode plate 50 with a gap therebetween. As the magnet 54, a magnet used in a known magnetron sputtering apparatus is used.
On the surface 52 a of the metal target 52. A region that matches between the magnets 54 is an erosion region.

  In the film forming unit 40, a discharge unit 42a and a discharge unit 42b are assembled, and a pulse power supply 44a is connected to the electrode plate 50 of the discharge unit 42a and the electrode plate 50 of the discharge unit 42b. Moreover, the discharge unit 42c and the discharge unit 42d are assembled, and the pulse power source 44b is connected to the electrode plate 50 of the discharge unit 42c and the electrode plate 50 of the discharge unit 42d. The film forming unit 40 has a so-called dual magnetron sputtering configuration.

The pulse power supplies 44a and 44b have a function of periodically generating a voltage in a rectangular wave shape and adjusting a voltage value and a voltage generation time. By the pulse power sources 44a and 44b, for example, a negative voltage of −V can be applied to each metal target 52 through the electrode plate 50 at predetermined time intervals for a predetermined time. In this manner, the pulse power supplies 44 a and 44 b can apply a predetermined negative voltage to one metal target 52 for a predetermined time and apply to the other metal target 52 for a predetermined time in one cycle.
For example, a pulse power source used in a known DC pulse sputtering apparatus or a known dual magnetron sputtering apparatus is used as the pulse power supplies 44a and 44b.

By applying a negative voltage (-V) alternately to the discharge unit 42a and the discharge unit 42b at predetermined time intervals for a predetermined time by the pulse power supply 44a, the adjacent discharge units 42a and 42b are alternately connected to the cathode. Acts as an anode.
The pulse power supply 44b also applies the negative voltage (−V) to the discharge unit 42c and the discharge unit 42d alternately at a predetermined time interval for a predetermined time, whereby the adjacent discharge units 42c and 42d are alternately connected. Acts as a cathode and an anode.
Moreover, it is not limited to pulse power supply 44a, 44b, For example, the high frequency power supply utilized with the well-known RF sputtering apparatus can also be used.

The DC power supply 46 has a function of generating a DC voltage or a DC pulse voltage (DC pulse voltage) and a function of adjusting a voltage value and a voltage generation time.
The DC power supply 46 applies a predetermined voltage to the metal target 52 of the discharge unit 42a disposed on the most upstream side for a predetermined time. As the DC power source 46, for example, various power sources used in a known DC sputtering apparatus or DC pulse sputtering apparatus can be used.

In the film forming apparatus 10 of this embodiment, pulse power sources 44a and 44b and a DC power source 46 are provided in the film forming unit 40, and the applied voltage pattern applied during film formation is as follows.
In the combination with the discharge units 42c and 42d, the pulse power supply 44b, for example, in one cycle T, the duty ratio is 100% and the applied voltage −V is in the form of a rectangular wave, so that the discharge units 42c and 42d (cathode (electrode plate 50, Applied alternately to the metal target 52)).

The pattern of the applied voltage in the set of the discharge unit 42a and the discharge unit 42b positioned at the most upstream will be described with reference to FIG.
As shown in FIG. 3, a negative voltage (−V) is first applied to the discharge unit 42 a for a time ta within one period T, and then a negative voltage (− V) is applied for a time tb. The time ta and the time tb are the same and are applied to any discharge unit 42a (cathode (electrode plate 50, metal target 52)) and discharge unit 42b (cathode (electrode plate 50, metal target 52)). Have no time, ie, 100% duty cycle.
In the present embodiment, when the negative voltage −V is applied to the discharge unit 42b, that is, when the negative voltage −V is not applied to the discharge unit 42a, as shown in the pattern 64, for example, the time δ is applied a positive voltage V _D.
In FIG. 3, reference numeral 60 indicates an applied voltage pattern of the discharge unit 42a (electrode plate 50, metal target 52), and reference numeral 62 indicates an applied voltage pattern of the discharge unit 42b (electrode plate 50, metal target 52). Indicates.
The negative voltage application to the discharge units 42c and 42d by the pulse power supply 44b, the negative voltage application to the discharge units 42a and 42b by the pulse power supply 44a, and the positive voltage application to the discharge unit 42a by the DC power supply 46 are 36 is controlled during film formation.

As shown in FIG. 1, the detectors 47a and 47b detect arcs caused by abnormal discharge of the discharge units 42a to 42d, respectively, and are provided on the upstream side Du of the discharge unit 42a and the downstream side Dd of the discharge unit 42d. ing.
Each detector 47a, 47b is connected to the control unit 36, and an arc detection signal from the detector 47a, 47b is input to the control unit 36. For this reason, the control unit 36 can detect the occurrence of an arc, that is, the presence or absence of abnormal discharge.
In the present embodiment, instead of always applying a positive potential to the most upstream discharge unit 42a, when detecting an abnormal discharge, for example, the positive voltage V _D is supplied from the DC power source 46 for the time δ, for example. You may apply to the electrode plate 50 of the upstream discharge unit 42a. For this reason, if a positive potential is always applied to the most upstream discharge unit 42a, the detectors 47a and 47b are not necessarily required.

  The sputter gas supply unit 48 supplies a sputter gas such as argon gas to the gap S between each discharge unit 42a to 42d and the surface 26a of the drum 26 via the pipe 48a. The sputtering gas supply unit 48 has a cylinder (not shown) filled with a sputtering gas such as argon gas, a mass flow controller (not shown), a flow rate adjusting valve (not shown), and the like. The cylinder is connected to the pipe 48a via, for example, a mass flow controller or a flow rate adjusting valve.

  The reactive gas supply unit 49 supplies a reactive gas corresponding to the composition of the film to be formed into the gap S between each discharge unit 42a to 42d and the surface 26a of the drum 26 via the pipe 49a. When forming the film, oxygen gas is supplied. When forming the nitride film, nitrogen gas is supplied. The reaction gas supply unit 49 includes a cylinder (not shown) filled with a reaction gas such as oxygen gas or nitrogen gas, a mass flow controller (not shown), or a flow rate adjusting valve (not shown). A cylinder is connected to the pipe 49a via, for example, a mass flow controller or a flow rate adjusting valve.

In the present embodiment, for example, when an Al ₂ O ₃ film is formed on the surface Zf of the substrate Z, the metal target 52 is made of aluminum, and the reaction gas is oxygen gas. Aluminum atoms jump out of the metal target 52, react with oxygen gas, become Al ₂ O ₃ atoms, and an Al ₂ O ₃ film is formed.
When forming the SiO ₂ film, the metal target 52 is made of silicon, and oxygen gas is used as the reaction gas. Silicon atoms jump out of the metal target 52, react with oxygen gas to become SiO ₂ atoms, and an SiO ₂ film is formed.
Furthermore, when forming a SiN film, the metal target 52 is made of silicon, and nitrogen gas is used as a reaction gas. Silicon atoms jump out of the metal target 52 and react with nitrogen gas to become SiN atoms, thereby forming a SiN film.

In the film forming apparatus 10 of the present embodiment, it is preferable that a shutter (not shown) is provided in the gap S between each of the discharge units 42a to 42d and the surface 26a of the drum 26 so as to freely enter and exit. This shutter is for preventing a film from being formed on the surface 26a of the drum 26 and the surface Zf of the substrate Z, and shields metal atoms jumping out from the metal target 52 of each of the discharge units 42a to 42d. For example, the shutter is configured to cover the entire area of each of the discharge units 42a to 42d, and is retracted from the gap S during film formation.
Since metal atoms adhere to the shutter, it is more preferable to have a removal mechanism that can remove the attached metal atoms using, for example, plasma, chemicals, polishing, or the like.

  In this embodiment, as shown in FIG. 2, the substrate Z is wound around the surface 26 a of the drum 26 and conveyed during film formation. At this time, when the substrate Z is exposed to the plasma P, the substrate Z is heated and the moisture contained in the substrate Z or the moisture attached to the surface Zf of the substrate Z evaporates. It is decomposed to produce oxygen. Thereby, it adheres to the surface 52a of the metal target 52, and the oxide 56 is formed. In particular, the portion of the substrate Z that is first exposed to the plasma P has a large amount of moisture w to be released, and the oxide 56 is formed on the surface 52a of the metal target 52 of the discharge unit 42a disposed on the most upstream side. Preferentially formed. As the film formation proceeds, the oxide 56 is positively charged.

However, in the present embodiment, at the time of film formation, the discharge unit 42a disposed on the most upstream side, by applying a positive voltage V _D time [delta], it is possible to neutralize the oxide 56 charged. Thereby, generation | occurrence | production of abnormal discharge can be suppressed.
A preferentially formed oxide 56 is charged even on a substrate made of an organic substance such as a PET film substrate or a PEN film substrate, or a substrate on which an organic layer is formed, which has a large amount of moisture w released. Therefore, the occurrence of abnormal discharge can be suppressed.

  In addition, in the present embodiment, even when the applied voltage value is high and the amount of moisture w released is large, the charged oxide 56 can be neutralized by applying a positive voltage for a predetermined time. Film formation can be performed without lowering the value. For this reason, it is possible to form a film without reducing the film formation speed. Thus, abnormal discharge can be suppressed while maintaining productivity.

In this embodiment, even when a film is formed at a high power density, the film can be formed without reducing the film formation speed while maintaining the high power density. Specifically, when a negative voltage (−V) is applied to each metal target 52 from the pulse power sources 44 a and 44 b via the electrode plate 50, for example, in any metal target 52 (discharge units 42 a to 42 d). The average power density is 5.9 kW / cm ² or more.
Note that the average value of the power density is calculated for each metal target 52 (for each discharge unit 42a to 42d) as described above. The average value of the power density is a value obtained by dividing the average value of the power within the time during which the negative potential is supplied from the pulse power supply to the metal target through the electrode plate of the discharge unit by the area of the metal target, that is, , (Average value of electric power during the time when a negative potential is supplied to the metal target) / (area of the metal target).

When the average value of the power density is 5.9 kW / cm ² or more, the plasma generation density during film formation is high, and more water is released from the substrate Z to generate oxygen. This oxygen causes the maximum in the transport direction. Localization of the oxide 56 formed on the metal target 52 of the discharge unit 42a arranged on the upstream side becomes more prominent, and the frequency of occurrence of abnormal discharge also increases. However, even when oxide localization becomes significant at the time of film formation, localization is more remarkable by applying a positive voltage to the discharge unit 42a disposed on the most upstream side for a predetermined time. The charging of the oxide can be neutralized, and the occurrence of abnormal discharge can be suppressed.

  Furthermore, in this embodiment, since the DC power supply 46 is only provided in the discharge unit 42a positioned at the most upstream among the plurality of discharge units 42a to 42d, the equipment cost is increased and the installation space is increased. Can also be suppressed.

  The effect of the present embodiment is that the inventor of the present application eagerly explains why abnormal discharge occurs when a film is formed while transporting a substrate made of an organic substance or a substrate on which an organic layer is formed by a dual magnetron method. This is based on the knowledge obtained through examination.

Hereinafter, the inventor's knowledge will be described by taking, as an example, a configuration in which two discharge units 100a and 100b are connected to a pulse power supply 100 as shown in FIG.
The two discharge units 100a and 100b have the same configuration. In the discharge unit 100a, the metal target 104 is disposed on the surface of the electrode 102, and a magnet (not shown) is disposed on the back surface of the electrode 100. .
A reactive gas and a sputtering gas are supplied above the metal target 104, and a voltage is alternately applied to each of the discharge units 100a and 100b by the pulse power source 110 to generate plasma and perform sputtering. These two discharge units 100a and 100b constitute a film forming portion.

  When the applied voltage is high (when high power is applied), the substrate Z is transported in the transport direction D and reaches the upper part (deposition portion) of the discharge unit 100a by the high-density plasma P due to high power. Z is heated, air and moisture contained in the substrate Z are released, and moisture w is decomposed by plasma P to generate oxygen. As described above, oxygen is generated by the decomposition of the surface of the substrate by the plasma P or the like, and this oxygen is concentrated on the non-erosion portion upstream of the transport direction D in the target 102 of the discharge unit 100a to generate a large oxide 106a. . As described above, the oxide 106a is localized and generated, and it is considered that abnormal discharge occurs due to this.

The presumed mechanism regarding the occurrence of abnormal discharge due to the localization of oxides is as follows.
In the initial state of oxide deposition, each oxide mass is independent, has a large surface area to the plasma, and a large amount of electrons to be neutralized. Further, since the contact area with the metal target is small, that is, the resistance is large. For this reason, abnormal discharge due to dielectric breakdown does not occur.
When the amount of oxide deposition increases and the oxide masses start to contact each other, the surface area to the plasma decreases, the amount of electrons to be neutralized decreases, and the contact area with the metal target increases. , Resistance decreases. For this reason, abnormal discharge tends to occur.

  On the other hand, when the applied voltage is low (when power is low), as shown in FIG. 4B, even if the substrate Z to be transported reaches the upper part (film formation portion) of the discharge unit 100a. The density of the plasma P is small and the degree to which the substrate Z is heated is small. For this reason, the air and moisture contained in the substrate Z are gradually released, and the moisture w is decomposed by the plasma P to gradually generate oxygen. For this reason, the oxide 106 is generated on the average in the transport direction D, and the oxide 106a is not localized and generated, so that abnormal discharge is less likely to occur. However, when the applied voltage is low, the film formation rate becomes slow, and the productivity is lowered.

As described above, it is considered that when high power is applied, oxygen is concentrated at the moment of reaching the film forming portion, and the plasma density is high and the reactivity is high.
For this reason, in the discharge unit arranged on the most upstream side in the transport direction, by providing means for applying a positive potential to neutralize electrons, abnormal discharge is suppressed even when the applied voltage value is high. I found out that I can do it.

Next, a film forming method of the film forming apparatus 10 of this embodiment will be described.
The film forming apparatus 10 is transported through the long substrate Z from the supply chamber 12 to the take-up chamber 16 through a predetermined path from the supply chamber 12 through the film-formation chamber 14 to the take-up chamber 16. In this embodiment, a film is formed on the substrate Z.

  In the film forming apparatus 10, a long substrate Z is transferred to the film forming chamber 14 via a guide roller 21 from a substrate roll 20 wound counterclockwise, for example. In the film forming chamber 14, the film is conveyed to the winding chamber 16 through the guide roller 24, the drum 26, and the guide roller 28. In the winding chamber 16, the long substrate Z is wound around the winding roll 30 through the guide roller 31. After passing the long substrate Z through this transfer path, the inside of the supply chamber 12, the film formation chamber 14, and the winding chamber 16 is maintained at a predetermined degree of vacuum (pressure) by the evacuation unit 32.

  In the film forming unit 40, an applied voltage (−V) applied to the discharge units 42 a to 42 d (electrode plate 50, metal target 52) from the pulse power sources 44 a and 44 b by the control unit 36 based on the film forming conditions, and The time (duty ratio) for applying the applied voltage is also determined.

  Next, a predetermined amount of argon gas is supplied as a sputter gas from the sputter gas supply unit 48 through the pipe 48a, and a reaction gas (oxygen gas, oxygen) is supplied to the gap S from the reaction gas supply unit 49 through the pipe 49a. A predetermined amount of nitrogen gas or the like is supplied. In this case, the inside of the film forming chamber 14 is maintained at a film forming pressure of, for example, 1 Pa or less by the vacuum exhaust unit 32 based on the set film forming conditions.

  Next, a negative voltage (−V) is applied to each electrode plate 50 (metal target 52) from the pulse power sources 44a and 44b during film formation, and plasma P is generated. The argon gas ionized by the plasma P collides with the surface 52 a of the metal target 52, and metal atoms jump out of the metal target 52. This metal atom reacts with the reaction gas to become a metal compound, which adheres to the surface Zf of the substrate Z as a metal compound, thereby forming a metal compound film.

In the present embodiment, at the time of film formation, the applied voltage −V is alternately applied to the pair with the discharge units 42c and 42d, for example, at a duty ratio of 50%.
As shown in FIG. 3, the applied voltage -V is alternately applied to the set of the discharge unit 42a and the discharge unit 42b positioned at the most upstream side by the applied voltage pattern 60 and the applied voltage pattern 62 as shown in FIG. when a negative voltage to the discharge unit 42a is not applied, a positive voltage V _D time [delta] (applied voltage pattern 64), is applied to the most upstream of the discharge unit 42a.
As described above, by applying the positive voltage V _D to the discharge unit 42a disposed on the most upstream side for a time δ during the film formation, the oxide 56 is formed and neutralized even when charged, and abnormal discharge is caused. Occurrence is suppressed.

Then, the substrate roll 20 around which the long substrate Z is wound counterclockwise is rotated clockwise by the motor, the long substrate Z is continuously fed out, and the drum 26 is rotated at a predetermined speed. Meanwhile, a film is continuously formed on the surface Zf of the long substrate Z by the film forming unit 40. Thereby, the functional film F is manufactured according to the board | substrate Z with which the predetermined film | membrane was formed in the surface Zf, ie, the property or kind of film | membrane. The substrate Z on which a predetermined film is formed on the surface Zf passes through the guide roller 28 and the guide roller 31, and the formed long substrate Z (functional film F) is wound on the winding roll 30. .
In this manner, in the film forming method of the film forming apparatus 10 of the present embodiment, the substrate Z on which the predetermined film f is formed on the surface Zf, that is, the functional film F can be manufactured.

In this embodiment, for example, when a gas barrier film (water vapor barrier film) is manufactured as a functional film, an inorganic film such as a silicon nitride film, an aluminum oxide film, or a silicon oxide film is formed as a gas barrier film.
Moreover, when manufacturing the protective film of various devices or apparatuses, such as a display apparatus like an organic EL display and a liquid crystal display, as a functional film, inorganic films, such as a silicon oxide film, are formed into a film.
Furthermore, when producing optical films such as antireflection films, light reflection films, and various filters as functional films, the film exhibits the desired optical characteristics or the desired optical characteristics. A film made of the material to be formed is formed.

In this embodiment, the film to be formed is not particularly limited, and a film having a function required according to the functional film to be manufactured is appropriately formed as long as it can be formed by reactive sputtering. can do. Further, the thickness of the film is not particularly limited, and a necessary film thickness may be appropriately determined according to the performance required according to the functional film.
Furthermore, the film to be formed is not limited to a single layer, and may be a plurality of layers. When a plurality of layers are formed, each layer may be the same or different from each other.

  In addition, in this embodiment, although discharge unit 42a-42d was made into two sets, this invention is not limited to this. For example, it is good also as a structure which provides a pulse power supply in each discharge unit 42a-42d. Even in this case, the positive voltage VD is applied to the discharge unit 42a for a time δ when the applied voltage (-V) for film formation (for sputtering) is not applied. Thereby, the same effect as this embodiment can be acquired.

  In the film forming apparatus 10 of the present embodiment, the reactive sputtering method has been described as an example, but the present invention is not limited to this. When the substrate Z is transported, moisture is contained in the substrate Z, and when exposed to plasma, moisture is released and an oxide is formed. The same effect as this embodiment can be obtained.

  The film forming apparatus of the present invention has been described in detail above. However, the present invention is not limited to the above-described embodiment, and various improvements and modifications may be made without departing from the gist of the present invention. Of course.

It is a schematic diagram which shows the film-forming apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows the principal part of the film-forming part of the film-forming apparatus shown in FIG. It is a graph which shows the pattern of the applied voltage applied to the discharge unit located in the most upstream, and the discharge unit which makes it, taking voltage on a vertical axis and taking time on a horizontal axis. (A) And (b) is a schematic diagram for demonstrating the effect of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Film-forming apparatus 12 Supply chamber 14 Film-forming chamber 16 Winding chamber 20 Substrate roll 21, 24, 28, 31 Guide roller 30 Winding roll 32 Vacuum exhaust part 36 Control part 40 Film-forming part 44a, 44b Pulse power supply D Conveyance direction Z substrate

Claims (11)

A film forming apparatus for forming a predetermined film on the surface of the substrate by performing sputtering while transporting a long substrate in a predetermined transport direction in a film forming chamber,
An evacuation unit for bringing the film forming chamber into a predetermined degree of vacuum;
A plurality of metal targets facing the surface of the substrate and arranged along the transport direction;
A first power supply for applying a negative voltage to each metal target;
A second power supply for applying a positive voltage to the metal target arranged on the most upstream side in the transport direction among the metal targets;
A sputtering gas supply unit for supplying a sputtering gas between the surface of the substrate and each of the metal targets;
At the time of film formation, the first power supply unit applies a negative voltage to the metal targets at predetermined time intervals for a predetermined time, and the metal target disposed on the most upstream side is negatively applied from the first power supply unit. And a control unit that applies the positive voltage to the metal target disposed on the most upstream side by the second power source unit when the voltage of 2 is not applied.   The film forming apparatus according to claim 1, further comprising a reactive gas supply unit configured to supply a reactive gas between a surface of the substrate and each metal target, and supplying the reactive gas during the film formation. .   The film forming apparatus according to claim 1, wherein each metal target is provided with a magnet.   The film forming apparatus according to claim 1, wherein the film is a gas barrier film.   The film forming apparatus according to claim 4, wherein the gas barrier film is an aluminum oxide film.   The film forming apparatus according to claim 1, wherein the first power supply unit is a pulse power supply or a high-frequency power supply. A film forming method for forming a predetermined film on the surface of the substrate by performing sputtering while transporting a long substrate in a predetermined transport direction facing a plurality of metal targets,
Supplying a sputtering gas between the substrate and each metal target;
When a negative voltage is applied to each metal target at a predetermined time interval for a predetermined time and a negative voltage is not applied to the metal target disposed on the most upstream side, the metal disposed on the most upstream side And a step of applying the positive voltage to the target.   The film forming method according to claim 7, wherein in the step of supplying a sputtering gas between the substrate and each metal target, a reactive gas is further supplied between the surface of the substrate and each metal target. . The film forming method according to claim 7 or 8, wherein when a negative voltage is applied to each metal target, an average value of power density in each metal target is 5.9 kW / cm ² or more.   The film formation method according to claim 7, wherein the film is a gas barrier film.   The film forming method according to claim 10, wherein the gas barrier film is an aluminum oxide film.

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