JP6265063B2 - Gas discharge unit and film forming apparatus having the same - Google Patents

Description

  The present invention relates to a film forming apparatus for performing continuous film formation by reactive sputtering on a long substrate conveyed by roll-to-roll in a vacuum chamber, and a reactive gas discharge unit attached to the film forming apparatus. It is.

  As a base material for a flexible wiring board used for a liquid crystal panel, a notebook personal computer, a mobile phone or the like, a coated film substrate obtained by coating an oxide film or a nitride film on a resin film is used. In order to produce this coated film substrate with high productivity and low cost, sputtering film formation is performed while winding a long resin film conveyed by a roll-to-roll method around the outer peripheral surface of a can roll having a cooling function and cooling from the back side. A sputtering web coater that performs the above is employed. In such a sputtering web coater, a coating film having a desired composition can be formed by mounting targets of various materials on a sputtering cathode disposed to face the outer peripheral surface of the can roll.

  However, if an oxide target is used to form an oxide film, or if a nitride target is used to form a nitride, the film formation rate may be slowed and productivity may be reduced. there were. Therefore, Patent Document 1 proposes a method of forming a sputtering film by employing a metal target capable of high-speed film formation and introducing a reactive gas while controlling the reactive gas. Further, in Patent Document 2, the amount of reactive gas released by externally fitting a sleeve having a plurality of holes having different inner diameters in the circumferential direction to a gas releasing pipe for introducing the reactive gas into the vacuum chamber. A technique for simply adjusting is described.

Patent 5347542 Japanese Patent No. 4196138

  In the case where the so-called reactive sputtering film formation is performed by the sputtering web coater, in which the sputtering film formation is performed while introducing the reactive gas described above, one gas release pipe is provided in the width direction of the film on the transport path in the vicinity of each sputtering cathode. The reactive gas is discharged from a plurality of gas discharge holes arranged along the longitudinal direction.

  However, in the gas discharge pipe having such a structure, a large amount of gas is discharged from the upstream gas discharge hole among the large number of gas discharge holes provided along the longitudinal direction of the gas discharge pipe, and from the downstream gas discharge hole. Almost no gas was released. As described above, when the amount of gas released from the gas discharge holes varies, the distribution of the reactive gas becomes non-uniform and the progress of the reaction in the width direction of the film becomes different. In some cases, the degree of oxidation or nitridation of the coating film was non-uniform in the width direction.

  The present invention has been made by paying attention to the above-mentioned conventional problems, and a plurality of gases are used in order to perform uniform reactive sputtering film formation on a long substrate conveyed by roll-to-roll in a vacuum chamber. It is an object of the present invention to provide a gas discharge unit capable of uniformly discharging a reaction gas from a discharge hole and a film forming apparatus including the same.

In order to achieve the above object, the gas discharge unit according to the present invention has a reactive structure in which at least three pipes sealed at both ends are sequentially communicated with each other through openings provided in each wall. A gas discharge unit for releasing a reactive gas in a sputtering chamber, wherein the at least three pipes receive a reactive gas received from an introduction hole provided in a longitudinal center of the most upstream pipe, After sequentially releasing into the pipe on the downstream side through a plurality of openings that connect adjacent pipes parallel to each other, the pipe is discharged into the chamber from a plurality of discharge holes provided in the most downstream pipe. is configured, prior Symbol plurality of openings and the plurality of discharge holes the longitudinal central portion are arranged symmetrically with respect to a plane perpendicular to the street longitudinal direction, and a plurality open According to the number and extent to which they extend in the longitudinal direction of the pipe in which the number of the plurality of openings of the discharge side and the range and the plurality of discharge holes which extend in the longitudinal direction of the pipe of the parts are toward the downstream side The adjacent pipes that are parallel to each other are separated by a distance equal to or smaller than the pipe thickness of the narrower one of these pipes.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to perform reactive sputtering film-forming uniformly in the width direction with respect to the film conveyed by a roll-to-roll system.

It is a typical front view which shows one specific example of the film-forming apparatus of the long resin film by reactive sputtering provided with the gas discharge | release unit of this invention. It is a perspective view which shows the conventional gas discharge pipe. It is a perspective view which shows the conventional gas discharge pipe. It is the perspective view (a) and exploded perspective view (b) which show one specific example of the gas discharge | release unit of this invention. It is a perspective view which shows the other specific example of the gas discharge | release unit of this invention. It is a graph illustrating the relationship between the transmittance of the SiO ₂ film formed by reactive sputtering in position and position opposite thereto of the provided gas discharge holes to the gas discharge unit. It is a graph illustrating the relationship between the transmittance of the SiO ₂ film formed by reactive sputtering in position and position opposite thereto of the gas discharge hole provided in the gas discharge unit of the comparative example. It is a graph showing the relationship between the thickness of the SiO ₂ film formed by reactive sputtering in position and position opposite thereto of the gas discharge hole provided in the gas discharge unit of the comparative example.

  Hereinafter, a specific example of a gas discharge unit of the present invention and a long substrate processing apparatus including the gas discharge unit will be described in detail with reference to the drawings. First, a long resin film vacuum film forming apparatus shown in FIG. 1 will be described as a specific example of a long substrate processing apparatus including the gas release unit of the present invention. A vacuum film forming apparatus 10 for a long resin film F shown in FIG. 1 is an apparatus called a sputtering web coater, such as a resin film such as a polyethylene terephthalate (PET) film or a heat resistant resin film such as a polyimide film. This is suitable for the case where a metal film is continuously formed by reactive sputtering on the surface of the long resin film F in the vacuum chamber 11 while being conveyed from the unwinding roll 12 to the winding roll 24 in a roll-to-roll manner. Used.

More specifically, the vacuum chamber 11 is subjected to a pressure reduction of about 0.1 to 10 Pa by introducing a sputtering gas and then reducing the pressure to an ultimate pressure of about 10 ⁻⁴ Pa for sputtering film formation. A known gas such as argon is used as the sputtering gas, and a reactive gas containing oxygen or nitrogen or both is introduced through a gas discharge unit described later. The shape and material of the vacuum chamber 11 are not particularly limited as long as they can withstand such a reduced pressure state, and various types can be used. As described above, in order to reduce the pressure in the vacuum chamber 11 and maintain the state, the vacuum chamber 11 is provided with various devices such as a dry pump, a turbo molecular pump, and a cryocoil (not shown).

  Various rolls are arranged in the vacuum chamber 11 that demarcate the transport path of the long resin film F that is unwound from the unwinding roll 12, passes through the can roll 16, and is wound up by the winding roll 24. The transport path from the unwinding roll 12 to the can roll 16 is fed from a free roll 13 that guides the long resin film F, a tension sensor roll 14 that measures the tension of the long resin film F, and a tension sensor roll 14. The motor-driven front feed roll 15 is arranged in this order in which the circumferential speed of the can roll 16 is adjusted in order to bring the long resin film F to be adhered to the outer peripheral surface of the can roll 16.

  Similarly to the above, the conveyance path from the can roll 16 to the take-up roll 24 is a tension sensor that measures the tension of the feed roll 21 and the long resin film F after the motor drive in which the peripheral speed of the can roll 16 is adjusted. A roll 22 and a free roll 23 for guiding the long resin film F are arranged in this order. In the unwinding roll 12 and the winding roll 24, the tension balance of the long resin film F is maintained by torque control using a powder clutch or the like. Further, the can roll 16 is rotationally driven by a motor, and a refrigerant whose temperature is adjusted outside the vacuum chamber 11 circulates inside.

  A magnetron as a film forming means is located at a position facing a region (also referred to as a wrap region) corresponding to the range of the angle A in FIG. 1 where the long resin film F defined by the outer peripheral surface of the can roll 16 is wound. Sputtering cathodes 17, 18, 19 and 20 are provided along the transport path in this order. Each magnetron sputtering cathode has a plate-like target mounted on the surface facing the outer peripheral surface of the can roll 16. If nodules (growth of foreign matter) on the target, which are likely to occur when using the plate-shaped target described above, become a problem, a cylindrical rotary target with no generation of nodules and high target usage efficiency is used. May be used. A shielding plate 25 is provided in the vacuum chamber 11 in order to prevent the sputtered particles struck from the target from deviating from a predetermined traveling path toward the unwinding roll or the like.

  Each magnetron sputtering cathode is provided with a gas release unit 30 extending in the width direction of the transport path of the long resin film F at the upstream end and the downstream end in the transport direction of the long resin film F, respectively. From here, the reactive gas for sputtering film formation is introduced while being controlled. As a result, when forming an oxide film or a nitride film, it is not necessary to use an oxide target or a nitride target with a low film formation speed as a target of the magnetron sputtering cathode, and a metal target capable of high-speed film formation can be obtained. Can be adopted.

In general, the reactive gas released from the gas releasing unit can be controlled by the following four methods.
(1) Release a constant flow of reactive gas (flow control)
(2) Release reactive gas to maintain constant pressure (pressure control)
(3) Release reactive gas so that impedance of sputtering cathode becomes constant (impedance control)
(4) Release reactive gas so that the plasma intensity of sputtering is constant (plasma emission control)

  As shown in FIG. 2, the gas discharge unit 30 has a plurality of gas discharge holes 40a whose ends are sealed and whose hole diameter is about 0.3 mm within the range corresponding to the end of the cathode in the width direction. In some cases, the gas discharge pipes 40 arranged in a row at substantially equal intervals may be used. However, if the number of the gas discharge holes 40a and the opening area thereof are not appropriate for the gas discharge amount, the plurality of the gas discharge pipes 40a may be used. A large amount of gas is discharged from the gas discharge hole 40a located upstream of the downstream side, and as a result, in the region of the film facing the upstream gas discharge hole, In some cases, the reaction progressed more than the area of the opposing film, resulting in variations in the quality of the coating film.

  As a countermeasure, a double pipe type gas discharge pipe as shown in FIG. 3 may be used. The double pipe type gas discharge pipe shown in FIG. 3 has a structure in which an inner pipe 51 having a sealed end is inserted inside an outer pipe 50 having a sealed end. 50, a plurality of gas discharge holes 50a having a hole diameter of about 0.3 mm are arranged in a line at equal intervals in a range corresponding to the end of the cathode in the width direction. A plurality of gas discharge holes 51a are arranged in a range narrower than the range from end to end of the gas discharge holes 50a.

  Such a double pipe structure can make the gas discharge amount from a plurality of gas discharge holes uniform to some extent, but since the gas is introduced from one end of the inner pipe, the gas is still more upstream than the downstream side. There is a problem that the amount of gas released from the discharge hole is slightly large. In addition, in order to prevent variation in the amount of gas discharged from the plurality of gas discharge holes, it is necessary to arrange the outer peripheral surface of the inner pipe and the inner peripheral surface of the outer pipe in parallel with each other in a state of being appropriately separated from each other. There is a possibility that a very thin pipe cannot be used as the inner pipe, and it is necessary to use a considerably larger outer pipe. For this reason, there is a case where such a double pipe structure and a triple pipe structure gas discharge pipe that can expect more uniform gas discharge cannot be installed in an apparatus with limited space.

  Therefore, in one specific example of the present invention, a gas discharge unit is used in which at least three pipes sealed at both ends are sequentially communicated through openings provided in the respective wall portions. Specifically, as shown in FIGS. 4 (a) and 4 (b), the gas discharge unit of one specific example of the present invention includes, for example, three pipes 61, 62, both ends of which are sealed. 63 are combined so as to be generally symmetric with respect to planes parallel to each other on one plane and perpendicular to the extending direction.

  Among these three pipes, the first distribution pipe 61 located on the most upstream side has one gas introduction hole 61a formed in the center in the longitudinal direction thereof, and an introduction pipe for introducing a reactive gas therein. The front end portion 60a of 60 is connected. A gas discharge hole 60b having an opening area smaller than that of the gas introduction hole 61a is provided at the distal end portion 60a of the introduction pipe 60, and this gas discharge hole 60b is introduced into the first distribution pipe 61 through the reactivity. The opening restricts the gas flow rate. The first distribution pipe 61 further has two gas discharge holes 61b that are symmetric with respect to a plane that passes through the center in the longitudinal direction and is perpendicular to the longitudinal direction. The opening area of each gas discharge hole 61 b is smaller than the opening area of the gas discharge hole 60 b of the introduction pipe 60. The total hole area of these two gas discharge holes 61b is wider than the hole area of the gas discharge holes 60b.

  In the second distribution pipe 62 that is the second from the upstream, two gas introductions having a larger opening area than the gas discharge holes 61b are provided at positions facing the two gas discharge holes 61b of the first distribution pipe 61 described above. A hole 62a is provided. Therefore, the gas discharge hole 61b on the gas distribution pipe 61 side is an opening that restricts the flow rate of the reactive gas introduced from the first distribution pipe 61 into the second distribution pipe 62. The second distribution pipe 62 is further provided with a total of three gas discharge holes 62b consisting of one in the central portion in the longitudinal direction and two symmetrical positions with respect to a plane passing through the central portion in the longitudinal direction and perpendicular to the longitudinal direction. It has been.

  The three gas discharge holes 62b are arranged so that the pitch between adjacent ones is substantially equal to the pitch of the two gas connection holes 62a. The opening area of each gas discharge hole 62b is smaller than the opening area of each gas discharge hole 61b. The total hole area of these three gas discharge holes 62b is wider than the total hole area of the two gas discharge holes 61b of the first distribution pipe 61. As a result, the gas released from the second distribution pipe 62 is released more widely and evenly than the first distribution pipe 61.

  The third distribution pipe 63 located on the most downstream side has a gas introduction hole 63a having a larger hole area than the gas discharge hole 62b at a position facing the three gas discharge holes 62b of the second distribution pipe 62 described above. Three are provided. Therefore, the gas discharge hole 62b on the second distribution pipe 62 side is an opening that restricts the flow rate of the reactive gas introduced from the second distribution pipe 62 into the third distribution pipe 63. In the third distribution pipe 63, eleven gas discharge holes 63b are arranged in a row at substantially equal intervals along the longitudinal direction at symmetrical positions with respect to a plane perpendicular to the longitudinal direction passing through the central portion in the longitudinal direction. Is provided.

  The plurality of gas discharge holes 63b have narrower pitches between adjacent ones than the adjacent gas introduction holes 63a, but they extend from end to end in the longitudinal direction of the third distribution pipe 63. The range to be arranged is wider than the gas introduction hole 63a. The opening area of each gas discharge hole 63b is smaller than the opening area of each gas discharge hole 62b. Further, the total hole area of these eleven gas discharge holes 63 b is larger than the total hole area of the three gas discharge holes 62 b of the second distribution pipe 62. As a result, the gas released from the third distribution pipe 63 is discharged more widely and evenly than the second distribution pipe 62.

The diameter of the gas discharge hole 63b of the third distribution pipe 63 that discharges the reactive gas in the vacuum chamber of the gas discharge unit is desirably 0.5 mm or less. This is because if this size is exceeded, the amount of gas released from the gas discharge hole 62b located in the vicinity of the gas discharge hole 63b in the second distribution pipe 62 may increase. Further, it is preferable that a small total opening area of the plurality of gas discharge holes than the cross-sectional area of a plane perpendicular to the longitudinal direction of the distributable pipe in each distribution pipe.

  By adopting the gas discharge unit having the above-described configuration, the reactive gas introduced from the gas introduction hole 61a drilled in the central portion in the longitudinal direction of the most upstream first distribution pipe 61 is passed between adjacent pipes. After being sequentially sent to the downstream pipe through a plurality of communicating openings, it can be evenly discharged in the chamber from a plurality of gas discharge holes 63b drilled in the most downstream third distribution pipe 63. become. This is because the total area of the plurality of gas discharge holes in each distribution pipe does not exceed the total area of the plurality of gas discharge holes of the subsequent distribution pipe, so that the reactive gas is discharged to the subsequent stage. This is because the gas flow rate can be increased, thereby increasing the differential pressure at a plurality of openings communicating with adjacent distribution pipes and making the pressure distribution in each distribution pipe more uniform. .

  Thus, the gas discharge unit according to an embodiment of the present invention can discharge the reactive gas evenly from the plurality of discharge holes into the chamber. Moreover, since a general pipe can be used without using a double tube or a triple tube, it can be made into a slim shape, and thus can be easily attached to a chamber space with limited space. In addition, the gas discharge unit of one specific example of the present invention is particularly effective when it is a long object having a width of 10 cm or more.

  The gas discharge unit having the above-described structure can be manufactured by a general method. For example, each of the first distribution pipe 61, the second distribution pipe 62, and the third distribution pipe 63 is drilled with a gas introduction hole and a gas discharge hole having a desired hole diameter and quantity using a drill or a laser, and then adjacent distributions are made. The pipes may be joined together by TIG welding (tungsten inert gas welding), laser welding, electron beam welding, or the like, and finally the connection portion 60a of the introduction pipe 60 may be joined to the first distribution pipe 61 by welding or the like. When drilling the gas introduction hole and the gas discharge hole, it is preferable to make the size of the gas introduction hole opposite to the gas discharge hole of the distribution pipe larger as described above or vice versa. Thereby, the alignment at the time of joining becomes easy.

  Next, another specific example of the gas discharge unit of the present invention will be described with reference to FIG. In the gas discharge unit shown in FIG. 5, the introduction pipe 70 and its connecting portion 70a, the first distribution pipe 71, the second distribution pipe 72, and the third distribution pipe 73 in which the gas discharge holes 73b are formed are described above. Although it is the same as that of the gas discharge | release unit of one specific example, the points which the connection pipe 74 is provided in the opening part which connects adjacent distribution pipes differ. Thus, the structure which connects adjacent distribution pipes via the connection pipe 74 can expect the homogeneous gas distribution similar to a triple pipe. In this case, by setting the thickness of the connection pipe 74 to be equal to or smaller than the thickness of the distribution pipe, it can be installed in a place where the space is limited, like the gas discharge unit shown in FIG. Further, it is preferable that the length of each connection pipe 74 is equal to or less than the thickness of the thinner pipe of the two distribution pipes communicated with each other.

  The gas discharge unit of the present invention has been described with reference to a plurality of specific examples. However, the present invention is not limited to these specific examples, and various modifications and alternatives are possible without departing from the spirit of the present invention. An example can be considered. For example, the gas discharge unit may be provided only at the upstream end or the downstream end of each cathode. The shape of the gas connection hole and the gas discharge hole is preferably a circle from the viewpoint of workability, but may be a polygon such as a square. Furthermore, the shape of each distribution pipe is not limited to a polygonal shape such as a rectangle as shown in FIGS. 4 and 5 in a cross section perpendicular to the longitudinal direction, and may be a general circular pipe. .

[Example]
Reactive sputtering film formation was performed using a film formation apparatus (sputtering web coater) as shown in FIG. More specifically, a stainless steel roll having a diameter of 600 mm and a width of 750 mm was used for the can roll 16, and the outer peripheral surface thereof was subjected to hard chrome plating. A stainless steel roll having a diameter of 150 mm and a width of 750 mm was used for the front feed roll 15 and the rear feed roll 21, and hard chrome plating was applied to the outer peripheral surface thereof. The can roll 16 was controlled to be cooled to 0 ° C. with a refrigerant circulating inside.

A SiC target (manufactured by Asahi Glass Ceramics) was mounted on the cathodes 17 to 20, and the pair of cathodes 17 and 18 and the pair of 19 and 20 were each a pair of dual magnetron cathodes and connected to a dual magnetron power source. The SiO ₂ film formed by reactive sputtering using a SiC target is a material suitable for evaluating the distribution of reactive gas because reactive gas is likely to be bonded to sputtered particles.

  A gas discharge unit 30 was installed on the upstream side and the downstream side of each of the cathodes 17, 18, 19, 20. A gas discharge unit as shown in FIG. 4 was adopted for each gas discharge unit, and a 1/4 inch pipe having a length of 400 mm was used for the introduction pipe 60. Table 1 below shows specific structures of the connection portion 60a provided at the end portion of the introduction pipe 60 and the first to third distribution pipes 61 to 63 sealed at both ends constituting the gas discharge unit. The hole pitch of the gas discharge holes 63b of the third distribution pipe 63 was 20 mm, and the other hole pitches were all 200 mm.

A thin quartz substrate having a thickness of 50 μm and a refractive index substantially equal to that of the SiO ₂ film was used as the substrate for film formation, and this was directly attached to the outer peripheral surface of the can roll 16 at intervals of 100 mm. This is a consideration for eliminating the difference in refractive index between the SiO ₂ film and the substrate and reducing the interference effect depending on the film thickness. In this state, the vacuum chamber 10 was first evacuated to 5 Pa by a plurality of dry pumps, and then evacuated to 3 × 10 ⁻³ Pa using a plurality of turbo molecular pumps and a cryocoil. Then, 300 sccm of argon gas was introduced, the power applied to each cathode was 20 kW, and film formation was performed under power control. Then, 500 sccm of oxygen was introduced as a reactive gas into the gas release unit to form a SiO ₂ film.

[Comparative Example 1]
In place of the gas release unit of FIG. 4, 41 pieces of gas discharge holes 40a with a hole diameter of 0.2 mm are provided in a 1/4 inch × 800 mm pipe 40 whose ends are sealed as shown in FIG. Total area: 1.29 mm ² ) Reactive sputtering film formation was performed in the same manner as in the above example, except that a single-tube type gas discharge pipe made of perforated material was used.

[Comparative Example 2]
In place of the gas discharge unit shown in FIG. 4, gas discharge holes 50a having a hole diameter of 0.2 mm are formed at a hole pitch of 20 mm in a ½ inch × 800 mm outer pipe 50 whose end is sealed as shown in FIG. pieces (total area: 1.29 mm ²⁾ 3 inside but bored, at the end the inner tube pipe 51 of 1/4 inch × 900 mm sealed gas discharge holes 51a having a pore size of 0.7mm in hole pitch 200mm Reactive sputtering film formation was performed in the same manner as in the above example except that a double-pipe type gas discharge pipe having a structure in which a plurality of holes (total area: 1.15 mm ² ) were inserted was used.

[Evaluation]
For each of the gas release units of the above-mentioned Examples, Comparative Example 1 and Comparative Example 2, the SiO ₂ film formed at the position of each gas discharge hole for discharging the reactive gas into the chamber and the portion facing this. FIG. 6 shows the relationship with the transmittance at a wavelength of 550 nm of the film. Here, the hole position 0 mm on the horizontal axis corresponds to the position of the most upstream gas discharge hole among the gas discharge holes 63 b provided in the third distribution pipe 63. Since the SiO ₂ film becomes transparent when completely oxidized, the high transmittance is an indicator of the degree of oxidation. From the result of FIG. 6, the transmittance at the position corresponding to the downstream gas discharge hole is higher in the order of Example, Comparative Example 2, and Comparative Example 1. In particular, it can be seen that in the examples, the transmittance value hardly changes even when the distance on the horizontal axis increases, and the reactive gas is uniformly discharged from the plurality of gas discharge holes.

FIG. 7 shows the relationship between the position of each gas discharge hole and the transmittance at a wavelength of 550 nm of the SiO ₂ film formed in the portion facing the gas discharge hole when the amount of reactive gas in Comparative Example 1 is increased. From the results of FIG. 7, it can be seen that even with the gas release pipe having the structure of Comparative Example 1, if the reactive gas is excessively released, the SiO ₂ film can be almost completely oxidized and the transmittance distribution can be made uniform. . However, FIG. 8 shows the relationship between the position of each gas discharge hole when the amount of reactive gas in Comparative Example 1 is increased and the film thickness at a wavelength of 550 nm of the SiO ₂ film formed in the portion facing this. As can be seen, if the reactive gas is released excessively, the transmittance distribution becomes uniform, but the release of the excessive reactive gas decreases the sputtering film formation rate, resulting in a non-uniform film thickness distribution.

DESCRIPTION OF SYMBOLS 10 Vacuum film-forming apparatus 11 Vacuum chamber 12 Unwinding roll 13 Free roll 14 Tension sensor roll 15 Feed roll 16 Can roll 17, 18, 19, 20 Magnetron sputtering cathode 21 Feed roll 22 Tension sensor roll 23 Free roll 24 Winding roll 25 Shield plate 30 Gas discharge unit 60 Introduction pipe 60a Connection portion 60b Gas discharge hole 61 First distribution pipe 62 Second distribution pipe 63 Third distribution pipe 61a, 62a, 63a Gas introduction hole 61b, 62b, 63b Gas discharge hole

Claims (6)

This is a gas discharge unit for reactive gas discharge in a reactive sputtering chamber in which at least three pipes sealed at both ends are sequentially communicated through openings provided in each wall. And
The at least three pipes sequentially receive the reactive gas received from the introduction hole provided in the longitudinally central portion of the most upstream pipe through a plurality of openings that connect the adjacent parallel pipes. after released into the downstream side of the pipe, it is composed of a plurality of discharge holes provided on the most downstream side of the pipe so as to release into the chamber, before Symbol plurality of openings and the plurality of release holes It is symmetrically arranged with respect to a plane that passes through the central portion in the longitudinal direction and is perpendicular to the longitudinal direction, and among the plurality of openings, the number of the plurality of openings on the discharge side and these extend in the longitudinal direction of the pipe range as well as the number and extent that they extend in the longitudinal direction of the pipe of the plurality of discharge holes are increased toward the downstream side, mutually parallel pipes to each other for the adjacent one of these pipes Gas discharge unit for a reactive gas discharge, characterized in that spaced in the stomach how the pipe thickness or less of the distance. A plurality of openings and the plurality of release holes before Symbol discharge side, characterized in that each opening area is reduced toward the downstream side, the gas discharge unit according to claim 1. The total open area of said at least three Oite the pipes, the most each except the downstream side of the pipe a plurality of openings of the discharge side of the cross-sectional area of the plane perpendicular to the extending direction of the pipe There rather small, the most total opening area of the downstream side of the pipe a plurality of discharge holes than the cross-sectional area of a plane perpendicular to the extending direction thereof is characterized by small Ikoto, to claim 1 or 2 The gas release unit described. The gas discharge unit according to any one of claims 1 to 3, wherein each of the plurality of discharge holes is a hole having a hole diameter of 0.5 mm or less. The at least three pipes increase as the total opening area of the plurality of openings on the discharge side of each pipe excluding the most downstream pipe and the total opening area of the plurality of discharge holes go downstream. The gas discharge unit according to claim 1, wherein the gas discharge unit is provided.   A film forming apparatus comprising: a transport mechanism that transports a long substrate in a vacuum chamber; and a sputtering cathode that forms a film in a state where the long substrate is supported by a support unit, the sputtering cathode and the support unit A gas discharge unit according to any one of claims 1 to 5 is used as a reactive gas discharge means provided between the two.

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