JP6876647B2 - Film formation method - Google Patents

Description

The present invention relates to a film forming method for forming a film by plasma CVD (Chemical Vapor Deposition) in a roll-to-roll method.

Various devices such as optical elements, liquid crystal displays and display devices such as organic EL (Electro Luminescence) displays, semiconductor devices, and thin-film solar cells, as well as optical films such as gas barrier films, protective films, optical filters and antireflection films, etc. , Various functional films (functional sheets) are used.
A film forming method by plasma CVD is used for producing these functional films.

Further, as a highly productive film forming method, a so-called roll-to-roll method (hereinafter, also referred to as RtoR) is known. As is well known, RtoR means that a substrate is sent out from a roll formed by winding a long substrate into a roll shape, and a film is formed while being conveyed in the longitudinal direction. It is a film forming method that is wound around.

When film formation is performed by plasma CVD, the product is deposited not only on the substrate to be deposited but also on each part in the film forming apparatus. In particular, in plasma CVD using an electrode pair such as CCP-CVD ((Capacitively Coupled plasma-CVD) capacitively coupled plasma CVD), the electrode pair for film formation for forming plasma is on the side facing the substrate. A large amount of product is deposited on the surface of the electrode facing the substrate.
Further, in RtoR, since continuous film formation is performed for a long time, the amount of product deposited on the electrode is also large.

The product deposited on the film-forming electrode self-destructs due to internal stress, and a part of the product is peeled off from the electrode and adheres to the substrate and the film-formed film as foreign matter, and also contaminates the inside of the film-forming apparatus.
Foreign substances present on the substrate, the surface of the substrate, the film, and the surface of the film cause deterioration of the quality of products such as gas barrier films. In particular, in film formation by RtoR, if the film peeled off from the electrode is present as foreign matter on the surface of the substrate, in the film, or on the surface of the film, stress is concentrated on the film in the presence of the foreign matter during transportation and winding of the substrate. Then, the film formed is cracked and becomes a defect.

In order to eliminate such inconvenience, it is generally possible to suppress peeling of products adhering to and accumulating on the surface of the electrode facing the substrate by roughening the surface of the electrode facing the substrate. It is done.

For example, Patent Document 1 describes a film forming apparatus using an electrode pair composed of a shower electrode (shower plate) and a columnar drum electrode as an apparatus for forming a film on a substrate by CCP-CVD by RtoR. .. In this film forming apparatus, the drum electrode and the shower electrode are arranged so as to face each other, and a long substrate is wound around the drum electrode and conveyed in the longitudinal direction, and a film forming region between the drum electrode and the shower electrode is formed. In, a film is formed on the substrate by plasma CVD.
As is well known, the shower electrode is a kind of gas supply electrode, and is configured to have, for example, a hollow portion and a large number of gas supply holes communicating with the hollow portion. In a film forming apparatus using a shower electrode, the shower electrode is arranged with the formation surface of the opening of the gas supply hole facing the other electrode, and the film forming gas is supplied to the hollow portion of the shower electrode to supply gas. The film-forming gas is supplied from the holes to the film-forming region between the electrodes.

The film forming apparatus described in Patent Document 1 has a sprayed film as a shower electrode on the surface facing the substrate, and further, from the surface of the sprayed film facing the substrate and the surface of the sprayed film facing the substrate. A shower electrode having a coating film made of a conductive non-oxide, which is formed up to a position beyond the boundary between the sprayed film on the inner surface of the gas supply hole and the shower plate body, is used.
The shower electrode described in Patent Document 1 forms a sprayed film on the surface facing the substrate to roughen the surface of the shower electrode facing the substrate to prevent peeling of accumulated products, and also to prevent peeling of accumulated products. By having a coating film made of a conductive non-oxide, it is possible to prevent the sprayed film from peeling off and also to prevent abnormal discharge.

Japanese Unexamined Patent Publication No. 2016-8315

According to the shower electrode described in Patent Document 1, by forming a sprayed film on the surface facing the substrate, the surface of the shower electrode facing the substrate is roughened to prevent peeling of accumulated products. At the same time, by having a coating film made of a conductive non-oxide, the plasma excitation power is improved and the amount of the film-forming gas supplied is increased in order to densify the film to be formed and improve the film-forming rate. However, the peeling of the sprayed film can be suppressed, and further, the instability of the plasma due to the abnormal discharge can be suppressed.

However, since the product adheres to and accumulates on the shower electrode, it is difficult to completely prevent the product from peeling off from the shower electrode, and further improvement is desired.

An object of the present invention is to solve such a problem of the prior art, and it is possible to suppress adhesion of a product to the shower electrode when forming a film by plasma CVD with RtoR using the shower electrode. The purpose is to provide a membrane method.

In order to solve this problem, the film forming method of the present invention has the following configurations.
[1] When forming a film on a substrate while transporting a long substrate in the longitudinal direction,
A gas supply electrode having a gas supply hole for supplying a film-forming gas on a surface facing the substrate, which is arranged facing the substrate, and a counter electrode constituting the gas supply electrode and an electrode pair are used on the substrate. It is for forming a film,
The radius of the gas supply hole is x [cm], the flow rate of the film-forming gas blown out from one gas supply hole is y [sccm], and the flow velocity of the film-forming gas blown out from one gas supply hole is v [sccm / cm ^2]. ], And when the parameter defined by the flow velocity v is L [cm],
v = y / (π × x ² ),
L = [(1.2 x 10 ^-4 ) x v] + x-0.3,
And
Satisfy 4000 ≦ v ≦ 5500, and further
90% or more of the gas supply region, which is the region where the gas supply hole is formed on the surface of the gas supply electrode facing the substrate, is covered by a circle centered on the center of the gas supply hole and having the parameter L as the radius. A film forming method characterized by.
[2] The film forming method according to [1], wherein the counter electrode is a cylindrical drum that wraps a substrate around a peripheral surface and conveys the substrate in the longitudinal direction.
[3] The film forming method according to [1] or [2], wherein the gas supply holes are regularly arranged in the gas supply electrode.
[4] The film forming method according to [3], wherein the gas supply holes are arranged in a square grid or a hexagonal grid.
[5] The film forming method according to any one of [1] to [4], wherein the radius of the gas supply hole is 50 to 250 μm.
[6] The film forming method according to any one of [1] to [5], wherein the flow velocity v satisfies 4500 ≦ v ≦ 5000.
[7] On the surface of the gas supply electrode facing the substrate, 95% or more of the gas supply region is covered with a circle centered on the center of the gas supply hole and having a radius of parameter L, [1] to [6]. ]. The film forming method according to any one of.

According to the present invention, in the film formation performed by plasma CVD with RtoR using the shower electrode, it is possible to suppress the adhesion of the product to the shower electrode and suppress the defect of the film-forming object due to the peeled material.

It is a figure which conceptually shows an example of the film-forming apparatus which carries out the film-forming method of this invention. It is schematic cross-sectional view of the shower electrode provided in the film forming apparatus shown in FIG. It is a schematic plan view of the shower electrode provided in the film forming apparatus shown in FIG. It is a conceptual diagram for demonstrating the gas supply area in this invention. It is a conceptual diagram for demonstrating the film formation method of this invention. It is a conceptual diagram for demonstrating the film formation method of this invention. It is a conceptual diagram for demonstrating the film formation method of this invention.

Hereinafter, the film forming method of the present invention will be described in detail with reference to the attached drawings.

FIG. 1 conceptually shows an example of a film forming apparatus that implements the film forming method of the present invention.
The film forming apparatus 10 shown in FIG. 1 is an apparatus for forming a film on the substrate Z by CCP-CVD with the above-mentioned RtoR, and includes a vacuum chamber 12 and a substrate chamber 14 formed on the upper side of the vacuum chamber 12. A film forming chamber 16 formed on the lower side of the vacuum chamber 12 and a drum 18 arranged in the vacuum chamber 12 are provided. Further, the film forming chamber 16 is provided with a shower electrode 20 facing the drum 18. In the film forming apparatus 10, the shower electrode 20 and the drum 18 form an electrode pair in CCP-CVD.
In the film forming apparatus 10, the upper part and the lower part are the upper part and the lower part on the drawing, and are irrelevant to the essence of the present invention.

The film formed by the film forming method of the present invention is not particularly limited, and all films that can be formed by CCP-CVD can be used.
Further, the substrate Z for forming a film by the film forming method of the present invention can also be a resin film, a laminate in which an organic layer is formed on the resin film, or a resin film, as long as the film can be formed by CCP-CVD by RtoR. All flexible, long sheets (webs), such as laminates of organic and inorganic layers, are available.

The drum 18 is a cylindrical member, and rotates counterclockwise in the drawing with the center line of the cylinder as the center of rotation.
The drum 18 hangs the substrate Z supplied from the substrate roll 26 around a predetermined region on the peripheral surface, holds the substrate Z at a predetermined position, and conveys the substrate Z in the longitudinal direction.
The drum 18 also acts as a counter electrode of the shower electrode 20 of the film forming chamber 16 described later. That is, in the film forming apparatus 10 of the illustrated example, the drum 18 and the shower electrode 20 form an electrode pair for performing film formation by CCP-CVD. Therefore, at least the outer peripheral surface of the drum 18 is formed of a conductive material such as metal.

If necessary, the drum 18 may be grounded, a bias power supply for applying a bias may be connected, or the ground and the bias power supply may be switchably connected. Good. As the bias power supply, various known power supplies such as a high-frequency power supply for applying a bias and a pulse power supply, which are used in the film forming apparatus, can be used.
Further, if necessary, the drum 18 may include temperature control means for heating and / or cooling the substrate Z. As the temperature control means, various known temperature control means such as a temperature control means using a Peltier element, a temperature control means using a heater, and a temperature control means by circulating a temperature control medium using a chiller unit or the like can be used.

In the film forming apparatus 10 shown in FIG. 1, as a preferred embodiment, the substrate Z is wound around the drum 18 constituting the electrode pair and conveyed, and the film is formed by CCP-CVD. Is not limited to.
For example, instead of the drum 18, a flat plate-shaped electrode is used to form an electrode pair with a shower electrode and a flat plate-shaped electrode, and a transfer roller pair is used to maintain the substrate Z in a flat shape while maintaining the electrode pair. The film may be formed by CCP-CVD by transporting the space between them. In this case, the surface of the shower electrode facing the substrate Z is also made flat.

In the vacuum chamber 12, in addition to the drum 18 described above, partition walls 28a and 28b extending from the inner wall surface 12a on the lateral side in the drawing of the vacuum chamber 12 to the vicinity of the peripheral surface of the drum 18 are arranged. The partition walls 28a and 28b are close to the peripheral surface of the drum 18 to a position where the tip end (opposite end to the inner wall surface 12a) does not come into contact with the substrate Z to be conveyed.
The film forming apparatus 10 is substantially airtightly separated in the vacuum chamber 12 from the partition walls 28a and 28b and the drum 18, and the upper side is the substrate chamber 14 and the lower side is the film forming chamber 16.

The substrate chamber 14 has a rotating shaft 32, a take-up shaft 34, guide rollers 36a and 36b, and a vacuum exhaust device 40.

The rotating shaft 32 is a known rotating shaft on which a substrate roll 26 around which a long substrate Z is wound is loaded. On the other hand, the take-up shaft 34 is a known long take-up shaft that winds the film-formed substrate Z into a film-formed substrate roll 42.
The guide rollers 36a and 36b are ordinary guide rollers that guide the substrate Z in a predetermined transport path. The substrate Z is guided by the guide rollers 36a and 36b and wound around a predetermined region of the drum 18.

The vacuum exhaust device 40 is a vacuum pump for reducing the pressure inside the substrate chamber 14 to a predetermined degree of vacuum. The vacuum exhaust device 40 reduces the pressure inside the substrate chamber 14 to a pressure that does not affect the film formation in the film formation chamber 16.
As the vacuum exhaust device 40, various known vacuum exhaust devices used in the vacuum film forming apparatus, which utilize a vacuum pump such as a turbo pump, a mechanical booster pump, a rotary pump, and a dry pump, can be used. In this respect, the same applies to the vacuum exhaust device 52 of the film forming chamber 16 described later.

In the film forming apparatus 10, the substrate roll 26 is mounted on the rotating shaft 32. Further, when the substrate roll 26 is mounted on the rotating shaft 32, the substrate Z passes through a predetermined path to the take-up shaft 34 via the guide roller 36a, the drum 18, and the guide roller 36b (). Will be passed).
In the film forming apparatus 10, the feeding of the substrate Z from the substrate roll 26 and the winding of the film-forming substrate Z on the take-up shaft 34 are performed in synchronization with each other to carry the long substrate Z through a predetermined transport path. A film is formed on the substrate Z in the film forming chamber 16 while being conveyed in the longitudinal direction.

A film forming chamber 16 is formed under the substrate chamber 14.
As described above, the film forming chamber 16 forms a film on the substrate Z by CCP-CVD by RtoR, and has a shower electrode 20, a gas supply unit 48, a high frequency power supply 50, and a vacuum exhaust device 52.

As described above, the shower electrode 20 is a gas supply electrode that constitutes an electrode pair for forming a film by CCP-CVD together with the drum 18.
The shower electrode 20 has a hollow portion 70 inside, and has a large number of gas supply holes 62 communicating with the hollow portion 70 on the discharge surface 20a which is a surface facing the drum 18. A film-forming gas is supplied to the hollow portion 70 from the gas supply portion 48.
The shower electrode 20 is basically a known shower electrode used for film formation by CCP-CVD. That is, in the film forming chamber 16, the film forming gas is supplied from the gas supply unit 48 to the shower electrode 20, and the film forming gas is discharged from the gas supply hole 62 of the discharge surface 20a of the shower electrode 20 to discharge the film forming gas to the shower electrode 20. The film-forming gas is supplied to the film-forming region between the 20 and the drum 18 (substrate Z).
The shower electrode 20 will be described in detail later with reference to FIG.

A gas supply unit 48 is connected to the shower electrode 20 by a gas supply pipe 48a. The gas supply unit 48 is a known film-forming gas (raw material gas, process gas) supply means used in the CVD apparatus, and supplies the film-forming gas to the hollow portion 70 of the shower electrode 20.
A high frequency power supply 50 is connected to the shower electrode 20. The high frequency power supply 50 is also a known high frequency power supply used in the CVD apparatus.

The film forming apparatus 10 for carrying out the film forming method of the present invention is RtoR for forming a film on the substrate Z by CCP-CVD.
That is, the film forming apparatus 10 sends out the substrate Z from the substrate roll 26 loaded on the rotating shaft 32 of the substrate chamber 14, guides the substrate Z to the drum 18 by the guide roller 36a, and winds the substrate Z around a predetermined region of the drum 18. In the film forming chamber 16, a film is formed on the substrate Z by CCP-CVD in the film forming region between the drum 18 and the shower electrode 20, and the film-formed substrate Z is wound up by the guide roller 36b. Guided by the shaft 34, the winding shaft 34 winds the roll into a film-formed substrate roll 42.

FIG. 2 shows a schematic cross-sectional view of the shower electrode 20.
In the following description, the transport direction of the substrate Z by the drum 18 (arrow t direction in the drawing), that is, the longitudinal direction of the substrate Z is the transport direction, and the direction of the rotation axis of the drum 18, that is, the direction orthogonal to the transport direction of the substrate Z. Also called the width direction. In FIGS. 1 and 2, the width direction is the direction perpendicular to the paper surface, and in FIG. 3, which will be described later, the direction is the arrow w direction in the drawing.

The shower electrode 20 has an electrode body 56 and an electrode base 58.
The electrode body 56 is a rectangular parallelepiped plate-shaped member formed of a conductive material, and a rectangular parallelepiped concave portion is formed in a central portion on one main surface. The other main surface facing the drum 18 is a discharge surface 20a, which is curved so as to be parallel to the peripheral surface of the drum 18. The main surface is the maximum surface of a plate-like object (sheet-like object).
Further, a large number of gas supply holes 62 are formed in the electrode body 56 by penetrating from the recess to the discharge surface 20a (the surface facing the drum 18). The gas supply hole 62 is a cylindrical through hole that is perpendicular to the main surface of a rectangular parallelepiped (electrode body without a curved surface) that serves as the electrode body 56.

The electrode base 58 is a rectangular plate-shaped member having a main surface having the same shape as the main surface of the electrode body 56 made of a conductive material. The electrode base 58 is provided so that the main surface of the electrode body 56 and the electrode body 56 are aligned with each other so as to close the recess of the electrode body 56. Further, the electrode body 56 and the electrode base 58 are fastened by bolts 68.
The hollow portion 70 is formed by closing the recess of the electrode body 56 with the electrode base 58.

A gas supply pipe 48a connected to the gas supply unit 48 is connected to the hollow portion 70 formed by the recess of the electrode body 56 and the electrode base 58. As a result, the film-forming gas is supplied from the gas supply unit 48 to the hollow portion of the shower electrode 20.
In the film forming apparatus 10 of the illustrated example, the number of gas supply pipes 48a for supplying the film forming gas to the hollow portion 70 is one, but if necessary, a plurality of gas supply pipes 48a are used to form a film on the hollow portion 70. Gas may be supplied.

The shower electrode 20 is provided so as to be separated from the drum 18 and to face the drum 18 with the curved surface side as the discharge surface 20a as described above. Therefore, the gas supply hole 62 opens in the discharge surface 20a of the shower electrode 20.
The shower electrode 20 discharges on the discharge surface 20a, which is the surface facing the drum 18, that is, the main surface on which the gas supply hole 62 opens.
When the film-forming gas is supplied from the gas supply unit 48 to the hollow portion 70 via the gas supply pipe 48a, the film forming gas is supplied between the shower electrode 20 and the drum 18 through the opening of the gas supply hole 62 on the discharge surface of the shower electrode 20. The film-forming gas is supplied to the film-forming region.

As described above, the discharge surface 20a of the shower electrode 20 (electrode body 56) has a curved surface along the peripheral surface of the drum 18, and the gas supply hole 62 opens on this curved surface.
In the film forming apparatus 10, since the discharge surface 20a is a curved surface, the distance between the peripheral surface of the drum 18 and the discharge surface in the region having the gas supply hole 62 for supplying the film forming gas is kept constant.
The distance between the discharge surface 20a and the drum 18 is not limited, but is usually about 5 to 40 mm.

In the film forming apparatus of the present invention, the structure of the shower electrode is not limited to that of a rectangular parallelepiped electrode body 56 having a recess and a plate-shaped electrode base 58 as shown in the illustrated example. , All known shower electrode configurations used in the CCP-CVD apparatus for forming a film by CCP-CVD with RtoR are available.
For example, the shower electrode may have a configuration in which the open surface of the housing to which one surface to which the gas supply pipe is connected is open is closed with a plate-like object having a gas supply hole (through hole in the thickness direction). Alternatively, a gas supply hole may be drilled in one main surface of the hollow rectangular housing, and a gas supply pipe may be connected to the other main surface (or side surface).

FIG. 3 conceptually shows the discharge surface 20a of the shower electrode 20 (electrode body 56). FIG. 3 is a view of the shower electrode 20 viewed from the drum 18 side, and is a plan view of the shower electrode 20. In FIG. 3, the transport direction is the arrow t direction, and the width direction is the arrow w direction.
As described above, the shower electrode 20 is formed with a large number of cylindrical gas supply holes 62 communicating with the hollow portion 70 from the discharge surface 20a so as to open to the discharge surface 20a.
In the present invention, the gas supply holes 62 are formed by being two-dimensionally arranged with respect to the main surface of the shower electrode 20 (electrode body 56). In the shower electrode 20 of the illustrated example, the gas supply holes 62 are arranged in a square grid pattern as shown in FIG. 3 as an example.

In the present invention, the arrangement of the gas supply holes 62 in the shower electrode 20 may be regular or irregular. However, it is regular in that it is easy to increase the coverage by a circle having the parameter L as a radius, which will be described later, it is easy to control the supply of the film-forming gas in the film-forming region, and it is easy to suppress abnormal discharge. preferable.
Further, when the gas supply holes 62 are regularly arranged, the arrangement of the gas supply holes 62 is not limited to the square lattice (square lattice) of the illustrated example, and various arrangements can be used. As an example, a hexagonal lattice (regular triangular lattice, hexagonal lattice), an oblique lattice (diamond lattice, central rectangular lattice, isosceles triangular lattice), a rectangular lattice (primitive rectangular lattice), and a parallel body lattice (distorted oblique lattice), etc. , So-called plane grid-like (periodic grid-like) arrangements are available in various ways.
Among them, the hexagonal lattice and the square lattice of the illustrated example are preferably used because the distance between the gas supply holes 62 can be made uniform and small and the formation density of the gas supply holes 62 can be easily increased.
In the present invention, when the gas supply holes 62 in the shower electrode 20 are regularly arranged, basically, the gas supply holes 62 are regularly arranged with a uniform density over the entire surface. However, in the present invention, even when the gas supply holes 62 are regularly arranged, for example, the density of the gas supply holes 62 gradually or gradually increases from the center to both ends in the width direction. The formation density of the gas supply hole 62 may be different in the plane direction of the discharge surface 20a, such that the density of the gas supply hole 62 gradually or gradually decreases toward the transport direction.

Here, in the film forming method of the present invention, the radius of the gas supply hole 62 in the shower electrode 20 is x [cm], and the flow rate of the film forming gas blown out from one gas supply hole 62 is y [sccm]. When the flow velocity of the film-forming gas blown out from the gas supply hole 62 of is v [sccm / cm ² ],
"V = y / (π × x ² )"
And the flow velocity v satisfies "4000 ≦ v ≦ 5500".
Further, when the parameter defined by the flow velocity v is L [cm],
"L = [(1.2 x 10 ^-4 ) x v] + x-0.3"
90% or more of the gas supply region S on the discharge surface 20a of the shower electrode 20 is covered with a circle centered on the center of the gas supply hole 62 and having the parameter L as the radius.

In the present invention, the gas supply region S is a region on the discharge surface 20a of the shower electrode 20 (gas supply electrode) where the gas supply hole 62 is formed. As described above, the discharge surface 20a is the surface of the shower electrode 20 facing the drum 18 (board Z).
Specifically, the gas supply region S is conceptually shown by exemplifying the shower electrode 20A in which the gas supply holes 62 are irregularly formed in FIG. 4.
From the most upstream position of the shower electrode 20A in the transport direction (arrow t direction), the line a (dashed line) that coincides with the width direction (arrow w direction) is moved in the transport direction, and the gas supply hole that first contacts. The line a at the position moved to the center of 62 is the first side (1st in the figure),
From the most downstream position of the shower electrode 20A in the transport direction, the line b corresponding to the width direction is moved in the direction opposite to the transport direction, and the line b at the position moved to the center of the gas supply hole 62 that first contacts is the first. 2 sides (2nd in the figure),
From the right end in the width direction of the shower electrode 20A, the line c corresponding to the transport direction is moved toward the left end, and the line c at the position moved to the center of the gas supply hole 62 that first contacts is the third side (FIG. 3rd in),
From the left end in the width direction of the shower electrode 20A, the line d corresponding to the transport direction is moved toward the right end, and the line d at the position moved to the center of the gas supply hole 62 that first contacts is the fourth side (FIG. 4th in the middle),
It is a rectangular area surrounded by the first side, the second side, the third side, and the fourth side. The rectangle that becomes the gas supply area S includes a square.
In the above definition, the right and left in the width direction are right and left in the transport direction.

That is, in the case of the shower electrode 20 shown in FIG. 3 in which the gas supply holes 62 are provided in a rectangular grid pattern, a line connecting the centers of the gas supply holes 62 arranged in the uppermost stream in the transport direction, which is indicated by a alternate long and short dash line in the figure. A line connecting the centers of the gas supply holes 62 arranged on the right end side in the width direction, a line connecting the centers of the gas supply holes 62 arranged on the most downstream side in the transport direction, and a line connecting the centers of the gas supply holes 62 arranged on the left end side in the width direction. The rectangle formed by the line connecting the centers of the gas supply holes 62 is the gas supply region S. In the present invention, 90% or more of such a gas supply region S is covered with a circle C conceptually shown in FIG. 5, centered on the center of the gas supply hole 62 and having a radius of parameter L. In the following description, "centered on the gas supply hole 62" is also simply referred to as "centered on the gas supply hole 62".
That is, 90% or more of the area of the region S shown by the alternate long and short dash line in FIG. 3 is covered by the circle C conceptually shown in FIG. 5 centered on the gas supply hole 62 and having the parameter L as the radius. In other words, the total area of the area centered on the gas supply hole 62 and not covered by the circle C having the parameter L, as shown by the diagonal line in FIG. 5, is less than 10% of the area of the gas supply area S. It becomes.

In the film forming method of the present invention, by having such a configuration, the product adheres to and accumulates on the discharge surface 20a of the shower electrode 20 (the surface facing the substrate Z (drum 18 serving as the counter electrode)). It is possible to prevent the product peeled from the shower electrode 20 from being mixed into the film or the like formed on the substrate Z and causing quality deterioration.

As described above, when the film is formed by CCP-CVD by RtoR using the shower electrode, the product adheres to and accumulates on the discharge surface of the shower electrode, particularly the shower electrode. Moreover, in RtoR, since the film is continuously formed for a long time, the amount of products deposited on the shower electrode becomes very large.
The product adhering to the shower electrode self-destructs due to its own internal embezzlement, peels off from the shower electrode, adheres to and mixes with the substrate and the film formed, and deteriorates the product quality. To contaminate.

Here, as a result of diligent studies, the present inventors have improved the flow velocity of the film-forming gas blown out from the gas supply hole 62, so that the discharge surface 20a (with the substrate Z) of the shower electrode 20 is formed around the gas supply hole 62. It was found that it is possible to prevent the product from adhering to the facing surface of the above.
The film-forming gas is blown out in the height direction of the gas supply hole 62 (the height direction of the cylinder), but some of the film-forming gas wraps around at the end of the opening of the gas supply hole 62. It proceeds along the discharge surface 20a of the shower electrode 20. During the film formation, the film-forming gas continues to be blown out from the gas supply hole 62 at the same flow velocity. Therefore, on the discharge surface 20a of the shower electrode 20, a flow of the film-forming gas is always generated outward from the gas supply hole 62 around the gas supply hole 62.
The film-forming gas immediately after being discharged from the gas supply hole 62 is not activated, and the film-forming gas does not form a film.
As described above, during the film formation, the film formation gas continues to be blown out from the gas supply hole 62. Therefore, on the discharge surface 20a of the shower electrode 20, a novel film-forming gas that is not activated outward from the gas supply hole 62, that is, is not used for film-forming is always generated around the gas supply hole 62. Flowing. In the region where the new film-forming gas is flowing, the film is not formed on the discharge surface 20a of the shower electrode 20.

The velocity of the film-forming gas flowing outward from the gas supply hole 62 on the discharge surface of the shower electrode 20 depends only on the flow velocity v of the film-forming gas injected from the gas supply hole 62.
That is, the film-forming gas injected from the gas supply hole 62 also determines to what region the film-forming gas that has not been activated and is not subjected to film formation reaches the outward direction centered on the gas supply hole 62. Depends only on the flow velocity v of.

Based on experiments and experiences, and studies using these results, the present inventors have "L = [(1.2 × 10 ^-4 ) × v] + x-0 from the center of the gas supply hole 62 outward. .3 ”
It was found that the film was not formed on the discharge surface 20a of the shower electrode 20 and the product did not adhere to the discharge surface 20a and was not deposited. That is, it was found that in the range of the circle C centered on the gas supply hole 62 and having the parameter L as the radius, the film is not formed on the discharge surface 20a of the shower electrode 20, and the product does not adhere and accumulate. It was.
The present invention has been made based on such findings. That is, the parameter L is a film-forming gas that is not activated and is not used for film-forming on the discharge surface 20a of the shower electrode 20 depending on the flow velocity v of the film-forming gas injected from the gas supply hole 62. , It is a parameter indicating to which position around the gas supply hole 62 to reach.

In other words, the parameter L is the length obtained by adding the non-deposited region a to the radius x of the gas supply hole 62, as conceptually shown in FIG.
The region a becomes so large that the unactivated film-forming gas does not exist in the vicinity of the gas supply hole 62, and depends only on the flow velocity of the film-forming gas around the gas supply hole 62 on the discharge surface 20a. Further, the flow velocity of the film-forming gas around the gas supply hole 62 on the discharge surface 20a depends only on the flow velocity v of the film-forming gas discharged from the gas supply hole 62.
That is,
"L = a + x-0.3"
And
"A = (1.2 x 10 ^-4 ) x v"
Is.

As described above, the larger the parameter L, the wider the region on the discharge surface 20a of the shower electrode 20 where the product does not adhere, centering on the gas supply hole 62. Therefore, the larger the parameter L, the more the adhesion and accumulation of the product on the discharge surface 20a of the shower electrode 20 can be suppressed.
Here, the parameter L is a function that depends only on the flow velocity v of the film-forming gas. Therefore, the faster the flow velocity v of the film-forming gas, the wider the region where the product does not adhere.
However, if the flow velocity v of the film-forming gas is too fast, the residence time of the activated film-forming gas is shortened in the film-forming region, and the film-forming rate (film-forming rate) is lowered.

The present invention has been made based on such findings, and the radius of the gas supply hole 62 is x [cm], and the flow rate of the film-forming gas blown out from one gas supply hole 62 is y [sccm]. When the flow velocity of the film-forming gas blown out from one gas supply hole 62 is v [sccm / cm ² ],
"V = y / (π × x ² )"
The parameter L [cm] defined by the flow velocity v is "L = [(1.2 × 10 ^-4 ) × v] + x−0.3”.
The flow velocity v satisfies 4000 ≦ v ≦ 5500 ”, and 90% or more of the gas supply region S on the discharge surface 20a of the shower electrode 20 is a circle centered on the gas supply hole 62 and having the parameter L as the radius. Covered by.
The flow rate y of the film-forming gas blown out from one gas supply hole 62 is the total flow rate [sccm] of the film-forming gas supplied from the gas supply unit 48 to the shower electrode 20. It may be calculated by dividing by the number of 62.

Further, in the following description, the circle centered on the gas supply hole 62 whose radius is the parameter L is also referred to as “a circle having the parameter L as the radius” for convenience.
Further, in the following description, the area ratio in which the circle having the parameter L as the radius covers the gas supply region S of the discharge surface 20a is also referred to as "coverage ratio in the gas supply region S" for convenience. That is, in the present invention, the coverage in the gas supply region S is 90% or more.

If the flow velocity v of the film-forming gas is less than 4000, it is difficult to increase the coverage in the gas supply region S to 90% or more, a sufficient film-forming rate cannot be obtained, and the film adheres to the shower electrode 20 or the like and peels off. Inconvenience such as generation of foreign matter occurs.
If the flow velocity v of the film-forming gas exceeds 5500, the flow velocity v of the film-forming gas is too fast to obtain a sufficient film-forming speed, and inconveniences such as abnormal discharge occur.
The flow velocity v is preferably 4500 ≦ v ≦ 5000, more preferably 4500 ≦ v ≦ 4800.

If the coverage in the gas supply region S is less than 90%, the effect of preventing the product from adhering to the discharge surface 20a is insufficient, and the contamination in the film forming apparatus and the product on the product such as the substrate Z and the gas barrier film are insufficient. Inconveniences such as inability to sufficiently prevent quality deterioration due to adhesion and mixing occur.
The coverage in the gas supply region S is preferably 95% or more, more preferably 97% or more, still more preferably 100%.

In the present invention, the coverage ratio in the gas supply region S is basically calculated as follows.
First, the gas supply area S is set as described above, and the area thereof is calculated.
Further, the area of the area covered by the circle having the parameter L as the radius in the gas supply area S is calculated. Alternatively, the area of the area not covered by the circle having the parameter L as the radius is calculated, and the total is calculated.
Then, the area covered by the circle having the parameter L as the radius or the total area of the area not covered by the circle having the parameter L as the radius is covered with the area of the gas supply area S. Calculate the rate.

Here, when the gas supply holes 62 are regularly provided like a plane lattice such as a square lattice and a hexagonal lattice as described above, and the formation density is uniform over the entire surface of the discharge surface 20a, In the gas supply region S, the same polygons such as the same triangle and the same quadrangle having the center of the adjacent gas supply hole 62 as an angle (top, apex angle) are arranged on the entire surface. In other words, if the gas supply holes 62 are regularly provided at a uniform density, the same polygons, such as the same triangle and the same quadrangle, formed by connecting the centers of the adjacent gas supply holes 62 are all over. It will be in a state as if it was arranged in.
For example, as conceptually shown on the left side of FIG. 7, when the gas supply holes 62 are arranged in a square grid pattern, the gas supply region S is connected to the centers of four adjacent gas supply holes 62. , The same squares whose corners are the centers of the four adjacent gas supply holes 62 are arranged on the entire surface. Further, as conceptually shown on the right side of FIG. 7, when the gas supply holes 62 are arranged in a hexagonal grid pattern, the centers of the three adjacent gas supply holes 62 are connected to the gas supply region S. , The same equilateral triangles whose corners are the centers of the three adjacent gas supply holes 62 are arranged on the entire surface.
Similarly, even when the gas supply holes 62 are arranged in an orthorhombic grid, a rectangular grid, a parallelepiped grid, or the like, the same quadrangle having the center of the adjacent gas supply holes 62 as a corner is formed on the entire surface of the gas supply region S. It will be in a state of being arranged in a quadrangle.

Therefore, when the gas supply holes 62 are regularly arranged, the shower coverage by the circle having the parameter L as the radius in the gas supply holes 62 forming the arranged triangles and quadrangles can be calculated. The coverage of the electrode 20 in the gas supply region S can be calculated.
For example, when the gas supply holes 62 are arranged in a square grid pattern, as shown in FIG. 5, the centers of the four adjacent gas supply holes 62 connecting the centers of the four adjacent gas supply holes 62 are connected. The shower electrode 20 is calculated by calculating the coverage ratio by the circle C having the parameter L as the radius or the area ratio of the area indicated by the diagonal line not covered by the circle C having the parameter L as the radius in the quadrangle S1 having the corner. The coverage of the gas supply region S on the discharge surface 20a can be calculated.

In the present invention, the closer the spacing between the arranged gas supply holes 62 is, the higher the coverage in the gas supply region S can be obtained even if the flow velocity v of the film-forming gas is slow.
In the present invention, the distance between the gas supply holes 62 is not limited, and may be appropriately set according to the size of the shower electrode 20, the assumed total flow rate of the film-forming gas, and the like. The distance between the gas supply holes 62 is preferably 0.9 cm or less, more preferably 0.45 cm or less, that is, the distance between the centers of the adjacent gas supply holes 62, that is, the pitch of the gas supply holes 62 is 0.9 cm or less. , 0.35 cm or less is more preferable.
By setting the pitch of the gas supply holes 62 to 0.9 cm or less, it is preferable in that the coverage in the gas supply region S can be preferably 90% or more.
The pitch of the gas supply holes 62 is not limited to the lower limit, but is usually 0.2 cm or more.
If the shape of the gas supply hole is not circular (cylindrical) including the center of the gas supply hole 62 when setting the gas supply area S described above, the center of the gas supply hole 62 is the gas supply. The hole 62 is set as the center (that is, the center of gravity) of the inscribed circle. The circle inscribed with the gas supply hole 62 is also used for the hole diameter of the gas supply hole 62 shown below.

Further, there is no limitation on the hole diameter (cylinder diameter) of the gas supply hole 62, depending on the size of the shower electrode 20, the number of gas supply holes 62, the amount of film-forming gas supplied from one gas supply hole, and the like. , It may be set as appropriate. The gas supply hole 62 preferably has a radius of 50 to 250 μm, more preferably 100 to 250 μm, and even more preferably 150 to 200 μm.
By setting the radius of the gas supply hole 62 to 50 μm or more, it is preferable in that a sufficient flow rate of the film-forming gas can be supplied.
Further, by setting the radius of the gas supply hole 62 to 250 μm or less, the flow velocity v can be suitably improved, and the flow velocity v can be easily controlled, which is preferable.

As described above, in the shower electrode 20, the gas supply hole 62 opens in the curved discharge surface 20a. Here, as described above, the gas supply hole 62 is formed by a cylindrical through hole perpendicular to the main surface of the rectangular parallelepiped forming the electrode body 56. Therefore, the shape of the opening of the gas supply hole 62 on the discharge surface 20a is not circular but elliptical.
However, in the present invention, the radius x of the gas supply hole 62 is the radius of the cylinder of the cylindrical gas supply hole 62, and the shape of the opening on the curved surface 56a is irrelevant. Further, even when the discharge surface 20a of the shower electrode 20 is a curved surface along the peripheral surface of the drum 18, the curved surface 56a has a very small curvature. That is, the difference between the major axis of the opening of the gas supply hole 62 on the curved surface and the radius x which is the radius of the cylinder of the cylindrical gas supply hole 62 is extremely small.

Further, in the shower electrode 20, the gas supply hole 62 is usually cylindrical. ^{In the present invention, correspondingly, the flow velocity v is calculated by "v = y / (π × x 2} )" by the area of the circle using the radius x of the gas supply hole 62.
However, in the present invention, the gas supply hole 62 is not limited to a cylindrical shape, and various types such as a square cylinder such as a square cylinder and a hexagonal cylinder, an elliptical cylinder, and a cylinder having an irregular upper and lower surfaces are used. The shape is available. In this case, the calculation of the flow velocity v is ^{changed to "(π × x 2} )", and the upper surface of the square cylinder, the elliptical cylinder, etc., which is the gas supply hole, is changed according to the shape of the cylinder which is the gas supply hole 62. An equation for calculating the area of the lower surface) may be used.
When the gas supply hole has a tubular shape with irregular upper and lower surfaces, a circle inscribed in the openings on the upper and lower surfaces is set, and the area of this circle (that is, the radius of the inscribed circle) is calculated as the flow velocity v. It may be used for.

Hereinafter, the film forming method of the present invention will be described by explaining the operation of the film forming apparatus 10 shown in FIG.
A substrate roll 26 formed by winding a long substrate Z into a roll shape is loaded on a rotating shaft 32, and the substrate Z is pulled out from the substrate roll 26 and wound up via a guide roller 36a, a drum 18, and a guide roller 36b. A predetermined transport path leading to the shaft 34 is inserted.

After inserting the substrate Z, the vacuum chamber 12 is closed and the vacuum exhaust devices 40 and 52 are driven to start exhausting each chamber.
After the substrate chamber 14 and the film forming chamber 16 are exhausted to a predetermined degree of vacuum or less, the gas supply unit 48 is then driven to supply the film forming gas to the shower electrode 20.

When the pressures in all the chambers are stabilized at a predetermined pressure, the driving of the drum 18 and the like is started, the transfer of the substrate Z is started, and then the high frequency power supply 50 is driven to supply the plasma excitation power to the shower electrode 20. While transporting the substrate Z in the longitudinal direction, the film formation on the substrate Z in the film forming chamber 16 is started, and the film is continuously formed on the long substrate Z.
The film-formed substrate Z is guided by the guide roller 36b and wound around the take-up shaft 34 to form a film-formed substrate roll 42.

Here, in the film forming apparatus 10, the gas supply unit 48 transfers the film forming gas to the shower electrode 20 according to the radius x [cm] of the gas supply holes 62 of the shower electrode 20 and the number of the gas supply holes 62. the supply amount [sccm], 1 piece of the gas flow velocity v of the supply hole 62 is blown film forming gas [sccm / cm ^2] is 4000~5500sccm / cm ² becomes and, the parameter L is defined by the flow velocity v and the radius The supply amount is such that the coverage of the gas supply region S by the circle centered on the gas supply hole 62 is 90% or more.
As a result, in the present invention, in the discharge surface 20a of the shower electrode 20, the product is formed in a region of 90% or more of the gas supply region S, which is covered with a circle centered on the gas supply hole 62 and having a radius of the parameter L. Can be prevented from adhering and accumulating.
Therefore, according to the present invention, it is possible to prevent the product from adhering to and accumulating on the shower electrode 20 even if the film is continuously formed on the substrate Z for a long time by RtoR, and the product is peeled off from the shower electrode 20. It is possible to prevent deterioration of product quality such as a gas barrier film due to contamination of the inside of the film forming apparatus by an object and adhesion and / or mixing of a product peeled from the shower electrode 20 to the substrate Z and the formed film.

Although the film forming method of the present invention has been described in detail above, the present invention is not limited to the above-mentioned examples, and various improvements and changes may be made without departing from the gist of the present invention. Of course.

Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

[Examples 1 to 10 and Comparative Examples 1 to 8]
An inorganic film containing amorphous silicon nitride as a main component is formed on a substrate by using a general film forming apparatus that deposits a film by CCP-CVD with RtoR using a drum such as the film forming apparatus 10 shown in FIG. A gas barrier film was produced by forming a film.

The drum used was made of stainless steel having a width direction (x direction) of 75 cm and a diameter of 100 cm.
The electrode body and electrode base of the shower electrode were made of aluminum, and the discharge surface had a curved surface parallel to the peripheral surface of the drum. The distance between the discharge surface of the shower electrode and the drum was set to 20 mm.
The shower electrodes have the same discharge surface size (75 x 30 cm (width direction x transport direction)), have cylindrical gas supply holes, and have a square grid-like arrangement of gas supply holes and a hexagonal shape. Two types of grid-like ones were used. In addition, as shown in Table 1, a plurality of types of shower electrodes having different radii of gas supply holes, pitch of gas supply holes, and at least one type of number of gas supply holes were used.

As the film-forming gas, silane gas (SiH ₄ ), ammonia gas (NH ₃ ), and hydrogen gas (H ₂ ) were used. The film-forming gas is supplied by changing the total flow rate supplied to the shower electrode in various ways, with the flow rate ratio of silane gas: ammonia gas: hydrogen gas being constant at 1: 2:10, as shown in Table 1. did.
The plasma excitation power supplied to the shower electrode was 6.5 kW, and the film formation pressure was 40 Pa.

As the substrate, a PET film (Cosmoshine A4300 manufactured by Toyobo Co., Ltd., 100 μm thick) having a 1 μm-thick base organic layer formed on one surface thereof was used. The inorganic film was formed on the underlying organic layer.
For the underlying organic layer, trimethylolpropane triacrylate (manufactured by Daicel Cytec) and a photopolymerization initiator (manufactured by Lamberti, ESACURE KTO46) are weighed so that the mass ratio is 95: 5, and these are weighed so that the solid content concentration is 95: 5. A polymerizable composition prepared by dissolving it in methyl ethyl ketone so as to have a concentration of 15% by mass was applied, dried, and cured by irradiation with ultraviolet rays to form a polymerizable composition.
In order to measure the film thickness of the inorganic film (silicon nitride film), a heat-resistant tape was attached to a part of the substrate (underlying organic layer) for masking prior to the film formation of the inorganic film.

As for the coverage in the gas supply region, as described above, in the shower electrode in which the gas supply holes are arranged in a square grid, the four adjacent gas supply holes connecting the centers of the four adjacent gas supply holes are connected. The coverage by a circle centered on the gas supply hole and the radius of the parameter L in the square as the corner was taken.
Similarly, the coverage in the gas supply region is positive in the shower electrode in which the gas supply holes are arranged in a hexagonal lattice, with the four adjacent gas supply holes connecting the centers of the three adjacent gas supply holes as corners. The coverage of the triangle with the gas supply hole as the center and the parameter L as the radius was taken.

[Evaluation]
The gas barrier film thus produced was evaluated for the film thickness, the number of defects, and the gas barrier performance of the inorganic film.

<Film thickness (film thickness) of inorganic film>
Prior to film formation of the inorganic film (silicon nitride film), the heat-resistant tape that masked a part of the underlying organic layer was peeled off, and the masked part and the normal film-forming part were contacted with a contact-type profilometer (manufactured by Bruker Nano). The film thickness of the formed inorganic film was measured by scanning with DECKTAC3ST) and measuring the step.
A, with a film thickness of 10 nm or more
B, if the film thickness is 4 nm or more and less than 10 nm
Those having a film thickness of less than 4 nm were evaluated as C.

<Number of defects>
The number of defects in the gas barrier film was measured using a laser microscope (OLS3100 manufactured by Olympus Corporation).
A, if the number of defects per 1 cm ^{2 is 3 or less}
B, with 4 to 9 defects per 1 cm ²
Those having 10 or more defects per 1 cm ^{2 were evaluated as C.}

<Gas barrier performance (barrier property)>
The water vapor transmittance [g / (m ² · day)] of the produced gas barrier film was measured by a calcium corrosion method (method described in Japanese Patent Application Laid-Open No. 2005-283561).
A, with a water vapor permeability of 3 x 10 ^-5 g / (m ² · day) or less
Water vapor transmission rate of ^{3 × 10 -5 g / (m} 2 · day) ^{Ultra, 4 × 10 -4 g / (} m 2 · day) or less of those B
Those having a water vapor permeability of more than 4 × 10 ^-4 g / (m ² · day) were evaluated as C.
The results are shown in the table below.

As shown in Table 1, according to the film forming method of the present invention, a gas barrier film having good gas barrier properties with few defects due to products deposited on the shower electrode can be produced at a good forming rate of the inorganic layer. ..
In particular, as shown in Example 1, Example 3, Example 6, and the like, when the flow velocity v is set to 4000 to 5000 sccm / cm ² , the film thickness, the number of defects, and the barrier property are excellent. A gas barrier film can be produced. Further, by setting the coverage to 95% or more, relatively favorable results can be obtained.
On the other hand, in Comparative Example 1 and Comparative Example 2 in which the flow velocity v of the film-forming gas is low, the coverage is low and the number of defects is large, and as a result, the gas barrier property is low. Further, in Comparative Example 3 and Comparative Example 4 in which the coverage rate exceeds 90% but the flow velocity v of the film-forming gas is also too low, the number of defects is small, but an inorganic layer having a sufficient thickness cannot be formed. As a result, the gas barrier property is low.
In Comparative Examples 5 and 6, the film thickness is sufficient because the flow velocity v of the film-forming gas is appropriate, but the number of defects is large due to the low coverage, and as a result, the gas barrier property is low.
In Comparative Example 7 and Comparative Example 8 in which the flow velocity v of the film-forming gas is too high, although the coverage is satisfied, an inorganic layer having a sufficient thickness cannot be formed, and as a result, the gas barrier property is low.
From the above results, the effect of the present invention is clear.

It can be suitably used for the production of gas barrier films and the like.

10 Film deposition equipment 12 Vacuum chamber 12a Inner wall surface 14 Substrate chamber 16 Film formation chamber 18 Drum 20 Shower electrode 20a Discharge surface 26 Substrate roll 28a, 28b Partition 32 Rotating shaft 34 Winding shaft 36a, 36b Guide roller 40, 52 Vacuum exhaust device 42 Pre-deposited substrate roll 48 Gas supply unit 48a Gas supply pipe 50 High frequency power supply 56 Electrode body 58 Electrode base 62 Gas supply hole 68 Bolt 70 Hollow part Z Substrate S Gas supply area S1 Square

Claims (6)

When forming a film on the substrate while transporting a long substrate in the longitudinal direction,
Using a gas supply electrode having a gas supply hole for supplying a film-forming gas on a surface facing the substrate, which is arranged facing the substrate, and a counter electrode constituting the gas supply electrode and an electrode pair. , A film is formed on the substrate.
The radius of the gas supply hole is x [cm], the flow rate of the film-forming gas blown out from one gas supply hole is y [sccm], and the flow velocity of the film-forming gas blown out from one gas supply hole is v. When [sccm / cm ² ] and the parameter defined by the flow velocity v are L [cm],
v = y / (π × x ² ),
L = [(1.2 x 10 ^-4 ) x v] + x-0.3,
And
Satisfy 4000 ≦ v ≦ 5500, and further
90% or more of the gas supply region, which is a region where the gas supply hole is formed on the surface of the gas supply electrode facing the substrate, is centered on the center of the gas supply hole, and the parameter L is a radius. circle that is not covered, in addition,
A film forming method, characterized in that the radius of the gas supply hole is 50 to 250 μm. The film forming method according to claim 1, wherein the counter electrode is a cylindrical drum that wraps the substrate around a peripheral surface and conveys the substrate in the longitudinal direction. The film forming method according to claim 1 or 2, wherein the gas supply holes are regularly arranged in the gas supply electrode. The film forming method according to claim 3, wherein the gas supply holes are arranged in a square grid or a hexagonal grid. The film forming method according to any one of claims 1 to 4 , wherein the flow velocity v satisfies 4500 ≦ v ≦ 5000. Claims 1 to 2, wherein 95% or more of the gas supply region is covered by a circle having the center of the gas supply hole as the center and the parameter L as the radius on the surface of the gas supply electrode facing the substrate . 5. The film forming method according to any one of 5.

Images