JP3170814B2 - Method for producing plasma polymerized film and plasma polymerization apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a plasma-polymerized film and a plasma-polymerized apparatus, for example, a plasma-polymerized film having excellent water vapor barrier properties and used as a protective film for magnetic disks, optical disks and the like. The present invention relates to a method for manufacturing a plasma-polymerized film for efficiently forming a surface without damaging the surface, and a manufacturing apparatus suitable for implementing the method.

[0002]

2. Description of the Related Art Plasma polymerization is a method in which almost all monomers can be polymerized. However, the surface of a substrate on which a plasma-polymerized film is formed or the plasma-polymerized film itself is ablated by plasma treatment or generated by polymerization. the film quality in the flying of the cluster and the large particles is a <br/> often child deterioration.

[0003]

A number of methods for forming a surface thin film using plasma polymerization or a method for forming a protective film having excellent water vapor barrier properties have been reported (for example, see JP-A-59-68818). ), All focus on film formation efficiency and materials, and it is hard to say that a treatment that does not damage the surface of the substrate or the plasma polymerized film has been pursued.

[0004] Although many surface protective films composed of a plasma-polymerized film have been reported, any of the resulting protective films contains many double bonds and polar groups peculiar to the plasma-polymerized film. Has been confirmed. When a double bond or a polar group peculiar to a plasma polymerized film is contained, the plasma polymerized film tends to be colored or the water vapor barrier property of the film tends to be reduced.

The inventors of the present invention have conducted intensive studies on a film forming method for obtaining a high quality plasma polymerized film without damaging the substrate surface and the film surface of the plasma polymerized film. By introducing
Separate the plasma generation source and the substrate surface position where the plasma polymerized film is formed, and obtain a high quality plasma polymerized film without damaging the substrate surface and the film surface of the plasma polymerized film without reducing the film forming speed. The inventors have found a film forming method and completed the present invention.

The present invention has been made in view of the above circumstances, and has been made in order to obtain a high quality plasma polymerized film without lowering the film forming rate, damaging the substrate surface and the film surface of the plasma polymerized film. and purpose thereof is to provide a manufacturing apparatus suitable for carrying out the manufacturing method and a method of film.

[0007]

To achieve the above Symbol purpose SUMMARY OF THE INVENTION The method for producing a flop plasma polymerized film of the present invention, a plasma onset
A guide cylinder is provided around the source, and outside the guide cylinder.
With the film-forming surface of the substrate facing downward or obliquely
Installed above the plasma source, and
An excited monomer gas is generated at the source,
-Gas is applied to the film-forming surface of the base material along the guide cylinder.
To the film surface of the substrate.
A polymerized film is formed.

Further, in order to achieve the above Symbol purpose, a plasma polymerization device of the present invention, flop that generates the excitation monomer gas
Seals the plasma source and the surrounding environment of this plasma source
A plasma polymerization apparatus having a sealed container
Around the plasma source inside the closed vessel,
The excited monomer gas generated by the plasma generation source
The guide tube inside the closed container.
Outside the cylinder and above the plasma source
On a substrate with the film deposition surface facing downward or obliquely
A plasma polymerized film is formed.

[0009]

In the method of manufacturing flop <br/> plasma polymerized film of the present invention using the plasma polymerization device of the present invention, by introducing the plasma guide cylinder body plasma polymerization device, and a plasma source, plasma polymerization Excitation monomer gas generated by the plasma generation source is guided to the surface of the substrate along the guide cylinder, and plasma polymerization is performed there. For this reason, it is possible to form a water vapor barrier protective film without damaging the substrate surface and minimizing ablation of the film.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for producing a plasma-polymerized film according to the present invention and a production apparatus used therefor will be described in detail with reference to the drawings. FIG. 1 is a schematic sectional view of a plasma polymerization apparatus according to one embodiment of the present invention, FIG. 2 is a graph showing film forming conditions in relation to a monomer flow rate and an internal pressure of the apparatus, and FIG. 3 is a plasma according to an embodiment of the present invention. FIGS. 4 and 5 are schematic cross-sectional views showing substrate positions in a method for producing a polymerized film, and FIGS.
6 and 7 are graphs showing the results of spectrum analysis in which the ESCA spectrum of Example 8 was subtracted from the ESCA spectrum of Comparative Examples 7 and 8.

First, an example of a plasma polymerization apparatus used in the method for producing a plasma polymerization film of the present invention will be described. As shown in FIG. 1, a plasma polymerization apparatus 2 according to one embodiment of the present invention has an anode shower electrode 4 and a cathode electrode 6 as a plasma generation source. The plasma generation source is housed in a closed container 8, and the inside of the closed container 8 is sucked through a pipe 10 and is maintained at a predetermined degree of vacuum.

The cathode electrode 6 is grounded. The anode shower electrode 4 is disposed parallel to the cathode electrode 6 at a predetermined distance from the cathode electrode 6, to which a DC voltage or a high-frequency voltage is applied. It is supposed to. Through holes are formed in the anode shower electrode 4, and monomers are released between the electrodes through the through holes.

As the plasma generating source, not only the above-mentioned parallel plate electrode but also an electrode of other shape or a means other than the electrode for emitting energy for plasma generation, for example, a laser generating device or the like is used. You may. Further, the monomer may not always be supplied from the shower electrode but may be supplied constantly from a portion other than the electrode.

In a closed vessel 8, a substrate 12 as a base material on which a plasma polymerized film is formed is rotatably held on a rotating shaft 14 above the electrodes 4 and 6 as plasma generating sources. The substrate 12 is made of, for example, a recording medium,
Although it is preferable that the rotation is performed by the rotation shaft, the rotation is not necessarily performed.

In the present invention, the substrate on which the plasma-polymerized film is formed is not limited to a mere substrate, but may be a single-layer or multilayer plate, tape, tape, or the like, such as a magnetic disk or optical disk having a recording layer formed thereon. Those having other shapes are applied. In addition, the substrate 12 as the base material is preferably arranged so that the surface on which the plasma polymerized film is formed faces downward in order to avoid the deposition of polymers and impurities deposited by gravity, but it is not necessarily required to face downward. Instead, it may be turned obliquely or sideways. It is preferable that the distance from the electrode as the plasma generation source to the substrate 12 as the substrate is a distance that can be reached within the lifetime of the excited monomer gas as the active species. The surface of the substrate 12 where the plasma polymerized film is not desired to be formed is
Mask it.

The closed container 8 is provided so that the inside can be observed.
Preferably, the outer surface is transparent. A protective wire mesh 16 is stretched on a side surface of the closed container 8. In the present embodiment, in such a plasma polymerization apparatus 2, an excited monomer gas generated between the electrodes so that the guide cylinder 18 surrounds the anode shower electrode 4 is provided around the periphery of the cathode electrode 6. Rotating substrate 12 arranged at
It is set to flow naturally toward the surface of. The guide cylinder is preferably made of a heat-resistant material such as a quartz tube or a Pyrex tube.

Next, a method for producing a plasma polymerized film according to the present invention using such a plasma polymerization apparatus 2 will be described. First, a substrate 12 on which a plasma-polymerized film is to be formed is placed in a sealed container 8. Thereafter, the pressure in the closed container is reduced. The pressure in the sealed container 8 varies depending on the voltage conditions applied between the electrodes 4 and 6, the monomer flow rate, and the like, and is not particularly limited, but is preferably 0.5 to 2 torr. As the polymerization conditions, any conditions can be used as long as the film formation conditions in the polymerization diagram shown in FIG. 2 are satisfied.

Next, electric power is supplied to the anode shower electrode 4, and at the same time, the monomer is discharged from the anode shower electrode 4 between the electrodes to bring the monomer into a plasma state to generate an excited monomer. The power applied to the anode shower electrode 4 is determined so as to generate a plasma state between the electrodes, and varies depending on the distance between the electrodes, and is not particularly limited.
A power of about 100 watts is preferred. The distance between the electrodes is preferably 2 to 6 cm.

The monomer released between the electrodes varies depending on the type of the plasma-polymerized film to be obtained, and is not particularly limited. For example, ethylene, ethane, styrene, tetrafluoroethylene, acetylene, xylene and the like can be used. it can. The flow rate of the monomer also varies depending on the type of the monomer.
rr, under the condition of output 50W) is 40-60cm ³ (STP) / m
in is preferred.

The excited monomer generated between the electrodes naturally moves upward by its own flow along the guide cylinder and reaches the rotating substrate surface, where a plasma polymerization reaction occurs, and the plasma surface is exposed to the plasma. A polymer film is formed.
At this time, in this embodiment, a high quality plasma polymerized film can be obtained without damaging the surface of the substrate 12 and the film surface of the plasma polymerized film itself. The plasma polymerization time varies depending on the thickness of the plasma-polymerized film to be obtained, but is preferably 15 to 30 minutes in the case of an ethylene plasma-polymerized film having a thickness of 2000 Å.

In the second method for producing a plasma-polymerized film of the present invention, after producing such a plasma-polymerized film, hydrogen gas is introduced into the closed vessel 8 through a pipe (not shown) to form the plasma-polymerized film. The environment around the substrate is set to a hydrogen gas atmosphere. In that case, of course,
No voltage is applied between the electrodes to generate plasma, and no monomer is released.

The purge pressure of the inside of the closed vessel with hydrogen gas is not particularly limited, but is preferably 1 to 10 atm. Further, the purge time by the hydrogen gas is not particularly limited, either.
1 minute to 10 hours are preferred. The higher the film temperature of the manufactured plasma polymerized film (below the glass transition temperature of the material constituting the substrate) or the higher the purge pressure, the shorter the purge time. After the completion of the hydrogen purging, the substrate 12 on which the plasma polymerization film is formed is taken out of the plasma polymerization apparatus 2.

In the second method for producing a plasma-polymerized film according to the present invention, after the plasma-polymerized film is polymerized, the inside of the apparatus is subjected to a hydrogen purge treatment, whereby the plasma-polymerized film is taken out into the atmosphere after the polymerization. In particular, the introduction of a double bond due to recombination of a residual radical or the introduction of a polar group due to oxidation can be efficiently suppressed. As a result, the water vapor barrier properties of the resulting plasma-polymerized film are significantly improved as compared with those without hydrogen purge.

In the second method for producing a plasma-polymerized film according to the present invention, the method for producing the plasma-polymerized film itself is not limited to the above-described embodiment, and is not limited to the conventionally known method for producing a plasma-polymerized film. The present invention can be applied to all the plasma polymerized film manufacturing methods proposed by the present applicant. In addition, as for the type of the monomer gas, any other than ethylene can be used as long as the residual radical forms a double bond or bonds with oxygen to form a polar group.

Next, more specific embodiments of the present invention will be described. However, the present invention is not limited to these embodiments, and can be variously modified within the scope of the present invention.

Embodiments 1 to 7 Using a parallel plate internal electrode type plasma polymerization apparatus as shown in FIG. (Electrode) Provided on the electrode 6. The anode electrode was a shower electrode from which the monomer was released.
An ethylene monomer is used as a monomer released from the anode electrode, and 13.56 MHz, 5
0 W of power was supplied. The flow rate of ethylene monomer is 4
It was 0 cm ³ (STP) / min. The pressure inside the closed container is 0.
1 torr, and the distance between the electrodes was 3.5 to 4 cm.
The polymerization time was 30 minutes.

The substrates on which the plasma polymerized film was to be formed were placed at positions A to G as shown in FIG. 3, and the film forming speed of the plasma polymerized film at each position was examined. As the substrate, a 100 μm-thick polycarbonate was used.
Table 1 shows the results. Examples 1 to 7 show examples in which plasma polymerization was performed at the positions A to G under the above conditions.

[0028]

[Table 1]

FIG. 4 shows the result of examining the infrared spectrum of the plasma-polymerized films in Examples 1 and 2.
Shown in As shown in FIG. 4, a clear spectrum close to low-density polyethylene was obtained. Further, the moisture permeability of the plasma polymerized film in Examples 1 and 2 was measured by the sun-resist method (St.
Regis method), it was found that 2.0 g 25 μm /
m ² · day .

Comparative Example 1 A plasma-polymerized film was produced in the same manner as in Examples 1 to 7, except that the substrate on which the plasma-polymerized film was to be formed was at the position H in FIG. Table 1 shows the film forming speed of the plasma polymerized film according to Comparative Example 1, and FIG. 5 shows the result of examining the infrared spectrum.

As shown in FIG. 5, in Comparative Example 1, it was found that a film containing a large amount of C 実 施 O, COOH and OH groups was obtained as compared with FIG. 4 corresponding to Example 1. When used as a water vapor barrier protective film or the like, the film of Example 1 containing no polar group is superior. When the moisture permeability is actually measured by the sun-resist method, it is 2.0 g 25 μm / m ² · day for Examples 1 and ² as described above, and 2.9 g 25 μm / m ^{2 for} Comparative Example 1. -It was day, and it was found that the plasma-polymerized films of Examples 1 and 2 placed at positions A and B were the most practically suitable films.

Comparative Example 2 Plasma polymerization was carried out in the same manner as in Example 1 except that the guide cylinder 18 was removed, and the substrate was placed at the position A in the figure.
A plasma polymerized film was obtained. The film formation rate of this plasma polymerized film is 6.7 nm / min, which is the same as that in Example 1. However, when the moisture permeability is measured by a sun-resist method, it is 3.5 g 25 μm / m ^2.
-It was day, and it was found that the water vapor barrier property was lower than that in Example 1.

Comparative Examples 3 to 6 A plasma polymerized film was obtained in the same manner as in Example 1 except that the positions of the substrates were changed to I to L in FIG. Comparative Examples 3 to
Table 1 shows the film forming rates of No. 6.

In Table 1, a comparison between each comparative example and the example shows that the polymerization efficiency of the examples 1, 2, 3 and the comparative example 1 is good. In Comparative Example 5 close to the anode electrode, it was found that the film thickness was reduced by ablation. Here, Example 3 and Example 6
In the plasma polymerized film, the polymerization rate was high, but the nonuniformity such as a gradient in the film thickness was large. Comparative Example 1
Then, although there is no problem in terms of the film formation speed, as described above,
It was found that A and B in Examples 1 and 2 were the optimal positions because of poor water vapor barrier properties.

Example 8 A plasma polymerized film was manufactured in the same manner as in Example 1 except that the substrate was set at the position B in FIG. Thereafter, the inside of the sealed container 8 was purged with hydrogen gas, and the internal pressure was set to 1 torr.
This state was maintained for 12 hours, and then the substrate on which the plasma polymerized film was formed was taken out. The composition of the film was examined using X-ray photoelectron spectroscopy (ESCA). Table 2 shows the results. In the table, the ratio of carbon atoms and oxygen atoms in the film is represented by atom%.

Comparative Example 7 A plasma polymerized film was obtained in the same manner as in Example 8, except that nitrogen gas was purged for 1 minute instead of hydrogen gas. ESC
Table 2 shows the results of A.

[Table 2]

Comparative Example 8 A plasma polymerized film was obtained in the same manner as in Example 8, except that ethylene gas was purged for 12 hours instead of hydrogen gas.
Table 2 shows the results of ESCA. The sample of Comparative Example 7 discharged into the atmosphere one minute later had the highest oxygen content, and the sample of Comparative Example 8 which had been purged with ethylene had the highest oxygen content.
The film according to (1) had the least amount of oxygen.

6 and 7 show the ESC spectrum of the sample of Example 8 and the ESC spectrum of the sample of Example 8, respectively.
The spectrum analysis results obtained by subtracting the A spectrum show that the ESCA spectrum of the sample of Comparative Example 8
The spectrum analysis result obtained by subtracting the CA spectrum is shown.

The peaks above the base line X are more components than those of the sample of Example 8, and the peaks below the base line X are those of Example 8.
Is a component that is more in the sample. Thus, the sample according to Comparative Example 7, which was returned to the atmospheric pressure one minute after the polymerization, had C = O, CO
It has been found that there is much oxygen in the form of polar groups such as O-. Further, in the film of Example 8 which had been purged with hydrogen, a structure such as CH and CC which further preserved the monomer structure was observed.

On the other hand, the film of Comparative Example 8 which was purged with ethylene and taken out into the air 12 hours later, had C = O, CO
Although there is a polar group such as O-, Comparative Example 7 of purge after 1 minute
The amount is smaller than that of the film. Also, the amount of C—O showing an ether bond is smaller than that of the hydrogen purged film. In view of the above, a film containing no polar group is desirable in view of the properties of the protective film, and thus the hydrogen-purged film of Example 8 can be said to be a better film.

Comparative Example 9 A plasma polymerized film was obtained in the same manner as in Example 8, except that the substrate was immediately taken out into the air after plasma polymerization without purging with hydrogen. The results of the moisture permeability measurement are shown below.
The measurement of the water vapor transmission rate was performed by the sun-register method.

After the polymerization, the sample of Comparative Example 9 which was immediately returned to the atmospheric pressure was 2 g at 25 μm / m ² · day, and the sample of Example 8 which had been purged with hydrogen was at 1.2 g at 25 μm / m ² · day. It was found that the sample of Example 8 had better water vapor barrier properties.

[0043]

According to the manufacturing method of the flop plasma polymerized film of the present invention using the plasma polymerization device of the present invention, by introducing the plasma guide cylinder body plasma polymerization device, and a plasma source, plasma polymerization Excitation monomer gas generated by the plasma generation source is guided to the surface of the substrate along the guide cylinder, and plasma polymerization is performed there. For this reason, it is possible to obtain a high-quality plasma polymerized film without lowering the film forming speed and without damaging the substrate surface and the film surface of the plasma polymerized film.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a plasma polymerization apparatus according to one embodiment of the present invention.

FIG. 2 is a graph showing film forming conditions in a relationship between a monomer flow rate and an internal pressure of the apparatus.

FIG. 3 is a schematic cross-sectional view showing a substrate position in a method for manufacturing a plasma-polymerized film according to an embodiment of the present invention.

FIG. 4 is a graph showing the result of examining the infrared spectrum of the plasma polymerized film.

FIG. 5 is a graph showing a result of examining an infrared spectrum of the plasma polymerized film.

FIG. 6 is a graph showing the result of spectrum analysis obtained by subtracting the ESCA spectrum of Example 8 from the ESCA spectrum of Comparative Example 7.

FIG. 7 is a graph showing a spectrum analysis result obtained by subtracting the ESCA spectrum of Example 8 from the ESCA spectrum of Comparative Example 8.

[Explanation of symbols]

2 plasma polymerization apparatus 4 anode shower electrode 6 cathode electrode 8 sealed container 12 substrate (base material) 18 guide cylinder

Claims (2)

(57) [Claims] 1. A guide cylinder is provided around a plasma source.
Only, an external of the guide cylinder, downward deposition surface of the substrate
Or, set obliquely above the plasma source.
And location, to generate excited monomer gas in the plasma generating source, said excitation monomer gas, said along said guide cylinder
It led to flow toward the deposition surface of the substrate, a manufacturing method of the plasma polymerization film, which comprises forming a plasma polymerized film on the deposition surface of the substrate. 2. A plasma polymerization apparatus comprising : a plasma generating source for generating an excited monomer gas; and a sealed container for covering an environment surrounding the plasma generating source in a sealed state, wherein the plasma generating source inside the sealed container is around guide the excitation monomer gas generated by the <br/> plasma source
Having a guide cylinder, outside the guide cylinder inside the closed container,
Installed above the plasma source and face down
A plasma polymerization apparatus characterized in that a plasma polymerization film is formed on a substrate which is oriented obliquely or obliquely .