JPH0518330B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a continuous plasma processing apparatus for elongated objects. More specifically, plasma treatment of long objects such as membranes, films, sheet cloths, fibers, etc., especially long objects that are flat or relatively thin and wide (hereinafter sometimes referred to as treated fabrics). It relates to a device for continuous operation.

(Prior Art) Many proposals have been made in the past regarding plasma processing apparatuses, particularly plasma processing apparatuses for flat sheet-like objects and long objects. For example, Tokuko Sho 60-11149
No. 60-31939 proposes a plasma processing apparatus in which a cloth is passed between a pair of opposing electrodes with a large area, and Japanese Patent Application Laid-Open No. 60-134061
No. 61-228028, Special Publication No. 60-59251, No. 61
JP-A-36862 proposes a plasma processing apparatus in which a plurality of non-grounded electrodes are arranged around a cylindrical grounded electrode. Furthermore, Special Publication No. 60-11150,
No. 60-54428 each proposes a plasma processing apparatus having multilayered parallel plate electrodes.

(Problem to be solved by the present invention) However, the above-mentioned Japanese Patent Publication No. 11149/1983, No. 60-
The proposals in each publication of No. 31939 have problems such as non-uniform treatment due to local variations in the degree of treatment on a large-area electrode surface, and a decrease in treatment efficiency due to plasma discharge occurring above, below, left and right of the electrode.
In addition, in the above-mentioned Japanese Patent Application Laid-Open No. 60-134061 and other proposals, the processing area of the electrode cannot be made very large, and discharge loss around the non-grounded electrode cannot be avoided. Said Special Publication No. 11150, No. 60-
In the proposals of each publication of No. 54428, there is a problem in obtaining stable operation and quality due to phase shift of high frequency waves etc. on each multilayered electrode and mutual interference between the electrodes.

As described above, none of the conventionally known plasma processing apparatuses can fully satisfy all of the requirements of operational stability, quality uniformity, and processing efficiency relative to input power.

In order to eliminate the drawbacks of these conventionally proposed devices, the present inventors have developed a vacuum container, a plurality of non-grounded electrodes each having a planar treated surface disposed therein, and a plurality of non-grounded electrodes facing the non-grounded electrode treated surface. Japanese Patent Application No. 62-33442 proposed a plasma processing apparatus comprising a grounded electrode provided with a ground electrode and guide means for passing the object to be processed between the non-grounded electrode and the grounded electrode. This proposed device succeeded in solving many of the various technical problems associated with conventionally known devices, but as a result of continued research, we found that there were still improvements in terms of making the device more compact and improving processing efficiency. They discovered the need for improvement and completed the present invention.

An object of the present invention is to provide a plasma processing apparatus that has a plurality of electrodes, but does not cause mutual interference of plasma between the electrodes, and suppresses unnecessary and harmful plasma discharge around the electrodes as much as possible. There is something to do. Another purpose is to enable more stable driving,
Another object of the present invention is to provide an apparatus that can more efficiently produce high-quality and uniform workpieces.

(Means for Solving the Problems) The present invention includes a vacuum container, a plurality of non-grounded electrodes having a planar treated surface disposed therein, and a grounded electrode provided opposite to the non-grounded electrode treated surface. Therefore, in a plasma processing apparatus equipped with a guide means for passing the object to be processed between the non-grounded electrode and the grounded electrode, a power introduction part is disposed in the center of the non-grounded electrode group, and the The plasma processing apparatus is characterized in that the non-grounded electrodes each connected to a power introduction part are arranged radially.

The objects to be treated to be applied in the present invention are not particularly limited as long as they are long, flat, or relatively thin, such as membranes, films, sheets, cloth, fibers, and threads.

The present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

FIG. 1 is a schematic front view showing one specific example of the device of the present invention, FIG. 2 is a schematic side view thereof, FIG. 3 is a schematic front view showing another specific example of the device of the present invention, and FIG. FIG. 4 is a schematic front view of a plasma processing chamber that forms the main part of FIG. 3;

In FIGS. 1 and 2, a power introduction part 1 is located in the center of four groups of non-grounded electrodes in a vacuum vessel A, and a plurality of electrode connecting members 2 extending from the power introduction part are arranged radially. It supports the plurality of non-grounded electrodes 4 and electrically connects the power introduction part 1 and each non-grounded electrode. The power introduction part 1 is electrically insulated and supported by the vacuum container by an insulating bearing part 3, and is coupled with a terminal 15 from a high frequency power source. The non-grounded electrode 4 has a planar treated surface, and the angle formed by both the front and back surfaces is not particularly limited, but it is set to an appropriate angle so that the traveling treated fabric guided by the guide means described later can be easily parallel to the electrode surface. . The electrode connecting member 2 and the non-grounded electrode 4 do not necessarily need to be coaxial. However, it is preferable to equalize the electrical resistance and distance from the electrode connecting member 2 to each non-grounded electrode 4 in terms of balance of power distribution.

In a radial arrangement, the angles between adjacent ungrounded electrodes need not all be equal, but it is most preferred that they be equiangular radially.

The planar ground electrode 5 is provided on both sides of the non-ground electrode 4.
They are installed facing each other. It is preferable that the ground electrode 5 and the non-ground electrode 4 are installed parallel to each other and separated from each other by an equal distance. The distance between electrodes depends on input energy, electrode shape, degree of vacuum, processing speed, plasma etching, plasma polymerization, plasma CVD.
It depends on the processing method, but in general, if the degree of vacuum is small and the input energy is small, it is better to make it narrower, usually less than 10 cm, preferably 5 cm.
It is. For example, in the case of oxygen plasma, the degree of vacuum is 1
At about mmHg, about 0.5 to 3 cm is effective.
The materials of the non-grounded electrode 4 and the grounded electrode 5 are preferably highly conductive metals, such as aluminum, copper, iron, stainless steel, and various metal platings thereof. The shape can be a flat plate, punched plate, or mesh (wire mesh), but the input power is limited.
At 0.1 W/cm ² or more, a flat plate without holes or irregularities is preferable.

It is preferable that the non-grounded electrode 4 and the grounded electrode 5 have a passage for a temperature regulating medium therein to enable temperature regulation, particularly cooling. Any medium can be used as long as it has fluidity, but pure water, which is an electrical insulator, organic solvents, various heat exchange gases, and steam are preferred. Further, as a temperature control device or a cooling device, it is preferable to install a coiled pipe or jacket through which a refrigerant passes through the electrodes. Various plasma treatments (e.g. plasma polymerization, plasma CVD, plasma etching, etc.) can be performed by controlling the temperature of the non-grounded electrode.
The substrate temperature can be set to the most appropriate temperature according to the In this way, the temperature of the non-grounded electrode can be set arbitrarily, and the sample to be processed can thereby be brought into contact with the non-grounded electrode, allowing stable processing over a long period of time. The vacuum vessel A further includes a supply roller 9 for the treated fabric and a take-up roller 10 driven by an electric motor 16 or the like in the space between the radial electrode pairs. It is preferable that the supply roller 9 and the take-up roller 10 be made reversible by making the coupling mechanism of the electric motor 16 capable of driving the rollers in reverse as appropriate.

Inside the vacuum container A, there is also a guide means, such as a guide bar, a guide, for sequentially guiding the fabric 8 supplied from the supply roller 9 into the gap between the grounded electrode and the non-grounded electrode and winding it onto the winding roller 10. Rollers 6 and 7 are arranged at appropriate positions near the base and tip of each electrode. As these guide means, fixed rolls, driven rolls, drive rolls, or a combination thereof can be used as appropriate depending on conditions such as fabric weight, running speed, tension, etc., and the treated fabric is kept as close to the non-grounded electrode or the grounded electrode surface as possible. , it is preferable to adjust and arrange them so that they can travel in sliding contact.

The material of the rollers 6 and 7 for running the treated fabric through the plasma space may be metal, ceramic, metal-coated ceramic, or rubber coating such as NBR or silicone, which has less etching property than the treated fabric and has excellent heat resistance. etc. is good. It is also better for the rollers to be grounded. The surface of the roller is preferably mirror-finished in order to prevent the treated fabric from slipping. More preferably, it is coated with a rubber coating or a rubber tube, such as silicone rubber, NBR rubber, SBR rubber, or fluorine rubber, in order to provide running stability for the object to be processed and to prevent heating.

Main components such as a non-grounded electrode, a grounded electrode, a treated fabric guide means, and a power introduction part in the vacuum container are supported by a frame 13, and are covered with a cover 14 that connects the grounded electrodes to each other, so that they are integrated. It travels along the guide rail 17 and is loaded into and removed from the vacuum container.

The material of the cover 14 may be an insulating material or a conductive material, but it is preferably made of the same material as the electrode material, such as stainless steel, aluminum, copper plate, etc., and more preferably has a see-through window in the center for monitoring the plasma space. Good. The material for the see-through window may be organic or inorganic as long as it can be seen through, but inorganic materials with excellent plasma resistance and heat resistance, such as glass and inorganic crystals, are preferable. Further, it is better that the cover is grounded, and in this case, the distance between the cover and the non-grounded electrode 4 is preferably larger than the distance between the grounded electrode and the non-grounded electrode in terms of plasma stability and uniformity.

The shape and dimensions of the vacuum container are not particularly limited as long as it can withstand an internal and external pressure difference of at least 1 atmosphere, but it is equipped with a gas introduction hole 11 and an exhaust hole 12 that communicates with a vacuum pump, so that the contents such as the above-mentioned main components can be kept inside the vacuum container. It has an opening/closing device for loading and unloading, and is preferably equipped with a see-through window for monitoring the contents. The shape of the gas outlet of the gas introduction hole 11 should be an elongated slit or have many small holes, and the gas outlet should be present over the entire width of the electrode to ensure an even ratio of the introduced gas to the decomposed gas. , which is preferable because a stable treatment effect can be obtained. The material of the gas introduction piping is
Organic materials such as plastics can be used, but for long-term stable use, metals that are chemically stable, have high plasma resistance, and can withstand high temperatures, such as stainless steel pipes, copper pipes, aluminum pipes, or glass pipes, etc. is preferred.

In the specific example shown in FIGS. 3 and 4, vacuum vessels B and C are separately provided which communicate with vacuum vessel A through passages 18 and 19, respectively, and electrodes are disposed within vacuum vessel A. , a treated fabric supply roller 9 and a take-up roller 10 are individually housed in vacuum containers B and C. In this way, the supply roller 9
and the respective occupied spaces of the winding roller 10 are placed in a vacuum container A.
By providing the electrodes outside the vacuum vessel A, the number of electrodes disposed inside the vacuum vessel A can be increased and the plasma processing capacity can be increased. In the examples of FIGS. 3 and 4, twice as many electrodes are provided as in the example shown in FIG. 1, and therefore the plasma processing capacity is doubled.
The fabric in the vacuum container B starts from the supply roller 9, has its running path regulated by the guide roller 20, enters the vacuum container A through the passage 18, passes through the electrode gap, and then is guided by the guide roller 21 through the passage 19 and wound. It is wound up on a take-up roller 10.

Vacuum containers B and C are combined into a single container,
The fabric supply roller 9 and take-up roller 10 can also be housed together and communicated with the vacuum vessel through one passage.

(Function) Electric power for plasma is introduced intensively through the power introduction section 1. Electric power is introduced into each non-grounded electrode 4 from the power introduction section 1 through the electrode connecting member 2. In addition, since the power supply has only one power introduction part, a single power supply can be used, and when multiple power supplies are used, mutual interference of high frequencies due to differences in oscillation frequency, etc. between each power supply, and plasma imbalance occur. almost disappears.

The non-grounded electrode 4 has 50Hz and 60Hz for plasma generation.
Power at commercial frequencies in Hz, low frequencies in kilohertz, and high frequencies in the megahertz to gigahertz range is introduced to generate a cold gas plasma between a ground electrode.

For stable generation of low-temperature gas plasma,
A low frequency or high frequency of several KHz to several hundred KHz is preferable, and a high frequency of 13.56 MHz is particularly preferable in terms of processing efficiency, processing cost, etc. In addition, the input energy of low frequency or high frequency varies depending on the electrode shape, distance between electrodes, degree of vacuum, processing speed, etc., but is usually 0.01 W/cm 2 or more per unit area, preferably 0.2 W/cm ² or more.
-10W/ ^cm2 , more preferably 0.1-1W/ ^cm2 .

Gases that generate low-temperature gas plasma include:
Non-polymerizable gases such as oxygen, nitrogen, argon, helium, and hydrogen, and polymerizable organic monomer gases such as methane, ethane, propane, butane, benzene, acrylic acid, and styrene can be used, and are selected depending on the purpose.

For plasma etching of polyester fibers, etc., oxygen, air, nitrogen, argon, hydrogen, carbon dioxide gas, helium, halogenated hydrocarbons such as CF ₄ , CF ₂ Cl ₂ , CFCl ₃ , CHF ₃ and their derivatives, either alone or in combination, are used. Gas can be used.

The degree of vacuum in the plasma space is in the region where low-temperature gas plasma is stably generated, that is, usually 0.001 to 10
Adjust to mmHg, preferably 0.1 to 5 mmHg, more preferably 0.2 to 1 mmHg. The degree of vacuum can be adjusted by adjusting the pumping speed and introducing gas or monomer gas, but in order to perform the desired treatment preferably, the amount of gas introduced is adjusted.

The gas is preferably introduced through a gas introduction pipe and blown out toward the processing surface of the object to be processed. As a result, the newly introduced gas always comes into contact with the processing surface of the object to be processed, and furthermore, the decomposed gas generated by plasma processing is efficiently discharged from the plasma space. The ratio of introduced gas to decomposed gas is at least 1, preferably 2 or more, more preferably 4 or more. Increasing the efficiency of plasma processing and preventing heterogeneous reactions are greatly influenced by how efficiently the introduced gas is turned into plasma and applied to the surface of the object to be treated, and how efficiently the decomposed gas is removed and discharged from the surface of the object to be treated. Cover 1 connecting ground electrodes
4 serves to efficiently replace the introduced gas and decomposed gas.

In the present invention, the treated fabric 8 is brought into contact between the grounded electrode 5 and the non-grounded electrode 4, preferably in the vicinity of the surface of the grounded electrode or the non-grounded electrode, more preferably in contact with the surface of the grounded electrode or the non-grounded electrode, and particularly preferably in the vicinity of the surface of the grounded or non-grounded electrode. Contact the ground electrode surface. When the object to be processed is brought into contact with a non-grounded electrode, the plasma etching effect increases, and this seems to be due to the following reasons.

In plasma, especially in low-temperature plasma caused by the application of low-frequency and high-frequency potentials, a self-bias is generated in the plasma space, but in the region where the self-bias is generated, the kinetic energy of large-mass ions is extremely large, and therefore, the kinetic energy of ions with large mass is extremely large, and therefore the ions are processed in that space. As a result, processing speed and processing effectiveness can be greatly increased.

It is possible to process the object continuously or to repeat running and stopping processes.

Preferred embodiments of the device of the present invention are summarized and described below.

(b) The device according to claim 1, wherein the surface of the ground electrode is planar.

(b) The device according to claim 1, wherein the non-grounded electrode surface and the grounded electrode surface face each other at an equal distance.

(c) The device according to claim 1, wherein the temperature of the non-grounded electrode surface and/or the grounded electrode surface is adjustable.

(d) The apparatus according to claim 1, further comprising guiding means so that the object to be treated comes into contact with the surface of the non-grounded electrode.

(e) The apparatus according to claim 1, further comprising a guiding means so that the object to be treated comes into contact with the surface of the ground electrode.

(Effects of the Invention) In the plasma processing apparatus according to the present invention, since the distances from the power introduction part to the non-grounded electrodes can be made equal, it is possible to introduce power of the same phase to each of the plurality of non-grounded electrodes. It became like that.

In addition, since the power introduction portions for each electrode could be unified, a single power source could be used. Therefore, it is possible to prevent mutual interference of plasma between multiple electrodes and mutual interference between multiple power supplies, which is seen in conventional plasma processing equipment with multilayered electrodes, and stable operation and stable quality can be achieved. It became like that.

In addition, the space around the non-grounded electrode is narrower than in the conventional case, making it possible to reduce unnecessary plasma discharge in this area, and making it possible to use input power more efficiently.

As described above, the apparatus of the present invention can provide plasma processing apparatuses and plasma-treated products that are significantly lower in cost, higher quality, and more stable than conventional apparatuses.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing one specific example of the device of the present invention, FIG. 2 is a schematic side view thereof, FIG. 3 is a schematic front view showing another specific example of the device of the present invention, and FIG. FIG. 4 is a schematic front view of a plasma processing chamber that forms the main part of FIG. 3; A, B, C...Vacuum container, 1...Power introduction part, 2...
Electrode connecting member, 3... Insulated bearing part, 4... Ungrounded electrode, 5... Grounded electrode, 6, 7... Guide means, 8... Fabric, 9... Supply roller, 10... Winding roller,
11... Gas introduction hole, 12... Exhaust hole, 13... Frame, 14... Cover, 15... Terminal, 16... Electric motor,
17... Guide rail, 18, 19... Passage, 20,
21...Guide roller.

Claims (1)

[Claims] 1 Consists of a vacuum container, a plurality of non-grounded electrodes disposed therein having a planar processing surface, and a grounded electrode provided opposite to the non-grounded electrode processing surface, and the object to be processed is connected to the non-grounded electrode. In the plasma processing apparatus equipped with a guide means for passing between the ground electrode and the ground electrode, a power introduction part is disposed in the center of the non-ground electrode group, and the non-ground electrodes each connected to the power introduction part are arranged in the center of the non-ground electrode group. A plasma processing apparatus characterized by being arranged in a radial manner.