JPH01256541A - Plasma treatment apparatus - Google Patents

Abstract

PURPOSE:To suppress unnecessary plasma discharge near the electrodes as much as possible, by radially arranging ungrounded electrodes connected to a power supply provided at the center. CONSTITUTION:A power supply part 1 supported by an insulated bearing part 3 is provided at the center of a group of ungrounded electrodes 4 arranged in a vacuum vessel A which is provided with a gas inlet hole 11 and a gas discharge hole 12 and can withstand a pressure difference between the outside and inside pressures of at least 1atm, and a plurality of the radially arranged electrodes 4 are supported by electrode connecting members 2 extending from said part 1. The supply part 1 is electrically connected to the electrodes 4, and flat grounded electrodes 5 are provided in positions opposed to and in parallel with both surfaces of the electrode 4. A winding roller 10 is driven by an electric motor 16, and a cloth 8 wound around a supply roller 9 is supplied through rollers 6 and 7 to the gap between the electrode 5 and the electrode 4, subjected to plasma treatment and wound around a roller 10.

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, sheets, cloth, fibers, etc., especially long objects that are flat or relatively thin and wide (hereinafter sometimes referred to as treated fabrics). This invention relates to a device for continuously performing

(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, Special Publication No. 6O-IL149, No. 60-3
No. 1,939 each proposes a plasma processing apparatus in which a cloth is passed between a pair of opposing electrodes with a large area, and Japanese Patent Laid-Open Nos. 60-134,061 and 61-2
No. 28.028, Special Publication No. 60-59.251, No. 61
No. 36.862 each proposes a plasma processing apparatus in which a plurality of non-grounded electrodes are arranged around a cylindrical grounded electrode. Furthermore, Special Publication No. 11,150 of 1980, 6
No. 0-54.428 each proposes a plasma processing apparatus having multilayered parallel plate electrodes.

(Problem to be solved by the present invention) However,
-31.939 The proposals in each publication have problems such as non-uniform treatment due to local variations in the degree of treatment on a large electrode surface, and a decrease in treatment efficiency due to plasma discharge occurring above, below, and on the left and right sides of the electrode. There is. Also, the aforementioned Unexamined Patent Application Publication No. 1986
In the proposals of Publication No. 134.061 and others, the processing area of the electrode cannot be made very large, and discharge loss around the non-grounded electrode cannot be avoided. Said Special Public Service 1986
-11,150 and No. 60-54.428 propose that the phases of high-frequency waves, etc., are shifted on each multilayered electrode, and mutual interference occurs between the electrodes, resulting in stable operation and quality. There is a problem above.

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.

The present inventors aimed to eliminate the drawbacks of these conventionally proposed devices (i.e., a vacuum container, a plurality of non-grounded electrodes each having a planar treated surface disposed therein, and facing the non-grounded electrode treated surface). Patent Application No. 1982-33, April 1982, a plasma processing apparatus is equipped with a plasma processing apparatus comprising a ground electrode provided with a ground electrode and a guide means for passing the object to be processed between the non-ground electrode and the ground electrode.
I proposed it as No. 42. 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 object is to provide an apparatus that can operate more stably and 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 an example of the device of the present invention;
The figure is a schematic side view thereof, FIG. 3 is a schematic front view showing another specific example of the apparatus of the present invention, and FIG. 4 is a schematic front view of a plasma processing chamber forming the main part of FIG.

In FIGS. 1 and 2, a power introduction part l is located in the center of four groups of non-grounded electrodes in a vacuum container 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 to 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 is set to an appropriate angle that allows the traveling treated fabric to be guided by the guide means described later to 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.

Planar ground electrodes 5 are provided on both sides of non-ground electrode 4, 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 the electrodes varies depending on the input energy, electrode shape, degree of vacuum, processing speed, and processing method such as plasma etching, plasma polymerization, or plasma CVD, but - when the degree of vacuum is low and the input energy is small It is better to make it narrower, usually less than 10 cra, preferably 5
cm. For example, in the case of oxygen plasma, the degree of vacuum is lm
At about mHg, about 0.5 to 3 cIIl 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 flat plate, punched plate or mesh (gold 1ii).
) can be used, but if the input power is 0.1 W/cm" 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 a jacket through which a refrigerant passes through the electrodes. By controlling the temperature of the non-grounded electrode, the substrate temperature can be set to the most appropriate temperature according to various plasma treatments (eg, plasma polymerization, plasma CVD, plasma etching, etc.).

In this way, the temperature of the non-grounded electrode can be set arbitrarily, and
As a result, the processing sample can be brought into contact with the non-grounded electrode, allowing stable processing over a long period of time. The vacuum container A further includes a treated fabric supply roller 9 and an electric motor 16.
A take-up roller IO driven by, etc. is provided in the space between the radial electrode pair. 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 etc. 6.7 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 as possible to the non-grounded electrode or the grounded electrode surface. , it is preferable to adjust and arrange them so that they can travel in sliding contact.

Roller 6 for running the treated fabric through the plasma space
．． The material 7 is preferably a 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. It is also better for the rollers to be grounded.

The surface of the roller is preferably mirror-finished to prevent the treated fabric from slipping. More preferably, silicone rubber, N
It is preferable to use BR rubber, SBR rubber, fluororubber, etc. coated with a rubber coating or a rubber tube.

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.
Preferably the same material as the electrode material, such as stainless steel,
It is made of aluminum, copper plate, etc., and more preferably has a see-through window in the center for monitoring the plasma space. 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. Also, it is better that the cover is grounded, and in this case, the distance between the cover and the non-grounded electrode 4 is
In terms of plasma stability and uniformity, it is better that the distance be larger than the distance between the grounded electrode and the non-grounded electrode.

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 a long and narrow slit with many small holes, and the gas outlet should be present over the entire width of the electrode so that the ratio of the introduced gas to the decomposed gas is even. , which is preferable because a stable treatment effect can be obtained. Although organic materials such as plastic can be used for the gas introduction piping, in order to use it stably over a long period of time, metals that are chemically stable, have high plasma resistance, and can withstand high temperatures, such as stainless steel pipes, steel pipes, etc. An aluminum tube or a glass tube is preferable.

In the specific example shown in FIGS. 3 and 4, vacuum containers B and C are separately provided, which communicate with vacuum container A through passages 18 and 19, respectively, and an electric grinder is provided in vacuum container A. Then, the treated fabric supply roller 9 and the winding roller 10 are individually housed in the vacuum containers B and C. In this way, by providing the spaces occupied by the supply roller 9 and the take-up roller 10 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 Figures 3 and 4, the first
Twice as many electrodes are provided as in the illustrated example, thus doubling the plasma processing capacity. 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 is guided by the guide roller 21 from the passage 9. It is wound up on a winding roller 10.

The vacuum containers B and C are combined into a single container, and the fabric supply roller 9 and take-up roller 10 are housed together,
It is also possible to communicate with the vacuum container 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 through the electrode connecting member 2 from the power introduction part l. 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 a frequency of 50 Hz for plasma generation.

Power at a commercial frequency of 60 Hz, a low frequency of kilohertz, and a high frequency in the megahertz to gigahertz range is introduced to generate a cold gas plasma with a ground electrode.

For stable generation of low temperature gas plasma, @K
A low frequency or high frequency from Hz 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 it is usually 0.01 per unit area.
W/cm2 or more, preferably 0.2~LOW/c
m", more preferably 0.1 to IW/cm2.

As the gas for generating low-temperature gas plasma, 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. Choose according to your purpose.

For plasma etching of polyester fibers, etc., oxygen,
Air, nitrogen, argon, hydrogen, carbon dioxide, helium and C
Fa, CFzCfi□, CFClz.

Single or mixed gases of halogenated hydrocarbons and their derivatives such as CHF s can be used.

The degree of vacuum in the plasma space is a region where low-temperature gas plasma is stably generated, that is, usually 0.01 to 10 mn+Hg.
, preferably adjusted to Q, l - 5n+mHg, more preferably 0.2 - lmmHg. 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 the decomposed gas generated by the plasma processing is efficiently discharged from the plasma space. The ratio of introduced gas to cracked gas is at least 1, preferably 2 or more, more preferably 4.
That's all. Increasing the efficiency of plasma processing and preventing foreign reactions is 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 decomposed gas is removed and discharged from the surface of the object to be treated. . The cover 14 connecting the ground electrodes functions to efficiently replace introduced gas and decomposed gas.

In the present invention, the treated fabric 8 has a ground electrode 5 and a non-ground electrode 4.
During the contact, the electrode is preferably brought into contact with a surface of a grounded electrode or a non-grounded electrode, more preferably with a surface of a grounded electrode or a non-grounded electrode, and particularly preferably with a surface of a non-grounded electrode. Plasma etching occurs when the workpiece is brought into contact with a non-grounded electrode.

The effect is greater, and this is thought to be due to the following reasons.

In plasma, particularly 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, so it is difficult to process them in that space. This can significantly increase processing speed and processing effectiveness.

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.

(a) 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 a guiding means so that the object to be processed 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 processed 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 distance from the power introduction part to the non-grounded electrode can be made equal,
It is now possible to introduce power of the same phase to multiple non-grounded electrodes.

Also, since the power introduction portions for each electrode could be unified, a single power source was required. Therefore, it is possible to prevent mutual interference of plasma between multiple electrodes and mutual interference between multiple power supplies, which was observed in conventional plasma processing equipment with multilayered electrodes, and to obtain stable operation and stable quality. Became.

In addition, the space around the non-grounded electrode is much narrower than in the conventional case, which reduces unnecessary plasma discharge in this area and allows input power to be used more efficiently.

As described above, the apparatus of the present invention can provide a plasma processing apparatus and plasma-treated products with significantly lower costs, higher quality, and higher stability 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...
Non-grounded electrode 5... Grounded electrode 6.7... Guide means 8... Fabric 9... Supply roller
IO... Winding roller 11... Gas introduction hole
12...Exhaust hole I3...Frame I4
...Cover 15...Terminal 16...
Electric motor 17... Guide rail 1B, 19...
・Passage 20.21 ・・・Guide roller

Claims (1)

[Claims] 1. Consisting 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, the object to be processed is In a plasma processing apparatus equipped with a guide means for passing between an electrode and a grounded electrode, a power introduction part is disposed in the center of the group of non-grounded electrodes, and the non-grounded electrodes are respectively connected to the power introduction part. A plasma processing apparatus characterized in that the following are arranged in a radial manner.