JPH0663101B2 - Plasma processing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a continuous plasma processing apparatus for an elongated object. More specifically, a long object such as a film, a film, a sheet, a cloth, and a fiber, particularly a flat object or a relatively small thickness,
The present invention relates to an apparatus for continuously performing a plasma treatment on a long object to be treated (hereinafter sometimes referred to as treated cloth) having a large width.

(Prior Art) Many proposals have hitherto been made as a plasma processing apparatus, particularly a plasma processing apparatus for a planar art-like object or a long object. For example, Japanese Patent Publication Nos. 60-11,149 and 60-31,939 each propose a plasma processing apparatus in which a cloth is processed between a pair of counter electrodes having a large area.
60-134,061, 61-228,028, Japanese Patent Sho 60-59,251
JP-A-61-36,862 and JP-A-61-36,862 propose a plasma processing apparatus in which a plurality of non-grounded electrodes are arranged around a cylindrical grounded electrode. Furthermore, Japanese Patent Publications Sho 60-11,150, and Sho 60-54,4
Each of the 28 publications proposes a plasma processing apparatus having a multilayer parallel plate electrode.

(Problems to be solved by the present invention) However, the proposals of the above Japanese Patent Publication Nos. 60-11,149 and 60-31,939 disclose the non-uniform treatment due to local variations in the degree of treatment on an electrode surface of a large area. However, there is a problem that the processing efficiency is lowered due to the generation of plasma discharge in the upper and lower spaces of the electrodes and the left and right spaces. Further, in the above-mentioned Japanese Patent Application Laid-Open No. 60-134,061 and other proposals, the treated area of the electrode cannot be made too large, and discharge loss around the non-grounded electrode cannot be avoided. According to the proposals of Japanese Patent Publication Nos. 60-11,150 and 60-54,428, a phase shift of high frequency occurs on each of the multi-layered electrodes, mutual interference between the electrodes, and stable operation and quality are obtained. I have a problem above.

As described above, none of the conventionally known plasma processing apparatuses can sufficiently satisfy all of the operation stability, the quality uniformity, and the processing efficiency with respect to the input power.

In order to solve the drawbacks of the conventionally proposed device, the present inventors have opposed a non-grounded electrode having a vacuum container and a planar processed surface disposed in the vacuum container and the non-grounded electrode processed surface. As a Japanese Patent Application No. 62-33,442, there was proposed a plasma processing apparatus comprising a grounding electrode provided as a reference numeral and provided with a guiding means for passing an object to be processed between the non-grounding electrode and the grounding electrode. The proposed device succeeded in solving many of the various technical problems associated with the conventionally known device, but as a result of continued research, the device was made compact.
Finding the need for further improvement in terms of improving processing efficiency,
The present invention has been completed.

An object of the present invention is to provide a plasma processing apparatus that has a plurality of electrodes, does not cause mutual interference of plasma between the electrodes, and suppresses unnecessary and harmful plasma discharge in the electrode peripheral portion as much as possible. There is. Another object is to provide an apparatus which can be operated more stably and which can efficiently produce a high-quality and uniform object to be treated.

(Means for Solving the Problem) The present invention is provided with a vacuum container, a plurality of non-grounded electrodes having a planar processed surface radially arranged therein, and a non-grounded electrode facing each other. In a plasma processing apparatus comprising a ground electrode and having a guide means for passing an object to be processed between the non-ground electrode and the ground electrode, a limited space communicating with the outside air and having a built-in power introduction unit is provided. In the plasma processing apparatus, the non-ground electrode is arranged in the center of the ground electrode group, and one end of the non-ground electrode is connected to the power introducing unit through the wall defining the restricted space.

The object to be treated according to the present invention is not particularly limited as long as it is a film, a film, a sheet and a cloth, a fiber, a thread or the like having a long shape, a flat shape or a relatively thin thickness.

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

FIG. 1 is a schematic front view showing a main part of a specific example of the device of the present invention, FIG. 2 is a schematic front view showing the whole thereof, and FIG. 3 is a schematic side view of FIG.

In FIG. 1 and FIG. 2, a restricted space 4 defined by a box or cylinder 28 is provided at the center of a group of non-grounded electrodes 9 in a vacuum container 1 that defines a plasma processing chamber. The restricted space 4 communicates with the outside air either before or after the vacuum container 1 or in any of them, and incorporates a power introduction unit 6.

A plurality of electrode connecting members 7 extending from the power introducing portion penetrate a wall of the box or cylinder 28 that defines the restricted space 4, and a plurality of non-ground electrodes 9 whose penetrating ends 8 are radially arranged. And electrically connect the power introducing unit 6 and each non-grounded electrode. The electrode connecting member 7 is electrically insulated and airtightly supported on the wall of the box or cylinder 28 by the insulating material 11, and the power introduction part 6 is coupled to the terminal 5 from the high frequency power supply.

The power introduction part 6 is located at the center of the restricted space 4 defined by the box or cylinder 28, and the electrode connecting members 7 extending from the power introduction part 6 and reaching the wall of the box or cylinder are all of equal length. Most preferably it is in an equiangular radial arrangement. Further, the lengths of the penetrating ends 8 extending from the wall of the box or the cylindrical body to the respective non-grounded electrodes 9 should be made as short as possible, and the lengths should be equal to each other, the surfaces thereof should be insulated and covered, and the non-grounded electrodes 9 should be formed in an equal angle radial pattern. The arrangement is also most preferred. The restricted space
The size and length of 31, that is, the dimensions of the box and the cylinder, as long as the length of the penetrating end 8 is kept as short as possible, the purpose of the apparatus and the shape of gas, water, etc. to be introduced into the plasma processing chamber. It can be set arbitrarily depending on the type and number of pipes.

The non-grounded electrode 9 has a planar treated surface, and the angle formed between the front and back surfaces is not particularly limited, but the traveling treated cloth guided by the guide means described later is set at an appropriate angle so as to be easily parallel to the electrode surface. The electrode connecting member 7 and the non-grounded electrode 9 do not necessarily have to be coaxial. However, it is preferable that the electric resistance and the distance from the electrode connecting member 7 to each non-grounded electrode 9 are equal in terms of balance of power distribution.

The planar ground electrodes 10 are provided on both surfaces of the non-ground electrode 9 so as to face each other. It is preferable to install the ground electrode 10 and the non-ground electrode 9 in parallel with each other at equal distances. 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 generally when the degree of vacuum is small and the input energy is small, It is better to narrow it, and it is usually 10 cm or less, preferably 5 cm.
For example, in the case of oxygen plasma, if the vacuum degree is about 1 mmHg,
0.5 to 3 cm is effective. The material of the non-grounded electrode 9 and the grounded electrode 10 is preferably a metal having high conductivity, such as aluminum, copper, iron, stainless copper and various metal plated products thereof. The shape can be flat plate, punching plate or mesh (wire mesh), but the input power is
At 0.1 W / cm ² or more, a flat plate having no holes or irregularities is preferable.

It is preferable that the non-grounded electrode 9 and the grounded electrode 10 are provided with a passage for a temperature adjusting medium therein so that the temperature can be adjusted, and in particular, they can be cooled. Any medium can be used as long as it has fluidity, but pure water, which is an electrically insulating material, an organic solvent, various heat exchange gases, and steam are preferable. As the temperature control device or the cooling device, it is preferable to install a flexible pipe or a jacket through which the refrigerant passes through the channels 24 and 25 as shown in FIG. 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 arbitrarily set and the sample to be treated can be brought into contact with the non-grounded electrode, so that stable treatment can be performed for a long time.

As shown in FIGS. 2 and 3, in this embodiment, the vacuum vessel 1 communicates with the vacuum vessels 2 and 3, respectively, via passages 15 and 15 ', the vacuum vessel 1 having the above-mentioned structure therein. Thus, the plasma processing chamber is provided with electrodes, and the processing cloth supply roller 18 and the winding roller 19 are separately housed in the vacuum containers 2 and 3. In this way, by providing the respective occupied spaces of the supply roller 18 and the winding roller 19 outside the vacuum container 1, the number of electrodes arranged in the vacuum container 1 is increased,
Plasma throughput can be increased.

It is preferable that the supply roller 18 and the take-up roller 19 are reversible by appropriately enabling the connection mechanism of the electric motor 26 to be reversed between them.

In the vacuum container 1, guide means for guiding the cloth 12 supplied from the supply roller 18 sequentially to the gap between the ground electrode and the non-ground electrode and sending it to the winding roller 19, for example, a guide bar or a guide roller. Etc. 13 and 14 are arranged at appropriate positions in the vicinity of each electrode base and the tip. As these guide means, a fixed roll, a driven roll, a drive roll or a combination thereof can be appropriately used depending on the conditions such as fabric weight, running speed, tension, etc., and the treated fabric should be as close as possible to the non-grounded electrode or the grounded electrode surface. It is preferable to arrange them so that they can run in sliding contact.

Roller for running treated fabric in plasma space 1
The material of 3,14 is preferably a metal, a ceramic, a metal-coated ceramic, or a rubber coating such as NBR or silicone, which has a smaller etching property than the treated cloth and is excellent in heat resistance. Also, the rollers should be grounded. The surface of the roller is preferably mirror-finished in order to prevent the treated cloth from slipping. More preferably, a silicone rubber, NBR rubber, SBR rubber, fluororubber, or the like coated with a rubber coating or a rubber tube is preferable for the running stability of the object to be treated and prevention of heating.

Main components such as the non-grounded electrode, grounded electrode, processing cloth guiding means, and power introduction section in the vacuum container are supported by the frame 27, and the grounded electrodes are covered with a cover that connects them to each other to be integrated. Can also supply roller 18,
The take-up roller 19 is supported by the frames 20 and 20 ', respectively, and can run on the guide rail 17 so as to be detachable from the vacuum container.

The material of the cover may be an insulating material or a conductive material,
Preferably the same material as the electrode material, such as stainless steel,
The plate is made of aluminum, copper plate, or the like, and more preferably has a see-through window in the center for monitoring the plasma space. The material of the see-through window may be an organic substance or an inorganic substance as long as it can be seen through, but an inorganic substance having excellent plasma resistance and heat resistance, such as glass or inorganic crystal, is preferable. The cover is preferably 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 preferable that the distance between the grounded electrode and the non-grounded electrode is larger than that.

The shape and size of the vacuum container are not particularly limited as long as it can withstand an internal / external pressure difference of at least 1 atm. However, the vacuum container is provided with a gas introduction hole 23 and an exhaust hole 22 communicating with a vacuum pump. It has a switchgear for loading and unloading,
It preferably comprises a see-through window for monitoring the contents.
The shape of the gas outlet of the gas introduction hole 23 is elongated slit-like or has a large number of small holes, and the fact that the gas outlet exists over the entire width of the electrode eliminates unevenness in the ratio of the introduced gas and the decomposed gas. A stable treatment effect is obtained, which is preferable. As the material of the gas introduction pipe, an organic substance such as plastic may be used, but in order to use it stably for a long period of time, it is chemically stable, has high plasma resistance, and a metal that can withstand high temperatures,
For example, a stainless tube, a copper tube, an aluminum tube or a glass tube is preferable.

The vacuum containers 2 and 3 may be combined to form a single container, and the cloth supply roller 18 and the winding roller 19 may be housed together, and the vacuum container 1 and the vacuum container 1 may be communicated with each other through a single passage.

The vacuum vessel 1 can be further designed to include a supply roller for the treated cloth and a winding roller driven by an electric motor or the like in the space between the radial electrode pairs.

(Operation) In the illustrated example of the device of the present invention, the cloth of the vacuum container 2 has its travel route regulated from the supply roller 18 by the guide roller 16 and enters the vacuum container 1 through the passage 15 so that the electrode gap is maintained. After passing, it is guided by the guide roller 17 through the passage 15 'and wound up by the winding roller 19.

The introduction of electric power for plasma is intensively performed by the electric power introduction unit 6. Electric power is introduced to each non-grounded electrode 9 from the electric power introducing portion 6 through the electrode connecting member 7 and the penetrating end 8.
In addition, since there is only one power supply in the power supply, a single power supply can be used, and when multiple power supplies are used, mutual interference of high frequencies due to deviation of the oscillation frequency between each power supply, plasma imbalance, etc. Is almost gone.

The non-grounded electrode 9 is supplied with plasma commercial frequencies of 50 Hz and 60 Hz, low frequency of kilohertz and high frequency power of megahertz to gigahertz region to generate low temperature gas plasma between the non-grounded electrode 9 and the 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.
A high frequency of MHz is particularly preferable in terms of processing efficiency and processing cost. Further, low frequency or high frequency input energy electrode shape, distance between the electrodes, the degree of vacuum, will vary with the processing speed, etc., per normal unit area 0.01 W / cm ² or more, preferably 0.2~10W / cm ^2, more preferably Is 0.1 to 1 W / cm ² .

As the gas for generating the low-temperature gas plasma, a non-polymerizable gas such as oxygen, nitrogen, argon, helium, or hydrogen, or a polymerizable organic monomeric gas such as methane, ethane, propane, butane, benzene, acrylic acid, or styrene may be used. You can choose it according to your purpose.

For plasma etching of polyester fiber etc., oxygen,
Air, nitrogen, argon, hydrogen, carbon dioxide, helium and CF
₄ , halogenated hydrocarbons such as CF ₂ Cl ₂ , CFCl ₃ and CHF ₃ and derivatives thereof can be used alone or as a mixed gas.

The degree of vacuum of the plasma space is a region where low-temperature gas plasma is stably generated, that is, 0.01 to 10 mmHg, preferably 0.
It is adjusted to 1 to 5 mmHg, more preferably 0.2 to 1 mmHg. The degree of vacuum can be adjusted by introducing a gas or a monomer gas together with the evacuation rate, but in order to preferably perform the intended treatment, the introduced gas is adjusted.

The gas is preferably introduced through the gas introduction pipe 23 to the processing surface side of the object to be processed. As a result, the new introduced gas is always in contact with the treated surface of the object to be treated, and the decomposed gas generated by the plasma treatment is efficiently discharged from the plasma space. The ratio of introduced gas to decomposed gas is at least 1, preferably 2 or more, and more preferably 4 or more. In order to improve the efficiency of plasma treatment and prevent different kinds of reactions, how efficiently the introduced gas is made 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 are greatly influenced. The cover connecting the ground electrodes mutually functions to efficiently replace the introduced gas and the decomposed gas.

In the present invention, the treated cloth 12 includes the ground electrode 10 and the non-ground electrode 9
In between, preferably in contact with the surface of the ground electrode or the non-ground electrode, more preferably in contact with the surface of the ground electrode or the non-ground electrode, particularly preferably in contact with the surface of the non-ground electrode. When the object to be processed is brought into contact with the non-grounded electrode, the plasma etching effect is increased, which is considered to be due to the following reason.

Plasma, especially in low temperature plasma due to application of low-frequency and high-frequency potential, self-bias is generated in the plasma space, but the kinetic energy of large-mass ions is extremely large in the self-bias generation region, and therefore processing must be performed in that space. The processing speed and processing effect can be extremely increased by the above.

It is possible to continuously process the object to be processed, or to repeat running and stop processing.

A preferred embodiment of the device of the present invention will be summarized and described below.

(A) The device according to claim 1, wherein the ground electrode surface is flat.

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

(C) The device according to claim 1, wherein the surface of the non-grounded electrode and / or the surface of the grounded electrode can be temperature-controlled.

(D) The apparatus according to claim 1, wherein the guide means is arranged 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, wherein the guide means is arranged 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 introducing portion to the non-grounded electrode can be made equal,
It has become possible to introduce electric power of the same phase to a plurality of non-grounded electrodes.

Also, since the power supply to each electrode can be unified, a single power supply is required. Therefore, it is possible to prevent the mutual interference of the plasma between the plurality of electrodes and the mutual interference between the plurality of power sources, which are seen in the plasma processing apparatus having the conventional multi-layered electrode, so that stable operation and stable quality can be obtained. Became. In particular, since unnecessary power can be supplied to the non-grounded electrode from the power introduction part in the restricted space inside the plasma processing chamber to the non-grounded electrode through the penetrating end of the electrode connecting member, unnecessary discharge in other than the required plasma processing space. In the meantime, the inconveniences experienced in the past, such as discharge between the electrode connecting members and damage to equipment due to the discharge, are significantly reduced.

Further, the space around the non-grounded electrode is much narrower than the conventional one, and unnecessary plasma discharge in this portion can be reduced, so that the input power can be used more efficiently.

As described above, the apparatus of the present invention can provide a plasma processing apparatus and a plasma processing product that are significantly cost-effective, high-quality, and highly stable as compared with the conventional apparatus.

[Brief description of drawings]

FIG. 1 is a schematic front view showing a main part of a specific example of the device of the present invention, FIG. 2 is a schematic front view showing the whole thereof, and FIG. 3 is a schematic side view of FIG. 1,2,3 ... Vacuum container, 4 ... Restricted space 5 ... Terminal, 6 ... Power introduction part 7 ... Electrode connecting member, 8 ... Penetration end 9 ... Ungrounded electrode, 10 ... Grounded electrode 11 ... Insulation material, 12 ... Cloth 13,14 ... Guide roll, 15,15 '... Passage 16,17 ... Guide roll, 18 ... Supply roller 19 ... Winding roller, 20, 20' ... … Frame 21 …… Guide rail, 22 …… Exhaust hole 23 …… Gas inlet hole, 24,25 …… Medium passage for temperature control 26 …… Electric motor, 27 …… Frame 28 …… Box or cylinder

Claims (1)

[Claims] 1. A vacuum container, a plurality of non-grounded electrodes having a planar processing surface radially arranged therein, and a ground electrode provided facing the non-grounding electrode processing surface,
In a plasma processing apparatus having a guide means for passing an object to be processed between the non-grounded electrode and the grounded electrode, a restricted space communicating with the outside air and containing a power introduction part is provided in the central part of the non-grounded electrode group. And the one end of the non-grounded electrode penetrates a wall defining the restricted space and is connected to the power introduction unit, respectively.