JP4630874B2 - Atmospheric pressure large area glow plasma generator - Google Patents

Description

  The present invention relates to a plasma generator, and more particularly to an atmospheric pressure and large area plasma generator capable of providing a low temperature glow discharge plasma that is stable at atmospheric pressure.

  A plasma is an ionized gas, and the particles that make up the plasma can easily overcome energy barriers such as gases, liquids, and solids, break atoms and molecules, and recombine new molecules and atoms. be able to. Thus, plasma can easily provide chemical and physical reaction properties that are difficult to reach by other methods. Further, due to the characteristics of plasma, processing using plasma is widely used in various industrial fields.

  In fact, in modern industry, plasma application technology is applied to materials that require high performance, high strength, and high workability, surface treatment of various materials, ion implantation, organic-inorganic film deposition and removal, cleaning work, and toxic substances. Attempts have been made in many fields ranging from point materials such as removal and sterilization to electronics and environmental industries. In addition, plasma processing technology can easily overcome the limitations of conventional machining technology, so it is used as a core equipment for manufacturing products and parts in the fields of semiconductors, LCDs, MEMS, etc. that require fine patterns. Yes.

  However, since the conventional plasma must be generated under a high temperature and vacuum atmosphere, there are many difficulties in actually applying the plasma processing technology.

  Once the ambient temperature is adjusted at a high temperature to generate a plasma, it can adversely affect materials such as polymers that must be processed at a low temperature, and to minimize the effects of temperature, In a process that must be processed in a short time, it is difficult to control the processing conditions.

  In addition, in order to generate plasma in vacuum, a closed system must be formed. However, the closed system has a disadvantage that it is difficult to implement in a continuous process or an automated process that should be performed while a substance is moving. . There is also a burden that expensive equipment for forming the vacuum chamber must be purchased and maintained.

  Therefore, if low-temperature plasma can be used in a continuous process under atmospheric pressure instead of a vacuum, it is possible to realize a continuous process and an automated process that were difficult to be realized with an existing vacuum low-temperature plasma closed system. The system that embodies the above is simplified and can be applied infinitely industrially. In addition, by including atmospheric pressure low temperature plasma processing in the industrial line, plasma processing can be performed in real time, which is expected to significantly increase productivity.

  As an example, in realizing information technology, MEMS, semiconductor, nano, biotechnology, etc., parts having higher functionality, higher strength, higher memory, and higher degree of integration are required. In manufacturing such parts, cleaning as a basic process has been positioned as a core technology rather than a peripheral technology. However, existing wet cleaning methods that use chemicals, ultrasonics, water jets, etc. for cleaning can cause environmental pollution and can only consume significant amounts of valuable water. Has a point.

  In order to solve such problems of wet cleaning, various dry processing methods such as ultraviolet (UV), ozone, carbon dioxide, and atmospheric pressure low temperature plasma have recently been proposed. When UV or ozone plasma processing is performed, there are problems such as excessive discharge of environmental pollutants, processing speed limitations, processing function limitations, and difficulty in maintenance and repair. Further, in the case of the cryogenic carbon dioxide treatment, there are difficulties such as expensive equipment, processing speed limit, and processing function limit. Thus, atmospheric pressure low temperature plasma has emerged as a powerful processing method that can solve such problems of wet processing and also solve the difficulties of existing dry processing.

  In atmospheric pressure discharge of atmospheric low temperature plasma, the increase in system pressure is accompanied by a significant decrease in mean free path, thereby requiring extreme electrical discharge conditions. Therefore, the atmospheric pressure electric discharge according to the existing technology requires a very strong electric field, which causes a problem that requires a very large voltage compared to the vacuum discharge. Accordingly, there is a need for a technique for producing plasma in a large amount that is easily inexpensive at atmospheric pressure.

  In response to such demands, most of the atmospheric pressure low-temperature plasma generators currently under development use the DBD (Dielectric Barrier Discharge) discharge method. The DBD discharge method is a method of discharging plasma by bringing one or more dielectric barriers into close contact with an electrode, and has an advantage of being able to generate a glow discharge that is possible in a vacuum state. . As a reference, in this specification, it can be said that the atmospheric pressure includes a pressure in the vicinity of atmospheric pressure similar to that in addition to the atmospheric pressure defined by science.

  FIG. 1 is a schematic diagram for explaining a conventional DBD discharge method.

  Referring to FIG. 1, the plasma generating apparatus 10 includes a power electrode 20 and a ground electrode 30, and a dielectric film 40 is formed on the surface of the power electrode 20 facing the ground electrode 30. By applying an RF power source having a predetermined frequency to the power source electrode 20, low temperature plasma can be generated between the power source electrode 20 and the ground electrode 30 even under atmospheric pressure. In the meantime, by providing a reactive gas containing an inert gas, particles having high activity such as ozone and radicals can be easily produced in large quantities. At this time, since the generated plasma is low in temperature so as not to cause thermal deformation of the object to be processed, not only metal but also materials such as plastic and glass can be processed. Cleaning, oxide film formation, etc. can be performed on the surface of the object to be processed that passes between 30 and 30.

  In addition, since the plasma generating apparatus 10 using the DBD discharge method can discharge at atmospheric pressure, it is much cheaper than the plasma generating apparatus using vacuum discharge, is hardly subject to space restrictions, and is an in-line continuous process. Or the applicable field becomes wider, such as being applicable to an automated process.

  In order to generate plasma by the DBD discharge method, a low frequency power supply of about 400 KHz or less is generally applied to the power supply electrode 20. When a low frequency power supply is used, plasma is more easily generated by the low frequency power supply because the voltage of the low frequency power supply is higher than the voltage of the high frequency power supply under the same power conditions. However, when using a low-frequency power source, there is a problem that the processing speed is slow because the current is small and the density of the generated plasma is low. In addition, when the object to be processed is metal, there is a problem that sample damage (charge damage) due to arc (Arc) and sample charge accumulation occurs, and glow plasma is realized in an open space even under atmospheric pressure. There is a disadvantage that it is difficult to do.

  A high-frequency power source of about 13.56 MHz or higher compared to the low-frequency power source maintains a relatively low voltage under the same power condition, and the current flows 10 to 100 times or more compared to the low-frequency power source. . Therefore, when using a high frequency power supply, plasma with a relatively higher density can be generated than when using a low frequency power supply, and the processing speed of a processing technique using plasma can be significantly increased. it can.

  However, when using a high-frequency power supply, the power consumption necessary for plasma generation is large even in a small area, and even if plasma is generated, the generated plasma is unstable, so the plasma is turned off while the workpiece is being transferred. The problem of becoming occurs. Further, when processing a metal workpiece, there is a problem that the risk of arcing is considerably high due to high power.

  FIG. 2 is a graph showing a current-voltage characteristic curve for explaining the characteristics of glow plasma.

  Referring to FIG. 2, the current-voltage characteristic curve when a normal glow plasma is generated has peaks at two points B and E, and becomes more stable as the current difference between the two peaks increases. It can be said that glow plasma can be generated. When the power is gradually increased from the initial state A, the voltage and current increase, and glow plasma begins to be generated while passing through the first peak B. As a result, the voltage between the electrodes rapidly decreases, and during a certain period, even if the power is increased, only the current CD is increased and the voltage is kept constant. In this way, a normal glow plasma is generated in a section where the voltage is constant, and the wider the section, the more stable the plasma without arcing even if there is a changing environment such as the conductor material passing between the electrodes. Can be generated. When a certain level of power is supplied, an abnormal glow plasma is generated (DE), the voltage decreases while passing through the second E, and an arc is generated.

  The current-voltage characteristic curve shown in FIG. 2 is an ideal curve and corresponds to the case where glow plasma is generated in a vacuum state, and generates glow plasma under atmospheric pressure where there are many surrounding change factors. It is difficult.

[Table 1]

  Table 1 summarizes each current-voltage characteristic curve so that the time when the glow plasma is formed under vacuum and the time when the glow plasma is formed under atmospheric pressure can be compared. As summarized in Table 1, the current-voltage characteristic curve for forming a conventional atmospheric pressure plasma has a single peak, unlike a vacuum condition, and forms a normal glow plasma. It is difficult to find a section. Even if there is a section where normal glow plasma is formed, it is difficult to form a stable glow plasma because the area is very narrow. Occurs and plasma processing becomes difficult.

  As described above, the conventional atmospheric pressure plasma processing technology is used to realize glow plasma, plasma instability, arc generation on metal workpieces, difficulty in realizing large area plasma, processing speed limitation, high density plasma generation. There are problems such as. In particular, when the object to be processed is a metal, the stability of plasma greatly depends on the surface roughness, shape, pattern size, etc. of the metal material.

  An object of the present invention is to provide a plasma generator for stably generating glow plasma.

  Another object of the present invention is to provide a plasma generator capable of freely controlling plasma generation and extinction.

  It is still another object of the present invention to provide a plasma generator that can easily generate a large-area plasma.

  Still another object of the present invention is to provide a plasma generating apparatus that enables glow plasma to directly contact an object to be processed even when processing a metal surface as well as a non-metal.

  Further, another object of the present invention is to provide a plasma generator that is not significantly limited by installation conditions in an open space at atmospheric pressure, and according to the present invention, plasma cleaning through a continuous process in real time, Ashing, etching, vapor deposition, and other processing can be performed quickly.

  To achieve the above object, according to an embodiment of the present invention, a plasma generator includes a power supply electrode, a first dielectric film, an auxiliary plasma ground electrode, a second dielectric film, a gas inflow portion, and a power supply controller. Including.

  The power supply electrode and the object to be processed are spaced apart from each other with a predetermined interval. When an RF power supply having a sufficient power is applied to the power supply electrode, a main plasma (main plasma) is provided between the power supply electrode and the object to be processed. ) Can occur. Generally, when the object to be processed is a conductor, the main plasma can be generated without a separate main plasma ground electrode. However, when the object to be processed is not a conductor, the main plasma can be generated. By providing the main plasma ground electrode, main plasma can be generated. In addition, when processing an object to be processed that is not a conductor, the main plasma ground electrode can be brought into contact with the object to be processed, but can also be maintained at a predetermined interval.

A first dielectric film made of a heat-resistant polymer such as silicon or polyimide or an oxide such as alumina (A1 ₂ O ₃ ) or quartz (SiO ₂ ) is provided between the power supply electrode and the object to be processed. The The first dielectric film is interposed between the power supply electrode and the object to be processed, thereby minimizing the generation of an arc through the object to be processed and assisting the stable generation of glow plasma. To do. However, since the first dielectric film is interposed, the generation of the arc cannot be completely interrupted, and the arc is still generated when the metal workpiece passes through. There is.

  Therefore, the plasma generating apparatus according to the present invention can generate stable plasma without arcing even with a metal object to be processed by using auxiliary plasma. For this purpose, an auxiliary plasma grounding electrode is disposed adjacent to the power supply electrode, and a second dielectric film is provided between the power supply electrode and the auxiliary plasma grounding electrode. Since the distance between the power supply electrode and the auxiliary plasma ground electrode is narrow or the area is small, the auxiliary plasma can be generated even with less power than the main plasma.

  While the plasma generator is in operation, it is possible to always maintain a state where the auxiliary plasma is turned on even if a low power RF power source is provided to the power source electrode. Therefore, when the power supply controller provides a high power RF power source to form the main plasma, the main plasma is generated between the power source electrode and the object to be processed, and at this time, the plasma state is easily generated from the auxiliary plasma. As a result, the main plasma can be generated quickly.

  According to experiments, the plasma generator according to the present invention can generate a current-voltage characteristic curve as shown in FIG. 2 by using auxiliary plasma. Therefore, as in the case of generating glow plasma in a vacuum, a broad glow plasma region having two peaks at atmospheric pressure is generated. That is, the plasma generator according to the present invention can form a stable glow plasma, and even when a metal workpiece is used, the plasma can directly contact the workpiece without arcing. In addition, the distance between the power supply electrode and the workpiece can be kept close.

  In particular, when a high frequency power source of about 13.56 MHz is used, high-density plasma can be generated, so that the processing speed can be increased. However, since the state of the main plasma is very unstable, The case where it turns off can occur regularly. However, when maintaining the low-power auxiliary plasma as in the present invention, the plasma state can be easily transferred from the auxiliary plasma, so that the main plasma is not turned off and the uniform plasma is maintained. Can be provided.

  In addition, since the stable main plasma can be maintained using the auxiliary plasma, the power for maintaining the main plasma can also be maintained at a minimum value as compared with the conventional plasma generator. Therefore, the plasma generator according to the present invention can use the power for maintaining the main plasma at a lower level than before, and can minimize energy consumption.

  While maintaining the auxiliary plasma, a mixed gas for generating plasma is supplied between the power supply electrode and the auxiliary plasma ground electrode through the gas inflow portion. The mixed gas for plasma can be composed of only an inert gas such as helium and argon, and can contain a small amount of mixed reaction gas such as oxygen and nitrogen in addition to the inert gas. By supplying the mixed gas in this way, the amount of active radicals can be maximized.

  As described above, the power supply controller controls the RF power applied to the power supply electrode. That is, even if the main plasma is not generated, a low-power power source capable of generating auxiliary plasma is always provided, and the power of the power source is increased to generate the main plasma that can process the object to be processed. In addition to supplying RF power, the power controller can include other functions. For example, when a high-frequency power source of about 13.56 MHz or more is used, a stable power source including a matching box or a similar function can be provided.

  Conventional atmospheric pressure low temperature plasma has the problem of arcing when processing metal objects. To solve this problem, plasma is generated by separating the power supply electrode from the metal object. (Remote plasma). However, at this time, the generated plasma does not directly contact the object to be processed, and only particles such as radicals generated by the plasma reach the object to be processed, so that the processing speed is remarkably slow. . However, the plasma generating apparatus according to the present invention can suppress the generation of arc even when the metal object to be processed passes, so that the object to be processed passes close to the power supply electrode. The plasma can be brought into direct contact with the object. Since plasma directly processes an object to be processed, it is possible to process an object with high workability and to significantly increase the processing speed.

  In order to achieve the above-mentioned object, according to another preferred embodiment of the present invention, a plasma generator includes a plurality of power supply electrodes, a plurality of auxiliary plasma ground electrodes, a dielectric film, a gas inflow portion, and a power supply controller. including. Although a plurality of power supply electrodes and auxiliary plasma grounding electrodes are alternately arranged to generate auxiliary plasma through each auxiliary plasma grounding electrode, auxiliary plasma is generated by the voltage difference between the power supply electrode and the auxiliary plasma grounding electrode. The plasma is generated with lower power than the main plasma.

  A power source electrode and a ground electrode are alternately arranged, and a plurality of plasma sources can be generated on a workpiece or a passage through which the workpiece passes, and each plasma source is used to connect each power source electrode and the workpiece. A large-area plasma can be generated between the object to be processed.

  In general, the power supply electrode and the ground electrode are each formed in a flat plate shape, and are alternately arranged. A dielectric film is formed around the power supply electrode or the ground electrode so that glow plasma can be generated at atmospheric pressure. To. By arranging such plasma generating units including a power supply electrode and a ground electrode in parallel, a sufficient amount of plasma can be supplied, and atmospheric pressure plasma can be provided over a large area. Such a parallel arrangement type plasma generator can use one main plasma ground electrode in common, and can use the workpiece itself as ground.

  To achieve the foregoing object, according to an embodiment of the present invention, a plasma generator includes a columnar power electrode, a dielectric film, an auxiliary plasma ground electrode, a gas inlet, and a power controller. The dielectric film can have a structure surrounding the periphery of the columnar power supply electrode. Since the columnar power supply electrode is easy to manufacture and is structurally supported by the dielectric film, it can be easily fixed without a separate support member. In addition, the power supply electrode can be easily and completely insulated, and even when a strong electric field is applied through the power supply electrode, a relatively large amount of reaction gas is supplied without causing dielectric breakdown, and a sufficient amount of plasma is supplied. Can be generated.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the scope of rights of the present invention is not limited to the following examples.

  FIG. 3 is a block diagram for explaining the plasma generator according to the first embodiment of the present invention, and FIG. 4 is a block diagram for explaining the plasma generation mechanism of the plasma generator according to the first embodiment. It is.

  Referring to FIG. 3, the plasma generating apparatus 100 according to the first embodiment includes a power electrode 110, a dielectric film 120, a main plasma ground electrode 140, an auxiliary plasma ground electrode 130, a gas inflow part 150, and a power controller 160. . The dielectric film 120 includes a first dielectric film 122 interposed between the power supply electrode 110 and the main plasma ground electrode 140, and a second dielectric material interposed between the power supply electrode 110 and the auxiliary plasma ground electrode 130. The film 124 is divided.

  The power electrode 110 is a metal such as stainless steel or aluminum alloy, and is electrically connected to the power controller 160. An RF power can be applied to the power electrode 110 by the power controller 160, and the RF power applied to the power controller 160 can be a low-frequency power source or a high-frequency power source depending on usage conditions. As shown in the figure, the power supply controller 160 is supplied with a low-power power supply that can basically generate auxiliary plasma (AP), and the interval between the power supply electrode 110 and the auxiliary plasma ground electrode 130 is very small. Therefore, the auxiliary plasma AP can be easily maintained with a low-power power source.

  The first dielectric film 122 and the second dielectric film 124 are made of alumina, quartz, silicon, or ceramic, and are connected together to form the dielectric film 120. The dielectric film 120 is an insulator formed along the periphery of the power supply electrode 110, which blocks direct contact between the power supply electrode 110 and the peripheral ground electrode, and between the power supply electrode and the peripheral ground electrode. Generation | occurrence | production of an arc can be suppressed. Here, the dielectric film 120 is formed with a thickness of about 0.1 to 10 mm.

  The auxiliary plasma ground electrode 130 is located adjacent to the lower side of the side surface of the power electrode 110 covered with the dielectric film 120, and the second dielectric film 124 is disposed between the auxiliary plasma ground electrode 130 and the power electrode 110. Is done. The auxiliary plasma ground electrode 130 must be able to generate the auxiliary plasma AP even when a low power source is applied to the power source electrode 110. For this reason, the auxiliary plasma ground electrode 130 is spaced from the power source electrode 110 by about 0.1 to 20 mm. Adjacent to each other. Further, since the auxiliary plasma ground electrode 130 is arranged side by side with the power supply electrode 110 and faces each other through a small area, the auxiliary plasma AP can be easily generated with low power. At this time, the generated auxiliary plasma AP is generated. Is formed long along the power supply electrode 110. Therefore, even when the auxiliary plasma AP is transferred to the main plasma MP, it can be transferred quickly over the entire section.

  In order to form a large amount of radicals and ions, a mixed gas is supplied between the power supply electrode 110 and the auxiliary plasma ground electrode 130. The mixed gas includes a non-active gas such as helium (He) or argon (Ar), and includes a reactive gas such as oxygen or nitrogen mixed in a small amount with the non-active gas. Further, since the reaction gas contains carbon, hydrogen, chlorine, ammonia, methane, etc., it can be used as an application for remodeling the surface chemical properties during the plasma treatment. The mixed gas is supplied between the electrodes from the outside through the gas inflow portion 150 and is uniformly supplied along the space between the power supply electrode 110 and the auxiliary plasma ground electrode 130. The mixed gas supplied between the power supply electrode 110 and the auxiliary plasma ground electrode 130 is dissociated by a strong electric field, and plasma is generated through such a process.

  The main plasma ground electrode 140 is positioned below the power supply electrode 110 and is spaced apart from the power supply electrode 110 by a predetermined distance. The main plasma ground electrode 140 is for generating the main plasma MP corresponding to the RF power supply of the power supply electrode 110. When the power supply applied to the power supply electrode 110 increases to a certain level or more, the main plasma ground electrode 140 is provided. MP can be generated. When the object to be processed is a metal, the main plasma can be formed without the main plasma ground electrode 140, but when the object to be processed is a non-metal, the main plasma can be formed so that an electric field can be formed. A plasma ground electrode 140 must be provided. In addition, it is preferable that the main plasma ground electrode 140 is kept in contact with the non-metal workpiece. However, in some cases, the main plasma ground electrode 140 and the workpiece are separated from each other with a small interval and come into contact with each other. It may not be.

  If the main plasma grounding electrode is for forming an electric field and can form the grounding corresponding to the power source electrode, it can be said that there is no strict limitation on the grounding form and the grounding position. For example, according to another embodiment of the present invention, the conveyor belt itself can be used as the main plasma ground electrode if the workpiece is continuously moved while being processed, By maintaining the ground state, it can function as an effective ground electrode.

  Referring to FIG. 4, the workpiece M is located between the power supply electrode 110 and the main plasma ground electrode 140. At this time, the power supply controller 160 applies an RF power supply with increased power to the power supply electrode 110, and glow plasma is generated between the power supply electrode 110 and the workpiece M as the power of the RF power supply increases. Is done.

  An auxiliary plasma AP is always formed between the power supply electrode 110 and the auxiliary plasma ground electrode 130. Therefore, when the main plasma MP is generated, the plasma state of the auxiliary plasma AP can be easily transferred to the main plasma MP, and the plasma generating apparatus 100 according to the present embodiment is compared with the conventional plasma generating apparatus. It is possible to generate plasma that is more stable and has less power loss.

  Since the power to maintain the auxiliary plasma AP is small compared to the power to maintain the main plasma MP, the auxiliary plasma AP does not turn off while the workpiece M is being processed. Can be maintained. Therefore, even if the supplied power is unstable and the state of the main plasma MP becomes unstable, the plasma state can be transferred from the stable auxiliary plasma AP to the main plasma MP at any time, and the main plasma MP is also turned off. It is possible to maintain a stable state without becoming.

  FIG. 5 is a block diagram for explaining a plasma generator according to another embodiment of the present invention similar to the first embodiment.

  Referring to FIG. 5, compared with the plasma generator 100 of the first embodiment, the plasma generator 101 according to the present embodiment has a third dielectric film 126 formed on the capacitance ground electrode 132 and the capacitance ground electrode 132. Further included. The capacitance ground electrode 132 forms a capacitance corresponding to the RF power supplied from the power supply controller 150, and functions to assist the formation of stable plasma by the RF power.

  The capacitance grounding electrode 132 includes the auxiliary plasma grounding electrode 130 and the capacitance grounding electrode 132 which are formed integrally with each other to form one grounding body. The power supply electrode 110 and the grounding body are both formed in a flat plate shape. A type of plasma generator can be constructed.

  FIG. 6 is a cross-sectional view showing a plasma generating apparatus according to a second embodiment of the present invention, FIG. 7 is a perspective view showing the plasma generating apparatus according to the second embodiment, and FIG. It is a partial cutaway view showing a grounding body of a plasma generator according to an example.

  6 to 8, the plasma generator 200 according to the second embodiment includes a power source electrode 210, a dielectric film 220, a main plasma ground electrode 240, an auxiliary plasma ground electrode 230, a capacitance ground electrode 232, a gas inflow. Path 250 and power supply controller 260 are included. The auxiliary plasma grounding electrode 230 and the capacitance grounding electrode 232 are made of stainless steel or an aluminum alloy and integrated to form one grounding body 235.

  The auxiliary plasma grounding electrode 230 is located below the grounding body 235, and the end of the auxiliary plasma grounding electrode 230 is separated from the power supply electrode 210 on which the dielectric film 220 is formed with a small interval. A spaced space between the auxiliary plasma ground electrode 230 and the power supply electrode 210 has a narrow area and is formed to be perpendicular to the transfer path of the workpiece M. Accordingly, the auxiliary plasma AP is formed wide enough to cover the entire width of the workpiece M.

  The workpiece M is continuously passed between the power supply electrode 210 and the main plasma ground electrode 240 by the transfer roller, and the plasma generator 200 is configured such that when a portion of the workpiece M to be treated with plasma passes, Main plasma can be generated to perform plasma processing continuously or discontinuously.

  The power supply electrode 210 is formed in a flat plate shape and is made of a metal such as stainless steel or aluminum alloy. The power supply electrode 210 is electrically connected to the power supply controller 260 through the coaxial cable terminal 212, and RF power is applied to the power supply electrode 210 by the power supply controller 260.

  The power controller 260 includes an impedance matching box 262, and the high frequency power is transmitted to the power pole 210 through the matching box 262. The power supply controller 260 is basically supplied with power enough to generate the auxiliary plasma AP, and the interval between the power supply electrode 210 and the auxiliary plasma ground electrode 230 is very narrow and the area is small. The auxiliary plasma AP can be easily maintained by the power source.

  Next, Table 2 summarizes the discharge maintenance power for maintaining the auxiliary plasma AP and the discharge maintenance power for maintaining the main plasma MP depending on the area and length of the plasma generated. The following conditions are all conditions for generating glow plasma, and according to the results, the auxiliary plasma can be sufficiently maintained at 50% or less of the power for maintaining the main plasma. it can.

[Table 2]

  The dielectric film 220 is made of alumina, quartz, silicon, or ceramic, and the dielectric film 220 is an insulator formed along the periphery of the power supply electrode 210, and directly between the power supply electrode 210 and the peripheral ground electrode. To prevent unwanted contact. Here, the dielectric film 220 is formed with a thickness of about 0.1 to 10 mm. The dielectric film 220 corresponds to one in which the first to third dielectric films 122 to 126 in the above embodiment are integrally formed, and the power supply electrode 210 is inserted into the dielectric film 220 or the dielectric film 220. Is applied or deposited on the surface of the power supply electrode 210.

  The grounding body 235 is formed in a flat plate shape corresponding to the power source electrode 210 and includes an auxiliary plasma grounding electrode 230 for generating the auxiliary plasma AP and a capacitance grounding electrode 232 for forming a capacitance. In addition, a gas inflow path 250 is formed inside the grounding body 235, and the mixed gas introduced from the outside for generating plasma passes through the gas inflow path 250 and flows between the auxiliary plasma ground electrode 220 and the power supply electrode 210. Evenly distributed between. The grounding body 235 is attached to the power supply electrode 210 to form one plasma generation unit.

  The gas inflow path 250 is connected to the first inflow path 252 and the first inflow path 252 through which the mixed gas is introduced from the outside, and is formed side by side with the power supply electrode 210, the second inflow path 254, the power supply electrode 210, and the auxiliary plasma. An inflow chamber 256 formed between the ground electrode 220 and a plurality of orifices 258 connecting the second inflow passage 254 and the inflow chamber 256 are included. As illustrated, the first inflow passage 252 and the second inflow passage 254 may be formed in the grounding body 235 by forming a hole in the grounding body 235, and are grounded along the second inflow passage 254. By cutting the body 235, the inflow chamber 256 can be formed. Further, by forming the orifice 258 that connects the second inflow path 254 and the inflow chamber 256, the mixed gas can be uniformly dispersed in the inflow chamber 256 through the orifice 258.

  Accordingly, the mixed gas enters the inside of the grounding body 235 through the first inflow path 252 and is uniformly distributed to the orifices 258 through the second inflow path 254. The mixed gas that has passed through the orifice 258 is totally dispersed between the power supply electrode 210 and the auxiliary plasma ground electrode 230 through the inflow chamber 256, and the dispersed mixed gas is supplied to the auxiliary plasma AP or the main at each position. Helps to generate plasma MP.

  As described above, since the auxiliary plasma ground electrode 230 must be able to generate the auxiliary plasma AP with a low-power power source, the auxiliary plasma ground electrode 230 is disposed close to the power source electrode 210 at an interval of about 0.1 to 20 mm and has an upper and lower width. It is better to make contact with a small and small area. Further, since the auxiliary plasma ground electrode 230 and the power supply electrode 210 are arranged side by side, even when the auxiliary plasma AP is transferred to the main plasma MP, it can be quickly transferred over a large area over the entire section.

  The main plasma ground electrode 240 is located below the power supply electrode 210 and is spaced apart from the power supply electrode 210 with a predetermined interval. The main plasma grounding electrode 240 is for generating the main plasma MP corresponding to the RF power source of the power source electrode 210. When the power source applied to the power source electrode 210 always increases to a certain level or higher, the power source A strong electric field is formed between the electrode 210 and the main plasma ground electrode 240, and the main plasma MP can be generated by the strong electric field.

  FIG. 9 is a cross-sectional view for explaining a process of operating the plasma generator according to the second embodiment.

  Referring to FIG. 9, the main plasma MP is formed between the power supply electrode 210 and the main plasma ground electrode 240. Of course, the auxiliary plasma AP is formed between the power source electrode 210 and the auxiliary plasma ground electrode 230 together with the main plasma MP.

  The main plasma MP is glow plasma, and the object to be processed is subjected to plasma processing such as cleaning or oxide film generation over a large area while passing through the power supply electrode 210 and the main plasma ground electrode 240. Further, since the auxiliary plasma AP is always formed, the plasma state can be easily transferred to the main plasma MP, and is stable and determined when the main plasma MP is generated for the first time or is maintained continuously. Help.

  Therefore, the operator who performs plasma processing can generate and extinguish the main plasma at a desired point in time, and this adjustment can be freely performed, so that precise plasma processing can be performed at atmospheric pressure and normal temperature. It means that. Since the plasma state of the auxiliary plasma AP can be easily transferred when the main plasma MP is generated, it is possible to generate a plasma that is more stable and has less power loss.

  FIG. 10 is a cross-sectional view for explaining a plasma generator according to a third embodiment of the present invention.

  Referring to FIG. 10, the plasma generator 300 according to the third embodiment includes a power source electrode 310, a dielectric film 320, a main plasma ground electrode 340, an auxiliary plasma ground electrode 330, a capacitance ground electrode 332, a gas inflow path 350, and A power supply controller 360 is included. The power supply electrode 310 and the dielectric film 320 are formed on both front and rear sides of the flat plasma generator 300, and a grounding body 335 including an auxiliary plasma grounding electrode 330 and a capacitance grounding electrode 332 is interposed between the power supply electrodes 310. Coupled with the power pole 310. The grounding body 335 is. It is made of stainless steel or aluminum alloy, and a gas inflow passage 350 is formed therein.

  Auxiliary plasma ground electrodes 330 are formed on both sides of the lower stage of the grounding body 335, and ends of the auxiliary plasma ground electrodes 330 are separated from the power supply electrode 310 on which the dielectric film 320 is formed with a small interval. Therefore, the auxiliary plasma AP is formed widely on both sides of the lower stage of one grounding body 335, and can be formed so wide that the entire width of the workpiece M can be covered double.

  The power pole 310 is formed in a flat plate shape and is provided on both sides of the grounding body 335. The power supply electrode 310 is made of a metal such as stainless steel or aluminum alloy, and is electrically connected to the power supply controller 360 through the coaxial cable terminal 312, and RF power is applied to the power supply electrode 310 by the power supply controller 360.

  The power supply controller 360 is basically supplied with power sufficient to generate the auxiliary plasma AP, and the interval between the power supply electrode 310 and the auxiliary plasma ground electrode 330 is very narrow and has a small area. Thus, the auxiliary plasma AP can be easily maintained. Of course, even if the auxiliary plasma AP is formed, the main plasma MP is not formed unless the power of the RF power source is sufficiently increased. In this regard, as summarized in Table 2, the auxiliary plasma could be sufficiently maintained with a power of 50% or less of the power for maintaining the main plasma.

  The dielectric film 320 is made of alumina, quartz, silicon, or ceramic, and the dielectric film 320 is an insulator formed along the periphery of the power supply electrode 310, and directly between the power supply electrode 310 and the peripheral ground electrode. To prevent unwanted contact.

  A gas inflow path 350 is formed inside the grounding body 335, and the mixed gas introduced from the outside passes through the gas inflow path 350 and is uniformly distributed between the auxiliary plasma ground electrode 320 and the power supply electrode 310 on both sides. Is done. The gas inflow path 350 is connected to the first inflow path 352 and the first inflow path 352 into which the mixed gas flows from the outside, and the second inflow path 354 formed on both sides of the grounding body 335 along with the power supply electrode 310. An inflow chamber 356 formed between the power source electrode 310 and the auxiliary plasma ground electrode 320 and a plurality of orifices 358 connecting the second inflow channel 354 and the inflow chamber 356 are included. As shown in the figure, the first inflow path 352 is branched toward the second inflow paths 354 on both sides inside the grounding body 335, and inflow chambers 356 are formed on both sides of the grounding body 335 along the second inflow path 354. can do. The mixed gas can be uniformly dispersed in the inflow chamber 356 through the orifice 358 by forming the orifice 358 connecting the second inflow path 354 and the inflow chamber 356.

  Accordingly, the mixed gas enters the grounded body 335 through the first inflow passage 352 and is uniformly distributed to the orifices 358 through the second inflow passage 354. The mixed gas that has passed through the orifice 358 is totally dispersed between the power supply electrode 310 and the auxiliary plasma ground electrode 330 through the inflow chamber 356, and the dispersed mixed gas is supplied to the auxiliary plasma AP or the main at each position. Helps to generate plasma MP.

  The main plasma ground electrode 340 is positioned below the power supply electrode 310 and is spaced apart from the power supply electrode 310 by a predetermined distance. The main plasma grounding electrode 340 is for generating the main plasma MP corresponding to the RF power supply of the power supply electrode 310. When the power supply applied to the power supply electrode 310 always increases above a certain level, A strong electric field is formed between the electrode 310 and the main plasma ground electrode 340, the plasma state of the auxiliary plasma AP is rapidly transferred, the main plasma MP can be generated immediately, and a stable plasma state is maintained. Can do.

  FIG. 11 is a cross-sectional view illustrating a plasma generator according to a fourth embodiment of the present invention, and FIG. 12 is a cross-sectional view illustrating a process in which main plasma operates in the plasma generator according to the fourth embodiment. It is. A plasma generator 201 shown in FIG. 11 is configured by arranging a power supply electrode 210 and a grounding body 235 in parallel in the plasma generation apparatus 200 described in the second embodiment. For the description, reference can be made to the description of the embodiment and the drawings. Therefore, in this embodiment, the description overlapping with the description of the embodiment is omitted.

  Referring to FIG. 11, the plasma generating apparatus 201 according to the fourth embodiment is disposed adjacent to the two power supply electrodes 210, the dielectric film 220 formed on the surface of each power supply electrode 210, and the power supply electrode 210. A grounding body 235, a gas inflow path 250 formed in the grounding body 235, and a power supply controller 260. The grounding body 235 includes an auxiliary plasma grounding electrode 230 and a capacitance grounding electrode 232. The grounding electrodes 230 and 232 are integrally formed and are electrically connected to each other.

  The power supply electrode 210 is formed in a flat plate shape and is made of a metal such as stainless steel or aluminum alloy. The power supply electrode 210 is electrically connected to the power supply controller 260 through a coaxial cable terminal, and RF power is applied to the power supply electrode 210 by the power supply controller 260. The power supply controller 260 is basically supplied with power enough to generate the auxiliary plasma AP, and the interval between the power supply electrode 210 and the auxiliary plasma ground electrode 230 is very narrow and the area is small. The auxiliary plasma AP can be easily maintained by the power source. Further, since the auxiliary plasma ground electrode 230 and the power supply electrode 230 are arranged side by side, even when the auxiliary plasma AP is transferred to the main plasma MP, it can be quickly transferred over a large area over the entire section.

  The grounding body 235 is also formed in a flat plate shape corresponding to the power supply electrode 210, and a gas inflow path 250 is formed inside the grounding body 235. The mixed gas introduced from the outside passes through the gas inflow path 250 and is uniformly distributed between the auxiliary plasma ground electrode 220 and the power supply electrode 210.

  The power supply electrode 210 and the grounding body 235 are alternately arranged in parallel, and the distance between the auxiliary plasma grounding electrode 230 forming the auxiliary plasma AP and the power supply electrode 210 is also arranged in parallel while forming a plurality of rows. When the power of the power source supplied to the power source electrode 210 by the power source controller 260 increases, main plasma is formed between the power source electrode 210 and the object to be processed. At this time, the main plasma is generated from the auxiliary plasma AP. The state is transferred and spreads quickly.

  Referring to FIG. 12, the power supply electrodes 210 are alternately arranged while forming a plurality of rows, and the main plasma MP is formed by each power supply electrode 210. Therefore, it is possible to increase the supply amount of plasma necessary for plasma processing. At the same time, it is possible to cause a plasma reaction in multiple workpieces.

  11 and 12, the power source electrode 210 and the grounding body 235 form a pair and are arranged in two rows. However, according to another embodiment of the present invention, the power source electrode 210 may vary depending on the type and size of the object to be processed. The number of rows of the grounding body 235 can be further increased.

  FIG. 13 is a cross-sectional view for explaining a plasma generator according to another embodiment of the present invention similar to the fourth embodiment.

  Referring to FIG. 13, in order for the reactive gas of the mixed gas to transition to the plasma state at the auxiliary plasma ground electrode 230, a process of igniting the reactive gas at the initial stage of plasma processing is required. For this purpose, a discharge probe 270 provided between the auxiliary plasma ground electrode 230 and the dielectric film 220 and an igniter 275 electrically connected to the discharge probe 270 are included. In addition, the conducting wire connecting the discharge probe 270 and the igniter 275 includes a gap 272 that is separated by a predetermined distance.

  By using the igniter 275, an instantaneous high voltage can be applied to the discharge probe 270, and a voltage difference for generating plasma at the initial stage of processing can be formed using the discharge probe 270 and the igniter 275. . The reactive gas is ignited by an instantaneous high voltage, and the auxiliary plasma AP is generated by the ignition of the reactive gas. Therefore, in the plasma generator, the power supply controller does not need to bear a high starting voltage, and can maintain low power consumption.

  The discharge probe 270 and the igniter 275 are connected by a gap 272 so as to be separated from each other at a predetermined interval. The discharge probe 270 is a metal having good conductivity and excellent arc resistance, such as platinum or tungsten. Made of material. An induced electromotive force is generated between the power supply electrode 210 and the auxiliary plasma ground electrode 230, but a gap 272 is formed between the discharge probe 270 and the igniter 275 and extends from the discharge probe 270 to the igniter 275. This is to prevent the induced electromotive current from being reverse-biased.

  FIG. 14 is a block diagram for explaining a plasma generator according to a fifth embodiment of the present invention, and FIG. 15 is a block diagram for explaining a plasma generation mechanism of the plasma generator according to the fifth embodiment. It is.

  Referring to FIG. 14, the plasma generator 400 according to the fifth embodiment includes a power electrode 410, a dielectric film 420, a main plasma ground electrode 440, an auxiliary plasma ground electrode 430, a gas inflow part 450, and a power controller 460. Including.

  The power supply electrode 410 is a metal such as a stainless steel or aluminum alloy formed in a cylindrical shape, and is electrically connected to the power supply controller 460. An RF power supply is applied to the power supply electrode 410 by the power supply controller 460. A low-frequency power source or a high-frequency power source can be applied according to the user's intention. As shown in the figure, the power supply controller 460 is basically supplied with power sufficient to generate the auxiliary plasma AP, and the interval between the power supply electrode 410 and the auxiliary plasma ground electrode 430 is very narrow and the area is small. Therefore, the auxiliary plasma AP can be easily maintained with a low power source.

  According to the present embodiment, the power supply electrode 410 is cylindrical, and its axial center is straight and formed straight. However, the power supply electrode can be curved into a concave shape or a convex shape depending on the shape of the object to be processed, and can have a surface including a curved surface instead of a flat surface depending on the shape of the object to be processed. In order to have a curved surface, the dielectric film covering the power supply electrode can be made of a stretchable and soft material such as silicon or polyimide.

  Around the power supply electrode 410, a dielectric film 420 made of alumina, quartz, silicon or ceramic is formed. The dielectric film 420 is an insulator formed along the periphery of the power supply electrode 410 and blocks direct contact between the power supply electrode 410 and the peripheral ground electrode. In addition, the dielectric film 420 also has a function of suppressing arc generation and assisting glow discharge between the power supply electrode 410 and the workpiece M during generation of the main plasma MP. Can do. Here, the dielectric film 420 is formed with a thickness of about 0.1 to 10 mm.

  The auxiliary plasma ground electrode 430 is positioned adjacent to the lower side of the side surface of the power supply electrode 410 covered with the dielectric film 420. The auxiliary plasma ground electrode 430 must be able to generate the auxiliary plasma AP even when a low power source is applied to the power source electrode 410. For this reason, the auxiliary plasma ground electrode 430 should be spaced from the power source electrode 410 by about 0.1 to 20 mm. Adjacent to each other. In addition, since the auxiliary plasma ground electrode 430 is arranged side by side with the power supply electrode 410, the auxiliary plasma AP is also formed long along the power supply electrode 410. Therefore, even when the auxiliary plasma AP is transferred to the main plasma MP, it can be transferred quickly over the entire section.

  A reactive gas is supplied between the power supply electrode 410 and the auxiliary plasma ground electrode 430 to form a large amount of ozone and radical ions. These reactive gases are inactive gases such as helium (He) and argon (Ar), or are reactive gases in which a small amount of oxygen or nitrogen is mixed with these inactive gases. These reaction gases are supplied between the electrodes from the outside through the gas inflow portion 450 and are uniformly supplied along the space between the power supply electrode 410 and the auxiliary plasma ground electrode 430. The reaction gas supplied between the power supply electrode 410 and the auxiliary plasma ground electrode 430 is dissociated by a strong electric field, and plasma is generated from the reaction gas through such a process.

  The main plasma ground electrode 440 is located below the power supply electrode 410 and is spaced apart from the power supply electrode 410 by a predetermined distance. The main plasma ground electrode 440 is for generating the main plasma MP corresponding to the RF power supply of the power supply electrode 410. When the power supply applied to the power supply electrode 410 increases to a certain level or more, the main plasma ground electrode 440 is provided. MP can be generated. When the object to be processed is a metal, the main plasma can be formed without the main plasma ground electrode 440, but when the object to be processed is a non-metal, the main plasma can be formed so that an electric field can be formed. A plasma ground electrode 440 must be provided. If the main plasma grounding electrode is for forming an electric field and can form the grounding corresponding to the power source electrode, it can be said that there are no strict restrictions on the grounding form and the grounding position. For example, according to another embodiment of the present invention, the conveyor belt itself can be used as the main plasma ground electrode if the workpiece is continuously moved while being processed, By maintaining the ground state, it can function as an effective ground electrode.

  Referring to FIG. 15, the workpiece M is located between the power supply electrode 410 and the main plasma ground electrode 440. At this time, the power supply controller 460 applies an RF power supply with increased power to the power supply electrode 410, and glow plasma is generated between the power supply electrode 410 and the workpiece M as the power of the RF power supply increases. Is done.

  An auxiliary plasma AP is always formed between the power supply electrode 410 and the auxiliary plasma ground electrode 430. Therefore, when the main plasma MP is generated, the plasma state of the auxiliary plasma AP can be easily transferred to the main plasma MP, and the plasma generator 400 according to the present embodiment is compared with the conventional plasma generator. It is possible to generate plasma that is more stable and has less power loss.

  Since the power to maintain the auxiliary plasma AP is small compared to the power to maintain the main plasma MP, the auxiliary plasma AP does not turn off while the workpiece M is being processed. Can be maintained. Therefore, even if the supplied power is unstable and the state of the main plasma MP becomes unstable, the plasma state can be transferred from the stable auxiliary plasma AP to the main plasma at any time, and the main plasma MP is also turned off. Therefore, a stable state can be maintained.

  FIG. 16 is a block diagram for explaining a plasma generator according to another embodiment of the present invention similar to the first embodiment.

  Referring to FIG. 16, the plasma generator 401 according to the present embodiment further includes a capacitance ground electrode 432 as compared with the plasma generator 400 according to the first embodiment. The capacitance ground electrode 432 forms a capacitance corresponding to the RF power supplied from the power controller 450, and functions to assist in forming a stable plasma by the RF power.

  The capacitance ground electrode 432 can serve as a body on which the power electrode 410 and the dielectric film 420 are mounted by accommodating the power electrode 410 and the dielectric film 420. The auxiliary plasma ground electrode 430 and the capacitance ground electrode 432 include They are formed integrally with each other and can constitute one grounding body.

  FIG. 17 is a cross-sectional view illustrating a plasma generating apparatus according to a sixth embodiment of the present invention, and FIG. 18 is a cross-sectional view illustrating a process in which the plasma generating apparatus according to the sixth embodiment operates.

  17 and 18, a plasma generator 500 according to the sixth embodiment includes a power source electrode 510, a dielectric film 520, a main plasma ground electrode 540, an auxiliary plasma ground electrode 530, a capacitance ground electrode 532, a gas inflow. A path 550 and a power supply controller 560 are included. The auxiliary plasma grounding electrode 530 and the capacitance grounding electrode 532 are made of stainless steel or an aluminum alloy, and are integrally formed to form one grounding body 535. A cylindrical hole is formed in the lower stage of the grounding body 535 so as to be perpendicular to the transfer path of the workpiece M. The lower stage part of the hole is partially opened, and the power supply electrode 510 and the dielectric film 520 are formed. Are inserted into the holes, a part of the dielectric film 520 is exposed from the lower stage of the grounding body 535. Therefore, even when the main plasma MP is formed by the power supply electrode 510, it can be uniformly formed over a wide area.

  The workpiece M is continuously passed between the grounding body 535 and the main plasma grounding electrode 540 by the transfer roller R, and the plasma generator 500 forms main plasma at a required point and continuously performs plasma processing. Can be done automatically.

  The power supply electrode 510 is formed in a cylindrical shape and is made of a metal such as stainless steel or aluminum alloy. The power supply electrode 510 is electrically connected to the power supply controller 560, and RF power can be applied to the power supply electrode 510 by the power supply controller 560.

  The power controller 560 includes an impedance matching box 562, and the high frequency power is transmitted to the power pole 510 through the matching box 562. The power supply controller 560 is basically supplied with power enough to generate the auxiliary plasma AP, and the interval between the power source electrode 510 and the auxiliary plasma ground electrode 530 is very narrow and the area is small, so that the power source controller 560 has low power. The auxiliary plasma AP can be easily maintained by the power source.

  As summarized in Table 2, the auxiliary plasma can be sufficiently maintained with a power of 50% or less of the power for maintaining the main plasma.

  The dielectric film 520 is made of alumina, quartz, silicon, or ceramic. The dielectric film 520 is an insulator formed along the periphery of the power supply electrode 510, and directly connects the power supply electrode 510 and the peripheral ground electrode. To prevent unwanted contact. Here, the dielectric film 520 is formed with a thickness of about 0.1 to 10 mm.

  The dielectric film 520 is formed and manufactured in a hollow cylindrical shape, and is obtained by inserting a cylindrical power supply electrode 510 into the dielectric film 520 or applying or depositing the dielectric film 220 on the surface of the power supply electrode 510. . As a result, unlike the conventional plate-type power supply electrode, the cylindrical dielectric film 520 has a simple structure in which the dielectric film 520 surrounds the power supply electrode 510 without a separate support member. It has the advantage that it can be insulated. Therefore, even when a strong electric field is applied through the power source electrode 510, a relatively large amount of reaction gas can be supplied and a sufficient amount of plasma can be generated without causing dielectric breakdown.

  The grounding body 535 forms a capacitance while partially accommodating the power supply electrode 510 and the auxiliary plasma grounding electrode 530 disposed adjacent to the power supply electrode 510 in order to generate the auxiliary plasma AP as one grounding electrode. Capacitance ground pole 532. In addition, a gas inflow path 550 is formed inside the grounding body 535, and the reaction gas introduced from the outside passes through the gas inflow path 550 and is uniformly between the auxiliary plasma ground electrode 520 and the power supply electrode 510. To be distributed.

  The gas inflow path 550 is connected to the first inflow path 552 and the first inflow path 552 into which the mixed gas is introduced from the outside, and is formed side by side with the power supply electrode 510. The second inflow path 554, the power supply electrode 510, and the auxiliary plasma. An inflow chamber 556 formed between the ground electrode 520 and a plurality of orifices 558 connecting the second inflow passage 554 and the inflow chamber 556 are included. The reaction gas enters the grounding body 530 through the first inflow passage 552 and is uniformly distributed to the orifices 558 through the second inflow passage 554. The reaction gas that has passed through the orifice 558 is totally dispersed between the power supply electrode 510 and the auxiliary plasma ground electrode 530 through the inflow chamber 556, and the dispersed reaction gas is supplied to the auxiliary plasma AP or the main at each position. Helps to generate plasma MP.

  As described above, since the auxiliary plasma ground electrode 530 must be able to generate the auxiliary plasma AP with a low-power power source, the auxiliary plasma ground electrode 530 is disposed close to the power source electrode 510 at an interval of about 0.1 to 20 mm. Further, since the auxiliary plasma grounding electrode 530 and the power supply electrode 510 are arranged side by side, even when the auxiliary plasma AP is transferred to the main plasma MP, it can be quickly transferred over a large area over the entire section.

  The main plasma ground electrode 540 is located below the power supply electrode 510 and is spaced apart from the power supply electrode 510 by a predetermined distance. The main plasma grounding electrode 540 is for generating the main plasma MP corresponding to the RF power supply of the power supply electrode 510. When the power supply applied to the power supply electrode 510 always increases above a certain level, A strong electric field is formed between the pole 510 and the main plasma ground electrode 540, and the main plasma MP can be generated by the strong electric field.

  Referring to FIG. 18, the main plasma MP is formed between the power supply electrode 510 and the main plasma ground electrode 540. Of course, the auxiliary plasma AP is formed between the power source electrode 510 and the auxiliary plasma ground electrode 530 together with the main plasma MP.

  The main plasma MP is glow plasma, and the object to be processed is subjected to plasma processing such as cleaning or oxide film generation over a large area while passing through the power source electrode 510 and the main plasma ground electrode 540. Further, since the auxiliary plasma AP is always formed, the plasma state can be easily transferred to the main plasma MP, and it is stable and determined when the main plasma MP is generated for the first time or is maintained continuously. Help.

  Therefore, the operator who performs plasma processing can generate and extinguish the main plasma at a desired point in time, and this adjustment can be freely performed, so that precise plasma processing can be performed at atmospheric pressure and normal temperature. It means that. When the main plasma MP is generated, the plasma state of the auxiliary plasma AP can be easily transferred, so that a more stable plasma with less power loss can be generated.

  FIG. 19 is a cross-sectional view for explaining a plasma generating apparatus according to another embodiment of the present invention similar to the sixth embodiment.

  Referring to FIG. 19, after one grounding body 535 is elongated in the transfer direction of the workpiece and a plurality of cylindrical holes are formed in parallel in the grounding body 535, the power supply electrode 510 and the dielectric are formed in each hole. A membrane 520 is inserted. Then, an auxiliary plasma ground electrode 530, a capacitance ground electrode 532, and a gas inflow path 550 are formed around each power supply electrode 510. This is for processing large-capacity plasma, and stable plasma processing can be performed over a wide area. Further, by making the reaction gas flowing into each power supply electrode different, the characteristics of the plasma processing performed at each power supply electrode can be made different.

  20 and 21 are cross-sectional views for explaining a plasma generator according to another embodiment of the present invention similar to the sixth embodiment.

  Referring to FIG. 20, two grounding bodies 535 are disposed vertically opposite to each other. Similarly to the sixth embodiment, a power pole 510 and a dielectric film 520 are inserted into each grounding body 535. An auxiliary plasma grounding electrode 530, a capacitance grounding electrode 532, and a gas inflow path 550 are formed around the power supply electrode 510.

  Thus, since two plasma generators are arrange | positioned up and down, a plasma processing process can be performed with respect to both surfaces of the to-be-processed object which passes between them. Of course, as described above, different processing treatments can be performed on both sides by making the plasma treatment process different on both sides.

  Referring to FIG. 21, the plasma generators shown in FIG. 19 are arranged vertically opposite to each other, and plasma processing can be simultaneously performed on both surfaces of the workpiece passing between them. .

  FIG. 22 is a cross-sectional view for explaining a plasma generating apparatus according to a seventh embodiment of the present invention.

  Referring to FIG. 22, the plasma generator 600 according to the seventh embodiment includes a power source electrode 610, a dielectric film 520, a main plasma ground electrode 540, an auxiliary plasma ground electrode 530, a capacitance ground electrode 532, a gas inflow path 550, And a power supply controller 560. The auxiliary plasma grounding electrode 530 and the capacitance grounding electrode 532 are made of stainless steel or an aluminum alloy, and are integrally formed to form one grounding body 535. In this embodiment, the other components except for the power supply electrode 610 are substantially the same as the components of the embodiment, and the description and drawings of the embodiment can be referred to.

  The outer diameter of the power electrode 610 is smaller than the inner diameter of the dielectric film 520, and a gap is provided between the power electrode 610 and the dielectric film 520. According to such a structure, even when the power supply electrode 610 is thermally expanded during operation, the dielectric film 520 accommodates the dielectric film 520 due to the interval between the dielectric films 520, and the dielectric film is generated by the expansion of the power supply electrode 610. Damage to 520 can be prevented.

  FIG. 23 is a cross-sectional view for explaining a plasma generator according to another embodiment of the present invention similar to the seventh embodiment.

  Referring to FIG. 23, a groove 612 formed in the longitudinal direction is formed on the surface of the cylindrical power supply electrode 610, and the unevenness provided by the groove 612 is oriented so as to face the object to be processed. Such unevenness promotes / strengthens the formation of an electric field by concentrating charges on the end of the unevenness under the same conditions.

  FIG. 24 is a cross-sectional view for explaining a plasma generator according to another embodiment of the present invention similar to the seventh embodiment.

  Referring to FIG. 24, a discharge probe 670 provided between the auxiliary plasma ground electrode 530 and the dielectric film 520 and an igniter 675 electrically connected to the discharge probe 670 are included. In addition, the conducting wire that connects the discharge probe 670 and the igniter 675 includes a gap 672 that is separated by a predetermined distance.

  By applying an instantaneous high voltage to the discharge probe 670 by the igniter 675, the reaction gas can be ignited using the igniter 675 at the initial stage when the process is to be ignited. Since ignition is performed through the igniter 675, it is not necessary to bear a high starting voltage with the high-frequency power supplied from the power controller, and power consumption can be suppressed.

  In addition, the discharge probe 670 and the igniter 675 are connected by a gap 672 so as to be separated from each other by a predetermined interval. This is due to an induced electromotive force generated between the power supply electrode 610 and the auxiliary plasma ground electrode 630. This is to prevent the induced electromotive current from being reverse-biased from the discharge probe 670 to the igniter 675.

  FIG. 25 is a sectional view showing a plasma generating apparatus according to the eighth embodiment of the present invention.

  Referring to FIG. 25, the plasma generator according to the eighth embodiment includes a power source electrode 510, a dielectric film 520, a main plasma ground electrode 540, an auxiliary plasma ground electrode 530, a capacitance ground electrode 532, a gas inflow path 550, and A power supply controller 560 is included, and an auxiliary plasma ground electrode 530 and a gas inflow path 550 are arranged on both sides of the power supply electrode 510, respectively. Further, the auxiliary plasma grounding electrode 530 and the capacitance grounding electrode 532 are made of stainless steel or aluminum alloy, and are integrated to form one grounding body 535.

  The auxiliary plasma grounding electrodes 530 on both sides share one power supply electrode 510, so that the plasma generator can be used without power deviating. In addition, since the gas flows flowing back and forth are opposite to each other, it is possible to easily cope with an object to be processed in a specific direction.

  The power supply electrode 510 is formed in a cylindrical shape and is made of a metal such as stainless steel or aluminum alloy. The power supply electrode 510 is electrically connected to the power supply controller 560, and RF power can be applied to the power supply electrode 510 by the power supply controller 560.

  The power supply controller 560 basically supplies power enough to generate the auxiliary plasma AP, and can easily maintain the auxiliary plasma AP with a low-power power supply.

  The dielectric film 520 is formed and manufactured in a hollow cylindrical shape, and is obtained by inserting a cylindrical power supply electrode 510 into the dielectric film 520 or applying or depositing the dielectric film 520 on the surface of the power supply electrode 510. . As a result, unlike the conventional plate-type power supply electrode, the cylindrical dielectric film 520 has a simple structure in which the dielectric film 520 surrounds the power supply electrode 510 without a separate support member. It has the advantage that it can be insulated. Therefore, even when a strong electric field is applied through the power source electrode 510, a relatively large amount of reaction gas can be supplied and a sufficient amount of plasma can be generated without causing dielectric breakdown.

  As described above, according to the present invention, the plasma generator can generate low-temperature plasma under atmospheric pressure, and can provide stable plasma by using auxiliary plasma. In particular, even when using a high frequency power source that is unstable and unstable in plasma discharge due to sample transfer or inflow of external gas, the auxiliary plasma functions as a stable plasma source. Even when the external gas is not flowing, a stable glow plasma that can be applied uniformly and over a large area can be generated.

  In addition, by using the auxiliary plasma, the generation and extinction of the main plasma can be quickly switched according to the operator's intention, thereby enabling precise plasma processing.

  In addition, since the plasma generating apparatus according to the present invention is not greatly limited by installation conditions in an open space at atmospheric pressure, plasma cleaning and other processing can be performed quickly through a continuous process in real time.

  On the other hand, since a plurality of power supply electrodes and auxiliary plasma grounding electrodes can be formed, the capacity of the plasma generator can be easily increased, and the width can be adjusted very freely with respect to the left and right widths.

  Also, by making the inner diameter of the dielectric film larger than the outer diameter of the power supply electrode, it is possible to safely accommodate the thermal expansion of the power supply electrode, and by forming irregularities around the power supply electrode, under the same conditions Electric field formation can be promoted and strengthened. In addition, for initial ignition at the auxiliary plasma ground electrode, a discharge probe is arranged between the power supply electrode and the ground electrode, and an igniter is connected to this to significantly reduce the power consumed during the initial ignition. be able to.

  Thus, atmospheric pressure low temperature plasma, regardless of metal or non-metal, for example, semiconductor wafer, LCD glass, lead frame, PCB, metal sheet, light guide plate, fiber, silicon, rubber, polymer cleaning, ashing, It can greatly contribute to etching, vapor deposition and other processing. In addition, when utilizing the activity of plasma, the organic component of the sample can be processed in-line, and the low temperature characteristics of the plasma can be used to prevent the product from being thermally deformed. New environmental processes to improve quality can be introduced.

  As a result, atmospheric pressure low temperature plasma technology is expected to be applicable not only to semiconductor and PCB industry development, but also to surface treatment technology for plastic and glass products, germs such as medical equipment and foodstuffs, and disinfection technology. The

  The present invention described above can be variously replaced, modified, and changed without departing from the technical idea of the present invention as long as it has ordinary knowledge in the technical field to which the present invention belongs. Therefore, the present invention is not limited to the above-described embodiment and attached drawings.

It is a block diagram for demonstrating the conventional DBD discharge method. It is a graph which shows the current-voltage characteristic curve for demonstrating the characteristic of glow plasma. It is a block diagram for demonstrating the plasma generator concerning 1st Example of this invention. It is a block diagram for demonstrating the plasma generation mechanism of the plasma generator which concerns on 1st Example. It is a block diagram for demonstrating the plasma generator concerning other Examples of this invention similar to 1st Example. It is sectional drawing which shows the plasma generator concerning 2nd Example of this invention. It is a perspective view which shows the plasma generator concerning 2nd Example. It is a partial cutaway figure which shows the grounding trunk | drum of the plasma generator concerning 2nd Example. It is sectional drawing for demonstrating the process in which a plasma generator operates by 2nd Example. It is sectional drawing for demonstrating the plasma generator concerning 3rd Example of this invention. It is sectional drawing which shows the plasma generator concerning 4th Example of this invention. It is sectional drawing for demonstrating the process in which the main plasma act | operates in the plasma generator which concerns on 4th Example. It is sectional drawing for demonstrating the plasma generator concerning other Examples of this invention similar to 4th Example. It is a block diagram for demonstrating the plasma generator which concerns on 5th Example of this invention. It is a block diagram for demonstrating the plasma generation mechanism of the plasma generator which concerns on 5th Example. It is a block diagram for demonstrating the plasma generator concerning other Examples of this invention similar to 5th Example. It is sectional drawing for demonstrating the plasma generator concerning 6th Example of this invention. It is sectional drawing for demonstrating the process in which the plasma generator concerning 6th Example operates. It is sectional drawing for demonstrating the plasma generator concerning other Examples of this invention similar to 6th Example. It is sectional drawing for demonstrating the plasma generator concerning other Example of this invention similar to 6th Example. It is sectional drawing for demonstrating the plasma generator concerning other Example of this invention similar to 6th Example. It is sectional drawing for demonstrating the plasma generator concerning 7th Example of this invention. It is sectional drawing for demonstrating the plasma generator concerning other Examples of this invention similar to 7th Example. It is sectional drawing for demonstrating the plasma generator concerning other Example of this invention similar to 7th Example. It is sectional drawing which shows the plasma generator concerning 8th Example of this invention.

Claims (16)

In an atmospheric pressure plasma generator for processing workpieces with plasma,
A power supply electrode disposed at a predetermined interval from the object to be processed;
A first dielectric film interposed between the power supply electrode and the workpiece;
An auxiliary plasma grounding electrode that is disposed adjacent to the power supply electrode and forms auxiliary plasma with a lower power than a main plasma generated between the power supply electrode and the workpiece, and is disposed adjacent to the power supply electrode. A grounding fuselage including a capacitance grounding electrode,
A second dielectric film interposed between the power supply electrode and the grounding body;
A gas inflow part for providing a mixed gas for a plasma reaction between the power supply electrode and the auxiliary plasma ground electrode;
A power controller for controlling an RF power applied to the power electrode;
A main plasma grounding electrode for generating the main plasma, located at a lower part of the power supply electrode and spaced apart from the power supply electrode;
The object to be processed is located between the power supply electrode and the main plasma ground electrode,
The power supply electrode is formed in a flat plate shape, and maintains a certain distance from the object to be processed above the object to be processed.
The grounding body is formed in a flat plate shape corresponding to the power supply electrode, and is disposed to face the power supply electrode, and the auxiliary plasma grounding electrode and the capacitance grounding electrode sandwich the second dielectric film. An atmospheric pressure plasma generator characterized by being in surface contact with a power supply electrode. The gas inflow portion communicates with the first inflow passage through which the mixed gas flows from the outside, the second inflow passage formed in line with the power supply electrode, and the mixed gas into the power supply electrode. 2. The atmospheric pressure plasma generator according to claim 1, further comprising a plurality of orifices formed in an inner wall surface of the second inflow passage. The gas inflow part further includes an inflow chamber provided between the auxiliary plasma ground electrode and the dielectric film, and the orifice connects the second inflow path and the inflow chamber. The atmospheric pressure plasma generator according to claim 2. The atmospheric pressure according to claim 1, further comprising a discharge probe positioned between the auxiliary plasma ground electrode and the second dielectric film, and an igniter electrically connected to the discharge probe. Plasma generator. 5. The atmospheric pressure plasma generation apparatus according to claim 4, wherein the conducting wire connecting the discharge probe and the igniter includes a gap separated by a predetermined interval. A plurality of the power supply electrodes are arranged in parallel so as to be perpendicular to the transfer path of the object to be processed, and the first and second dielectric films are formed on the surface of the power supply electrode, each between the power supply electrodes. The atmospheric pressure plasma generator according to claim 1, wherein the grounding body is interposed. In an atmospheric pressure plasma generator for processing workpieces with plasma,
A columnar power supply electrode disposed at a predetermined interval from the object to be processed;
A dielectric film surrounding the power supply electrode;
An auxiliary plasma ground electrode disposed adjacent to the power supply electrode and forming an auxiliary plasma at a lower power than a main plasma generated between the power supply electrode and the workpiece;
A gas inflow portion for providing a reaction gas between the power supply electrode and the auxiliary plasma ground electrode;
A power controller for controlling an RF power applied to the power electrode;
A main plasma grounding electrode for generating the main plasma, located at a lower part of the power supply electrode and spaced apart from the power supply electrode;
The object to be processed is located between the power supply electrode and the main plasma ground electrode,
A side surface of the power supply electrode faces the workpiece,
A groove is formed on a surface of the power electrode, and the groove is directed to the object to be processed. The atmospheric plasma generator according to claim 7, wherein the main plasma grounding electrode includes a conveyor device capable of transferring the object to be processed while maintaining a grounded state. The atmospheric pressure plasma generating apparatus according to claim 7, wherein the dielectric film is formed in a hollow shape, and an inner diameter of the dielectric film is larger than an outer diameter of the power supply electrode. A discharge probe positioned between the auxiliary plasma ground electrode and the dielectric film or between the main plasma ground electrode and the dielectric film; and an igniter electrically connected to the discharge probe. The atmospheric pressure plasma generator according to claim 7. The apparatus of claim 10 , wherein the conducting wire connecting the discharge probe and the igniter includes a gap separated by a predetermined interval. A plurality of the power supply electrodes and the dielectric film are arranged in parallel so as to be perpendicular to the transfer path of the workpiece, and the auxiliary plasma ground electrode is provided adjacent to each of the dielectric films. The atmospheric pressure plasma generator according to claim 7, wherein A plurality of the power supply electrodes and the dielectric film are arranged in parallel above and below the transfer path of the workpiece, and the auxiliary plasma ground electrode is provided adjacent to each of the dielectric films. The atmospheric pressure plasma generator according to claim 7. The atmospheric pressure plasma generator according to claim 7, wherein the power electrode is formed in a cylindrical shape. The atmospheric pressure plasma generation apparatus according to claim 7, wherein the power supply electrode and the dielectric film have surfaces that are partially curved. The apparatus of claim 7, wherein the auxiliary plasma ground electrode and the gas inflow portion are provided on both sides of the power supply electrode and the dielectric film, respectively.

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