JP5961899B2 - Atmospheric pressure plasma generator - Google Patents

Description

  The present invention relates to an atmospheric pressure plasma generator. More specifically, the present invention relates to an atmospheric pressure plasma generator that suppresses electrode deterioration and prevents metal fine particles from being scattered on an object to be processed. The metal fine particles are particles such as sputtered particles generated from the electrodes by discharge.

  In the plasma atmosphere, a part of the source gas is radicalized. This radical is used when a thin film of source gas is formed or when an object to be processed is etched. In addition, it is also used when cleaning the surface of a glass substrate or a semiconductor substrate.

  As a method for generating plasma, a method of applying a voltage between a pair of opposed electrodes to discharge is often used (Patent Document 1). Further, Patent Document 2 discloses a plasma generator that generates a wide atmospheric pressure plasma under atmospheric pressure. By using atmospheric pressure plasma, in-line processing can be performed without a decompression device. Therefore, plasma treatment can be performed at low cost.

JP 2008-010373 A JP 2010-218801 A

  By the way, in the electrode, sputtered particles (metal fine particles) are generated during discharge. When the metal fine particles adhere to the periphery of the electrode, it causes deformation of the electrode. That is, the electrode deteriorates. Further, when the metal fine particles adhere to the insulating member disposed around the electrodes, there is a possibility that the discharge between the electrodes becomes unstable. Due to these causes, the durability life is shortened. That is, the electrode needs to be replaced.

  In addition, the metal fine particles may be scattered toward the plasma generation part. And there exists a possibility of adhering to the surface of the process target object which plasma-processes. If metal fine particles adhere to the surface of the object to be treated, there is a high possibility that it will be a defective product. Therefore, it is necessary to prevent scattering to the processing object.

  The present invention has been made to solve the above-described problems of the prior art. That is, an object of the present invention is to provide a plasma generator that suppresses electrode deterioration and contamination of the surface of a processing object.

The atmospheric pressure plasma generator in a 1st aspect has the 1st electrode part which has a 1st electrode, and the 2nd electrode part which has a 2nd electrode. At least one of the first electrode portion and the second electrode portion includes a first chamber or a spare chamber surrounding the second electrode, a gas supply path for supplying gas to the spare chamber, and a gas from the spare chamber. A gas discharge path for discharging the gas , and an insulating member including the first electrode or the second electrode and a spare chamber . The insulating member has a communication portion that communicates the gas supply path and the gas discharge path. The first electrode and the second electrode are micro hollow electrodes having a recess formed at the tip.

  In this atmospheric pressure plasma generator, the gas to be supplied enters the preliminary chamber from the gas supply path through the communication portion and flows to the gas discharge path. For this reason, in the preliminary chamber, which is the space around the electrode, the gas flows in the direction toward the gas discharge section. Therefore, even if metal fine particles are scattered from the first electrode or the second electrode, these metal fine particles are carried to the gas discharge path. And metal particulates are discharged | emitted with gas from a gas discharge part. Therefore, there is almost no possibility of adhering to the insulating members around the first electrode and the second electrode, and there is almost no possibility of adhering again to the first electrode and the second electrode. Moreover, there is almost no possibility of scattering toward the processing object. Electrons are emitted from the micro hollow electrode with high density. Therefore, the density of the generated plasma can be increased. Moreover, the density of radicals can also be high.

The atmospheric pressure plasma generation apparatus according to the second aspect includes a first electrode portion having a first electrode and a second electrode portion having a second electrode. At least one of the first electrode portion and the second electrode portion includes a spare chamber surrounding the first electrode or the second electrode, a gas supply path for supplying gas to the spare chamber, and exhausting gas from the spare chamber A gas exhaust path, a communication portion that communicates the gas supply path and the gas exhaust path, a covering insulating member that covers the first electrode or the second electrode except for the tip portion, and outside the covering insulating member, And an insulating member provided with a communication portion. The insulating member includes a spare chamber. And the gas exhaust path is formed between the insulating member provided with a communicating part, and a covering insulating member. This is because the metal fine particles around the electrode can be easily discharged into a gas discharge path provided between the covering insulating member and the insulating member.

  In the atmospheric pressure plasma generating apparatus according to the third aspect, the communicating portion communicates the spare chamber of the first electrode portion and the spare chamber of the second electrode portion. Thereby, it is possible to suitably generate plasma inside the housing unit based on the preliminary plasma generated inside the preliminary chamber.

  In the atmospheric pressure plasma generation device according to the fourth aspect, the communication portion is a plurality of through holes formed in the insulating member. This is because gas flows in from a plurality of through holes.

  In the atmospheric pressure plasma generating apparatus according to the fifth aspect, the insulating member including the communication portion has a cylindrical shape, and the through hole is formed over the cylindrical surface of the cylindrical shape. This is because the gas easily flows around the electrode.

The atmospheric pressure plasma generation apparatus according to the sixth aspect includes a first electrode portion having a first electrode and a second electrode portion having a second electrode. At least one of the first electrode portion and the second electrode portion includes a spare chamber surrounding the first electrode or the second electrode, a gas supply path for supplying gas to the spare chamber, and exhausting gas from the spare chamber And a communication part that communicates the gas supply path and the gas discharge path. The communication part is a plurality of through holes formed in the insulating member. The insulating member including the communication portion includes a spare chamber and has a cylindrical shape. The through hole is formed over a cylindrical surface of a cylindrical shape.

  ADVANTAGE OF THE INVENTION According to this invention, the plasma generator which aimed at suppression of deterioration of an electrode and suppression of the contamination of the process target object surface is provided.

It is a schematic block diagram which shows the structure of the plasma generator which concerns on embodiment. It is sectional drawing which shows schematic structure of the periphery of the electrode part in the plasma generator which concerns on embodiment. It is FIG. (1) which shows the periphery of an electrode part at the time of use of the plasma generator which concerns on embodiment. It is FIG. (2) which shows the periphery of an electrode part at the time of use of the plasma generator which concerns on embodiment.

  Hereinafter, specific embodiments will be described with reference to the drawings, taking as an example a plasma generator that generates plasma under atmospheric pressure.

1. Configuration of Plasma Generator The plasma generator of this embodiment will be described. The plasma generator 100 of this embodiment is an atmospheric pressure plasma generator that generates plasma under atmospheric pressure. As shown in FIG. 1, the plasma generator 100 includes a first electrode unit E10, a second electrode unit E20, a first electrode unit gas supply unit 110, and a second electrode unit gas supply unit 120. The first electrode unit gas discharge unit 130, the second electrode unit gas discharge unit 140, the main gas supply units 150 and 160, and the housing unit 170 are provided.

  The first electrode portion E10 and the second electrode portion E20 are for discharging between them. The first electrode part E10 and the second electrode part E20 each have an electrode. Details will be described later.

  The first electrode part gas supply part 110 is a gas supply part for supplying gas to the first electrode part E10. The 1st electrode part gas discharge part 130 is a gas discharge part for discharging | emitting gas from the 1st electrode part E10. The second electrode unit gas supply unit 120 is a gas supply unit for supplying gas to the second electrode unit E20. The 2nd electrode part gas discharge part 140 is a gas discharge part for discharging | emitting gas from the 2nd electrode part E20.

  Specifically, the first electrode unit gas supply unit 110, the second electrode unit gas supply unit 120, the first electrode unit gas discharge unit 130, and the second electrode unit gas discharge unit 140 are: It is a valve. When the valve is opened, gas can be supplied or discharged.

  Inside the casing 170 is a space 180 for generating plasma. The main gas supply units 150 and 160 are for supplying a source gas for generating plasma in the space 180 of the housing unit 170. For example, oxygen, hydrogen, fluorine, and nitrogen are listed. Of course, other gases may be used. Further, it may be a mixed gas in which a predetermined amount of a rare gas such as Ar is mixed. Radicals generated are determined by this source gas. Therefore, a part of the space 180 is a plasma generator that generates plasma.

2. Configuration of Electrode Unit FIG. 2 shows a schematic configuration of the first electrode unit E10 and the second electrode unit E20. The configurations of the first electrode portion E10 and the second electrode portion E20 are substantially the same. Therefore, the first electrode part E10 will be mainly described. In FIG. 2, the reference numerals indicating the configuration of the second electrode portion E20 are shown in parentheses.

  The first electrode portion E10 has a first electrode E11. The second electrode part E20 has a second electrode E21. The plasma generator 100 has a high voltage power source (not shown). This high-voltage power supply is a voltage application unit that applies a voltage between the first electrode E11 and the second electrode E21. As the high voltage power supply, for example, a high voltage power supply or a high frequency high voltage power supply obtained by boosting 60 Hz alternating current or 50 Hz alternating current can be used.

  As shown in FIG. 2, in addition to the first electrode E11, the first electrode portion E10 includes a covering insulating member 20, an inner insulating member 30, an outer insulating member 40, a gas supply path 60, and gas discharge. It has a path 70 and a first preliminary chamber P11. A hollow H11 is formed at the tip of the first electrode E11. The hollow H11 is a micro hollow in which fine concave portions are repeatedly formed.

  In addition to the first electrode E11, the second electrode portion E20 includes the covering insulating member 20, the inner insulating member 30, the outer insulating member 40, the gas supply path 60, the gas discharge path 70, 2 spare chambers P21. A hollow H21 is formed at the tip of the second electrode E21. The hollow H21 is the same as the hollow H11.

  The shape of the first electrode E11 is a cylindrical shape except for the location of the hollow H11. Of course, other shapes may be used. The material of the first electrode E11 may be a metal that does not undergo deformation or the like (including deformation, dissolution, or evaporation) by discharge. For example, molybdenum, tungsten, titanium, and stainless steel can be used. Of these, copper is preferred. More preferably, it is oxygen-free copper. The same applies to the second electrode E21.

  The covering insulating member 20 is an insulating member for covering the first electrode E11 or the second electrode E21. However, the covering insulating member 20 does not cover the tip portion of the first electrode E11 or the second electrode E21. Therefore, the hollow H11 or the hollow H21 is exposed from the covering insulating member 20. The shape of the covering insulating member 20 is a cylindrical shape. The first electrode E11 is accommodated on the inner surface of the cylinder. The material of the covering insulating member 20 is, for example, ceramic. Of course, other things may be used.

  The inner insulating member 30 is a cylindrical insulating member. The inner insulating member 30 accommodates the first electrode E11 and the covering insulating member 20 inside the cylinder. A plurality of through holes 31 are formed in the inner insulating member 30. The through hole 31 is formed over the cylindrical surface of the inner insulating member 30. That is, the through hole 31 is a communication portion that communicates the gas supply path 60 and the gas discharge path 70. And by having the through-hole 31, the preliminary chamber P11 of the first electrode portion E10 and the preliminary chamber P21 of the second electrode portion E20 communicate with each other. Thus, the inner side insulation member 30 is an insulation member provided with a communication part. In FIG. 2, these through holes 31 are formed in two rows. Further, these through holes 31 may be in one row or in three or more rows. The diameter of the through hole 31 is about φ1 mm. Of course, this is merely an example, and other values may be used.

  The outer insulating member 40 is a cylindrical insulating member. The outer insulating member 40 accommodates the inner insulating member 30 inside the cylinder. That is, the outer insulating member 40 is located outside the inner insulating member 30.

  The insulating member 50 is a part of the housing 170 that covers a part of the outer insulating member 40. A through hole 51 is provided in the insulating member 50. The through hole 51 communicates with the plasma generation part P1. In addition, the material of the inner side insulation member 30, the outer side insulation member 40, and the insulation member 50 is a ceramic, for example. Of course, other things may be used.

  The first preliminary chamber P11 and the second preliminary chamber P21 are spaces surrounding the first electrode E11 and the second electrode E21, respectively. The first preliminary chamber P11 and the second preliminary chamber P21 are for generating preliminary plasma.

2-2. Gas supply path and gas discharge path The gas supply path 60 is formed between the inner insulating member 30 and the outer insulating member 40. The gas supply path 60 is for supplying gas into the preliminary chamber P11 of the first electrode E11. Therefore, the gas supply path 60 is in communication with the first preliminary chamber P11 or the second preliminary chamber P21 through the through hole 31.

  The gas discharge path 70 is formed between the inner insulating member 30 and the covering insulating member 20. The gas discharge path 70 is for discharging gas from the preliminary chamber P11 of the first electrode E11. Therefore, the gas discharge path 70 is in communication with the first preliminary chamber P11 or the second preliminary chamber P21.

  The through hole 31 of the inner insulating member 30 communicates the gas supply path 60 and the gas discharge path 70. Therefore, the gas sent out from the gas supply path 60 is directed to the gas discharge path 70 through the through hole 31. The same applies to the second electrode portion E20 side.

  The through hole 51 communicates with the plasma generation part P1 and the gas supply path 60. The gas supply path 60 communicates with the preliminary chamber P11 and the gas discharge path 70 through the through hole 31. Further, the through hole 31 communicates with the plasma generation part P1. Therefore, the plasma generating part P1 communicates with the preliminary chamber P11 of the first electrode part E10 and the preliminary chamber P21 of the second electrode part E20.

3. 3. Plasma generator in use 3-1. Before the start of discharge As shown in FIG. 3, when the plasma generator 100 is used, the source gas is supplied from the main gas supply units 150 and 160. This source gas is a gas that becomes a radical source. Examples of the source gas include oxygen, hydrogen, fluorine, and nitrogen. Of course, other gases may be used. Alternatively, a mixed gas obtained by mixing these gases with a rare gas such as Ar gas may be supplied.

  Then, Ar gas is supplied from the first electrode part gas supply part 110 and the second electrode part gas supply part 120 to the respective locations of the first electrode E11 and the second electrode E21. That is, Ar gas flows through the gas supply path 60 in the direction of the arrow D1. Therefore, a part of Ar gas flowing through the gas supply path 60 passes through the through hole 31 and enters the spare chamber P11 or the spare chamber P21. And Ar gas advances to the direction of arrow D2 of FIG.

  On the other hand, the remaining Ar gas flowing through the gas supply path 60 flows through the through hole 51 in the direction of the arrow D3. That is, it flows toward the plasma generation part P1. However, the flow rate is small. In the plasma generation part P <b> 1, source gas flows from the main gas supply parts 150 and 160 and Ar gas flows from the through hole 51. In addition, the atmospheric pressure X in the plasma generation part P1 is about atmospheric pressure (0.8 atm ≦ X ≦ 1.2 atm).

  Thus, the Ar gas flowing through the gas supply path 60 flows into the preliminary chambers P11 and P21 or the plasma generation unit P1. In the preliminary chambers P11 and P21, Ar gas flows into the gas discharge path 70.

3-2. After the start of discharge, a voltage is applied between the first electrode E11 and the second electrode E21. Thereby, as shown in FIG. 4, preliminary plasma PP is generated around the hollow H11 of the first electrode E11 and around the hollow H21 of the second electrode E21. And the preliminary plasma PP is
It expands to the space 180 side between the first electrode E11 and the second electrode E21. Then, it further spreads through the through hole 51.

  Eventually, the preliminary plasma PP reaches the space 180. Thereby, plasma is generated between the first preliminary chamber P11 and the second preliminary chamber P21. A part of the source gas converted to plasma collides with the inner wall of the housing 170 to be neutralized to become radicals. A part of the radical is discharged from a large number of through holes R1 provided in the casing 170. This radical is used for cleaning the substrate.

3-3. Discharge effect of metal fine particles In the first preliminary chamber P11, metal fine particles generated from the first electrode E11 are scattered by discharge. Here, the gas that has entered from the through hole 31 flows toward the gas discharge path 70 as described above. That is, the Ar gas flow that flows toward the gas discharge path 70 is already in the first preliminary chamber P11. Therefore, the metal fine particles are discharged from the first electrode portion gas discharge portion 130 through the gas discharge passage 70. That is, there is almost no possibility of adhering to the insulating member around the first electrode E11, and there is almost no possibility of adhering again to the first electrode E11. Moreover, there is almost no possibility of scattering to the plasma generation part P1.

  In addition, Ar gas flows in the first preliminary chamber P11. Therefore, there is no possibility that an oxide film is formed on the first electrode E11. Of course, other rare gases may be used instead of Ar gas. The same applies to the second electrode portion E20.

3-4. Comparison with the Conventional A conventional plasma generator is not provided with the gas supply path 60 and the gas discharge path 70 as in the present embodiment. Accordingly, fine particles such as sputtering particles are scattered around the electrode. Such fine particles may adhere to insulating members around the electrodes. Thereby, there exists a possibility that discharge may become unstable. If the discharge becomes unstable, it becomes difficult to control the generated plasma.

  Further, the fine particles may be scattered toward the plasma generation part P1. In that case, there is a possibility that the fine particles are scattered toward the object to be processed and adhere to the surface of the object to be processed. This becomes a cause of impairing the quality of the processing object as a product.

4). Modified example 4-1. In the present embodiment, the plurality of through holes 31 have the same shape and the same size around the inner insulating member 30. However, the through hole 31 having a large diameter may be disposed on the discharge side (plasma region P1 side).

4-2. The shape of the through hole The shape of the through hole 31 may be a slit shape instead of a circle. Moreover, it is good also as another polygon. Thus, the shape of the through-hole 31 is not ask | required. This is because the same effect is produced regardless of the shape of the through hole 31.

4-3. Direction of Ar Gas Flow In this embodiment, the gas supply path 60 is provided outside, and the gas discharge path 70 is provided inside the gas supply path 60. However, these positional relationships may be reversed. That is, Ar gas is allowed to flow from the inner passage and is discharged from the outer passage.

5. Summary As described in detail above, in the plasma generator 100 according to the present embodiment, the gas supply path 60 that supplies gas to the vicinity of the first electrode E11 and the second electrode E21, and the gas that discharges the gas. A discharge path 70 is provided. Therefore, when the plasma generator 100 is used, the fine particles generated from the first electrode E11 and the second electrode E21 are discharged together with the exhaust gas. Therefore, the plasma generator 100 that prevents the deterioration of the first electrode E11 and the second electrode E21 is realized.

  This embodiment is merely an example. Therefore, naturally, various improvements and modifications can be made without departing from the scope of the invention. For example, the shape of the electrode pair is not limited to that described in the embodiment. That is, it is not limited to the one in which the hollow is formed. Further, the materials of the electrode and the insulator are not limited to those described. An atmospheric pressure plasma generator having a relatively long distance between electrodes (about 5 cm) has been described. However, the present invention can be applied regardless of the distance between the electrodes. Further, the arrangement of the gas supply path 60 and the gas discharge path 70 is effective even in at least one of the electrode portions.

DESCRIPTION OF SYMBOLS 100 ... Plasma generator 110 ... 1st electrode part gas supply part 120 ... 2nd electrode part gas supply part 130 ... 1st electrode part gas discharge part 140 ... 2nd electrode part gas discharge part 150, 160 ... main Gas supply part 170 ... Case 180 ... Space part 20 ... Coating insulating member 30 ... Insulating insulating member 31 ... Through hole 40 ... Outer insulating member 50 ... Insulating member 51 ... Through hole 60 ... Gas supply path 70 ... Gas discharge path E10 ... 1st electrode part E11 ... 1st electrode E20 ... 2nd electrode part E21 ... 2nd electrode H11, H21 ... Hollow P11 ... 1st spare chamber P21 ... 2nd spare chamber P1 ... Plasma generating part R1 ... Through hole

Claims (6)

A first electrode portion having a first electrode;
A second electrode portion having a second electrode;
In an atmospheric pressure plasma generator having
At least one of the first electrode portion and the second electrode portion is:
A spare chamber surrounding the first electrode or the second electrode;
A gas supply path for supplying gas to the preliminary chamber;
A gas discharge path for discharging gas from the preliminary chamber;
An insulating member comprising the first electrode or the second electrode and the preliminary chamber;
I have a,
The insulating member is
Having a communication part for communicating the gas supply path and the gas discharge path;
The first electrode and the second electrode are:
An atmospheric pressure plasma generator characterized in that it is a micro-hollow electrode having a recess formed at the tip. A first electrode portion having a first electrode;
A second electrode portion having a second electrode;
In an atmospheric pressure plasma generator having
At least one of the first electrode portion and the second electrode portion is:
A spare chamber surrounding the first electrode or the second electrode;
A gas supply path for supplying gas to the preliminary chamber;
A gas discharge path for discharging gas from the preliminary chamber;
A communication part for communicating the gas supply path and the gas discharge path;
A covering insulating member that covers the first electrode or the second electrode except for a tip portion; and
An insulating member provided with the communication part on the outside of the covering insulating member;
Have
The insulating member includes the preliminary chamber,
The atmospheric pressure plasma generating apparatus, wherein the gas discharge path is formed between an insulating member having the communication portion and the covering insulating member. In the atmospheric pressure plasma generator according to claim 1 or 2,
The communication part is
An atmospheric pressure plasma generator characterized in that the preliminary chamber of the first electrode section and the preliminary chamber of the second electrode section communicate with each other. In the atmospheric pressure plasma generator according to any one of claims 1 to 3 ,
The communication part is
An atmospheric pressure plasma generator comprising a plurality of through holes formed in the insulating member. In the atmospheric pressure plasma generator according to claim 4 ,
It said insulating member having the communicating portion,
It has a cylindrical shape,
The through hole is
The atmospheric pressure plasma generator is formed over the cylindrical surface of the cylindrical shape. A first electrode portion having a first electrode;
A second electrode portion having a second electrode;
In an atmospheric pressure plasma generator having
At least one of the first electrode portion and the second electrode portion is:
A spare chamber surrounding the first electrode or the second electrode;
A gas supply path for supplying gas to the preliminary chamber;
A gas discharge path for discharging gas from the preliminary chamber;
A communication part for communicating the gas supply path and the gas discharge path;
Have
The communication part is
A plurality of through holes formed in the insulating member;
The insulating member provided with the communication part is
It has a cylindrical shape with the preliminary chamber ,
The through hole is
The atmospheric pressure plasma generator is formed over the cylindrical surface of the cylindrical shape.

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