TWI440085B - Plasma processing device - Google Patents

Description

Plasma processing device

The present invention relates to a device for surface treatment of a workpiece after it is passed through a discharge space close to atmospheric pressure and plasmad, and then disposed on the object to be treated outside the discharge space, in particular, Three or more plasma processing apparatuses that form electrodes of the above discharge space.

An atmospheric piezoelectric slurry processing apparatus in which three or more electrodes are arranged is known (see Patent Document 1, etc.). The opposite faces (discharge generating faces) of the adjacent electrodes are covered by a solid dielectric. As the solid dielectric material, for example, a ceramic plate (dielectric member) such as alumina can be used. A ceramic plate having a facing surface facing the adjacent electrode is formed with a slit-like passage therebetween. By applying an electric field between the electrodes, a discharge is generated between the electrodes at a pressure close to atmospheric pressure, and the slit-shaped space becomes a discharge space. The process gas is introduced into the discharge space and plasmad. The plasma gas after the plasma treatment is led out from the discharge space and ejected to the object to be treated. Thereby, the object to be treated is subjected to surface treatment.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-333096

A creeping discharge is likely to occur at a corner portion formed by the periphery of the discharge generating surface of the electrode of the atmospheric piezoelectric slurry processing apparatus and the ceramic plate. When an ambient gas such as air is present in the corner portion, a corrosive component such as ozone is generated by creeping discharge. The ambient gas is heated by the heat of the electrode and forms convection. The corrosive component may also form a convection with the ambient gas and away from the electrode to diffuse toward the periphery. However, when there are three or more electrode arrangements, the corrosive component generated at the corner portion on the lower side of the inner electrode comes into contact with the lower end surface of the electrode and forms convection due to the high temperature. Therefore, the lower end portion of the above inner electrode is easily corroded.

The present invention has been developed to solve the above problems, and is a plasma processing apparatus that allows a processing gas to pass through a discharge space close to atmospheric pressure and is in contact with an object to be processed disposed outside the discharge space, and is characterized by comprising: Each of the three or more electrodes is formed in a plate shape having a lower end surface and a discharge generating surface that intersects the lower end surface, and is arranged to intersect the discharge generating surface so that the discharge generating surfaces of the adjacent ones face each other. a dielectric member covering the respective discharge generating surfaces and including a plate-shaped solid dielectric material dividing the discharge space; and a scrubbing nozzle for rinsing the scrubbing gas along the three or more The electrode is disposed in such a manner that the lower end surface of the electrode disposed on the inner side flows.

According to the above configuration, even if a corrosive component due to the creeping discharge is generated in a corner portion formed by the lower end surface of the inner electrode and the dielectric member, the corrosive component can be removed from the inner electrode by the scrubbing gas. The periphery of the lower end face is removed (washed). Thereby, corrosion of the lower end portion of the inner electrode can be prevented.

Preferably, the rinsing nozzle is disposed on one end side in the longitudinal direction orthogonal to (or intersecting with) the end surface of the inner electrode.

The scrubbing gas ejected from the washing nozzle flows from one end side to the other end side along the longitudinal direction of the lower end surface of the inner electrode. Thereby, the corrosive component caused by the creeping discharge can be surely removed from the periphery of substantially the entire lower end surface of the inner electrode.

A gas lead-out portion is provided below the three or more electrodes so as to straddle the electrodes via a gap, and the dielectric member protrudes downward from the electrode and is connected to the gas lead-out portion. A gas export path connected to the discharge space may be formed inside the lead-out portion. The washing nozzle is configured such that a gap (hereinafter referred to as an "inner gap") between the inner electrode and the gas lead-out portion faces an opening on one end side in the longitudinal direction orthogonal to (or intersects with) the parallel direction. In the arrangement, the opening on the other end side in the longitudinal direction of the inner gap may be opened.

A creeping discharge is likely to occur at a corner portion formed by the lower end surface of the electrode and the protruding portion of the dielectric member toward the lower portion. When a creeping discharge occurs, oxygen in the ambient gas in the gap is ozonated, and a corrosive component is generated in the gap. Therefore, the scrubbing gas is ejected from the above-mentioned washing nozzle into the inner gap. The scrubbing gas flows from one end side to the other end side along the longitudinal direction of the inner side gap, and flows out from the opening of the other end side. Thereby, the gas in the inner gap can be replaced with a scrubbing gas. Thereby, even if the creeping discharge occurs in the corner portion, the formation of corrosive components can be suppressed or prevented. That is, it is convenient to generate a corrosive component in the inner gap, and the corrosive component may be removed from the inner gap together with the scrubbing gas. As a result, corrosion of the lower end portion of the inner electrode can be prevented.

The present invention is suitable for a plasma surface treatment apparatus which generates plasma at a pressure close to atmospheric pressure and performs surface treatment. Here, the term "atmospheric pressure" means a range of 1.013 × 10 ⁴ to 50.663 × 10 ⁴ Pa, and in consideration of ease of pressure adjustment or simplification of the device configuration, it is preferably 1.333 × 10 ⁴ to 10.664 × 10 ⁴ Pa. More preferably, it is 9.331 × 10 ⁴ ~ 10.397 × 10 ⁴ Pa.

According to the present invention, even if the lower end surface of the inner electrode and the corner portion of the dielectric member in the three or more electrodes are corroded by the creeping discharge, the corrosive component can be self-electrode by the scrubbing gas. The periphery of the lower end face is removed. Therefore, corrosion of the lower end portion of the inner electrode can be prevented.

Hereinafter, an embodiment of the present invention will be described based on the drawings.

The object to be processed of the present embodiment is, for example, a glass substrate for a flat panel display. However, the present invention is not limited thereto, and can be applied to various objects to be processed such as a semiconductor wafer or a resin film.

The processing content is, for example, etching of a film containing germanium such as amorphous germanium. However, the present invention is not limited thereto, and can be applied to various processes such as ashing, cleaning, surface modification (waterproofing, hydrophilization, etc.), and film formation.

As shown in FIG. 1 , the plasma processing apparatus 1 includes a processing gas source 2, a plasma generating unit 3, and a processing gas nozzle 5.

The processing gas source 2 mixes the components of the processing gas before the plasma formation at an appropriate flow ratio, and supplies the mixed gas to the plasma generating unit 3. The processing gas component is appropriately selected depending on the processing content. For example, in the case of etching containing a film of ruthenium, the process gas contains a fluorine-based component such as CF ₄ . The fluorine-based component can also be diluted by a diluent gas such as Ar. Further, H ₂ O may be added to the processing gas. H ₂ O can be added by a humidifier.

As the fluorine-based component, a fluorine-containing substance such as other PFC (Perfluorocarbon) or HFC (Hydrofluorocarbon) may be used instead of CF ₄ . As the diluent gas, other inert gases such as N ₂ and He may be used instead of Ar. As an additive component, alcohol or H ₂ O ₂ may be used instead of H ₂ O.

In the etching of the film containing ruthenium, the processing gas before the plasma treatment may contain O ₂ , N ₂ and does not contain H ₂ O in addition to the fluorine-containing substance such as CF ₄ .

The process gas supply path 2a extends from the process gas source 2. This supply path 2a is connected to the plasma generating unit 3. The plasma generating unit 3 includes a cover 10 and an electrode unit 20. A gas introduction path 12 is formed in the top plate 11 of the outer cover 10. The top plate 11 constitutes a gas introduction portion. The supply path 2a is connected to the gas introduction path 12. The gas introduction path 12 is a dispersion path structure in which the gas from the supply path 2a is dispersed in the longitudinal direction (left and right in FIG. 2) and the parallel direction (left and right in FIG. 3) of the plurality of slit-shaped passages 34 described below (see FIG. 2). And Figure 3).

The exhaust path 19 extends from the side of the outer cover 10. The exhaust path 19 is connected to an exhaust device (not shown) such as an exhaust pump. The gas in the outer casing 10 can be extracted and discharged from the exhaust path 19 by the exhaust device. Alternatively, the gas in the outer cover 10 can be replaced.

The electrode unit 20 is housed inside the outer cover 10. A discharge space 35 close to atmospheric pressure is formed inside the electrode unit 20. The gas introduction path 12 is connected to the upper end of the discharge space 35. The processing gas of the processing gas source 2 is introduced into the discharge space 35 through the supply path 2a and the gas introduction path 12 in order, and is plasma-plasmaized. Thereby, the reaction gas reactivity is imparted. For example, when the processing gas before the plasma formation contains CF ₄ , Ar or H ₂ O, a reaction component such as HF or COF ₂ is produced by plasma formation. When the processing before the plasma gas containing CF _4, O _2, N ₂ H ₂ O and does not include the case, to generate COF _2, OF reactive components _{2, O 2 F 2, NO} x and the like.

The structure of the electrode unit 20 will be described in detail below.

A gas outlet portion 40 is provided below the electrode unit 20. A gas lead-out path 41 is formed inside the gas lead-out portion 40. The lower end of the discharge space 35 is connected to the lead-out path 41. The lead-out path 41 is a merging path structure for merging the gas from the discharge space 35 (see FIGS. 2 and 3). The connection path 4 extends from the export path 41. The connection path 4 is connected to the process gas nozzle 5.

The processing gas nozzle 5 is disposed so as to face the workpiece 9 . A nozzle 5a is formed in a surface (for example, a bottom surface) of the processing gas nozzle 5 facing the workpiece 9. The spout 5a may be formed by a plurality of small holes which are disposed to be dispersed in one direction orthogonal to the transport direction described below, and may have a slit shape extending in the one direction.

The workpiece 9 is supported by the support unit 6. The support unit 6 is constituted by, for example, a roller conveyor, a roller conveyor, a moving platform, a mechanical actuator, or the like. The support unit 6 also serves as a transport mechanism that transports the workpiece 9 in the transport direction.

The support portion 6 and the workpiece 9 may be fixed in position to move the processing gas nozzle 5 in the transport direction.

The process gas that is plasma-formed in the discharge space 35 is sequentially transported to the process gas nozzle 5 via the lead-out path 41 and the connection path 4, and is ejected from the nozzle 5a. This processing gas is in contact with the workpiece 9. Further, ozone may be generated by an ozone generator, mixed with the processing gas, and brought into contact with the workpiece 9. Thereby, an etching reaction or the like of an amorphous germanium is generated on the surface of the workpiece 9, and the surface treatment of the workpiece 9 is performed.

The ozone may be supplied from an ozone tank in which ozone is accumulated instead of the ozone generator.

The electrode unit 20 will be described in detail below.

As shown in FIG. 3, the electrode unit 20 includes three or more electrodes 21. The electrode unit 20 of the present embodiment includes five electrodes 21. The electrodes 21 are made of a metal such as aluminum. As shown in FIGS. 2 and 3, each of the electrodes 21 has a square shape in which the horizontal direction is the horizontal direction and the thickness direction, and the upper and lower sides (vertical directions) face the short side direction. Each of the electrodes 21 has an upper end surface and both end faces in the longitudinal direction, and a discharge generating surface 27 that intersects the end faces.

As shown in FIGS. 2 and 3, a temperature adjustment path 28 is formed inside each electrode 21. A medium such as temperature-adjusted water flows to the temperature adjustment path 28. Thereby, the temperature adjustment of the electrode 21 can be performed. Specifically, the amount of heat generated when the electrode 21 is discharged can be removed. As shown in FIG. 2, metal plugs 29 for clogging the processing holes for the temperature adjustment path 28 are provided on both end faces of the lower end surface and the longitudinal direction of each electrode 21.

Three or more (here, five) electrodes 21 are arranged in parallel with each other in the parallel direction (the thickness direction of each electrode 21). When the electrodes 21 are distinguished from each other, A, B, C, D, and E are sequentially added to the symbols 21 from the left side in FIG. The ground electrodes 21A, 21C, and 21E that are electrically grounded are alternately arranged with the hot electrodes 21B and 21D connected to a power source (not shown). The illustration of the power supply structure and the ground structure is omitted. Ground electrodes 21A and 21E are disposed on the outermost side in the parallel direction. The above-described power source supplies, for example, pulse wave-shaped high-frequency power to the electrode unit 20. Thereby, an electric field is applied to the adjacent two electrodes 21 and 21, and a plasma discharge is generated at a pressure close to atmospheric pressure. As shown in FIGS. 3 and 4, the discharge generating surface 27 is formed on a surface facing the adjacent electrode 21 of each of the electrodes 21A to 21E. The discharge generating surface 27 and the electrode 21 are orthogonal to each other in the direction in which they are arranged. The discharge generating faces 27 and 27 of the adjacent two electrodes 21 and 21 face each other.

As shown in FIGS. 3 and 4, a dielectric member 30 is provided on the discharge generating surface 27 of each electrode 21. The dielectric member 30 is made of a ceramic such as alumina. The dielectric member 30 has a square shape in which a horizontal direction faces the longitudinal direction and the thickness direction, and the upper and lower sides (vertical directions) face the short side direction. The dielectric member 30 has a larger area than the discharge generating surface 27 and completely covers the discharge generating surface 27 of the corresponding electrode. As shown in FIG. 3, the upper end portion of the dielectric member 30 protrudes upward from the electrode 21. An upper flange 31 is formed at an upper end portion of the dielectric member 30. The lower end portion of the dielectric member 30 protrudes downward from the electrode 21. A corner portion 15 is formed by a lower end surface of each electrode 21 and a protruding portion of the dielectric member 30 facing downward. A lower flange 32 is formed at a lower end portion of the dielectric member 30. Both end portions of the dielectric member 30 in the longitudinal direction protrude more toward the outer side in the longitudinal direction than the end portions on the same side of the electrode 21.

As shown in FIG. 3, a slit-like via 34 is formed between the dielectric members 30 and 30 disposed adjacent to the discharge generating surfaces 27 and 27 of the adjacent two electrodes. The electrode unit 20 has four slit-like passages 34 as a whole. The portion corresponding to the electrode (the inner portion excluding the portion where the electrode is more protruded) in each of the slit-like passages 34 constitutes the discharge space 35 described above.

As shown in FIG. 4, a sealing portion 33 is formed at both end portions (only one side is illustrated in FIG. 4) of the dielectric members 30 of the two dielectric members 30 and 30 in the longitudinal direction. The sealing portion 33 extends up and down (the direction orthogonal to the plane of the drawing in FIG. 4) and protrudes toward the side of the other dielectric member 30, and touches the other dielectric member 30. The slit portion 34 is blocked by the sealing portion 33 to block both end portions of the discharge space 35 in the longitudinal direction.

As shown in FIGS. 2 and 3, the gas introduction portion 11 of the top plate 11 of the outer cover 10 is disposed so as to straddle between the five electrodes 21. The gas introduction portion 11 is away from the electrode 21 from above. An upper gap 13 is formed between the upper end surface of each electrode 21 and the gas introduction portion 11. The upper end portion of each dielectric member 30 protrudes upward from the electrode 21 and is coupled to the gas introduction portion 11. The upper end portion of the slit-like passage 34 between the dielectric members 30 and 30 that are in contact with each other is connected to the gas introduction path 12.

The ambient gas of the inner space 18 of the outer cover 10 (in detail, the space between the inner wall of the outer cover 10 and the electrode unit 20) enters into the upper gap 13. The upper end surface of each electrode 21 is in contact with the ambient gas (air) in the gap 13. By slightly isolating the gas introduction portion 11 from the respective electrodes 21, creeping discharge can be suppressed or prevented from occurring on the lower surface of the gas introduction portion 11.

As shown in FIGS. 2 and 3, the gas lead-out portion 40 at the lower portion of the electrode unit 20 is disposed so as to straddle between the five electrodes 21. The gas discharge portion 40 is away from the electrode 21 from below. The lower end portion of each dielectric member 30 protrudes downward from the electrode 21 and is coupled to the gas discharge portion 40. The slit-like passages 34 between the mutually abutting dielectric members 30 and 30 and the lower end portions of the discharge spaces 35 are connected to the gas discharge path 41.

As shown in FIGS. 2 and 3, a lower gap 14 is formed between the lower end surface of each electrode 21 and the gas discharge portion 40. That is, as shown in FIGS. 3 and 4, a gap 14A is formed between the lower end surface of the electrode 21A and the gas discharge portion 40. A gap 14B is formed between the lower end surface of the electrode 21B and the gas discharge portion 40. A gap 14C is formed between the lower end surface of the electrode 21C and the gas discharge portion 40. A gap 14D is formed between the lower end surface of the electrode 21D and the gas discharge portion 40. A gap 14E is formed between the lower end surface of the electrode 21E and the gas discharge portion 40. By slightly isolating the gas lead-out portion 40 from each of the electrodes 21, creeping discharge can be suppressed or prevented from occurring on the upper surface of the gas lead-out portion 40.

As shown in FIG. 3, the side portions on the outer side in the direction in which the electrodes of the gaps 14A and 14E at both ends are arranged in the parallel direction (left and right in FIG. 3) and the electrode longitudinal direction (the direction orthogonal to the plane of the paper in FIG. 3) are opened, and It is connected to the inner space 18 of the outer cover. The side portions on the inner side in the direction in which the electrodes of the gaps 14A and 14E at both ends are juxtaposed are blocked by the dielectric member 30.

As shown in FIGS. 2 and 3, one end portion of the inner side gaps 14B, 14C, and 14D in the longitudinal direction (the right side in FIG. 2 and the back side in the paper surface of FIG. 3) is closed by the following washing nozzle 70. The other end portion of the inner gaps 14B, 14C, and 14D in the longitudinal direction (the left side of FIG. 2 and the front side of the paper surface of FIG. 3) is opened and connected to the outer space 18 of the outer cover. Both side portions of the inner gaps 14B, 14C, and 14D in the side-by-side direction (left and right of FIG. 3) are blocked by the dielectric member 30.

When the scrubbing device 7 described below is stopped, the ambient gas in the outer casing 10 enters into the respective gaps 14. The lower end surface of each electrode 21 is in contact with the ambient gas in the gap 14. As shown in Fig. 2, the end faces on both sides in the longitudinal direction of each electrode 21 face the outer cover inner space 18 and are in contact with the ambient gas of the inner space 18 of the outer cover.

As shown in FIG. 1, the plasma processing apparatus 1 further includes a washing and washing apparatus 7. The scrubbing device 7 includes a scrubbing gas source 7a and a scrubbing nozzle 70. As the scrubbing gas of the scrubbing gas source 7a, for example, nitrogen (N ₂ ) can be used. As the scrubbing gas, an inert gas other than air or nitrogen may be used instead of nitrogen. The scrubbing gas supply path 7b is taken out from the scrubbing gas source 7a. The supply path 7b extends toward the plasma generating unit 3.

As shown in FIGS. 1 and 2, the washing nozzle 70 is housed inside the plasma generating unit 3. The scrubbing nozzle 70 is disposed at a lower side portion of one end portion of the electrode unit 20 in the longitudinal direction.

As shown in FIG. 4 and FIG. 5, the washing nozzle 70 is made of, for example, a fluorine-resistant resin such as polyvinylidene fluoride (PVDF), and is integrated as a whole. The washing nozzle 70 includes a nozzle body 71, three nozzle ends 73, and a mounting portion 74. The nozzle body 71 has a block shape and spans between the three inner electrodes 21B, 21C, and 21D. As shown in FIGS. 2 and 4, the surface 72 of the nozzle body 71 facing the electrode unit 20 is in contact with the lower side portion of the one end surface of the inner electrodes 21B, 21C, and 21D in the longitudinal direction.

As shown in FIGS. 3 and 5, the mounting portion 74 is formed so as to protrude upward at positions corresponding to the electrodes 21B and 21D on the upper surface of the nozzle body 71. As shown in FIG. 2, the mounting portion 74 is screwed to the electrodes 21B, 21D. Thereby, the washing nozzle 70 is fixed to the electrode unit 20.

As shown in FIG. 5, two slits 75 are formed in the contact surface 72 of the nozzle body 71 facing the electrode unit 20. The contact surface 72 is divided into three faces 72b, 72c, and 72d by two slits 75. As shown in FIG. 4, the end portions of the two dielectric members 30, 30 between the adjacent electrodes 21, 21 are inserted into the slits 75.

As shown in FIG. 2 and FIG. 5, the nozzle end 73 is provided in each of the three divided surfaces 72b, 72c, and 72d. Each of the nozzle ends 73 has a flat and flat plate shape and protrudes from the nozzle body 71 toward the side of the electrode unit 20. As shown in FIGS. 2 and 3, the nozzle end 73 is located below the electrode 21. The nozzle ends 73 are opposed to the inner gaps 14B, 14C, and 14D.

As shown in FIGS. 3 and 4, the three nozzle ends 73 correspond to the inner electrodes 21B, 21C, and 21D one-to-one. Hereinafter, when the three nozzle ends 73 are distinguished from each other, the same symbol B to D as the corresponding electrode 21 is added to the symbol 73. As shown in FIGS. 2 and 3, the nozzle end 73B corresponding to the electrode 21B protrudes from the contact surface 72b and is inserted into the gap 14B. The nozzle end 73C corresponding to the electrode 21C protrudes from the contact surface 72c and is inserted into the gap 14C. The nozzle end 73D corresponding to the electrode 21D protrudes from the contact surface 72d and is inserted into the gap 14D.

A scrubbing gas outlet 76 is provided at one side of the scrubbing nozzle 70. The outlet 76 is connected to the front end of the supply path 7b. A purge gas guiding path 77 extending from the outlet 76 is formed inside the nozzle 70. Three washing gas discharge paths 78 are branched from the guiding path 77. These discharge paths 78 correspond to the three nozzle ends 73B, 73C, and 73D one-to-one. The discharge path 78B corresponding to the nozzle end 73B passes through the inside of the nozzle end 73B, reaches the front end surface of the nozzle end 73B, and is opened. The discharge path 78C corresponding to the nozzle end 73C passes through the inside of the nozzle end 73C, reaches the front end surface of the nozzle end 73C, and is opened. The discharge path 78D corresponding to the nozzle end 73D passes through the inside of the nozzle end 73D, reaches the front end surface of the nozzle end 73D, and is opened.

As shown in FIG. 1 and FIG. 2, an exhaust path 19 is disposed in the plasma generating unit 3 on the side opposite to the side on which the cleaning nozzle 70 is disposed (the left side in FIG. 2).

In the plasma processing apparatus 1 having the above configuration, in order to plasma-treat the workpiece 9, when the electric power is supplied to the electrode unit 20 and the processing gas is plasma-formed, the scrubbing apparatus 7 is simultaneously operated. That is, the scrubbing gas (N ₂ ) is introduced from the scrubbing gas source 7a to the scrubbing nozzle 70 via the supply path 7b. The scrubbing gas system is introduced into the guide path 77 from the scrubbing gas outlet 76, and is further branched into the three discharge paths 78B, 78C, and 78D. The scrubbing gas is ejected from the respective discharge paths 78B, 78C, and 78D into the respective inner gaps 14B, 14C, and 14D.

The scrubbing gas flows in the inner gaps 14B, 14C, and 14D along the other end side (the left side in FIG. 2) of the lower end faces of the inner electrodes 21B, 21C, and 21D in the longitudinal direction. Further, the opening from the other end side in the longitudinal direction of each of the inner gaps 14B, 14C, and 14D flows out to the outer cover inner space 18. Thereby, the ambient gas in the gaps 14B, 14C, and 14D can be replaced with the scrubbing gas (N ₂ ). Thereby, even if creeping discharge occurs in the corner portions 15 of the gaps 14B, 14C, and 14D, corrosive components such as ozone can be prevented from being generated in the gaps 14B, 14C, and 14D. Even if a corrosive component is generated in the gaps 14B, 14C, and 14D, the corrosive component can be pushed out from the gaps 14B, 14C, and 14D by the flow of the scrubbing gas. Therefore, it is possible to suppress or prevent the lower end faces of the inner electrodes 21B, 21C, and 21D from coming into contact with corrosive components. As a result, it is possible to suppress or prevent corrosion of the lower end portions of the inner electrodes 21B, 21C, and 21D.

Further, when a creeping discharge occurs in a corner portion formed by the upper end surface of each electrode 21 and the dielectric member 30, and a corrosive component such as ozone is generated, the corrosive component is generated by heat from the electrode 21. The convection is away from the upper end surface of the electrode 21, and further flows out from the upper gap 13 to the outer cover space 18. Further, when a corrosive component due to creeping discharge is generated in a corner portion formed by the lower end surface of the outer electrode 21A, 21E and the dielectric member 30, the corrosive component follows the gas in the gap 14A, 14E. The convection easily flows out of the outer casing inner space 18 from the opening of the side portions of the gaps 14A and 14E. Further, when a corrosive component due to creeping discharge is generated in a corner portion formed by the end faces of the respective electrodes 21 in the longitudinal direction and the dielectric member 30, the corrosive component faces the end face of the electrode 21 in the longitudinal direction. The ambient gas around it is convectively separated from the electrode 21 and easily flows out into the inner space 18 of the outer cover. Therefore, the end portions of the upper electrodes and the longitudinal direction of the respective electrodes 21A to 21E and the lower end portions of the outer electrodes 21A and 21E are substantially not corroded.

The ozone flowing out or diffusing into the inner space 18 of the outer casing is taken out from the exhaust path 19 together with the ambient gas in the inner space 18 of the outer casing and discharged. Since the exhaust path 19 is located on the flow side below the flow direction of the scrubbing gas in the gaps 14B, 14C, and 14D, the washing can be performed more smoothly.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit and scope of the invention.

For example, the number of electrodes of the electrode unit 20 may be three or more, and may be four or six or more. It is preferable to arrange a ground electrode at both ends of the parallel direction.

The longitudinal direction of the electrode 21 may be vertically oriented, and the short side direction may be horizontally oriented. The electrode 21 can also be inclined with respect to the vertical.

The flow direction of the scrubbing gas in the adjacent gaps 14B, 14C, 14D may also be reversed. In this case, a washing nozzle may be separately provided on both sides of the electrode unit 20.

The scrubbing nozzle can also be inserted into the process gas discharge portion 40. The scrubbing gas paths 77 and 78 may also be formed in the process gas discharge unit 40. The scrubbing gas may also be supplied into the gap 14 from the intermediate portion in the longitudinal direction of the gap 14.

The scrubbing gas may also flow in the outer gaps 14A, 14E. The scrubbing gas may also flow in the upper side gap 13 of each of the electrodes 21A to 21E. The scrubbing gas may also flow along the end portions of the respective electrodes 21A to 21E in the longitudinal direction.

The workpiece 9 may be placed below the gas discharge unit 40, and the plasma-treated process gas may be discharged downward from the outlet path 41 and brought into contact with the workpiece 9. The connection path 4 and the process gas nozzle 5 can also be omitted. Alternatively, the processing gas nozzle 5 and the gas outlet portion 40 may be integrated.

When the uneven discharge is generated, irregularities may be formed on the discharge generating surface 27. Further, it is not necessary to be parallel to one of the pair of discharge generating faces 27.

[Industrial availability]

The present invention is applicable to, for example, the manufacture of semiconductor devices.

1. . . Plasma processing device

2. . . Process gas source

2a. . . Process gas supply path

3. . . Plasma generation department

4. . . Connection path

5. . . Process gas nozzle

5a. . . spout

6. . . Object support department

7. . . Washing device

7a. . . Washing gas source

7b. . . Washing gas supply path

9. . . Treated object

10. . . Cover

11. . . Top plate (gas introduction part)

12. . . Gas introduction path

13. . . Upper gap

14 (14A, 14B, 14C, 14D, 14E). . . Lower gap

15. . . Corner

18. . . Inside the enclosure

19. . . Exhaust path

20. . . Electrode unit

twenty one. . . electrode

21A, 21E. . . Outer electrode

21B, 21C, 21D. . . Inner electrode

27. . . Discharge generating surface

28. . . Cooling path

29. . . Plug

30. . . Dielectric member

31. . . Upper flange

32. . . Lower flange

33. . . Sealing part

34. . . Slit path

35. . . Discharge space

40. . . Gas export department

41. . . Gas export path

70. . . Washing nozzle

71. . . Nozzle body

72 (72b, 72c, 72d). . . Touch surface

73 (73B, 73C, 73D). . . Nozzle end

74. . . Installation department

75. . . incision

76. . . Washing gas outlet

77. . . Washing gas guiding path

78 (78B, 78C, 78D). . . Washing gas ejection path

Fig. 1 is a front view showing the schematic configuration of a plasma processing apparatus according to an embodiment of the present invention.

Fig. 2 is a front cross-sectional view showing the plasma generating portion of the plasma processing apparatus taken along line II-II of Fig. 3;

Fig. 3 is a side cross-sectional view showing the plasma generating portion taken along line III-III of Fig. 2;

Fig. 4 is a plan sectional view showing a portion of the cleaning nozzle of the plasma generating portion taken along line IV-IV of Fig. 2;

Figure 5 is a perspective view of the above-described washing nozzle.

1. . . Plasma processing device

2. . . Process gas source

2a. . . Process gas supply path

3. . . Plasma generation department

4. . . Connection path

5. . . Process gas nozzle

5a. . . spout

6. . . Object support department

7. . . Washing device

7a. . . Washing gas source

7b. . . Washing gas supply path

9. . . Treated object

10. . . Cover

11. . . Top plate (gas introduction part)

12. . . Gas introduction path

13. . . Upper gap

14. . . Lower gap

18. . . Inside the enclosure

19. . . Exhaust path

20. . . Electrode unit

twenty one. . . electrode

30. . . Dielectric member

40. . . Gas export department

41. . . Gas export path

70. . . Washing nozzle

73. . . Nozzle end

Claims (3)

A plasma processing apparatus for discharging a processing gas through a discharge space close to atmospheric pressure, and contacting the processed gas after the derivation with a workpiece disposed outside the discharge space, comprising: three Each of the electrodes has a plate shape that intersects the thickness direction with respect to the vertical direction, and is arranged at intervals in the thickness direction. The plurality of dielectric members include an opposite surface of the electrode facing the adjacent electrode. And a plate-shaped solid dielectric material protruding downward from the opposite direction; and an outer cover accommodating the electrode and the dielectric member; respectively disposed on a surface opposite to the adjacent electrode of the three or more electrodes A dielectric path is formed between the dielectric members, and an electric field is applied between the adjacent electrodes to form the discharge space in the slit-shaped passage, and the processing gas is led out from the outer cover via the slit-shaped passage. Supplying to the object to be treated; the plasma processing device further comprising a scrubbing device, which will contain an inert gas different from the process gas The gas is introduced into the outer cover so as to be in contact with the opposing surface of the inner electrode disposed on the inner side of the three or more electrodes, and is in contact with the lower end surface, and flows along the lower end surface, and the corner portion is The gas is replaced by the scrubbing gas, wherein the corner portion is formed by the lower end surface of the inner electrode and the downwardly projecting portion of a dielectric member provided on the opposite surface of the inner electrode. The plasma processing apparatus according to claim 1, wherein the cleaning device includes one end side disposed in a longitudinal direction orthogonal to the thickness direction of the lower end surface of the inner electrode, and ejecting the cleaning gas along the longitudinal direction Washing nozzle. The plasma processing apparatus of claim 2, wherein the gas outlet portion is located below the three or more electrodes in the outer cover, and is disposed across the electrodes, and the lower ends of the dielectric members are The gas lead-out portion is connected to the inside of the gas lead-out portion, and a gas lead-out path connected to the slit-shaped passage is formed, and the processing gas is supplied from the slit-shaped passage to the workpiece through the gas lead-out path. An inner gap including the corner portion is formed between the lower end surface of the inner electrode and the gas lead-out portion, and the cleaning nozzle is disposed to face the one end side opening in the longitudinal direction of the inner gap. And the opening on the other end side in the longitudinal direction of the inner gap is open.