JP2010097935A - Surface treatment device, and surface treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment device capable of continuously and effectively performing surface treatment for a plurality of processed objects or an long-sized processed object. <P>SOLUTION: The surface treatment device 100 lets a workpiece 190 pass through a gap 1022 while streamer discharge is generated in the gap 1022 by applying repetitive electric pulses between a first electrode 106 and a second electrode 114. A processing gas supplier 118 spouts processing gas from a nozzle 1189, and supplies the processing gas to the gap 1022 from an upstream side of a conveyance route. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a surface treatment apparatus and a surface treatment method for performing a surface treatment of an object to be treated.

  2. Description of the Related Art Conventionally, surface treatment apparatuses that perform surface treatment of an object to be processed by applying plasma to the surface of the object to be processed are known.

  For example, the surface treatment apparatus of Patent Document 1 performs surface treatment of an object to be processed by causing plasma generated in nitrogen gas to act on the surface of the object to be processed. Paragraphs 0056 to 0060 of Patent Document 1 refer to the progress of the streamer when generating plasma.

  The surface treatment apparatus of Patent Document 2 also performs surface treatment of the object to be processed by causing the plasma generated in the nitrogen gas to act on the surface of the object to be processed. In order to improve the homogeneity of the surface treatment, the surface treatment apparatus of Patent Document 2 generates streamer discharge and causes plasma generated by the streamer discharge to act on the surface of the workpiece.

JP 2005-251444 A JP 2008-95131 A

  However, the surface treatment apparatus of Patent Document 1 or Patent Document 2 cannot efficiently perform surface treatment of a plurality of objects to be processed or a long object to be processed continuously.

  The present invention has been made to solve this problem, and provides a surface treatment apparatus and a surface treatment method capable of continuously and efficiently performing surface treatment of a plurality of objects to be processed or long objects to be processed. The purpose is to do.

  In order to solve the above-mentioned problem, the invention of claim 1 is a surface treatment apparatus, and includes a first electrode structure including a first electrode and a second electrode facing the first electrode structure. A second electrode structure, a pulse power source that repeatedly applies an electric pulse between the first electrode and the second electrode, and a gap between the first electrode and the second electrode. A transport mechanism for passing a gap between the first electrode structure and the second electrode structure in which streamer discharge is generated by application of an electric pulse to the object to be processed; And a processing gas supply body for supplying a processing gas mainly containing nitrogen gas to the gap.

  According to a second aspect of the present invention, in the surface treatment apparatus according to the first aspect, the pulse power source is an inductive energy storage type power source.

A third aspect of the present invention is the surface treatment apparatus according to the second aspect, wherein one pulse of an electric pulse used for a reaction that is supplied to each of the pair of the first electrode and the second electrode and generates plasma. The energy density per pulse obtained by dividing the per-energy by the facing area between the first electrode and the second electrode constituting each of the pair is 0.1-10 mJ / cm ² .

  According to a fourth aspect of the present invention, in the surface treatment apparatus according to any one of the first to third aspects, the first electrode structure further includes a first dielectric barrier.

  According to a fifth aspect of the present invention, in the surface treatment apparatus according to any one of the first to fourth aspects, the second electrode structure further includes a second dielectric barrier.

  According to a sixth aspect of the present invention, in the surface treatment apparatus according to any one of the first to fifth aspects, the processing gas supply body includes nitrogen gas and oxygen gas, and the content of oxygen gas in the whole is 1-. A process gas of 4% is supplied.

  According to a seventh aspect of the present invention, in the surface treatment apparatus according to any one of the first to sixth aspects, the processing gas supply body extends in a direction in which a processing gas introduction path to the gap extends, and the gap The processing gas is ejected in a direction perpendicular to the first direction toward the direction and the extending direction of the introduction path and intermediate between the second direction toward the introduction path from the processing gas supply body.

  According to an eighth aspect of the present invention, in the surface treatment apparatus according to the seventh aspect, the processing gas supply body ejects a processing gas in a direction that forms 30-50 ° with the first direction.

  A ninth aspect of the present invention is the surface treatment apparatus according to any one of the first to eighth aspects, wherein the processing gas blowout port of the processing gas supply body and the first electrode reach the gap. 20-40 mm apart in the direction of extension of the introduction path.

  According to a tenth aspect of the present invention, in the surface treatment apparatus according to any one of the first to ninth aspects, the second electrode has a plate shape and is installed perpendicular to the transport path, and the second dielectric The body barrier has a sheath shape and accommodates at least the transport path of the second electrode.

  The invention according to claim 11 is the surface treatment apparatus according to any one of claims 1 to 10, wherein the gap between the first electrode structure and the second electrode structure is 1-5 mm. Have.

  The invention of claim 12 is a surface treatment method, comprising: a preparation step of preparing a first electrode structure including a first electrode and a second electrode structure including a second electrode; An electric pulse applying step of repeatedly applying an electric pulse by an inductive energy storage type pulse power source between the first electrode structure and the second electrode structure, and a processing gas containing nitrogen gas as a main component A process gas supply step for supplying a gap between the first electrode structure and the second electrode structure, and a conveying step for passing the gap in which streamer discharge is generated by the electric pulse applying step to the object to be processed. And comprising.

According to a thirteenth aspect of the present invention, in the surface treatment method according to the twelfth aspect, the surface treatment method is used for a reaction in which plasma is generated by being supplied to each of the pair of the first electrode and the second electrode by the electric pulse applying step. The energy density per pulse obtained by dividing the energy per pulse of the electric pulse divided by the facing area between the first electrode and the second electrode constituting each of the pair is 0.1-10 mJ / cm ^2. It is.

  According to a fourteenth aspect of the present invention, in the surface treatment method according to the twelfth or thirteenth aspect, the treatment gas supply step includes a nitrogen gas and an oxygen gas, and the content of oxygen gas in the whole is 1-4%. A process gas is supplied.

  According to a fifteenth aspect of the present invention, in the surface treatment method according to any one of the twelfth to fourteenth aspects, the preparation step has a gap of 1 between the first electrode structure and the second electrode structure. The first electrode structure and the second electrode structure are prepared so as to have an interval of −5 mm.

  According to invention of Claim 1 thru | or 15, since the surface treatment of the to-be-processed object to be conveyed can be performed efficiently, the surface treatment of a several to-be-processed object or a long to-be-processed object is performed continuously. It can be done efficiently.

  According to the second to third aspects of the invention, the uniformity of the surface treatment can be improved and the efficiency of the surface treatment can be improved.

  According to the fourth to fifth aspects of the invention, since the occurrence of arc discharge can be suppressed, streamer discharge can be stably generated.

  According to the invention of claim 6, the efficiency of the surface treatment can be improved.

  According to the seventh to eighth aspects of the invention, air entrainment in the processing gas can be reduced, so that the efficiency of the surface treatment can be improved.

  According to the invention of claim 9, since the processing gas can be made uniform, the efficiency of the surface treatment can be improved.

  According to the invention of claim 10, the second electrode structure can be easily manufactured.

  According to the invention of claim 11, the uniformity of the surface treatment can be improved.

  According to the inventions of the twelfth to thirteenth aspects, the uniformity of the surface treatment can be improved and the efficiency of the surface treatment can be improved.

  According to the fourteenth aspect of the invention, the efficiency of the surface treatment can be improved.

  According to the invention of claim 15, the uniformity of the surface treatment can be improved.

It is a perspective view of the surface treatment apparatus concerning desirable embodiment. It is sectional drawing of a reactor. It is a schematic diagram which shows the state of streamer discharge. It is a schematic diagram which shows the state of streamer discharge. It is a perspective view of the 1st electrode structure. It is a perspective view of the 2nd electrode structure. It is a perspective view of the 2nd electrode structure concerning another example. It is a perspective view of a processing gas supply body. It is the enlarged view to which the vicinity of the blower outlet of FIG. 2 was expanded. It is sectional drawing which shows the structure of the conveyance mechanism which concerns on another example. It is a figure which shows the rough waveform of an IES pulse and a CES pulse. It is a figure which shows the rough waveform of an IES pulse and a CES pulse. It is a figure which shows the rough waveform of an IES pulse and a CES pulse. It is a circuit diagram of an IES power supply. It is a circuit diagram of the IES power supply concerning another example. It is a figure which shows the table | surface which shows the influence of the type of a power supply and the composition of a process gas with respect to a maximum conveyance speed and temperature rise. It is a figure which shows the graph which shows the influence of oxygen content with respect to water contact angle (theta). It is a figure which shows the graph which shows the influence of blowing angle (delta) with respect to water contact angle (theta). It is a figure which shows the graph which shows the influence of the conveyance speed with respect to water contact angle (theta). It is a figure which shows the graph which shows the influence of the distance L of a blower outlet and a 1st electrode with respect to water contact angle (theta). It is a figure which shows the graph which shows the influence of 1 pulse energy density with respect to water contact angle (theta). It is a figure which shows the outline of a structure of a 1st electrode structure and a 2nd electrode structure. It is a figure which shows the graph which shows the influence of the electrode space | interval with respect to water contact angle (theta). It is a figure which shows the outline of a structure of a 1st electrode structure and a 2nd electrode structure. It is a figure which shows a mode that the glass substrate was arrange | positioned on the work carrier.

<1 Outline of surface treatment apparatus 100>
FIG. 1 is a schematic diagram of a surface treatment apparatus 100 according to a preferred embodiment of the present invention. FIG. 1 is a perspective view of the surface treatment apparatus 100.

  As shown in FIG. 1, the surface treatment apparatus 100 includes a reactor 102 that performs surface treatment of a workpiece 190 that is an object to be processed, a first workpiece mounting table 126 that holds a workpiece 190 before performing surface treatment, and a surface treatment. The second workpiece mounting table 128 that holds the workpiece 190 after performing the above, the transfer mechanism 130 that transfers the workpiece 190, the height adjustment table 140 that adjusts the height of the reactor 102, and the insulating stage that holds them. 142 and a pulse power supply 144 that generates electrical pulses.

  FIG. 2 is a schematic diagram of the reactor 102. FIG. 2 is a cross-sectional view of the reactor 102.

  As shown in FIG. 2, the reactor 102 includes a first electrode structure 104 including a first electrode 106, a second electrode structure 112 including a second electrode 114, and a first electrode structure 104. The processing gas supply body 118 for supplying a processing gas containing nitrogen gas as a main component to the gap 1022 between the second electrode structure body 112 and the second electrode structure body 112, and the distance between the second electrode structure body 112 and the processing gas supply body 118 is adjusted. A distance adjusting body 122 and a housing 124 for housing them.

  The surface treatment apparatus 100 allows the work 190 to pass through the gap 1022 while generating streamer discharge in the gap 1022 by repeatedly applying an electric pulse that rises quickly between the first electrode 106 and the second electrode 114. Then, the surface treatment of the workpiece 190 is performed. “Surface treatment” here refers to cleaning to remove contamination attached to the surface, etching to erode the surface, ashing to ash the fluorine compound film and other films formed on the surface, and improve the wettability of the surface. There is a process for changing the surface state such as modification.

<2 Principle of surface treatment>
The surface treatment of the workpiece 190 is performed by passing the gap 1022 in which the streamer discharge is generated through the workpiece 190. Mainly, the pulse electric field, nitrogen radicals, and short wavelength ultraviolet rays act on the surface of the workpiece 190 in a complex manner. By doing. Depending on the state of the streamer discharge, etc., only one or two of the three elements of the pulse electric field, nitrogen radical, and short wavelength ultraviolet light may be dominant in the surface treatment.

<2.1 Action of nitrogen radicals>
When streamer discharge is generated in the gap 1022, plasma containing nitrogen radicals with extremely high activity is generated in the gap 1022. Therefore, by passing the gap 1022 in which the streamer discharge is generated through the work 190, nitrogen radicals can be chemically applied to the region to be treated 192, and the surface 1902 can be treated.

The reason why nitrogen radicals are selected as the chemical species used for processing, that is, the reason why plasma is generated in a processing gas containing nitrogen gas as a main component is that the activity of nitrogen radicals is extremely high. This is clear from the fact that the dissociation energy of the nitrogen molecule is very high at 9.76 eV. The lifetime of triplet nitrogen ( ³ Σu) radicals reaching 10 milliseconds also contributes to efficient reforming.

  In addition, the fact that nitrogen gas can be easily obtained at a low price and is easy to handle is one of the reasons for selecting nitrogen radicals as the active species used in the treatment.

<2.2 Action of short wavelength ultraviolet rays>
When the streamer discharge is generated in the gap 1022, the processing gas emits short wavelength ultraviolet rays due to the streamer discharge. Therefore, by passing the gap 1022 in which the streamer discharge is generated through the work 190, the short wavelength ultraviolet light can be photochemically acted on the processing region 192, and the surface 1902 can be processed.

  “Short wavelength ultraviolet rays” are ultraviolet rays mainly containing a wavelength component of 100 to 280 nm, and are also called “far infrared rays” or “UV-C”. The reason why short-wavelength ultraviolet rays are applied is that short-wavelength ultraviolet rays do not penetrate deep into the workpiece 190, so that they can concentrate on only a very thin region to be treated 192 to give a photochemical action.

<3 Streamer discharge>
FIG. 3 shows a streamer discharge generated in the gap 1022 when an electric pulse is applied between the first electrode 106 and the second electrode 114 using the first electrode 106 as a cathode and the second electrode 114 as an anode. It is a schematic diagram which shows a state. The electric pulse for generating the streamer discharge has a peak voltage of approximately 10 to 100 kV, a full width at half maximum (FWHM) of approximately 100 to 50000 ns, and a time rise rate dV / dt of the rising voltage of approximately 1 to 500 kV / It is an electric pulse with μs and a frequency of approximately 1 to 50 kHz. The electric pulse may be a unipolar electric pulse whose polarity does not change, or may be a bipolar electric pulse whose polarity changes alternately.

  When the streamer discharge is generated in the gap 1022, as shown in FIG. 3, the streamer 194 is directed from the second electrode structure 112 to the first electrode structure 104 but does not reach the first electrode structure 104. As shown in FIG. 2, the stripe-shaped plasma 198 that spreads from the lower surface 1122 of the second electrode structure 112 toward the upper surface 1042 of the first electrode structure 104 emits light purple. is doing. “The streamer 194 does not reach the first electrode structure 104” means that the application of the electric pulse is stopped before the occurrence of the arc discharge. On the other hand, when glow discharge is generated in the gap 1022, the streak-like plasma 198 emitting light purple as shown in FIG. 2 is not seen.

  It is also desirable to stop the application of electrical pulses before the long branched streamer 194 as shown in FIG. 3 grows. That is, an electric pulse having a half-value width FWHM of approximately 100 to 50000 ns is applied between the first electrode 106 and the second electrode 114, and streamer discharge in which short streamers 196 are scattered as shown in FIG. It is also desirable to generate it. Since the fine streamer discharge in which the application of the electric pulse is stopped in the initial stage of the streamer growth is excellent in the uniformity of the discharge, the surface treatment of the workpiece 190 can be uniformly performed when the fine streamer discharge is generated. In addition, local damage to the workpiece 190 due to non-uniform discharge can be suppressed.

  In the above description, the range of the half-value width or the like is “substantially” because the structure and material of the first electrode structure 104 and the second electrode structure 112, the interval of the gap 1022, the pressure of the processing gas, etc. This is because, depending on the specific configuration of the surface treatment apparatus 100, the range such as the half width at which streamer discharge occurs may be wider than the above range. Therefore, it is desirable to determine whether or not the discharge is a streamer discharge by observing the actual discharge.

<Details of 4 Surface Treatment Apparatus 100>
<4.1 Reactor 102>
(A) Arrangement of each part;
The details of the surface treatment apparatus 100 will be described with reference to FIGS. 1 and 2 again.

  As shown in FIG. 2, in the reactor 102, the first electrode structure 104 is provided below the transfer path 199 of the work 190, and the processing gas supply body 118, the distance adjustment body 122, and the second electrode structure are provided. A body 112 is provided above the transport path 199. The first electrode structure 104 and the second electrode structure 112 face each other with the transport path 199 interposed therebetween. The second electrode structure 112 is placed in a range where the first electrode 106 of the first electrode structure 104 is present. The interval of the gap 1022 is preferably 1 to 20 mm, more preferably 1 to 5 mm. If the gap 1022 is narrower than 1 mm, it tends to be difficult to pass the gap 1022 through the workpiece 190, supply the processing gas to the gap 1022, and keep the gap 1022 uniform. It is because it will become difficult to generate plasma when it exceeds. In addition, since the gap 1022 is 1 to 5 mm in distance, streamer discharge can be uniformly generated in the gap 1022. By passing the gap 1022 through the workpiece 90, the position disposed on the workpiece carrier 132. The surface treatment of the workpiece 190 can be performed uniformly without being influenced by the above.

  The processing gas supply body 118, the distance adjusting body 122, and the second electrode structure 112 are referred to as an upstream side (hereinafter referred to as “transport path upstream side”) of the transport path 199 and a downstream side (hereinafter referred to as “transport path downstream side”). ). The processing gas supply body 118 and the distance adjustment body 122 face the first electrode structure 104 with the transport path 199 interposed therebetween. A gap between the first electrode structure 104, the processing gas supply body 118, and the distance adjustment body 122 serves as a processing gas introduction path 1024 that reaches the gap 1022. The introduction path 1024 also serves as a path for the work 190 and the work carrier 132 toward the gap 1022. The extending direction of the introduction path 1024 is parallel to the conveyance direction of the workpiece 190, that is, the traveling direction of the workpiece carrier 132. The lower surface 1182 of the processing gas supply body 118, the lower surface 1222 of the distance adjusting body 122, and the lower surface 1122 of the second electrode structure 112 constitute a flat and identical plane. Thereby, the disturbance of the flow of the processing gas toward the gap 1022 can be suppressed, and the surface treatment of the workpiece 190 can be performed uniformly. 2 includes the two second electrode structures 112, the number of the second electrode structures 112 may be increased or decreased to one or three or more.

(B) a first electrode structure 104;
FIG. 5 is a schematic diagram of the first electrode structure 104. FIG. 5 is a perspective view of the first electrode structure 104.

  As shown in FIGS. 2 and 5, the first electrode structure 104 has a plate-like outer shape. The first electrode structure 104 includes a first electrode 106, a holder 108 that holds the first electrode 106, and a first dielectric barrier 110 that covers the first electrode 106. Note that the holder 108 and the first dielectric barrier 110 may be formed of the same insulating material and integrated. When the holder 108 and the first dielectric barrier 110 are integrated, the first electrode 106 is embedded in the integrated object.

  The first electrode 106 is made of a conductive material such as aluminum or copper. The first electrode 106 has a plate shape. The first electrode 106 is disposed in parallel with the lower surface 1182 of the processing gas supply body 118, the lower surface 1222 of the distance adjusting body 122, and the lower surface 1122 of the second electrode structure 112. The first electrode 106 preferably has a rectangular or square planar shape. In the case where the first electrode 106 has a rectangular or square planar shape, it is desirable that the first electrode 106 be installed so that one set of opposite sides is parallel to the transport path 199.

  When the first electrode 106 is a cathode and the second electrode 114 is an anode, the width of the first electrode 106 (dimension in the direction perpendicular to the transport path 199) is not narrower than the width of the second electrode 114. It is desirable to do so. This is to prevent the plasma 198 from spreading from the lower surface 1122 of the second electrode structure 112 toward the upper surface 1042 of the first electrode structure 104. Further, the width of the first electrode 106 is desirably wider than the width of the workpiece 190. This is because the surface treatment is uniformly performed to the periphery of the workpiece 190.

  The plate thickness of the first electrode 106 is preferably about 5 to 20 mm.

  The holder 108 is made of an insulating material such as glass or alumina. The holder 108 has a plate shape. In the upper surface 1082 of the holder 108, an accommodation hole 1084 having a substantially same three-dimensional shape as the first electrode 106 is formed. The first electrode 106 is accommodated in the accommodation hole 1084. In a state where the first electrode 106 is accommodated in the accommodation hole 1084, the upper surface 1062 of the first electrode 106 and the outside of the accommodation hole 1084 of the upper surface 1082 of the holder 108 constitute a flat and identical plane.

  The first dielectric barrier 110 is made of an insulating material such as glass or alumina. The first dielectric barrier 110 has a plate shape. The first dielectric barrier 110 has substantially the same planar shape as the holder 108. The first dielectric barrier 110 is placed on the upper surface 1062 of the first electrode 106 and the upper surface 1082 of the holder 108. The first dielectric barrier 110 can protect the first electrode 106, suppress the occurrence of arc discharge, and stably generate streamer discharge.

  The upper surface 1102 of the first dielectric barrier 110 is flat. Thereby, the disturbance of the flow of the processing gas toward the gap 1022 can be suppressed, and the surface treatment of the workpiece 190 can be performed uniformly. The plate thickness of the first dielectric barrier 110 is preferably approximately 0.5 to 5 mm. This is because if the plate thickness of the first dielectric barrier 110 is below this range, arc discharge tends to occur, and if it exceeds this range, the first electrode 106 and the second electrode 114 This is because the capacitance between the first electrode 106 and the second electrode 114 tends to be difficult to apply between the first electrode 106 and the second electrode 114.

(C) the second electrode structure 112;
FIG. 6 is a schematic diagram of the second electrode structure 112. FIG. 6 is a perspective view of the second electrode structure 112.

  As shown in FIGS. 2 and 6, the second electrode structure 112 has a plate-like outer shape. The second electrode structure 112 includes a second electrode 114 and a second dielectric barrier 116.

  The second electrode 114 is made of a conductive material such as aluminum or copper. The second electrode 114 has a plate shape. The second electrode 114 is installed perpendicular to the first electrode 106 and the transport path 199. The second electrode 114 is preferably installed so that its lower surface is parallel to the first electrode 106. Thereby, streamer discharge can be generated uniformly and the surface treatment of the workpiece 190 can be performed uniformly. The width of the second electrode 114 is preferably wider than the width of the workpiece 190. This is because the surface treatment is uniformly performed to the periphery of the workpiece 190.

  The plate thickness of the second electrode 114 is desirably about 1 to 20 mm.

  The second dielectric barrier 116 is made of an insulating material such as glass or alumina. The second dielectric barrier 116 has a sheath shape having an elongated rectangular opening on the upper surface. The second dielectric barrier 116 is formed with a receiving hole 1162 having the substantially same three-dimensional shape as the second electrode 114. In the accommodation hole 1162, the second electrode 114 is accommodated in parallel to the main surface of the second dielectric barrier 116. Note that the second dielectric barrier 116 shown in FIG. 2 accommodates the entire second electrode 114, but it is the first of the second electrodes 114 that mainly contributes to the generation of streamer discharge. Therefore, there is no problem even if only the transport path 119 below the second electrode 114 is accommodated in the second dielectric barrier 116. The second dielectric barrier 116 can protect the second electrode 114, suppress the occurrence of arc discharge, and stably generate streamer discharge.

  The thickness t1 of the portion covering the lower end surface of the second electrode 114 of the second dielectric barrier 116 is preferably about 0.5 to 5 mm. This is because if the thickness t1 of the second dielectric barrier 116 is less than this range, arc discharge tends to occur, and if it exceeds this range, the first electrode 106 and the second electrode 114 This is because it tends to be difficult to apply an electric pulse that rises quickly between the first electrode 106 and the second electrode 114 due to an increase in capacitance between the first electrode 106 and the second electrode 114. Further, it is desirable that the thickness t2 of the portion covering the main surface of the second electrode 114 of the second dielectric barrier 116 is approximately 2 to 20 mm. If the thickness t2 of the second dielectric barrier 116 is below this range, the overlap of the bottom of the plasma 198 tends to be too large, and if it exceeds this range, the gap of the plasma 198 tends to be too large. is there.

  FIG. 7 is a schematic diagram of a second electrode structure 212 that can be employed in place of the second electrode structure 112. FIG. 7 is a perspective view of the second electrode structure 212.

  As shown in FIG. 7, instead of the second electrode structure 112 in which the second electrode 114 having a plate shape is covered with a second dielectric barrier 116 having a sheath shape, a round bar shape or a round pipe shape is used. The streamer discharge can be generated in the gap 1022 even when the second electrode structure 212 in which the second electrode 214 having the above is covered with the second dielectric barrier 216 having a round pipe shape is employed. However, the first electrode structure 112 has an advantage over the second electrode structure 212 that it can be easily manufactured.

(D) omission of the first dielectric barrier 110 or the second dielectric barrier 116;
In the reactor 102 shown in FIG. 2, both the first electrode structure 104 and the second electrode structure 112 include a dielectric barrier, but the first dielectric barrier 110 or the second dielectric barrier. 116 may be omitted, and only one of the first electrode structure 104 and the second electrode structure 112 may include a dielectric barrier.

(E) process gas supply 118;
FIG. 8 is a schematic diagram of the processing gas supply body 118. FIG. 8 is a perspective view of the processing gas supply body 118.

  As shown in FIGS. 2 and 8, the processing gas supply body 118 has a substantially rectangular parallelepiped outer shape, and a gas reservoir 1186 for retaining the processing gas and a processing gas from the upper surface 1184 to the gas reservoir 1186 are contained therein. A flow path 1187 for guiding the processing gas from the gas reservoir 1186 to the lower surface 1182 is formed. Further, a shower plate 120 is installed in the processing gas supply body 118 in contact with the gas reservoir 1186. The shower plate 120 is regularly formed with through holes having a diameter of 0.1 to 1 mm at intervals of 1 to 20 mm. Instead of the shower plate 120, a pressure loss member in which a large number of through holes are formed, for example, a mesh laminate or a ceramic porous body may be employed.

  The processing gas supply body 118 passes the processing gas supplied from the processing gas supply source through the flow path 1187, the gas reservoir 1186, the shower plate 120, and the flow path 1188 in order to make the processing gas flow uniform, and then slits. A processing gas is ejected from the blowout port 1189 having a shape to the introduction path 1024.

  FIG. 9 is an enlarged view in which the vicinity of the outlet 1189 of FIG. 2 is enlarged.

  As shown in FIG. 9, the flow path 1188 has a first direction toward the gap 1022 in which the flow direction of the processing gas from the blowout port 1189 (the direction indicated by the arrow D102) is parallel to the extending direction of the introduction path 1024. 1 direction (direction indicated by arrow D104) and a direction perpendicular to the extending direction of the introduction path and a second direction (direction indicated by arrow D106) from the processing gas supply body 118 toward the introduction path 1024 It is formed to be in the direction. Accordingly, most of the processing gas ejected to the introduction path 1024 flows in the direction toward the gap 1022 (direction indicated by the arrow D104) and flows into the gap 1022, and the remaining small part flows in the direction toward the gap 1022 (arrow D104). In the direction opposite to the direction indicated by (1), the flow of air into the introduction path 1024 is inhibited. Thereby, since the entrainment of air into the processing gas can be reduced, the efficiency of the surface treatment can be improved.

  The blowing direction of the processing gas is desirably a direction that forms 30-50 ° with the first direction described above. This is because if the angle (hereinafter referred to as “blowing angle”) δ formed between the blowing direction of the processing gas and the first direction is outside this range, the efficiency of the surface treatment tends to decrease.

  The supply amount of the processing gas varies depending on the interval of the gap 1022, the conveyance speed of the workpiece 190, and the like, but is preferably approximately 10 liters / minute or more.

(F) the distance adjuster 122;
The distance adjuster 122 is made of a highly rigid insulating material such as glass or alumina. The distance adjusting body 122 has a rectangular parallelepiped shape. The distance adjuster 122 is provided perpendicular to the transport path 199. The surface on the upstream side of the transport path of the distance adjusting body 122 is in contact with the processing gas supply body 118, and the surface on the downstream side of the transport path is in contact with the second electrode structure 112. Since the distance between the outlet 1189 and the gap 1022 can be increased by the distance adjusting body 122, the flow of the processing gas can be made uniform until the processing gas reaches the gap 1022, and the surface treatment of the workpiece 190 can be performed. It can be performed uniformly.

  The size of the distance adjuster 122 is preferably determined so that the outlet 1189 and the first electrode 114 are separated by 20-40 mm in the extending direction of the introduction path 1024. This is because the efficiency of the surface treatment tends to decrease when the distance L between the outlet 1189 and the first electrode 114 is outside this range.

(G) Process gas composition;
The processing gas is desirably a gas mainly composed of nitrogen gas, and is desirably a gas composed of only nitrogen gas or a mixed gas composed of nitrogen gas and oxygen gas. When a mixed gas composed of nitrogen gas and oxygen gas is used as the processing gas, it is desirable that the content of oxygen gas in the whole is 1-4% by volume. This is because the surface treatment efficiency can be improved if the oxygen gas content is within this range.

<4.2 First Work Placement Table 126 and Second Work Placement Table 128>
As shown in FIG. 1, the first workpiece mounting table 126 and the second workpiece mounting table 128 have a substantially rectangular parallelepiped shape. The first workpiece mounting table 126 and the second workpiece mounting table 128 are installed on the upstream side of the transport path and the downstream side of the transport path of the reactor 102, respectively. The upper surface 1262 of the first workpiece mounting table 126 and the upper surface 1282 of the second workpiece mounting table 128 are flat.

<4.3 Transport mechanism 130>
As shown in FIG. 1, the transport mechanism 130 is a traveling mechanism that holds the work 190 on the upper surface 1322 and slides the work carrier 132 that slides on the upper surface 1042 of the first electrode structure 104 and the work carrier 132 in the transport direction. An axis stage robot 134.

  The work carrier 132 is made of an insulator such as a fluororesin. If the thickness does not become extremely hot, the work carrier 132 may be made of a conductor. The work carrier 132 has a long sheet shape. The workpiece carrier 132 passes from the upper surface 1262 of the first workpiece mounting table 126 to the upper surface 1282 of the second workpiece mounting table 128 via the loading port 1026 of the reactor 102, the introduction path 1024, the gap 1022, and the loading port 1028 of the reactor 102. Extending across. The work carrier 132 is in contact with the upper surface 1262 of the first work mounting table 126, the upper surface 1102 of the first dielectric barrier 110, and the upper surface 1282 of the second work mounting table 128, and the upper surface 1262 of the first work mounting table 126. The upper surface 1042 of the first electrode structure 104 and the upper surface 1282 of the second workpiece mounting table 128 are slid.

  The single-axis stage robot 134 is installed further downstream of the second work platform 128 on the transport path. The single-axis stage robot 134 includes a fixed rail 136 that guides the moving stage 138 in the conveyance direction of the workpiece 190 and a moving stage 138 that moves along the fixed rail 136. The fixed rail 136 is fixed to the insulating stage 142. The moving stage 138 is connected to an end portion on the downstream side in the transport direction of the work carrier 132. Accordingly, when the moving stage 138 is moved in the conveyance direction of the workpiece 190, the workpiece carrier 132 travels in the conveyance direction of the workpiece 190, and the workpiece 190 held by the workpiece carrier 132 is conveyed in the conveyance direction.

  The traveling speed of the work carrier 132, that is, the conveying speed of the work 190 is desirably 30 m / min or less. This is because if the conveying speed of the workpiece 190 exceeds this range, the surface treatment efficiency of the workpiece 190 tends to decrease.

  Instead of the transport mechanism 130 including the work carrier 132 and the single-axis stage robot 134, another type of transport mechanism may be employed. For example, another traveling mechanism such as a roller that winds the work carrier 132 may be employed to cause the work carrier 132 to travel in the conveyance direction of the workpiece 190. Further, a plurality of rollers may be arranged in the conveyance direction of the workpiece 190, and the workpiece 190 may be conveyed in the conveyance direction by the plurality of rollers.

<4.4 Conveying Mechanism 230>
FIG. 10 is a cross-sectional view showing an outline of the configuration of a transport mechanism 230 that can be employed in place of the transport mechanism 130. The transport mechanism 230 includes a film-like work carrier 232 that holds the work 190 on the upper surface 1322 and slides on the upper surface 1042 of the first electrode structure 104 (hereinafter also referred to as a transport film 232), and a first work installation Disposed on the upstream side of the stage 126 in the transport direction, and is disposed on the downstream side of the second work installation base 128 in the transport direction, and is wound up to wind up the transport film 232. A roll 234 for use.

  In addition to strength, the transport film 232 is required to have heat resistance that can withstand the heating temperature and cleanness that does not generate gas or dust even when heated. For example, a stainless steel foil having a thickness of about 40 to 100 μm is required. Can be used. In addition, the material of the film 232 for conveyance is not necessarily limited to this, A heat resistant resin film can also be used depending on heating temperature.

  The transport film 232 is set in a state of being wound around the payout roll 233, and the transport film 232 drawn out from the payout roll 233 slides on the upper surface 1042 of the first electrode structure 104 and winds up. It is wound on a roll 234 for use. Thereby, when the conveyance film 232 is wound up by the winding roll 234, the conveyance film 232 travels in the workpiece conveyance direction, and the workpiece 190 held by the conveyance film 232 is conveyed in the conveyance direction.

<4.5 Height adjustment stand 140>
As shown in FIG. 1, the height adjusting table 140 is fixed to the upper surface 1422 of the insulating stage 142, and the reactor 102 is placed on the upper surface. As shown in FIG. 2, the height adjustment table 140 allows the height of the upper surface 1102 of the first dielectric barrier 110 to be the same as the height of the upper surface 1262 of the first workpiece mounting table 126 and the second workpiece mounting table 128. To the height of the upper surface 1282. Thereby, since the workpiece | work carrier 132 can maintain a flat attitude | position, the workpiece | work carrier 132 can be driven horizontally and the workpiece | work 190 can be conveyed stably horizontally.

<4.6 Pulse Power Supply 144>
(A) Power supply type;
As the pulse power supply 144, any pulse power supply may be used as long as an electric pulse that can generate a streamer discharge without generating an arc discharge is applied between the first electrode 106 and the second electrode 114. However, an inductive energy storage (IES) power source (hereinafter referred to as “IES power source”) that releases energy stored in the form of a magnetic field in the inductive element in a short time is desirable. . This is because the IES power supply is compared with a capacitive energy storage (CES) power supply (hereinafter referred to as “CES power supply”) that discharges energy stored in the form of an electric field in the capacitive element in a short time. This is because remarkably large energy can be input to the reactor 102. Typically, when the electrode structure is the same, when an IES power supply is employed, the energy per pulse used for the reaction for generating plasma (hereinafter referred to as “one pulse energy”) is a CES power supply. Approximately one order of magnitude larger than the case. This difference between the IES power supply and the CES power supply is caused by the fact that the electric pulse generated by the IES power supply has a rapid increase in voltage, whereas the electric pulse generated by the CES power supply has a slow increase in voltage. That is, when the IES power source is adopted, the discharge starts after the voltage has sufficiently increased, and one pulse energy can be sufficiently increased, whereas when the CES power source is employed, the voltage does not sufficiently increase. Discharge starts and occurs because the energy of one pulse cannot be increased sufficiently.

  FIGS. 11 to 13 are diagrams showing schematic waveforms of an electric pulse generated by the IES power supply (hereinafter referred to as “IES pulse”) and an electric pulse generated by the CES power supply (hereinafter referred to as “CES pulse”). is there. 11A and 11B are voltage waveforms of the IES pulse and the CES pulse, respectively. FIGS. 12A and 12B are current waveforms of the IES pulse and the CES pulse, respectively. (A) and FIG.13 (b) are figures which show the waveform of the product of the voltage and electric current of an IES pulse and a CES pulse, respectively.

  One pulse energy is calculated by integrating the product of the voltage and current shown in FIGS. 13 (a) and 13 (b) over time. As shown in FIG. 11 and FIG. 12, the current flows in the positive direction almost synchronously with the voltage increase, and flows in the negative direction almost synchronously with the voltage decrease. And it is proportional to the area which reduced the area of the area | region B where a waveform becomes negative from the area of the area | region A where the waveform becomes positive in FIG.13 (b).

(B) a switching element;
As the IES power supply, it is desirable to employ a power supply using an electrostatic induction thyristor (hereinafter referred to as “SI thyristor”) as a switching element for controlling the supply of current to the inductive element. This is because by using the SI thyristor as a switching element, an electrical pulse having a fast rise can be generated, and thus the above-described streamer discharge can be easily generated. The use of the SI thyristor as a switching element can generate an electrical pulse that rises quickly, because the SI thyristor is not insulated from the gate and can quickly extract carriers from the gate, so it turns off at high speed. Because it can. For details on the operating principle of the IES power supply, see, for example, Katsuji Iida, Ken Sakuma: “Ultra-short pulse generation circuit using an SI thyristor (IES circuit)”, SI Device Symposium Proceedings, Vol. 15, Page. 40-45 (issued on June 14, 2002).

(C) a circuit diagram of an IES power supply 150 using the SI thyristor 158 as a switching element;
FIG. 14 is a circuit diagram of an IES power supply 150 using an SI thyristor 158 that can be suitably used for the pulse power supply 144 as a switching element. Of course, the circuit diagram shown in FIG. 14 is only an example, and various modifications can be made.

  As shown in FIG. 14, the IES power supply 150 includes a DC power supply 152 that supplies electric energy and a capacitor 154 that enhances the discharge capability of the DC power supply 152.

  The voltage of the DC power supply 152 is allowed to be significantly lower than the peak voltage of the electric pulse generated by the IES power supply 150. For example, even if the peak voltage of the primary side voltage V1 generated on the primary side of the step-up transformer 156, which will be described later, reaches 4 kV, the voltage of the DC power source 152 is sufficient to be several tens to several hundreds volts. The lower limit of this voltage is determined by the latching voltage of the SI thyristor 158 described later. Since the IES circuit 150 can use such a low-voltage DC power source 152 as an electrical energy source, it can be constructed in a small size and at a low cost.

  Capacitor 154 is connected in parallel with DC power supply 152. Capacitor 154 enhances the discharge capability of DC power supply 152 by apparently reducing the impedance of DC power supply 152.

  The IES power supply 150 further includes a step-up transformer 156, an SI thyristor 158, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) 160, a gate drive circuit 162, and a diode 164.

  In the IES power supply 150, the DC power supply 152, the primary side of the step-up transformer 156, the anode (A) and cathode (K) of the SI thyristor 158, and the drain (D) and source (S) of the MOSFET 160 are connected in series. Connected. That is, one end on the primary side of the step-up transformer 156 is the positive electrode of the DC power supply 152, the other end on the primary side of the step-up transformer 156 is the anode of the SI thyristor 158, and the cathode (K) of the SI thyristor 158 is the drain of the MOSFET 160 ( D), the source (S) of the MOSFET 160 is connected to the negative electrode of the DC power source 152. As a result, a current can be supplied from the DC power source 152 to these circuit elements. In the IES power supply 150, the gate (G) of the SI thyristor 158 is connected in parallel with one end on the primary side of the step-up transformer 156 via the diode 164. That is, the gate (G) of the SI thyristor 158 is connected to the anode (A) of the diode 164, and the cathode (K) of the diode 164 is connected to one end on the primary side of the step-up transformer 156 (positive electrode of the DC power supply 152). A gate drive circuit 162 is connected between the gate (G) and source (S) of the FET.

  The step-up transformer 156 further boosts the electric pulse given to the primary side and outputs it to the secondary side. A load (here, between the first electrode 106 and the second electrode 114) 166 is connected to the secondary side of the step-up transformer 156. The primary side of the step-up transformer 156 is an inductive element having self-inductance.

  The SI thyristor 158 can be turned on and off in response to a signal applied to the gate (G).

  The MOSFET 160 is a switching element in which the conduction state between the drain (D) and the source (S) changes in response to a signal given from the gate drive circuit 162. The on-voltage or on-resistance of MOSFET 160 is preferably low. Further, the withstand voltage of MOSFET 160 needs to be higher than the voltage of DC power supply 152.

  The diode 164 prevents the current that flows when a positive bias is applied to the gate (G) of the SI thyristor 158, that is, when the positive bias is applied to the gate (G) of the SI thyristor 158, the diode 164 It is provided to prevent driving.

(D) Outline of operation of IES power supply 150 using SI thyristor 158 as a switching element;
When an electric pulse is generated in the IES power supply 150, first, an ON signal is given from the gate drive circuit 162 to the gate of the MOSFET 164, and the drain (D) and the source (S) of the MOSFET 160 are brought into conduction. Then, the SI thyristor 158 is a normally-on type switching element, and the anode (A) and the cathode (K) of the SI thyristor 158 are in a conductive state, so that a current flows to the primary side of the step-up transformer 156. In this state, since a positive bias is applied to the gate (G) of the SI thyristor 158, the conduction state between the anode (A) and the cathode (K) of the SI thyristor 158 is maintained.

  Subsequently, the application of an ON signal from the gate drive circuit 162 to the MOSFET 164 is stopped, and the drain (D) and the source (S) of the MOSFET 160 are made non-conductive. Then, carriers are discharged from the gate (G) of the SI thyristor 158 at high speed by current driving, and the anode (A) and cathode (K) of the SI thyristor 158 are in a non-conductive state. Inflow of current is stopped at high speed. As a result, an induced electromotive force is generated on the primary side of the step-up transformer 156, and a high voltage is also generated on the secondary side of the step-up transformer 156.

(E) a circuit diagram of an IES power supply 250 using the IGBT 258 as a switching element;
FIG. 15 is a circuit diagram of an IES power supply 250 using an IGBT (Insulated Gate Bipolar Transistor) 258 that can be used in place of the SI thyristor 158 as a switching element. The same components as those of the IES power supply 150 are denoted by the same reference numerals, and the description thereof is omitted. Of course, the circuit diagram shown in FIG. 15 is only an example, and various modifications can be made.

  In the IES power supply 250, the DC power supply 152, the primary side of the step-up transformer 156, and the collector (C) and emitter (E) of the IGBT 258 are connected in series. That is, one end of the primary side of the step-up transformer 156 is connected to the positive electrode of the DC power supply 152, the other end of the primary side of the step-up transformer 156 is connected to the collector (C) of the IGBT 258, and the emitter (E) of the IGBT 258 is connected to the negative electrode of the DC power supply 152. Is done. As a result, a current can be supplied from the DC power source 152 to these circuit elements. In the IES power supply 250, a gate drive circuit 162 is connected between the gate (G) and the emitter (E) of the IGBT 258.

  The IGBT 258 is a switching element in which the conduction state between the collector (C) and the emitter (E) changes in response to a signal given from the gate drive circuit 162.

(F) Outline of operation of IES power supply 250 using IGBT 258 as a switching element;
When an electric pulse is generated in the IES power supply 250, first, an ON signal is given from the gate drive circuit 162 to the gate (G) of the IGBT 258, and the collector (C) and the emitter (E) of the IGBT 258 become conductive, and the step-up transformer Current flows on the primary side of 156.

  Subsequently, when the ON signal is stopped from the gate drive circuit 162 to the IGBT 258 and the collector (C) and the emitter (E) of the IGBT 258 are made non-conductive, the current flows into the primary side of the step-up transformer 156 Is stopped at high speed. As a result, an induced electromotive force is generated on the primary side of the step-up transformer 156, and a high voltage is also generated on the secondary side of the step-up transformer 156.

(G) 1 pulse energy density;
1 pulse energy of an electric pulse supplied to each of the pair of the first electrode 106 and the second electrode 114, the opposing area of the first electrode 106 and the second electrode 114 constituting each of the pair, That is, the energy density per pulse divided by the total projected area when the second electrode 114 constituting each of the pair is projected onto the first electrode 106 constituting each of the pair (hereinafter, “ The “one-pulse energy density” is preferably 0.1-10 mJ / cm ² . This is because the surface treatment efficiency of the workpiece 190 can be particularly improved within this range. If the one-pulse energy density is smaller than this range, it tends to be difficult to generate a uniform plasma. Tend to be.

When the IES power source 150 using the SI thyristor 158 as a switching element is used as the pulse power source 144 in the surface treatment apparatus 100, one pulse energy supplied to one pair of the first electrode 106 and the second electrode 114 Is about 5 mJ. For this reason, in the surface treatment apparatus 100, in order to obtain a one-pulse energy density of about 0.1 mJ / cm ² included in the above-described desirable range, each of the second electrodes 114 has a facing area of 50 cm ^2. The width of the substrate is 40 cm and the thickness (the length in the transport direction) is 0.625 cm (the surface treatment apparatus 100 includes two second electrodes 114, and the facing area is 40 cm × 0.625 cm × 2 Book = 50 cm ² ). Needless to say, the shape and size of both or one of the first electrode 106 and the second electrode 114 may be changed within a range in which one pulse energy density within the above-described preferable range can be obtained.

In addition, when the surface treatment apparatus 100 adopts a CES power supply instead of the IES power supply 150, one pulse energy supplied to a pair of the first electrode 106 and the second electrode 114 is about 2 mJ. For this reason, if the facing area is 50 cm ² , the one-pulse energy density is remarkably reduced to about 0.04 mJ / cm ² . This is the same even if the first electrode parallel to the second electrode 114 is employed instead of the first electrode 106 perpendicular to the second electrode 114. That is, even when the first electrode parallel to the second electrode 114 is employed, when the IES power source 150 is employed, the one-pulse energy density is about 0.1 mJ / cm ² , whereas the CES power source is When employed, the one-pulse energy density is extremely small, 0.04 mJ / cm ² or less.

Further, in the surface reforming apparatus disclosed in Patent Document 2 referred to in the “Background Art” column, since the anode is an extremely thin object such as a 0.5 mm round bar, the one-pulse energy density is remarkably increased. For example, if the width of the anode is 20 cm, one pulse energy density is about 5 mJ / cm ² .

<5 Workpiece>
The workpiece 190 processed by the surface treatment apparatus 100 is mainly a plate-shaped object such as a semiconductor substrate or a glass substrate. However, the surface treatment apparatus 100 can also perform surface treatment of a long sheet-shaped object such as a polyethylene sheet or a polypropylene sheet. In this case, instead of the work carrier 132, a sheet-shaped object that is an object to be processed may be run and the sheet-shaped object may pass through the gap 1022.

<6 Surface Treatment Method Performed Using Surface Treatment Apparatus 100>
Next, a surface treatment method performed using the surface treatment apparatus 100 configured as described above will be described with reference to FIGS.

  First, the work 190 is placed on the work carrier 132 on the first work setting table 126. Subsequently, the moving stage 138 to which the end of the work carrier 132 on the downstream side in the conveyance direction is connected is moved in the conveyance direction to convey the workpiece 190 in the conveyance direction.

  Next, an electric pulse is repeatedly applied between the first electrode 106 and the second electrode 114 by the pulse power source 144 (IES power source 150). At this time, a processing gas mainly containing nitrogen gas is supplied from the outlet 1189 to the introduction path 1024 by the processing gas supply body 118. Then, plasma containing nitrogen radicals with extremely high activity is uniformly generated in the gap 1022. Then, nitrogen radicals are caused to chemically act on the region to be treated 192 by passing the gap 1022 where streamer discharge is generated through the workpiece 190. Then, the workpiece 190 is taken out after being conveyed onto the second workpiece setting table 128.

  By using such a surface treatment method, surface treatment of a plurality of objects to be processed or a long object to be processed can be performed continuously and efficiently.

<7 Experiment>
Below, the experiment which performed the surface treatment of the glass substrate using the above-mentioned surface treatment apparatus is demonstrated. Unless otherwise specified, using an IES power supply with a pulse transformer / inductance of 20 μH and an SI thyristor as a switching element, an electric pulse with a half-value width FWHM of 800 ns was applied, and the glass substrate transport speed was The experiment was conducted under the conditions of 10 m / min, the water contact angle θ before the surface treatment was 55 °, and the gap 1022 was 5 mm. Of course, in the experiment described below, consideration is given to sufficiently reducing the influence other than the factor to be examined.

<7.1 Change in water contact angle θ due to surface treatment>
In this experiment, when using an IES power source using an SI thyristor as a switching element and when using an IES power source using an IGBT as a switching element, the contact angle (hereinafter referred to as “water” Changes in the surface treatment of θ) (referred to as “contact angle”) were investigated. When the SI thyristor is used as a switching element, the pulse transformer / inductance of the IES power supply is 20 μH, the peak voltage of the applied electric pulse is 25 kV, the full width at half maximum FWHM is 800 ns, the frequency is 20 kHz, and the power is 400 W. On the other hand, when the IGBT is used as a switching element, the pulse transformer / inductance of the IES power supply is 1 mH, the peak voltage of the applied electric pulse is 25 kV, the full width at half maximum FWHM is 10 μs, the frequency is 5 kHz, and the power is 200 W.

  As a result, when the SI thyristor is used as a switching element, the water contact angle θ is 55 ° before the surface treatment and the surface of the glass substrate is water-repellent, but after the surface treatment is performed. The water contact angle θ was less than measurable 5 °, and the surface of the glass substrate was hydrophilic. On the other hand, when the IGBT is used as a switching element, the water contact angle θ is 55 ° before the surface treatment and the surface of the glass substrate is water-repellent. The contact angle θ was 6 °, and the surface of the glass substrate was hydrophilic. Thus, it was confirmed that a favorable surface treatment can be performed by using an IES power source.

<7.2 Effects of power supply type and processing gas composition on maximum transfer speed and workpiece temperature rise>
In this experiment, the influence of the type of power supply and the composition of the processing gas on the maximum transfer speed and workpiece temperature rise was investigated. The results are shown in the list of FIG.

  In this experiment, two levels of inductive energy storage type and electrostatic energy storage type are set as the type of power supply, and two levels of nitrogen gas 100% and nitrogen gas 98% + oxygen gas 2% (volume percentage) are set as the composition of the processing gas. did. The “maximum transport speed” is the maximum value of the transport speed of the glass substrate that can reduce all seven water contact angles θ defined on the surface of the glass substrate from 50 ° to 5 °. The “work temperature rise” is an increase in the temperature of the glass substrate when the glass substrate is transported at the maximum transport speed. The supply amount of the processing gas is 30 liters / minute, the power of the applied electric pulse is 500 W, and the gap 1022 is 5 mm. The glass substrate as a workpiece is a square plate having a side length of 350 mm and a plate thickness of 1.1 mm.

  As shown in FIG. 16, the maximum conveyance speed was faster and the temperature increase was smaller when the power source type was the inductive energy storage type than when it was the electrostatic energy storage type. This is because when the electrostatic energy storage type power supply is used, the uniformity of the surface treatment becomes small, and when the glass substrate is transported at a high speed, there are places where the surface treatment is insufficient. When the power source of the mold is adopted, the uniformity of the surface treatment becomes high, so that a portion where the surface treatment is insufficient does not occur even when the glass substrate is conveyed at a high speed.

  Such suppression of temperature rise is effective for avoiding damage to the organic EL substrate and the mask in the ashing process and the mask cleaning process in the manufacture of the organic EL device. That is, in the manufacture of the organic EL device, the temperature of the workpiece needs to be lower than 100 ° C., but it takes several minutes or more to remove the organic film attached to the workpiece. When the power supply is adopted, the work needs to be cooled, whereas when the induction energy storage type power supply is adopted, it is not necessary.

  Further, as shown in FIG. 16, the maximum conveyance speed is faster and the temperature rise is smaller when the composition of the processing gas is 98% nitrogen gas + 2% oxygen gas than when the composition is 100% nitrogen gas. It was. This is because the efficiency of the surface treatment can be improved when the treatment gas of nitrogen gas 98% + oxygen gas 2% is employed rather than nitrogen gas 100%.

<7.3 Effect of Oxygen Content on Water Contact Angle θ>
In this experiment, the influence of the oxygen content on the water contact angle θ was investigated. The result is shown in the graph of FIG. In the graph of FIG. 17, the change in the average value of the water contact angle θ is indicated by a solid line, and the change in the variation of the water contact angle θ is indicated by a dotted line. The processing gas supply rate is 30 liters / minute, the applied electric pulse power is 400 W, the glass substrate transport speed is 10 m / minute, the blowing angle δ is 45 °, and the distance L between the blowing port and the first electrode is 30 mm. It is. The glass substrate is a square plate having a side length of 300 mm and a plate thickness of 1.1 mm.

  As shown in FIG. 17, the average value of the water contact angle θ was small when the oxygen gas content was in the range of 1-4%.

<7.4 Influence of the blowing angle δ on the water contact angle θ>
In this experiment, the influence of the blowing angle δ on the water contact angle θ was investigated. The result is shown in FIG. In the graph of FIG. 18, the water contact angle θ when the glass substrate conveyance speed is 10 m / min is indicated by a solid line, and the water contact angle θ when it is 25 m / min is indicated by a dotted line. The supply amount of the processing gas is 30 liters / minute, the composition of the processing gas is 98% nitrogen + 2% oxygen, the power of the applied electric pulse is 400 W, and the distance L between the outlet and the first electrode is 30 mm. The glass substrate is a square plate having a side length of 300 mm and a plate thickness of 1.1 mm.

  As shown in FIG. 18, the water contact angle θ was small when the blowing angle δ was approximately in the range of 30-50 °.

<7.5 Effect of transport speed on water contact angle θ>
In this experiment, the influence of the conveyance speed on the water contact angle θ was investigated. The result is shown in FIG. In the graph of FIG. 19, the average value of the water contact angle θ is indicated by a solid line, and the variation of the water contact angle θ is indicated by a dotted line. The supply amount of the processing gas is 30 liters / minute, the composition of the processing gas is 98% nitrogen + 2% oxygen, the power of the applied electric pulse is 400 W, the blowing angle δ is 45 °, and the distance between the blowing port and the first electrode L is 30 mm. The glass substrate is a square plate having a side length of 300 mm and a plate thickness of 1.1 mm.

  As shown in FIG. 19, when the conveyance speed of a glass substrate is 25 m / min or less, the average value of water contact angle (theta) becomes large, so that the conveyance speed of a glass substrate becomes high. However. When the conveyance speed of the glass substrate is 25 m / min or less, the variation in the water contact angle θ is 2 ° or less. The allowable variation in the water contact angle θ varies depending on the purpose of use of the glass substrate and other circumstances, but if the variation in the water contact angle θ is 2 ° or less, it is considered sufficient in most cases. Such a small variation is due to the use of an IES power supply as a pulse power supply, and cannot be realized when a CES power supply is used.

<7.6 Effect of Distance L between Blowout Port and First Electrode on Water Contact Angle θ>
In this experiment, the influence of the distance L between the outlet and the first electrode on the water contact angle θ was investigated. The result is shown in FIG. In the graph of FIG. 20, the water contact angle θ when the conveyance speed of the glass substrate is 10 m / min is indicated by a solid line, and the water contact angle θ when it is 25 m / min is indicated by a dotted line. The supply amount of the processing gas is 30 liters / minute, the composition of the processing gas is 98% nitrogen + 2% oxygen, the power of the applied electric pulse is 400 W, and the blowing angle δ is 45 °. The glass substrate is a square plate having a side length of 300 mm and a plate thickness of 1.1 mm.

  As shown in FIG. 20, the water contact angle θ was generally small when the distance between the outlet and the first electrode was approximately in the range of 20-40 mm.

<7.7 Effect of 1-pulse energy density on water contact angle θ>
In this experiment, the influence of one-pulse energy density on the water contact angle θ was investigated. The results are shown in Table 1, Table 2 and FIG. In the graph of FIG. 21, a solid line is obtained by applying an electrical pulse having a half-width FWHM of 800 ns using an IES power source having a pulse transformer / inductance of 20 μH under the conditions shown in Table 1. A dotted line indicates that an electrical pulse having a half-value width FWHM of 10 μs is applied using an IES power source having a transformer inductance of 1 mH. In each example, the supply amount of the processing gas is 30 liters / minute, the composition of the processing gas is 98% nitrogen + 2% oxygen, and the distance L between the outlet and the first electrode is 30 mm. The glass substrate which is a workpiece is a square plate having a side length of 300 mm and a plate thickness of 1.1 mm.

  FIG. 22A is a diagram showing an outline of the configuration of the first electrode structure and the second electrode structure when an electric pulse with a half width FWHM of 800 ns is applied. The second electrode is made of stainless steel, and the second dielectric barrier is made of quartz. On the other hand, FIG. 22B is a diagram showing an outline of the configuration of the first electrode structure and the second electrode structure when an electric pulse with a half-value width FWHM of 10 μs is applied. The second electrode is made of tungsten having a round bar shape, and the second dielectric barrier is made of quartz having a round pipe shape.

As shown in FIG. 21, in both cases of applying an electric pulse with a half-value width FWHM of 800 ns and applying an electric pulse with a half-value width FWHM of 10 μs, the one-pulse energy density is approximately 0.1-10 mJ / The water contact angle θ was small when it was within the range of cm ² . As described above, it was confirmed that the efficiency of the surface treatment of the workpiece can be improved if the one-pulse energy density is approximately in the range of 0.1-10 mJ / cm ² .

<7.8 Effect of electrode spacing on water contact angle θ>
In this experiment, the influence of the gap 1022 spacing on the water contact angle θ was investigated. The results are shown in Table 3 and FIG. The graph of FIG. 23 shows the change in the average value of the water contact angle θ when an electric pulse having a half-value width FWHM of 10 μs is applied using an IES power source having a pulse transformer inductance of 1 mH under the conditions shown in Table 3. A solid line indicates a change in variation of the water contact angle θ by a dotted line. In each example, the supply amount of the processing gas is 30 liters / minute, the composition of the processing gas is 98% nitrogen + 2% oxygen, and the distance L between the outlet and the first electrode is 30 mm. The glass substrate serving as a workpiece was a square plate having a side length of 18 mm and a plate thickness of 0.2 mm, and five glass substrates were carried on a work carrier.

  FIG. 24 is a diagram showing an outline of the configuration of the first electrode structure and the second electrode structure in this experiment. The second electrode is made of tungsten having a round bar shape, and the second dielectric barrier is made of quartz having a round pipe shape. The arrow shown in FIG. 24 has shown the conveyance direction of the glass substrate. FIG. 25 is a diagram illustrating a state in which the glass substrate is disposed on the work carrier. As shown in FIG. 25, the five glass substrates are arranged on a line perpendicular to the transport direction.

  As shown in FIG. 23, the variation in the water contact angle θ was small when the gap 1022 was in the range of 1.0 to 5.0 mm. Thus, it was confirmed that the streamer discharge can be uniformly generated in the gap 1022 when the gap 1022 has an interval of 1 to 5 mm.

<8 Others>
The above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Surface treatment apparatus 102 Reactor 104 1st electrode structure 106 1st electrode 108 Holder 110 1st dielectric barrier 112 2nd electrode structure 114 2nd electrode 116 2nd dielectric barrier 118 Process gas supply Body 120 Shower plate 122 Distance adjusting body 124 Housing 126 First work placing table 128 Second work placing table 130 Transfer mechanism 132 Work carrier 134 Single axis stage robot 136 Fixed rail 138 Moving stage 140 Height adjusting table 142 Insulating stage 144 Pulse power supply 150 IES circuit 158 Static induction thyristor (SI thyristor)
190 Workpiece

Claims (15)

A surface treatment apparatus,
A first electrode structure comprising a first electrode;
A second electrode structure comprising a second electrode and facing the first electrode structure;
A pulse power source that repeatedly applies an electric pulse between the first electrode and the second electrode;
A gap between the first electrode structure and the second electrode structure in which streamer discharge is generated by applying an electric pulse between the first electrode and the second electrode is processed. A transport mechanism to pass through,
A processing gas supply body for supplying a processing gas mainly composed of nitrogen gas into the gap from the upstream side of the conveyance path of the workpiece;
A surface treatment apparatus comprising: The surface treatment apparatus according to claim 1,
The pulse power supply is
An inductive energy storage type power supply,
Surface treatment equipment. The surface treatment apparatus according to claim 2,
The first electrode constituting each of the pair, and the energy per pulse of the electric pulse supplied to each of the pair of the first electrode and the second electrode and used for the reaction for generating plasma. The energy density per pulse divided by the area facing the second electrode is 0.1-10 mJ / cm ² ;
Surface treatment equipment. In the surface treatment apparatus according to any one of claims 1 to 3,
The first electrode structure includes:
A first dielectric barrier;
A surface treatment apparatus further comprising: In the surface treatment apparatus according to any one of claims 1 to 4,
The second electrode structure is
A second dielectric barrier;
A surface treatment apparatus further comprising: In the surface treatment apparatus according to any one of claims 1 to 5,
The processing gas supply is
Supplying a processing gas consisting of nitrogen gas and oxygen gas and having an oxygen gas content of 1-4% in the whole;
Surface treatment equipment. In the surface treatment apparatus in any one of Claims 1 thru | or 6,
The processing gas supply is
The extending direction of the processing gas introduction path to the gap, which is a direction perpendicular to the first direction toward the gap and the extending direction of the introduction path, from the processing gas supply body to the introducing path. Jetting process gas in a direction intermediate to the second direction toward
Surface treatment equipment. The surface treatment apparatus according to claim 7,
The processing gas supply is
Jetting process gas in a direction that forms 30-50 ° with the first direction;
Surface treatment equipment. In the surface treatment apparatus according to any one of claims 1 to 8,
The processing gas supply port of the processing gas supply body and the first electrode are separated by 20-40 mm in the extending direction of the processing gas introduction path to the gap,
Surface treatment equipment. The surface treatment apparatus according to any one of claims 1 to 9,
The second electrode has a plate shape and is installed perpendicular to the transport path;
The second dielectric barrier has a sheath shape and accommodates at least the transport path of the second electrode;
Surface treatment equipment. In the surface treatment apparatus in any one of Claims 1 thru | or 10,
A gap between the first electrode structure and the second electrode structure has an interval of 1-5 mm;
Surface treatment equipment. A surface treatment method comprising:
A preparation step for preparing a first electrode structure including a first electrode and a second electrode structure including a second electrode;
An electric pulse applying step of repeatedly applying an electric pulse between the first electrode structure and the second electrode structure by an inductive energy storage type pulse power source;
A process gas supply step of supplying a process gas containing nitrogen gas as a main component to a gap between the first electrode structure and the second electrode structure;
A surface treatment method comprising: a conveying step of passing the gap in which streamer discharge is generated by the electric pulse applying step through an object to be treated. The surface treatment method according to claim 12,
The energy of one electric pulse used for the reaction of generating plasma supplied to each pair of the first electrode and the second electrode by the electric pulse applying step constitutes each of the pair. The energy density per pulse divided by the facing area between the first electrode and the second electrode is 0.1-10 mJ / cm ² ;
Surface treatment method. The surface treatment method according to claim 12 or 13,
The process gas supply step includes:
Supplying a processing gas consisting of nitrogen gas and oxygen gas and having an oxygen gas content of 1-4% in the whole;
Surface treatment method. The surface treatment method according to any one of claims 12 to 14,
The preparation step includes
Preparing the first electrode structure and the second electrode structure such that a gap between the first electrode structure and the second electrode structure has a spacing of 1-5 mm;
Surface treatment method.

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