JP2005116900A - Atmospheric pressure plasma processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an atmospheric pressure plasma processing apparatus that sequentially performs plasma processing on substrates while transporting many setters carrying the substrates by arranging the setters in a row and can relieve the influence of another gas flow, such as sucked air etc., exerted upon the blown-off flow of a process gas. <P>SOLUTION: The atmospheric pressure plasma processing apparatus M1 transports a plurality of setters carrying the substrates W by putting the setters in a row. Along the transporting line 1 of the device M1, a heating section 2 which heats the substrates W to a prescribed temperature, a processing section 3 which forms a small thickness space 100 between the row of the setters 5 and the section 3, and a cooling section 4 which cools the substrates W are sequentially arranged. The section 3 is provided with a processing unit 10 which blows off a gas used for plasma processing and, at the same time, sucks the gas in the vicinity of the section 3. Ventilating ducts 20 which connect the small thickness space 100 to the outside are provided in front of and behind the processing unit 10, respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus for performing plasma processing under a pressure environment of substantially normal pressure (near the atmosphere).

  For example, Patent Document 1 describes an apparatus that performs plasma processing under a substantially normal pressure. A processing unit is provided in the plasma processing apparatus. The processing unit converts the processing gas into plasma between the electrodes and blows it out, and sucks and exhausts the processed gas in the vicinity thereof. Further, curtain gas is blown out around the intake port to prevent leakage of processing gas.

  In thermal CVD, a method is known in which a large number of setters on which silicon wafers are placed as objects to be processed are arranged in a line and film formation is carried while being conveyed by a conveyor (Patent Document 2). Moreover, the apparatus of patent document 3 makes a glass base material into a to-be-processed object, and arrange | positions the heating part, the process part, and the cooling part side by side along the outgoing path direction of the reciprocating carrier which carries this.

Japanese Patent Laid-Open No. 9-92493 (first page) Japanese Patent Laid-Open No. 61-19117 (first page) JP-A-6-101050 (first page)

  The inventors have developed an apparatus that continuously performs heating, plasma processing, and cooling while conveying a large number of setters in a line under substantially normal pressure. In the apparatus, a very thin space corresponding to a so-called working distance is formed between the processing unit including the processing unit and the setter row. In this thin space, not only the processing gas is blown out from the processing unit, but also the intake air and the curtain gas are blown out at the same time, and further, the circulating air from the heating unit and the cooling unit flows. As a result, the blow-out flow of the processing gas is affected and there is a problem that it is not easy to ensure the uniformity of the processing.

  The present invention has been made in order to solve the above-described problems, and is an apparatus for performing plasma processing under a substantially normal pressure while conveying a plurality of setters carrying a workpiece in a row, A heating unit that heats up to a predetermined temperature, a processing unit that forms a thin space between the rows of setters, and a cooling unit that cools an object to be processed are sequentially arranged from the front side along the transport line, The processing unit includes a processing unit that blows out gas for plasma processing and sucks air in the vicinity thereof, and a ventilation duct that connects the thin space to the outside. As a result, it is possible to mitigate the influence of other gas flows such as intake air on the blow-out flow of the processing gas, and to ensure the uniformity of the processing.

The substantially normal pressure in the present invention refers to a range of 1.333 × 10 ^{4 to} 10.664 × 10 ⁴ Pa. Among these, the range of 9.331 × 10 ^{4 to} 10.9797 × 10 ⁴ Pa is preferable because pressure adjustment is easy and the apparatus configuration is simple.

It is desirable that the processing unit is provided with intake ports on the front side and the rear side, respectively, across the processing gas blowout port. It is more desirable that curtain gas outlets are provided further upstream and downstream of the intake ports.
It is desirable that the ventilation duct is disposed so as to sandwich the processing unit from the front side and the rear side.

  The processing unit is provided with a plurality of the processing units arranged along the transfer line, between the adjacent processing units, and at the front side and the last (last stage) processing unit of the first (frontmost) processing unit. It is desirable that the ventilation ducts are respectively disposed on the rear stage side. Accordingly, the plasma processing can be performed in a plurality of stages, and the processing gas blowing flow in each processing unit can be less affected by other gas flows, and uniformity in each processing stage can be ensured.

  In the processing section, auxiliary heaters for reheating the workpiece are disposed between adjacent processing units, on the front side of the first processing unit, and on the rear side of the last processing unit, respectively. It is desirable that the ventilation duct is interposed between the processing units. Thus, the object to be processed being conveyed can be reliably maintained at a predetermined temperature, and the process gas blow-off flow in each processing unit can be less affected by other gas flows.

  The heating unit includes, for example, a hood that covers the transfer line and thus the setter that is being transferred, and heats the object to be processed by forming a heated circulating air between the hood and the setter. In this case, it is desirable to provide a ventilation duct at the boundary between the hood and the processing unit of the heating unit. As a result, it is possible to mitigate the influence of the process gas blow-off flow from the heating circulation wind, and to ensure the uniformity of the process.

  The cooling unit includes, for example, a hood that covers the transfer line and thus the setter that is being transferred, and forms a circulating air between the hood and the setter to cool the workpiece. In this case, it is desirable to provide a ventilation duct at the boundary between the hood and the processing unit of the cooling unit. Thereby, it is possible to mitigate the influence of the circulating flow of the processing gas blowout flow, and to ensure the uniformity of the processing.

  According to the present invention, the blow-out flow of the processing gas can be less affected by other gas flows such as intake air, and the processing uniformity can be ensured.

  FIG. 1 shows a continuous atmospheric plasma CVD apparatus M1 according to an embodiment of the present invention. The plasma CVD apparatus M1 includes a roller conveyor 1, a heating unit 2 (heating unit), a processing unit 3, and a cooling unit 4 (cooling unit).

  The roller conveyor 1 extends along one horizontal direction and constitutes a “conveyance line”. On the roller conveyor 1, a large number of setters 5 are arranged in a line without any gaps. The setter 5 is made of alumina and has a rectangular plate shape. As shown in FIG. 2, a shallow rectangular recess 5 a is formed on the upper surface of the setter 5. A glass substrate W is accommodated and placed in the recess 5a of each setter 5 as an object to be processed. The roller conveyor 1 continuously conveys the setter 5 and the glass substrate W in a row. A setter 5 on which a new glass substrate W is placed is sequentially added to the front end portion (left end in FIG. 1) of the roller conveyor 1. At the rear end of the roller conveyor 1 (the right end in FIG. 1), the setter 5 on which the processed glass substrate W is placed is sequentially taken out.

  As shown in FIG. 1, the heating unit 2, the processing unit 3, and the cooling unit 4 are sequentially disposed above the roller conveyor 1 from the front side.

  Although the detailed illustration is omitted, the heating unit 2 in the foremost stage includes a hood 2a that covers the roller conveyor 1 and thus the setter that is being transported, and wind circulation means that forms circulating air between the hood 2a and the setter. And heating means for heating the circulating air. The setter 5 and the glass substrate W being conveyed are heated to a predetermined temperature suitable for film formation by the heated circulating air in the hood 2a. The predetermined temperature is preferably about 200 to 500 ° C. If it is not in this temperature range, no film is formed, and even if a film is formed, good film quality cannot be obtained. The predetermined temperature is more preferably around 350 ° C.

  The cooling unit 4 at the last stage includes a hood 4a that covers the roller conveyor 1 and thus the setter that is being transported, and wind circulation means that forms a circulating air between the hood 4a and the setter. The setter 5 and the glass substrate W are cooled by normal temperature circulating air in the hood 4a.

  The processing unit 3 between the heating unit 2 and the cooling unit 4 includes two (plural) film forming units 10 (processing units), three (plural) auxiliary heaters 20, and six (plural). A ventilation duct 30 is provided.

  The two film forming units 10 are separated forward and backward along the roller conveyor 1.

  The auxiliary heaters 20 are arranged on the further front side of the front (first) film forming unit 10, between the front and rear film forming units 10, and further on the rear side of the rear (final) film forming unit 10. Yes.

  The ventilation duct 30 is interposed between the film forming unit 10 and the auxiliary heater 20, respectively. Furthermore, between the heating unit 2 and the front auxiliary heater 20 (between the heating unit 2 and the processing unit 3) and between the rear auxiliary heater 20 and the cooling unit 4 (between the processing unit 3 and the cooling unit 4). Each intervenes. (The air duct 30 is provided so as to sandwich each film forming unit 10 from the front and back, and is provided so as to sandwich each auxiliary heater 20 from the front and back.)

  The hood 2a of the heating unit 2, each component 10, 20, 30 of the processing unit 3 and the hood 4a of the cooling unit 4 are closely aligned with each other adjacent to each other in the front and rear to form a line. Further, the lower surfaces (surfaces to be opposed to the setter 5 and the glass substrate W) of the constituent elements 10, 20, and 30 of the processing unit 3 are flush with each other. Between the lower surface of the processing unit 3 and the row of setters 5 on the roller conveyor 1, a thin space 100 that is elongated in the front-rear direction is formed. The upper and lower thickness of the space 100 corresponds to a so-called working distance (the distance between the blowout ports 10f, 10m, and 10r described later and the glass substrate W), and is very thin, for example, 4 mm. Note that both sides of the space 100 in the left-right width direction are substantially closed by the chamber walls 9 (FIG. 4).

A specific structure of each component 10, 20, and 30 of the processing unit 3 will be described in detail.
As shown in FIG. 2, each film forming unit 10 includes an upper gas uniform introduction portion 12, a lower electrode portion 13, and an outer casing 11 that surrounds them.

  As shown in FIGS. 2 and 4, the outer casing 11 includes an outer frame 14 having a rectangular shape in plan view, and a pair of exhaust ducts 15 (intake ports) integrally provided on the front and rear long portions of the outer frame 14. And have. The outer frame 14 and the exhaust duct 15 are made of metal such as stainless steel.

  The exhaust duct 15 opens downward and extends left and right (in a direction orthogonal to the transport line, a direction orthogonal to the paper surface in FIG. 2). An upper end portion of the exhaust duct 15 is connected to the exhaust pump 7 via a suction pipe 7a.

A curtain gas blowing path 14 a is formed in the outer frame 14 outside the front and rear sides of the exhaust duct 15. The curtain gas outlet 14 a extends in a slit shape from side to side and opens at the lower end surface of the outer frame 14. The curtain gas outlet holes may be a large number of small holes arranged on the left and right. The upper end of the curtain gas outlet 14a is connected to a curtain gas supply source 6C through a curtain gas supply pipe 6f. For example, N ₂ is stored as curtain gas in the curtain gas supply source 6C.

  As shown in FIG. 2, the gas uniform introduction section 12 is formed with three gas uniformization paths 12 f, 12 m, and 12 r arranged side by side. Although not shown in detail, the gas uniform introduction section 12 is configured by stacking a plurality of flat plates made of a metal such as aluminum on the top and bottom. Each metal plate is formed with a large number of small holes dispersed in the left and right, slit-like chambers extending in the left and right, etc. arranged in three rows in the front and rear. In the metal plates stacked one above the other, small holes and chambers in each row are connected to each other, and thereby gas uniformization paths 12f, 12m, and 12r are configured.

  A source gas supply pipe 6d from the source gas supply source 6A is connected to the upper end portion of the central gas uniformizing path 12m. A plasma gas supply pipe 6e from a plasma gas supply source 6B is branched and connected to the gas equalization paths 12f and 12r on both the front and rear sides.

  Here, of the two types of processing gas supply sources 6A and 6B, the source gas supply source 6A stores the silicon source, the dopan source, and the carrier gas separately and mixes them at a predetermined flow rate ratio to generate the source gas. The gas is supplied to the gas supply pipe 6d. The original liquid source is vaporized using a vaporizer. They may be mixed after being vaporized independently, or may be vaporized after being mixed in a liquid state.

  As the silicon source, for example, alkoxy compounds such as TMOS, TEOS, and MTMOS, and siloxane compounds such as HMDSO and TMCTS are used.

  Examples of the dopan sauce include phosphate esters such as TEOP and TMOP, phosphite esters such as TMP and TEP, alkyl borates such as TEB and TMB, and alkoxygermanium such as TMGe and TEGe.

For example, O ₂ , N ₂ , or N ₂ O is used as the carrier gas. When the carrier gas and the curtain gas are the same substance, these gas tanks may be shared.

A plasma gas supply source 6B, which is another type of processing gas supply source, stores a plasma gas that is turned into plasma by application of an electric field.
As the plasma gas, for example, any one of O ₂ , N ₂ O, NO ₂ , NO, H ₂ O, and O ₃ , or a mixture selected from a plurality of these is used.

  The processing gases (source gas and plasma target gas) guided from the processing gas supply sources 6A and 6B to the gas uniformization paths 12f, 12m, and 12r of the gas uniform introduction section 12 through the supply pipes 6d and 6e are the paths 12f. , 12m, and 12r are made uniform in the left-right direction in the course of sequentially circulating the small holes, chambers, and the like.

  Further, the gas uniform introduction section 12 is provided with a heater (temperature adjusting means) (not shown). Thereby, the gas uniform introduction part 12 is heated in the range of about 50 to 200 ° C. (temperature adjustment), for example. If it is less than 50 degreeC, there exists a possibility that the vaporized silicon source and dopan sauce may re-liquefy, and if it exceeds 200 degreeC, there exists a possibility of causing a thermal reaction.

Next, the electrode part 13 of the film forming unit 10 will be described.
As shown in FIGS. 2 and 3, the electrode section 13 includes four (plural) electrodes 18 </ b> H and 18 </ b> E, a holder 16 that accommodates and holds the electrodes 18 </ b> H and 18 </ b> E while insulating and holds the holder 16. A casing 17 is provided.

  The casing 17 is made of a rigid metal such as stainless steel, and has a left and right elongated box shape that opens on both upper and lower sides. The gas uniform introduction portion 12 is fixed to the upper end portion of the casing 17 with a bolt (not shown) or the like. A step 17 a is formed on the entire outer periphery of the lower end of the casing 17, and the step 17 a is hooked on the inner flange 19 of the outer casing 11. Thus, the electrode portion 13 and the gas uniform introduction portion 12 are supported by the outer casing 11.

  Each of the electrodes 18H and 18E has a plate shape elongated in the left and right directions with the width direction facing up and down. For example, stainless steel is used as the material of the electrodes 18H and 18E, but the material is not limited to this, and other conductive metals such as aluminum may be used.

  The four electrodes 18H and 18E are arranged at intervals in the front-rear direction. Between the adjacent electrodes 18H and 18E, left and right elongated spaces 18f, 18m, and 18r are formed. The thickness of these interelectrode spaces 18f, 18m, and 18r (distance between the electrodes 18H and 18E) is preferably 0.1 to 50 mm, and more preferably 5 mm or less.

  As shown in FIG. 3, a power supply line 8h extends from the pulse power supply 8 (electric field applying means) and is connected to one end of two electrodes 18H at the center. Thus, the central two electrodes 18H are electric field application electrodes. Therefore, an electric field is not applied to the central inter-electrode space 18m.

  Here, the pulse power supply 8 outputs a pulse voltage. It is desirable that the rise time and / or fall time of this pulse is 10 μs or less, the pulse duration is 200 μs or less, the electric field strength is 1-1000 kV / cm, and the frequency is 0.5 kHz or more.

  A ground wire 8e is connected to the other end of the two electrodes 18E on the front and rear sides. By grounding the ground line 8e, the electrodes 18E on both sides serve as ground electrodes. As a result, electric fields are applied to the interelectrode spaces 18f and 18r on both sides by the voltage supply from the power supply 8 to become plasmatized spaces.

Although detailed illustration is omitted, a solid dielectric layer is coated by, for example, thermal spraying on the surface where the plasmatized spaces 18f and 18r are formed and the upper and lower surfaces of the electrodes 18H and 18E. The dielectric constant of the solid dielectric is preferably 2 or more, and more preferably 10 or more. As the material of the solid dielectric, a resin such as polytetrafluoroethylene, a metal oxide such as Al ₂ O ₃ , or a double oxide such as BaTiO ₃ is used. The solid dielectric layer may be a single layer or a laminated structure of a plurality of layers. For example, it is preferable to coat a BaTiO ₃ layer on the side of the metal surfaces constituting the electrodes 18H and 18E and coat an Al ₂ O ₃ layer on the outer side thereof to ensure a dielectric constant of 10 or more.

  Although illustration is omitted, a temperature control refrigerant path is formed in each of the electrodes 18H and 18E, and heating the electrodes 18H and 18E (temperature adjustment) in a range of about 50 to 200 ° C., for example, by passing the refrigerant through the electrodes. ) Is now possible. If it is less than 50 degreeC, there exists a possibility that the vaporized silicon source and dopan sauce may reliquefy. The upper limit of 200 ° C. takes into account the difference in thermal expansion between the stainless steel constituting the electrodes 18H and 18E and the solid dielectric layer.

  As shown in FIGS. 2 to 4, the holder 16 of the electrode portion 13 includes an upper plate 16 </ b> A straddling between the upper surfaces of the four electrodes 18 </ b> H and 18 </ b> E, a lower plate 16 </ b> B straddling between the lower surfaces, Side plates 16C and end caps 16D arranged on the left and right sides.

  As shown in FIG. 3, three plate spacers 16E are provided on the left and right end caps 16D made of insulating resin. By inserting the spacer 16E into the gap between the adjacent electrodes 18H and 18E, the distance between the electrodes 18H and 18E is maintained.

  Each plate 16A, 16B, 16C before and after the holder 16 is made of ceramic (insulating material) such as alumina. As a result, the electrodes 18H and 18E are insulated. The material of the ceramic is not particularly limited, but the dielectric constant is preferably 20 or less, and more preferably 10 or less. When the dielectric constant exceeds 20, current may leak locally to the surrounding metal members.

  The upper plate 16A of the holder 16 has an elongated plate shape on the left and right. As shown in FIG. 2, the upper plate 16A is sandwiched from above and below by the gas uniform introduction section 12 and the electrodes 18H and 18E. Three gas introduction paths 13f, 13m, and 13r are formed in the upper plate 16A. These introduction paths 13f, 13m, and 13r extend in the left-right direction orthogonal to the paper surface of FIG. 2 and are spaced apart from each other. The front introduction path 13f is continuous with the gas uniformization path 12f on the front side of the gas uniform introduction section 12, and is inclined rearward downward, and is continuous with the front interelectrode space 18f. The central introduction path 13m is connected to the central gas uniformization path 12m of the gas uniform introduction section 12 and extends directly below, and is connected to the central inter-electrode space 18m. The rear introduction path 13r is continuous with the gas uniformization path 12r on the rear side of the gas uniform introduction section 12 and is inclined forward and is continued with the rear inter-electrode space 18r.

  The ceramic lower plate 16 </ b> B (blowout port constituent member) of the holder 16 has a long and narrow plate shape. A shallow recess 16g is formed on the upper surface of the lower plate 16B. The lower ends of the electrodes 18H and 18E are accommodated and placed in the recess 16g. (The lower plate 16B is addressed to the lower end surfaces (surfaces to be processed) of the electrodes 18H and 18E.) A step is formed at the peripheral edge of the lower plate 16B. It is caught by a step on the inner peripheral surface. Thus, the lower plate 16B is supported by the casing 17.

As shown in FIGS. 2 and 4, the lower plate 16B is formed with three outlets 10f, 10m, and 10r penetrating in the vertical thickness direction. These outlets 10f, 10m, and 10r are slit-shaped and extend left and right, and are spaced apart from each other. The front plasma gas outlet 10f is connected to the front inter-electrode space 18f. The central source gas outlet 10m is connected to the central inter-electrode space 18m. The rear plasma gas outlet 10r is connected to the rear inter-electrode space 18r. The outlets 10f, 10m, and 10r are opened on the lower surface of the film forming unit 10.
The lower plate 16B is provided with a joint channel for joining the source gas from the central inter-electrode space 18m and the plasma target gas from the inter-electrode spaces 18f and 18r on both sides, and a single outlet is connected to the joint channel. You may make it open in the lower surface of the lower plate 16B.

  The lower surface (surface to be opposed to the glass substrate W) of the film forming unit 10 is composed of a radiant heat reflecting material that reflects radiant heat from the setter 5 and the glass substrate W.

More specifically, as shown in FIGS. 2 and 4, radiant heat reflection is applied to constituent members to be opposed to the glass substrate W in the film forming unit 10, that is, lower surfaces of the lower plate 16 </ b> B, the casing 17, and the outer casing 11. Films A ₁₆ , A ₁₇ , A ₁₄ , A ₁₉ are respectively coated.

Radiant heat reflective film _{A 16} of the lower plate 16B is extends without Kuma the entire lower surface of the plate 16B. Of course, it is not provided in the portions of the outlets 10f, 10m, and 10r.

The radiant heat reflecting film A ₁₇ of the casing 17 extends over the entire exposed portion of the lower end of the casing 17. The step 17a hooked on the inner flange 19 is not coated, but may be coated.

The radiant heat reflecting films A ₁₄ and A ₁₉ of the outer casing 11 extend over the entire lower end surface of the outer casing 11. That is, the film A ₁₄ is coated on the entire lower end surface of the outer frame 14, and the film A ₁₉ is coated on the entire lower end surface of the inner flange 19. Of course, the film A ₁₄ of the outer frame 14 is not provided in the curtain gas outlet path 14a. A coating may also be applied to the outer surface of the outer frame 14 and the inner peripheral surface of the duct 15.
As a result, the radiant heat reflection films A ₁₆ , A ₁₇ , A ₁₄ , and A ₁₉ extend over the entire area of the lower surface of the film forming unit 10.

These radiant heat reflecting films A ₁₆ , A ₁₇ , A ₁₄ and A ₁₉ are made of aluminum which is a good radiant heat reflecting material. The films A ₁₆ , A ₁₇ , A ₁₄ , and A ₁₉ are coated on the substrate facing members 16 B, 17, and 11 by a pasting means such as vapor deposition, thermal spraying, and adhesion. The surfaces (lower surfaces) of the films A ₁₆ , A ₁₇ , A ₁₄ and A ₁₉ are smooth mirror surfaces. As radiant heat reflective material, a silica or ceramic powder, each substrate opposing member 16B by mixing the powder with a binder, was applied to 17,11, by sintering, radiant heat reflective film A _16, A ₁₇ , A ₁₄ , A ₁₉ may be configured.

Next, the specific structure of the auxiliary heater 20 will be described.
As shown in FIG. 5, the auxiliary heater 20 has a housing 21 and a heat source 22 accommodated in the housing 21. The housing 21 is in the shape of a flat container having a square shape in plan view. As shown in FIG. 4, the left and right length of the housing 21 is the same as the left and right length of the film forming unit 10. As shown in FIG. 1, the front-rear length of the housing 21 is about the front-rear length of the film forming unit 10 or slightly smaller. In addition, although the front-back length of the housing 21 of the front side auxiliary heater 20 is larger than the center and rear side auxiliary heaters 20, it is not limited to this. The housing 21 is made of aluminum which is a good heat conductive metal, but is not limited to this, and may be made of other good heat conductive metal such as Cu or Au. Or you may comprise with stainless steel.

  As shown in FIG. 5, the heat source 22 of the auxiliary heater 20 has a panel shape and is attached to the upper surface of the bottom plate of the housing 21 (the inner surface of the plate portion that should face the glass substrate W). For example, a rubber heater is used as the heat source 22, but the heat source 22 is not limited to this, and other resistance heating heaters such as a stainless steel heater and a ceramic heater may be used. It may be used.

  The interior of the housing 21 on the upper side (back side) from the heat source 22 is divided into two upper and lower chambers 21 a and 21 b by a partition plate 23. Each chamber 21a, 21b is filled with a heat insulating material 24. The heat insulating material 24 is preferably a material that generates little dust and has high heat resistance, and is made of, for example, glass wool as such a material, but is not limited thereto. The partition plate 23 is made of a material having high heat reflectivity, and prevents the heat of the heat source 22 from escaping upward.

As shown in FIG. 2, the lower surface of the auxiliary heater 20 (the surface that should face the glass substrate) is made of a far-infrared radiation material that radiates far-infrared rays by receiving heat from the heat source 22. More specifically, as shown in FIGS. 4 and 5, a far-infrared radiation film B ₂₁ is coated on the lower surface of the bottom plate of the housing 21. The far-infrared radiation film B ₂₁ is formed, for example, by mixing powder made of a metal oxide such as Al ₂ O ₃ , ZrO ₂ , CoO, etc. with a binder, applying it to the housing 21, and sintering it. The surface (lower surface) of the far-infrared radiation film B21 is rough to improve radiation efficiency.

Next, a specific structure of the ventilation duct 30 will be described.
As shown in FIGS. 4 and 6, the ventilation duct 30 has a duct main body 31 having an elongated container shape with the longitudinal direction facing left and right and the width direction facing up and down. The left and right lengths of the duct body 31 are the same as those of the film forming unit 10. The front and rear thickness of the duct body 31 is extremely thin, for example, about 20 mm. An external communication member 32 is provided on the upper side of the duct body 31 so as to protrude forward and backward. The external communication member 32 extends to the left and right (in the direction orthogonal to the paper surface of FIG. 6) over the entire length of the duct body 31. The projecting end surface of the external communication member 32 is opened all over, and serves as an external communication port 32 a that connects the inside of the ventilation duct 30 to the external space above the processing unit 3. At the inner end portion of the external communication member 32, a slit-shaped throttle portion 32c extending over the entire length on the left and right is formed. The inside of the external communication member 32 (ventilation chamber 32b) and the inside of the upper portion of the duct body 31 (ventilation chamber 31a) are connected via the throttle portion 32c.

  A rectifying plate 33 is accommodated in the lower portion of the duct body 31 and extends in the left-right direction with a vertically long and narrow U-shaped cross section. Between the pair of plate portions of the rectifying plate 33 and the front and rear side walls of the duct main body 31, a ventilation chamber 30b is formed that is vertically thin and extends left and right. The upper ends of the pair of plate portions of the rectifying plate 33 are bent forward and backward, respectively. Between these upper end bent portions and the front and rear side walls of the duct body 31, slit-like throttle portions 30a extending left and right are formed. The upper and lower ventilation chambers 31a and 30b are connected to each other through the throttle portion 30a.

The bottom of the duct body 31 is opened, and the bottom of the rectifying plate 33 faces the opening. As a result, two slit-shaped throttle portions 30c extending to the left and right of the ventilation duct 30 are formed. Each throttle portion 30c is connected to the ventilation chamber 30b and is connected to the thin space 100, and serves as a communication port to the thin space 100 of the ventilation duct 30.
Therefore, the thin space 100 passes through the throttle portion 30c, the vent chamber 30b, the throttle portion 30a, the vent chamber 31a, the throttling portion 32c, the vent chamber 32b, and the communication port 32a of the vent duct 30 in order, and then the external space above the processing portion 3. It is connected to.

The lower surface of the ventilation duct 30 (the surface that should face the glass substrate) is located on the same horizontal plane as the lower surfaces of the film forming unit 10 and the auxiliary heater 20. The radiant heat reflecting film A ₃₀ is also coated on the lower surface of the ventilation duct 30 as in the film forming unit 10.

The operation of the continuous atmospheric plasma CVD apparatus M1 having the above configuration will be described.
A new setter 5 on which the glass substrate W to be processed is placed is added to the forefront portion of the setter row on the roller conveyor 1. The setter 5 is first passed through the heating unit 2. Thereby, the setter 5 and the glass base material W on it can be heated with warm air to a predetermined temperature.

Next, the setter 5 is passed under the front auxiliary heater 20 and reheated. As a result, even if the glass substrate W with low heat retention attempts to lower the temperature, this can be prevented. Moreover, since the far infrared rays are radiated from the film B ₂₀ of the auxiliary heater 20, a glass substrate W to the inside can be sufficiently heated, can be reliably prevented a temperature drop. Moreover, since the setter 5 can also be heated sufficiently to the inside, heat can be supplied from the setter 5 to the glass substrate W, and a temperature drop of the glass substrate W can be prevented more reliably.

Next, the setter 5 is passed under the front film forming unit 10. Thereby, plasma film formation is performed on the glass substrate W.
More specifically, the plasma target gas from the supply source 6B is homogenized left and right in the gas homogenization paths 12f and 12r before and after the front film forming unit 10 through the pipe 6e, and then introduced into the introduction paths 13f and 13r. As described above, it is introduced into the front and rear inter-electrode spaces 18f and 18r. A pulse voltage from the pulse power source 8 is applied between the electrodes 18H and 18E. As a result, a pulse electric field is generated in the spaces 18f and 18r between the front and rear electrodes 18H and 18E, glow discharge occurs, and the plasma gas is turned into plasma (excited and activated). The plasma-treated plasma gas is blown out to the substantially closed space 100 from the front and rear outlets 10f and 10r. Since the gas to be plasma does not contain the raw material of the film, it does not adhere to the interelectrode space 18f, 18r formation surface of the electrodes 18H, 18E even if it is converted to plasma.

  Simultaneously with the flow of the plasma gas, the source gas from the supply source 6A is homogenized to the left and right in the central gas homogenization path 12m of the front film forming unit 10 via the pipe 6d, and then the introduction path It passes through 13 m and is introduced into the central interpolar electrode space 18 m. Since no electric field is applied in the interelectrode space 18m, the source gas passes through without being converted into plasma. Therefore, no film adheres to the space 18m formation surface of the electrode 18H.

  The source gas that has passed through the central inter-electrode space 18m is blown out from the central blow-out port 10m to the substantially closed space 100, is divided into two front and rear hands, and comes into contact with the plasma-formed plasma gas from the blow-out ports 10f and 10r. (Refer to the arrow line in FIG. 2). Thereby, a reaction of the source gas occurs, and a film such as amorphous silicon can be formed on the upper surface (front side surface) of the glass substrate W.

Further, the curtain gas from the supply source 6C is blown out from the curtain gas blowing path 14a of the outer casing 11 of the front film forming unit 10 through the pipe 6f. Thereby, a gas curtain can be formed between the front and rear edges of the unit 10 and the glass substrate W, and leakage of the processing gas can be prevented.
The treated gas and reaction by-products are sucked into the exhaust duct 15 and exhausted by the exhaust pump 7.

  As described above, since the glass substrate W subjected to the film forming process in the front film forming unit 10 is sent while being maintained at a predetermined temperature by the front auxiliary heater 20, the film forming efficiency is increased. The film quality can be improved. In addition, since the central auxiliary heater 20 is provided at the rear stage of the front film formation unit 20, heat can be prevented from escaping backward from the glass substrate W during film formation, and the film formation efficiency can be further improved. A better film quality can be obtained.

On the other hand, during film formation in the front film forming unit 10, radiant heat is radiated from the glass substrate W heated to a predetermined temperature toward the unit 10. This radiant heat can be reflected to the glass substrate W by the aluminum films A ₁₆ , A ₁₇ , A ₁₄ , A _{19 on} the lower surface of the film forming unit 10. Therefore, it is possible to prevent the film forming unit 10 from taking heat of the glass substrate W. Thereby, the film formation efficiency can be reliably increased, and the film quality can be further improved. The same applies to the action of the lower surface film _{A 30} of the ventilation duct 30.

  The setter after passing through the front film forming unit 10 is passed under the central auxiliary heater 20 and reheated. As a result, the temperature drop of the glass substrate 20 moving to the rear film forming unit 10 can be prevented and maintained at a predetermined temperature. Further, even if the temperature of the glass substrate W decreases during film formation in the front film formation unit 10, it can be returned to a predetermined temperature. It goes without saying that, similarly to the front auxiliary heater 20, it is possible to sufficiently heat the glass substrate W and the setter 5 by far infrared rays.

Next, the setter 5 is passed below the rear film forming unit 10. Thereby, the film formation on the glass substrate W can be performed repeatedly. Since it is sent through the central auxiliary heater 20 and there is the rear auxiliary heater 20 in the subsequent stage, and the radiant heat is reflected by the films A ₁₆ , A ₁₇ , A ₁₄ , A ₁₉ and A ₃₀ . As in the previous film formation, the temperature drop can be reliably prevented and good film quality can be obtained.

  Thereafter, the setter 5 passes through the cooling unit 4 through the lower side of the rear auxiliary heater 20. Thereby, the glass substrate W and the setter 5 that have been subjected to the film formation treatment can be cooled by ventilation to a temperature at which they can be handled.

In the atmospheric pressure plasma CVD apparatus M1, film formation can be continuously performed while sequentially feeding a large number of glass substrates W by the conveyor 1, and the entire processing time can be shortened.
By performing reheating at the front stage and the rear stage of the film forming unit 10, heating during film formation can be made unnecessary. The film forming unit 10 and the auxiliary heater 20 for reheating need only be shifted back and forth along the transfer line, and it is not necessary to devise to avoid interference at the same position on the transfer line. Can be simplified.

  The lower plate 16B itself, which is a base material facing member of the film forming unit 10, is made of ceramic such as alumina instead of aluminum (radiant heat reflecting material), so that the electrodes 18H and 18E can be reliably insulated, and the glass base material. While it is possible to prevent the arc from falling on W, the effect of reflecting the radiant heat can be secured by coating aluminum on the lower surface of the plate 16B. The casing 17 and the outer casing 11 themselves are made of stainless steel to ensure rigidity and prevent bending, while the lower surface of these casings is coated with aluminum to ensure the reflection of radiant heat. Can do.

The housing 21 itself of the auxiliary heater 20 can be made of aluminum to ensure thermal conductivity. On the other hand, the far-infrared radiation film B ₂₁ is coated on the lower surface of the auxiliary heater 20 to sufficiently reheat the glass substrate W. Can be secured. Further, the material cost can be greatly reduced as compared with the case where the entire housing 21 is made of the far-infrared radiation material.

  In the thin space 100 between the processing unit 3 and the row of setters 5 in the continuous atmospheric plasma CVD apparatus M1, not only gas is blown out from the blowing ports 10f, 10m, 10r of the film forming unit 10, but also At the same time, intake air is taken in the exhaust duct 15, and curtain gas is blown out from the blow-out passage 14a. Furthermore, circulating air flows from the heating unit 2 at the front end and the cooling unit 4 at the rear end. On the other hand, the processing unit 3 is provided with a ventilation duct 30 that connects the thin space 100 and the outside. Thereby, it is possible to alleviate the influence of the blowout flow from each of the blowout ports 10f, 10m, and 10r from the influence of other gas flows such as the intake air. As a result, it is possible to ensure the uniformity of the film thickness formed directly under each film forming unit 10.

  The heat of the heat source 22 of the auxiliary heater 20 is transmitted from the bottom plate of the housing 21 to the side plate and is transmitted to the ventilation duct 30. Thereby, the inside of the ventilation duct 30 can be heated. Therefore, when outside air is taken into the ventilation duct 30, it can be heated in the ventilation duct 30 and then flow into the thin space 100. In addition, since the ventilation duct 30 is provided with ventilation chambers 32b, 31a, and 30b having the narrow throttle portions 30c, 30a, and 32c as entrances and exits, the flow of outside air that has entered is suppressed, and the ventilation chambers 32b and 31a. , 30b for a long period of time, and can be made to flow into the thin space 100 after sufficiently warming during this stay. As a result, the temperature drop of the glass substrate W can be more reliably prevented, the film thickness uniformity can be reliably ensured, and the film formation characteristics can be reliably stabilized.

  In the continuous atmospheric plasma CVD apparatus M1, the auxiliary heater 30 for reheating the glass substrate W also serves as a heating means for the ventilation duct 20, and it is not necessary to provide a dedicated heating means for the ventilation duct 30. The configuration can be rationalized and the cost can be reduced.

The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, three or more film forming units 10 of the processing unit 3 may be provided in parallel along the transfer line, or only one may be provided. Of course, in the case of three or more, the auxiliary heaters 20 may be provided between the adjacent front and rear film forming units 10, and the ventilation duct 30 may be provided between each auxiliary heater 20 and the front and rear film forming units 10.

The radiant heat reflecting material of the film forming unit 10 and the far infrared ray radiating material of the auxiliary heater 20 may have a plate shape having a certain thickness. The processing head lower end constituting member itself such as the casing 17 and the outer casing 11 may be made of a radiant heat reflecting material such as aluminum instead of the radiant heat absorbing material such as stainless steel.
You may comprise the housing 21 itself of the auxiliary heater 20 with a far-infrared radiation material. Instead of the entire housing 21, at least the bottom plate portion that should face the glass substrate W may be made of a far-infrared radiation material.

The auxiliary heater 20, the ventilation duct 30, and the like are not limited to the above, and various forms can be adopted.
As the heating means for the ventilation duct 30, the auxiliary heater 20 is also used, but a dedicated one may be provided.

  The present invention can be applied not only to glow discharge but also to plasma processing by corona discharge or creeping discharge, and is not limited to plasma CVD (film formation), but can be applied to various plasma processing such as cleaning, surface modification, etching, and ashing. Applicable.

1 is a schematic configuration diagram of a continuous atmospheric pressure plasma CVD apparatus according to an embodiment of the present invention. It is sectional drawing centering on the film-forming unit of the process part of the said apparatus. FIG. 3 is a cross-sectional plan view of an electrode portion of the film forming unit along the line III-III in FIG. 2. It is a bottom view centering on the film-forming unit of the said process part. It is sectional drawing of the auxiliary heater of the said process part. It is sectional drawing of the ventilation duct of the said process part.

Explanation of symbols

W Glass substrate (object to be treated)
M1 Continuous atmospheric pressure plasma CVD equipment (plasma processing equipment)
1 Roller conveyor (conveyance line)
2 Heating unit (heating unit)
2a Hood 3 Processing unit 4 Cooling unit (cooling unit)
4a Hood 5 Setter 10 Deposition unit (processing unit)
10f, 10m, 10r Process gas outlet 11 Outer casing (component to be opposed to object to be processed)
14a Curtain gas outlet (curtain gas outlet)
15 Exhaust duct (intake port)
16B Lower plate (component to be treated, component to be blown out)
17 Casing (component to be opposed to workpiece)
18H, 18E electrodes 18f, 18m, 18r inter-electrode space 20 auxiliary heater 21 housing 22 heat source 24 heat insulating material 30 ventilation ducts 30b, 31a, 32b venting chamber 30a, 30c, 32c throttle section _{A 14, A 16, A 17} , A 19 , A ₃₀ Radiant heat reflective film B ₂₀ Far infrared radiation film

Claims (6)

A device for plasma processing under a substantially normal pressure while conveying a plurality of setters carrying workpieces in a row, between a heating unit for heating a workpiece to a predetermined temperature and the setter row A processing unit that forms a thin space and a cooling unit that cools an object to be processed are sequentially arranged from the previous stage along the transfer line, and a gas for plasma processing is blown into the processing unit and the vicinity thereof. A normal-pressure plasma processing apparatus, comprising: a processing unit that sucks in the air; and a ventilation duct that connects the thin space to the outside. The atmospheric pressure plasma processing apparatus according to claim 1, wherein the ventilation duct is disposed so as to sandwich the processing unit from the front side and the rear side. The processing unit is provided with a plurality of the processing units arranged along the transfer line, and the ventilation unit is disposed between the adjacent processing units, the front side of the first processing unit, and the rear side of the last processing unit. The atmospheric pressure plasma processing apparatus according to claim 1, wherein a duct is disposed. In the processing section, auxiliary heaters for reheating the workpiece are disposed between adjacent processing units, on the front side of the first processing unit, and on the rear side of the last processing unit, respectively. The atmospheric pressure plasma processing apparatus according to claim 3, wherein the ventilation duct is interposed between processing units. The heating unit has a hood that covers the transfer line and thus the setter being transferred, and heats the object to be processed by forming a heated circulating air between the hood and the setter. The atmospheric pressure plasma processing apparatus according to any one of claims 1 to 4, wherein a ventilation duct is also provided at a boundary between the unit hood and the processing section. The cooling unit has a hood that covers the transfer line and thus the setter that is being transferred, and forms a circulating air between the hood and the setter to cool the object to be processed. The atmospheric pressure plasma processing apparatus according to any one of claims 1 to 5, wherein a ventilation duct is also provided at a boundary between the hood and the processing section.

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