JP4876055B2 - Plasma processing apparatus and workpiece transfer method - Google Patents

Description

  The present invention relates to a plasma processing apparatus and a workpiece transfer method, and more specifically, a plasma processing apparatus for performing plasma processing on the surface of a plate-like workpiece using a vacuum chamber, and such plasma processing. The present invention relates to a workpiece transport method for transporting a workpiece in an apparatus.

  Generally, when manufacturing a semiconductor thin film on the surface of a substrate which is a plate-like object, a plasma processing apparatus using a plurality of vacuum chambers is used. In such a plasma processing apparatus, at least one of the plurality of vacuum chambers is a plasma processing vacuum chamber for performing plasma processing on the surface of the substrate, and further, the substrate is transferred between the plurality of vacuum chambers. It is common to have a transport mechanism.

  As a transport mechanism, a guide plate for placing the substrate is provided in each vacuum chamber, the substrate is lifted from the guide plate by gas in the vacuum chamber, and the lifted substrate is transported along the guide plate to the adjacent vacuum chamber. It is known to use a floating transport system.

  That is, a plasma processing apparatus using such a levitation conveyance method supplies a levitation gas to each guide plate and a levitation conveyance guide plate having a plurality of levitation gas ejection holes provided in each vacuum chamber. And a gas supply source. Then, the substrate is levitated from the guide plate by injecting the levitation gas from the gas ejection holes of the guide plate, and the levitated substrate is conveyed along the guide plate between the plurality of vacuum chambers by an external force.

As a plate-like workpiece transfer device or transfer facility that uses this type of transfer method, for example, those described in Patent Document 1 or Patent Document 2 are also known.
Japanese Utility Model Publication No. 61-178725 JP 7-228342 A

  In the plasma processing apparatus using the above-described levitation transfer method, the guide plate of the plasma processing vacuum chamber also serves as the plasma processing anode electrode, and the plasma processing cathode electrode is provided above the anode electrode in a facing manner. In the type of plasma processing apparatus, the following problems occur.

  The upward levitation gas is supplied from below the plurality of levitation gas ejection holes provided on the levitation conveyance guide plate. The levitation gas is supplied from all the gas ejection holes at the same time.

  That is, when the workpiece to be lifted moves in the conveying direction by external force, the gas ejection hole where the workpiece is not yet present above, the gas ejection hole where the workpiece is currently present, and the upper The floating gas is supplied from all of the gas ejection holes in which the object to be processed is no longer present. For this reason, the workpiece cannot always receive a constant levitation force during conveyance, and the levitation accuracy may become unstable.

  Further, during the transfer of the workpiece, there is a rising gas from the gas ejection hole where the workpiece is not yet present above, and a floating gas from the gas ejection hole where the workpiece is no longer present. The upper cathode electrode is sprayed. For this reason, the cathode electrode is locally cooled by the levitation gas, and it may be difficult to perform a desired plasma treatment such as formation of a thin film having a certain performance on the object to be processed.

  The present invention has been made in consideration of the above circumstances. The problem is that a plasma processing apparatus capable of stabilizing the flying accuracy of the workpiece and performing a desired plasma treatment on the workpiece, and such a plasma processing apparatus. An object of the present invention is to provide a workpiece conveying method capable of conveying a workpiece by performing a desired plasma treatment on the workpiece while stabilizing the flying accuracy.

  According to one aspect of the present invention, a plurality of vacuum chambers that are adjacent to each other with an openable and closable isolation gate valve, and a levitation conveyance device that is provided in each vacuum chamber and has a plurality of levitation gas ejection holes. A plurality of vacuum chambers are plasma processing chambers for performing plasma processing on a plate-shaped workpiece, each of which includes a guide plate and a gas supply source that supplies a levitation gas to each guide plate. The plasma processing chamber guide plate also serves as an anode electrode for plasma processing, and a cathode electrode for plasma processing is provided above the anode electrode so as to face the plasma processing chamber. A reaction gas introduction section for introducing a reaction gas, a reaction gas discharge section for discharging a reaction gas, and an object to be processed placed on a guide plate are A plurality of gas ejection holes in the guide plate are connected to a conveyance function section that conveys the chambers along the guide plate and a control function section that performs predetermined control. These ejection hole groups are formed transversely with respect to the transport direction and at predetermined intervals in the transport direction, and the control function unit opens the gate valve to communicate with the adjacent vacuum chambers, In the levitation transfer control in which the levitation gas is ejected from the gas ejection holes in the guide plates of these vacuum chambers, and the workpiece floated by the ejected levitation gas is conveyed along the guide plate by the transfer function unit, these vacuums are controlled. The levitation gas is sequentially ejected from the group of ejection holes that are involved in the floating of the workpiece on the guide plate of the chamber, and the jet that is no longer involved in the floating of the workpiece Controlling to sequentially stop the ejection of the floating gas from the group, the plasma processing apparatus is provided, characterized in that.

  In the plasma processing apparatus according to the present invention, the plurality of vacuum chambers are not particularly limited as long as they have a sealable structure and can withstand a predetermined atmospheric pressure and temperature. The plurality of vacuum chambers can be configured, for example, by dividing one casing extending linearly in the longitudinal direction into a plurality of parts by an isolation gate valve that can be opened and closed, and is connected to a vacuum pump.

  As the guide plate, a plurality of floating gas ejection holes are provided, and the floating plate-like object--for example, a tray placed on the guide plate and a plasma processing substrate mounted on the tray Or a plasma processing substrate that is directly placed on the guide plate may be used as a guide when being transported by an external force. There are no particular restrictions on its shape and material.

  A floating gas is supplied to each guide plate from a gas supply source outside the vacuum chamber. The levitation gas is not particularly limited as long as it does not damage the vacuum chamber, the guide plate, the object to be processed, and for example, nitrogen gas, helium gas, argon gas, etc. are preferably used.

  At least one of the plurality of vacuum chambers is a plasma processing chamber for performing plasma processing on a plate-shaped workpiece. The other vacuum chamber is, for example, a workpiece carrying-in chamber for carrying in a workpiece, which is connected to the plasma processing chamber, or a workpiece carrying out for carrying out the workpiece, which is connected to the plasma processing chamber. It is in a room.

  The guide plate of the plasma processing chamber also serves as an anode electrode for plasma processing. Further, a plasma processing cathode electrode is provided above the anode electrode in the plasma processing chamber in an opposing manner. The plasma processing chamber includes a reactive gas introduction unit for introducing a reactive gas for plasma processing, a reactive gas discharge unit for discharging the reactive gas, and an object to be processed placed on the guide plate by using a plurality of vacuums. It is connected to the conveyance function part which conveys along a guide plate between chambers, and the control function part which performs predetermined | prescribed control.

  A plurality of (for example, 100 to 200) gas ejection holes (for example, a circular hole having a diameter of 0.5 to 5.0 mm) in each guide plate independently control the gas ejection, the gas ejection amount, and the gas ejection pressure. It consists of a plurality of controllable ejection hole groups (for example, 5 to 10 groups). These ejection hole groups are formed transversely to the transport direction and at a predetermined interval in the transport direction.

  A conveyance function part conveys the to-be-processed object mounted in the guide plate along a guide plate between several vacuum chambers with external force. As the transfer function unit, for example, a transfer arm for moving an object to be processed between a plurality of vacuum chambers and a transfer drive unit for driving the transfer arm are provided, and the transfer drive unit is spaced in the transfer direction. A configuration comprising a pair of pulleys that are placed, wires wound around these pulleys, and a motor connected to one pulley is used.

  The control function unit performs at least the following control. That is, the gate valve is opened to allow communication between adjacent vacuum chambers. Further, the levitation gas is ejected from the gas ejection holes in the guide plates of these vacuum chambers. And, in the levitation transfer control in which the object to be processed that has been levitated by the ejected levitation gas is conveyed along the guide plate by the conveyance function unit, the ejection holes that are involved in the levitation of the object to be processed in the guide plates of these vacuum chambers The levitation gas is sequentially ejected from the group, and the levitation gas from the ejection hole group that is no longer involved in the levitation of the workpiece is sequentially stopped.

  With regard to this control function unit, “a group of ejection holes that are involved in the levitation of an object to be processed” refers to a plurality of ejection hole groups provided in one guide plate. This means a group of gas ejection holes in which the processed material currently exists.In other words, the group of ejection holes that are no longer involved in the levitation of the object to be processed means, This means a group of gas ejection holes in which the processed material no longer exists.

  The guide plate in the plasma processing apparatus according to the present invention is formed of, for example, a rectangular plate having a floating gas supply pipe connected to the gas supply source, and is transported in a plurality of vacuum chambers adjacent to each other with a gate valve interposed therebetween. It is arranged in a line along the direction.

  When the guide plate is configured in this way, when the plurality of vacuum chambers are composed of a plasma processing chamber, a workpiece loading chamber, and a workpiece unloading chamber, the workpiece is spread over each vacuum chamber. By carrying it in a single line, it becomes possible to perform predetermined processing continuously.

  The rectangular plate-shaped body constituting the guide plate is, for example, a plurality of internal grooves formed transversely to the transport direction and spaced from each other in the transport direction, and communicated with each of these internal grooves. A plurality of levitation gas supply pipes connected to each other, and a plurality of levitation gas ejection holes formed in communication above the internal grooves, and these gas ejection holes are formed as a plurality of independent strips. It consists of a group of jet holes.

  When the plate-like body is such, a plurality of internal grooves are formed at predetermined intervals in the transport direction, and a plurality of levitation gas ejection holes formed in continuous communication above these internal grooves are provided. Since it is composed of a plurality of strip-shaped ejection hole groups independent from each other, the above-described levitation conveyance control by the control function unit can be reliably performed for each belt-shaped ejection hole group.

  The plasma processing apparatus according to the present invention further includes a sensor for detecting the position of the object to be processed, and each levitation gas supply pipe has one end connected to the internal groove inside the plate-like body. A main body, an extension extending from the other end of the main body to the outside of the plate-like body, and a flow rate adjusting valve provided in the extension. More preferred.

  When the plasma processing apparatus is like this, the control function unit detects the position of the object to be processed by the sensor and operates the flow rate adjusting valve so that the flow rate of the levitation gas can be accurately adjusted. Adjusted.

  That is, the control function unit operates the valve according to the position of the object to be processed detected by the sensor, and thereby raises the levitation gas from the ejection hole group involved in the levitation of the object to be processed. , And the ejection of the levitation gas from the ejection hole group that is no longer involved in the levitation of the workpiece can be controlled in sequence.

  In some cases, the control function unit controls the levitation gas ejected from the gas ejection hole group closest to the gate valve to have a higher ejection pressure than the levitation gas ejected from the other gas ejection hole groups. It may be possible.

  When the control function unit is configured in this way, the gas injection hole group closest to the gate valve, i.e., the gas injection hole group at the end of the guide plate in each vacuum chamber has a jetting pressure of the levitation gas. By making it higher than that of the levitation gas to be ejected from other gas ejection holes, the levitation force at the end of the guide plate and the vicinity of the gate valve, where the levitation force tends to decrease, is improved. It is possible to reliably avoid the possibility that the floating accuracy of the object becomes unstable.

  In the plasma processing apparatus according to the present invention, it is more preferable that the area density of the gas ejection holes in the gas ejection hole group closest to the gate valve is higher than that in the other gas ejection hole groups.

  In such a plasma processing apparatus, the area density of the gas ejection holes in the gas ejection hole group at the end of the guide plate in each vacuum chamber is higher than the area density of the gas ejection holes in the other gas ejection hole groups. As a result, the levitation force at the end of the guide plate where the levitation force tends to be reduced is improved, and the levitation accuracy of the workpiece at the end of the guide plate in each vacuum chamber may become unstable. Can be reliably avoided.

  According to another aspect of the present invention, a plurality of vacuum chambers, at least one of which is a plasma processing chamber for performing plasma processing on a plate-like workpiece, are provided adjacent to each other, and a plurality of vacuum chambers are provided in each vacuum chamber. A levitation conveyance guide plate having a levitation gas ejection hole is provided, and the object to be treated is ejected from the gas ejection hole provided in the guide plate to the lower surface of the object to be treated placed on the guide plate. A workpiece processing method for a plasma processing apparatus, wherein the workpiece is levitated and transported by an external force, wherein a plurality of gas ejection holes in a guide plate are arranged transversely to the transport direction and in the transport direction. It is composed of a plurality of nozzle holes that are spaced apart from each other and separated from each other, and floats only from the gas nozzle holes that are located directly under the workpiece being transported during the levitation transportation. By ejecting the gas, in the plasma processing chamber, the levitation gas is prevented from directly hitting the plasma processing cathode electrode provided opposite to the guide plate also serving as the plasma processing anode electrode. A method for conveying an object to be processed of a plasma processing apparatus is provided.

  The configurations of the vacuum chamber, the plasma processing chamber, and the guide plate in the workpiece processing method of the plasma processing apparatus according to the present invention are the same as those of the plasma processing apparatus according to the present invention. The configuration of the plurality of gas ejection holes and the plurality of ejection hole groups in the guide plate is also the same as those of the plasma processing apparatus according to the present invention.

  In the workpiece processing method of the plasma processing apparatus according to the present invention, when the workpiece is levitated and conveyed, the levitation gas is ejected from only the gas ejection hole group located immediately below the workpiece to be conveyed among the above-mentioned ejection hole groups. Let As a result, in the plasma processing chamber, the levitation gas is prevented from directly hitting the plasma processing cathode electrode provided opposite to the guide plate that also serves as the plasma processing anode electrode.

  The object to be processed in the method for conveying an object to be processed by the plasma processing apparatus according to the present invention is, for example, a tray placed on a guide plate and a plasma mounted on the tray, as with the object to be processed in the plasma processing apparatus according to the present invention. A substrate made of a processing substrate or a plasma processing substrate placed directly on a guide plate.

  In the workpiece processing method of the plasma processing apparatus according to the present invention, by controlling the pressure in the vacuum chamber, the ejection pressure of the levitation gas ejected from the gas ejection hole group of the guide plate in the vacuum chamber is controlled. Also good.

  In the plasma processing apparatus according to the one aspect of the present invention, the plurality of gas ejection holes in the guide plate are composed of a plurality of ejection hole groups independent from each other, and these ejection hole groups are transverse to the transport direction. And formed at predetermined intervals in the transport direction. In addition, the control function unit opens the gate valve to allow communication between adjacent vacuum chambers, causes the gas for levitation to be ejected from the gas ejection holes in the guide plates of these vacuum chambers, and is levitated by the ejected levitation gas In the levitation conveyance control in which the conveyance function unit conveys the object along the guide plate, the levitation gas is sequentially ejected from the ejection hole groups involved in the levitation of the object to be processed in the guide plates of these vacuum chambers. Control is performed so as to sequentially stop the ejection of the levitation gas from the ejection hole group that is no longer involved in the levitation of the processed material.

  Therefore, according to the plasma processing apparatus according to the above aspect of the present invention, the levitation gas is sequentially ejected from the ejection hole group involved in the levitation of the workpiece in the guide plate of the vacuum chamber by the levitation conveyance control. At the same time, since the ejection of the gas for levitation from the group of ejection holes that are no longer involved in the levitation of the object to be processed is sequentially stopped, the levitation accuracy of the object to be processed can be stabilized. In addition, since the cathode electrode is not locally cooled by such levitation conveyance control, a desired plasma treatment can be performed on an object to be processed such as formation of a thin film having a certain performance.

  In the workpiece processing method of the plasma processing apparatus according to another aspect of the present invention, the plurality of gas ejection holes in the guide plate are arranged transversely to the transport direction and at predetermined intervals in the transport direction. It is composed of a plurality of ejection hole groups independent of each other. At the time of levitation conveyance, the levitation gas is ejected only from the gas ejection hole group located immediately below the workpiece being conveyed among these ejection hole groups. As a result, in the plasma processing chamber, the levitation gas is prevented from directly hitting the plasma processing cathode electrode provided opposite to the guide plate that also serves as the plasma processing anode electrode.

  Therefore, according to the workpiece transfer method of the plasma processing apparatus according to the another aspect of the present invention, the levitation gas is ejected only from the gas ejection hole group located immediately below the workpiece being transferred during the levitation transfer. Therefore, the workpiece can be transported with stable flying accuracy. Further, in the plasma processing chamber, since the levitating gas does not directly hit the cathode electrode, the target object can be transported by performing a desired plasma process on the target object, such as forming a thin film having a certain performance. .

  Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. However, this does not limit the present invention.

  FIG. 1 is a partially cutaway perspective view of a plasma processing apparatus according to one embodiment of the present invention. FIG. 2 is an explanatory diagram of the configuration of the plasma processing apparatus shown in FIG. FIG. 3 is a plan view of a guide plate which is one component of the plasma processing apparatus shown in FIG. 4, 5, and 6 are cross-sectional views taken along lines AA, BB, and CC in FIG. 3, respectively.

  As shown in FIG. 1 and FIG. 2, the plasma processing apparatus D in this embodiment includes a first vacuum chamber 1 and a second vacuum chamber 2 that are provided adjacently from the transport upstream side to the transport downstream side. And a third vacuum chamber 3. These three vacuum chambers 1 to 3 are configured by dividing one casing extending linearly in the longitudinal direction into three by two isolation gate valves 4 and 4 that can be opened and closed. The three vacuum chambers 1 to 3 are made of stainless steel, and the inner surface is mirror-finished. The gate valves 4 and 4 are configured to be able to move up and down, and the two adjacent vacuum chambers 1, 2, 2, and 3 are in communication with each other in the raised position, and the two adjacent vacuum chambers 1, 2, or 2 are in the lowered position. , 3 is isolated.

  The first vacuum chamber 1 is a workpiece carrying-in chamber for carrying a plate-like workpiece (here, composed of a tray 5 and a plasma processing substrate 6 mounted on the tray 5). . The second vacuum chamber 2 is a plasma processing chamber connected to the workpiece carrying-in chamber 1 for performing plasma processing on the workpiece. The third vacuum chamber 3 is a workpiece discharge chamber connected to the plasma processing chamber 2 for discharging the workpiece.

  The workpiece carrying-in chamber 1, the plasma processing chamber 2, and the workpiece carrying-out chamber 3 are each formed of a rectangular plate-like body and provided with a levitation conveyance guide plate 7 on which the workpieces 5 and 6 are placed. Yes. The guide plate 7 is also made of stainless steel and has a partially hollow structure as will be described later. The guide plate 7 is mirror-finished on the surface, and has dimensions of a width (short side length) of 600 mm, a length (long side length) of 1000 mm, and a thickness of 30 mm. These three guide plates 7, 7, 7 are arranged along the transfer direction in the workpiece loading chamber 1, the plasma processing chamber 2, and the workpiece unloading chamber 3 that are adjacent to each other with the two gate valves 4, 4 interposed therebetween. It is arranged in a line.

  As shown in FIGS. 1 to 3, each guide plate 7 has a plurality of levitation gas ejection holes 8,. That is, on the upper surface of each guide plate 7, seven rows are arranged in one row in the direction in which the rectangular short sides extend (direction perpendicular to the conveying direction), and sixteen rows in the direction in which the long rectangular sides extend (direction parallel to the conveying direction). A total of 112 circular gas ejection holes 8, ..., 8 are formed. The diameter of each gas ejection hole 8 is 1.0 mm.

  These 112 gas ejection holes 8,..., 8 are divided into eight belt-shaped ejection hole groups 9,. These ejection hole groups 9,..., 9 are formed transversely to the transport direction, which is the direction in which the long sides of the guide plate 7 extend, and at a predetermined interval in the transport direction.

  As shown in FIGS. 3 to 6, the guide plate 7 is formed of eight belt-like ejection hole groups 9,... Formed in a shape transverse to the conveyance direction and spaced from each other in the conveyance direction. .., 9 corresponding to each of the eight inner grooves 10,..., 10 and eight floating gas supply pipes 11 connected to each of the inner grooves 10,. ......, 11 are provided. The guide plate 7 is formed into a hollow shape at the positions of the internal grooves 10,..., 10 by forming the eight internal grooves 10,.

  Each internal groove 10 is formed to communicate with the corresponding 14 gas ejection holes 8,..., 8 below the corresponding band-shaped ejection hole group 9. Each gas supply pipe 11 includes a main body portion 11a whose one end is connected to the internal groove 10 inside the guide plate 7, and an extension extending from the other end of the main body portion 11a to the outside of the guide plate 7. Part 11b and a flow rate adjusting valve 11c provided in the extension part 11b.

  As shown in FIGS. 1 and 2, the plasma processing apparatus D includes a gas for ascending to the guide plates 7, 7, 7 in the workpiece loading chamber 1, the plasma processing chamber 2 and the workpiece loading chamber 3. Is provided with a gas supply source 12. The gas supply source 12 is to be processed via floating gas supply valves 13, 13, 13 provided outside the bottom walls of the workpiece loading chamber 1, the plasma processing chamber 2, and the workpiece unloading chamber 3. Connected to the gas supply pipes 11,..., 11 of the guide plates 7, 7, 7 in the object loading chamber 1, the plasma processing chamber 2, and the workpiece unloading chamber 3.

  In addition, the workpiece carrying-in chamber 1, the plasma processing chamber 2, and the workpiece carrying-out chamber 3 are connected to external vacuum pumps 14, 14, and 14 via open / close valves 16a, respectively. The workpiece carrying-in chamber 1 is provided with a workpiece carrying-in door 15 on the inlet side. The plasma processing chamber 2 is connected to the vacuum pump 14 via a pressure adjusting valve 16b for maintaining the interior of the chamber at a predetermined degree of vacuum, and is connected to a reaction gas introduction tube 19 for introducing a plasma processing reaction gas. It is connected. The workpiece unloading chamber 3 is provided with a workpiece unloading door 15 on the exit side. Furthermore, the workpiece carry-in chamber 1 and the workpiece carry-out chamber 3 are each connected to a leak gas introduction pipe 20.

  The guide plate 7 of the plasma processing chamber 2 also serves as a plasma processing anode electrode. Further, a plasma processing cathode electrode 18 is provided above the anode electrode 7 in the plasma processing chamber so as to face each other. The cathode electrode 18 is electrically connected to a high frequency power source 23 via a capacitor 21 and a matching circuit 22 outside the plasma processing chamber 2.

  In the plasma processing apparatus D, the workpieces placed on the guide plate 7 are guided between the workpiece loading chamber 1, the plasma processing chamber 2, and the workpiece unloading chamber 3 by external force. A transport function unit for transporting along is also provided. Hereinafter, the transfer function unit will be described mainly with reference to FIG.

  In FIG. 1, the workpiece carrying-in chamber 1 and the workpiece carrying-out chamber 3 are provided with a transfer function unit. The transfer function unit is configured to transfer a workpiece (consisting of a tray 5 and a plasma processing substrate 6) between the workpiece carrying-in chamber 1, the plasma processing chamber 2, and the workpiece carrying-out chamber 3. 24, a pair of pulleys (driving pulleys and driven pulleys) 25, 25 arranged at intervals in the conveying direction, a wire 26 wound around these pulleys 25, 25, and one pulley (driving pulley) The motor 27 is connected to the motor 25. The other pulley (driven pulley) 25 is attached with a spring 29 biased in a direction in which the wire 26 is slackened. The driven pulley 25 is pulled outward by the spring 29, and the tension of the wire 26 is kept constant.

  The transfer arm 24 is connected to a wire 26 and is mounted on a rail 28 provided behind the bottom surfaces of the workpiece carry-in chamber 1 and the workpiece carry-out chamber 3 and moves along the rail 28. 24a, an upright guide portion 24b provided so as to be movable up and down with respect to the base portion 24a, a base end portion connected to the guide portion 24b along the rail 28, and an intermediate portion horizontally extending forward from the base end portion. And an arm portion 24c having a L-shaped planar shape, the tip portion of which extends vertically downward. The transfer arm 24 moves by the same distance as the moving distance of the wire 26. The arm portion 24c is driven by a drive device built in the base portion 24a and the guide portion 24b, and moves up and down with respect to the base portion 24a. The moving distance of the transfer arm 24 in the transfer direction is set to 650 mm.

  In the workpiece carrying-in chamber 1, a single plate tray 5 is placed on the guide plate 7. The tray 5 is made of stainless steel and has a rectangular planar shape. The rear surface of the tray 5 (the surface facing the guide plate 12) is mirror-finished in order to realize smooth transport movement. The tray 5 has dimensions of a width (short side length) of 605 mm, a length (long side length) of 900 mm, and a thickness of 2 mm.

  Locking portions 51 that are slidably locked to the front and rear side edges of the guide plate 7 are provided on both front and rear side edges of the tray 5. These locking portions 51 have shapes in which both side edges of the tray 5 are folded inward. Further, two fitting holes 52, 52 for fitting the tip of the arm portion 24c of the transport arm 24 are provided at a position near the rear edge of the tray 5 at a predetermined interval in the transport direction. Yes.

  The plasma processing apparatus D further includes a sensor (not shown) that detects the position of the tray 5 being conveyed and a control function unit that performs predetermined control. The control function unit mainly performs the following control. That is, the gate valves 4 and 4 are opened, and the adjacent workpiece loading chamber 1, the plasma processing chamber 2, and the workpiece unloading chamber 3 communicate with each other. Further, the floating gas is ejected from the gas ejection holes 8,..., 8 in the guide plates 7, 7, 7 of the workpiece carrying-in chamber 1, the plasma processing chamber 2, and the workpiece carrying-out chamber 3. Then, in the levitation transfer control in which the objects to be processed 5 and 6 that have been levitated by the ejected levitation gas are conveyed along the guide plates 7, 7, and 7 by the conveyance function unit, The levitation gas is sequentially ejected from the ejection hole groups 9,... 9 involved in the floating of the workpieces 5 and 6 in the workpiece unloading chamber 3 and is also involved in the floating of the workpieces 5 and 6. The ejection of the ascending gas from the group of exhaust holes 9,.

  Hereinafter, the transfer operation of the plasma processing apparatus D in which the transfer function unit and the control function unit are combined will be described.

  1 and 2, the arm of the transfer arm 24 is inserted into the fitting hole 52 on the front end side in the traveling direction of the tray 5 placed on the guide plate 7 of the workpiece loading chamber 1 and on which the substrate 6 is mounted. The tip portion of the portion 24c is fitted. In this state, the transfer arm 24 and the tray 5 are at the home position of the workpiece carry-in chamber 1. In this home position, the tray 5 covers the six ejection hole groups 9,..., 9 out of the eight belt-like ejection hole groups 9,. In addition, the distal end portion of the arm portion 24c is driven by a driving device built in the base portion 24a and the guide portion 24b at this home position, and is lowered with respect to the base portion 24a to be fitted into the fitting hole 52. Has been. Furthermore, the gate valve 4 between the workpiece carrying-in chamber 1 and the plasma processing chamber 2 is opened.

  Next, the control function unit ejects the floating gas (in this case, nitrogen gas) from the gas ejection holes 8,... Is lifted from the guide plate 7. Then, the transfer arm 24 is moved in the transfer direction along the rail 28. At this time, since the tray 5 is in a floating state, the transport arm 24 can smoothly transport and move the tray 5 with a slight force.

  At this time, the control function unit does not eject the levitation gas from all the gas ejection holes 8,..., 8 of the guide plate 7 at the same time, but ejects the ejection holes involved in the levitation of the workpieces 5, 6. The ascending gas is sequentially ejected from the groups 9,... That is, the control function unit is configured to eject groups 9,... Involved in the floating of the workpieces 5, 6 according to the position of the tray 5 detected by the sensor that detects the position of the tray 5 being conveyed. .., 9 are sequentially ejected from the levitation gas, and the levitation gas from the ejection hole groups 9,... .

  More specifically, at the home position of the workpiece carrying-in chamber 1, the control function unit is configured to start from the six outlet hole groups 9,..., 9 out of the eight belt-like outlet hole groups 9,. Only the levitation gas is injected, and the levitation gas is not ejected from the one ejection hole group 9 on the traveling front end side and the one ejection hole group 9 on the traveling rear end side.

  Next, at the point of time when the transport movement has progressed by the width of one ejection hole group 9 from the home position, the control function unit has six of the eight belt-like ejection hole groups 9,. The levitation gas is injected only from the ejection hole groups 9,..., 9 and the levitation gas is not ejected from the two ejection hole groups 9 and 9 on the rear end side. After that, at the point of time when the transport movement has progressed by the width of the two ejection hole groups 9 from the home position, the control function unit has five of the eight belt-like ejection hole groups 9,. The levitation gas is injected only from the ejection hole groups 9,..., 9 and the levitation gas is not ejected from the three ejection hole groups 9, 9 on the rear end side.

  In the same manner, the control function unit sequentially ejects the levitation gas from the ejection hole groups 9,... 9 involved in the levitation of the workpieces 5 and 6, and The ejection of the ascending gas from the ejection hole groups 9,..., 9 that are no longer involved in the ascent is stopped sequentially. The ejection of the levitation gas as described above is performed by the control function unit operating the flow rate adjusting valve 11c provided in the extending portion 11b of each gas supply pipe 11.

  Such sequential ejection and sequential stop of the levitation gas by the control function unit is such that the conveyance of the tray 5 progresses, and the leading end side end of the traveling gas flows from the guide plate 7 of the workpiece carry-in chamber 1 to the plasma processing chamber 2. Even in the state where it is transferred to the guide plate 7, it is continuously performed.

  In some cases, the control function unit causes the levitation gas ejected from the gas ejection hole group 9 closest to the gate valve 4 to be higher than the levitation gas ejected from the other gas ejection hole groups 9,. What can be controlled so that it may become a high jet pressure may be sufficient. Further, the area density of the gas ejection holes 8 in the gas ejection hole group 9 closest to the gate valve 4 may be made higher than that in the other gas ejection hole groups 9.

  When the transfer arm 24 is moved to the end of the rail 28 on the gate valve 4 side in the workpiece carrying-in chamber 1 (at this time, the advancing tip side end is plasma-treated from the guide plate 7 of the workpiece carrying-in chamber 1). The control function unit stops the ejection of the levitation gas, and then raises the arm portion 24a of the tray 5 along the guide portion 24b to move the tip portion of the arm portion 24a. Is removed from the fitting hole 52 on the front end side in the traveling direction of the tray 5. Next, the transfer arm 24 is returned to the home position in the workpiece carry-in chamber 1.

  Thereafter, the arm portion 24 a is lowered along the guide portion 24 b, and the tip portion of the arm portion 24 a is fitted into the fitting hole 52 on the rear end side of the tray 5. Then, the control function unit sequentially ejects and sequentially stops the ascending gas from the gas ejection hole groups 9,..., 9 of the guide plates 7, 7 of the workpiece loading chamber 1 and the plasma processing chamber 2. Then, the transfer arm 24 is moved to the end of the rail 28 on the gate valve 4 side. By this second transfer movement, the tray 5 and the substrate 6 are transferred to the home position on the guide plate 7 in the plasma processing chamber 2 and sandwiched between the guide plate 7 also serving as the anode electrode and the cathode electrode 18 thereabove. It becomes a state.

  Next, after blowing out the gas for levitation from the guide plate 7 in the plasma processing chamber 2 and positioning the tray 5 on the guide plate 7, the tip of the arm portion 24 c is moved to the rear end side of the tray 5. The fitting hole 52 is removed. Then, after returning the transfer arm 24 to the home position of the workpiece carrying-in chamber 1 again, the gate valve 4 that has been raised is lowered to isolate the workpiece carrying-in chamber 1 and the plasma processing chamber 2 again.

  Next, the vacuum pump 14 (see FIG. 2) connected to the plasma processing chamber 2 is operated to maintain the plasma processing chamber 2 at a predetermined degree of vacuum. Then, a predetermined plasma treatment is performed on the substrate 6 mounted on the tray 5 with the guide plate 7 also serving as the anode electrode and the cathode electrode 18 thereabove.

  Hereinafter, an example of the pressure control of the workpiece carry-in chamber 1 and the plasma processing chamber 2 when the tray 5 is transported as described above will be described.

  First, the tray 5 on which the substrate 6 is mounted is placed on the guide plate 7 in the workpiece carry-in chamber 1. At this time, the workpiece carrying-in chamber 1 and the plasma processing chamber 2 are isolated by the gate valve 4, and the plasma processing chamber 2 is maintained in a vacuum state.

  Next, the workpiece carrying-in chamber 1 is sealed, and the vacuum pump 14 is driven to exhaust the inside. Thereafter, a predetermined process is performed on the substrate 6 in the cleaned object carrying-in chamber 1.

  After processing in the workpiece carrying-in chamber 1, the workpiece carrying-in chamber 1 is evacuated. Thereafter, the gate valve 4 is opened to allow the workpiece carrying-in chamber 1 and the plasma processing chamber 2 to communicate with each other. Then, in order to reduce the floating vibration of the tray 5 during conveyance, the pressure in the workpiece carrying-in chamber 1 and the plasma processing chamber 2 is increased to a substantially equal value by introducing nitrogen gas from the leak gas introduction pipe 20. Let

  The pressure can be set by the sum of the weight of the tray 5 and the weight of the substrate 6 on the tray 5, or the floating for later ejecting gas from the gas ejection holes 8, 8 of the guide plates 7, 7. It can be set to be 1 / several hundred to 1 / several times the gas introduction pressure of the working gas supply source 12.

  Next, the control function unit ejects the floating nitrogen gas from the gas ejection holes 8,..., 8 of the guide plates 7, 7 of the workpiece carrying-in chamber 1 and the plasma processing chamber 2, so that the tray 5 and the substrate 6 is lifted from the guide plate 7. Then, the transfer arm 24 is moved in the transfer direction along the rail 28. At this time, as described above, the control function unit does not eject the levitation gas from all the gas ejection holes 8,..., 8 of the guide plate 7, but is involved in the levitation of the tray 5 and the substrate 6. The ascending gas is sequentially ejected from the ejection hole groups 9,. Further, control is performed so as to sequentially stop the ejection of the levitation gas from the ejection hole groups 9,..., 9 that are no longer involved in the levitation of the tray 5 and the substrate 6.

  After the tray 5 on which the substrate 6 is placed is conveyed to the position directly above the guide plate 7 in the plasma processing chamber 2, the supply of the floating nitrogen gas from the floating gas supply source 12 is stopped. As a result, the tray 5 descends onto the guide plate 7, so that a predetermined plasma process is performed on the substrate 6 in the plasma processing chamber 2.

FIG. 1 is a partially cutaway perspective view of a plasma processing apparatus according to one embodiment of the present invention. FIG. 2 is an explanatory diagram of the configuration of the plasma processing apparatus shown in FIG. FIG. 3 is a plan view of a guide plate which is one component of the plasma processing apparatus shown in FIG. 4 is a cross-sectional view taken along line AA in FIG. FIG. 5 is a cross-sectional view taken along line BB in FIG. FIG. 6 is a cross-sectional view taken along line CC in FIG.

Explanation of symbols

1 ... 1st vacuum tank (object to be processed)
2 ... Second vacuum chamber (plasma processing chamber)
3 ... Third vacuum chamber (workpiece unloading chamber)
4 ... Gate valve 5 ... Workpiece (tray)
6 ... Processed object (substrate)
DESCRIPTION OF SYMBOLS 7 ... Guide plate 8 ... Gas ejection hole 9 ... Gas ejection hole group 10 ... Internal groove | channel 11 ... Gas supply pipe 11 for levitation 11a ... Body part 11b ... Extension part 11c ... Flow adjustment valve 12 ... Levitation gas supply source 13 ... Levitation gas supply valve 14 ... Vacuum pump 15 ... Unloading door 16a ... Open / close valve 16b ... Pressure adjustment valve 17 ... object to be processed outlet door 18 ... cathode electrode 19 ... reaction gas inlet tube 20 ... leak gas introducing pipe 21 ... condenser 22 ... matching circuit 23 ... high frequency power supply 24 .. -Transfer arm 24a-Base part 24b-Guide part 24c-Arm part 25 ... Pulley 26 ... Wire 27 ... Motor 28 ... Rail 29 ... Spring 51 ... Locking part 52 ...・ Fitting hole

Claims (10)

A plurality of vacuum chambers that are adjacent to each other across an isolation gate valve that can be opened and closed, a guide plate for levitation conveyance that is provided in each vacuum chamber and has a plurality of gas ejection holes for levitation, and floats to each guide plate A gas supply source for supplying the working gas,
The plurality of vacuum chambers are plasma processing chambers for performing plasma processing on a plate-shaped workpiece, and the guide plate of the plasma processing chamber also serves as an anode electrode for plasma processing. A cathode electrode for plasma processing is provided on the upper side in an opposing manner, and the plasma processing chamber includes a reaction gas introduction portion for introducing a plasma treatment reaction gas, a reaction gas discharge portion for discharging the reaction gas, and a guide. Connected to a transport function unit that transports the workpiece placed on the plate along the guide plate between the plurality of vacuum chambers by external force, and a control function unit that performs predetermined control,
The plurality of gas ejection holes in the guide plate are composed of a plurality of ejection hole groups independent from each other, and these ejection hole groups are formed in a shape transverse to the conveyance direction and at a predetermined interval in the conveyance direction. And
The control function unit opens the gate valve to allow communication between adjacent vacuum chambers, ejects a levitation gas from the gas ejection holes in the guide plates of these vacuum chambers, and removes the workpiece that has been levitated by the ejected levitation gas. When the levitation conveyance control is carried out along the guide plate by the conveyance function unit, the levitation gas is sequentially ejected from the ejection hole groups involved in the levitation of the object to be treated in the guide plates of these vacuum chambers, and the object to be treated The buoyant gas that is controlled so as to stop the buoyant gas from the blast holes that are no longer involved in the buoyancy of the gas and to be ejected from the gas blast holes closest to the gate valve is the other gas blast holes. A plasma processing apparatus, characterized in that it is controlled so as to have an ejection pressure higher than that of a levitation gas ejected from a group . A plurality of vacuum chambers that are adjacent to each other across an isolation gate valve that can be opened and closed, a guide plate for levitation conveyance that is provided in each vacuum chamber and has a plurality of gas ejection holes for levitation, and floats to each guide plate A gas supply source for supplying the working gas,
The plurality of vacuum chambers are plasma processing chambers for performing plasma processing on a plate-shaped workpiece, and the guide plate of the plasma processing chamber also serves as an anode electrode for plasma processing. A cathode electrode for plasma processing is provided on the upper side in an opposing manner, and the plasma processing chamber includes a reaction gas introduction portion for introducing a plasma treatment reaction gas, a reaction gas discharge portion for discharging the reaction gas, and a guide. Connected to a transport function unit that transports the workpiece placed on the plate along the guide plate between the plurality of vacuum chambers by external force, and a control function unit that performs predetermined control,
The plurality of gas ejection holes in the guide plate are composed of a plurality of ejection hole groups independent from each other, and these ejection hole groups are formed transversely to the transport direction and at predetermined intervals in the transport direction, Furthermore, the area density of the gas ejection holes in the gas ejection hole group closest to the gate valve is higher than that in the other gas ejection hole groups,
The control function unit opens the gate valve to allow communication between adjacent vacuum chambers, ejects a levitation gas from the gas ejection holes in the guide plates of these vacuum chambers, and removes the workpiece that has been levitated by the ejected levitation gas. When the levitation conveyance control is carried out along the guide plate by the conveyance function unit, the levitation gas is sequentially ejected from the ejection hole groups involved in the levitation of the object to be treated in the guide plates of these vacuum chambers, and the object to be treated The plasma processing apparatus is characterized in that control is performed so as to sequentially stop the ejection of the levitation gas from the group of ejection holes that are no longer involved in the levitation of the gas. The guide plate is formed of a rectangular plate having a floating gas supply pipe connected to the gas supply source, and is arranged in a line along the transport direction in a plurality of vacuum chambers adjacent to each other across the gate valve. The plasma processing apparatus according to claim 1 or 2, wherein The plate-like body has a plurality of internal grooves formed transversely to the transport direction and spaced from each other in the transport direction, and a plurality of floating surfaces connected to each of the internal grooves. Gas supply pipes and a plurality of floating gas jet holes formed in communication above the internal grooves, and these gas jet holes are composed of a plurality of band-like jet hole groups independent of each other. The plasma processing apparatus according to claim 3 . A sensor for detecting the position of the object to be processed is further provided, and each levitation gas supply pipe has a main body portion whose one end is connected to the internal groove inside the plate-like body, The plasma processing apparatus of Claim 4 provided with the extension part extended to the exterior of the plate-shaped object from the other end part, and the flow volume adjustment valve provided in this extension part. The control function unit operates the valve in accordance with the position of the object to be processed detected by the sensor, and thereby sequentially raises the rising gas from the ejection hole group involved in the floating of the object to be processed. The plasma processing apparatus according to claim 5 , wherein the plasma processing apparatus is controlled so as to sequentially stop the ejection of the levitation gas from the ejection hole group that is no longer involved in the levitation of the workpiece. A plurality of vacuum chambers, at least one of which is a plasma processing chamber for performing plasma processing on a plate-like workpiece, are provided adjacent to each other with an openable / closable isolation gate valve, and a plurality of vacuum chambers are provided in each vacuum chamber. The floating conveying guide plate having the floating gas ejection holes is provided, and the floating gas is ejected from the gas ejection holes provided in the guide plate to the lower surface of the workpiece placed on the guide plate. A workpiece processing method for a plasma processing apparatus, wherein the workpiece to be lifted is transported by an external force,
A plurality of gas ejection holes in the guide plate are composed of a plurality of independent ejection hole groups that are transverse to the conveyance direction and spaced apart from each other in the conveyance direction. In the plasma processing chamber, the levitation gas is ejected only from the gas ejection hole group located directly under the object to be processed in the group, so that it is opposed to the guide plate that also serves as the plasma processing anode electrode. The levitation gas is prevented from directly hitting the provided plasma processing cathode electrode, and the levitation gas ejected from the gas ejection hole group closest to the gate valve is ejected from the other gas ejection hole group. by such that the higher ejection pressure than improves levitation force at the end of the guide plate, it object to be processed in the plasma processing apparatus characterized by Method Carriage. A plurality of vacuum chambers, at least one of which is a plasma processing chamber for performing plasma processing on a plate-like workpiece, are provided adjacent to each other with an openable / closable isolation gate valve, and a plurality of vacuum chambers are provided in each vacuum chamber. The floating conveying guide plate having the floating gas ejection holes is provided, and the floating gas is ejected from the gas ejection holes provided in the guide plate to the lower surface of the workpiece placed on the guide plate. A workpiece processing method for a plasma processing apparatus, wherein the workpiece to be lifted is transported by an external force,
A plurality of gas ejection holes in the guide plate are composed of a plurality of independent ejection hole groups that are transverse to the conveyance direction and spaced at a predetermined interval in the conveyance direction, and further, the gas closest to the gate valve The area density of the gas ejection holes in the ejection hole group is made higher than that in the other gas ejection hole groups, and the gas ejection holes located immediately below the workpiece being transported among these ejection hole groups during levitation transportation By ejecting the levitation gas only from the group, in the plasma processing chamber, the levitation gas does not directly hit the plasma processing cathode electrode provided opposite to the guide plate that also serves as the plasma processing anode electrode. And a method for conveying an object to be processed in a plasma processing apparatus, wherein the levitation force at the end of the guide plate is improved. The object to be processed is composed of a tray placed on the guide plate and a plasma processing substrate mounted on the tray, or is a plasma processing substrate placed directly on the guide plate. Item 9. A method for conveying an object to be processed in a plasma processing apparatus according to Item 7 or 8. 9. The object to be processed of the plasma processing apparatus according to claim 7 or 8, wherein the pressure of the vacuum chamber is controlled to control the ejection pressure of the levitation gas ejected from the gas ejection hole group of the guide plate in the vacuum chamber. Method.

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