JP5378706B2 - Plasma processing apparatus and processing gas supply apparatus used therefor - Google Patents

Abstract

The present invention discloses a processed air supply apparatus, air pressure in a pipeline downstream of which is remained below atmosphere pressure, and optimum processed air is supplied corresponding to FPD cardinal plate procession. A supplier (400) supplies processed air to an upper electrode (300), and a buffering chamber (330) in the upper electrode separates a central chamber with perimeter chamber; the processed air supply apparatus is provided with branched pipe (404, 406) that shunts processed air from an air box (410) in two; and a flow adjustment unit (420, 430) that adjusts flow that flows over these branched pipes, and imports the processed air in each branched pipe into the central chamber and the perimeter chamber; each flow adjustment unit is provided with switch valve (422, 432) and fixed throttling controller (424, 434) that set on each branched pipe; the flow adjustment unit connected with the central chamber branched pipe is provided with a bypass pipe (404A) that parallel to the switch valve and the fixed throttling controller, at the same time the bypass pipe is provided with a switch valve (422A).

Description

  INDUSTRIAL APPLICABILITY The present invention relates to a plasma processing apparatus that performs a predetermined process on a flat panel display (Flat Panel Display) substrate such as a liquid crystal display and an electroluminescence display (Electro-Luminescence Display), and a plasma processing apparatus used in the plasma processing apparatus. The present invention relates to a processing gas supply device.

  For example, in the process of forming a pattern on the surface of a flat panel display substrate (hereinafter also referred to as an FPD substrate), plasma treatment such as etching, sputtering, and CVD (chemical vapor deposition) is performed. An example of a plasma processing apparatus for performing such plasma processing is a parallel plate plasma processing apparatus.

  In this type of plasma processing apparatus, a mounting table having a lower electrode in a processing chamber and an upper electrode that also serves as a processing gas introduction unit are arranged in parallel, and a processing gas is introduced into the processing chamber through the upper electrode, A high frequency electric field is applied to at least one of the electrodes to form a high frequency electric field between the electrodes, and plasma of a processing gas is formed by the high frequency electric field to perform plasma processing on the FPD substrate.

  By the way, since the FPD substrate has a large processing area unlike a semiconductor wafer, various proposals have been made to supply a processing gas from the upper electrode uniformly distributed over the entire surface of the FPD substrate. For example, as shown in Patent Document 1, a partition wall is provided that divides a hollow portion of the upper electrode into a central chamber that ejects processing gas into the central region of the substrate and a peripheral chamber that ejects processing gas into the peripheral region, for example, Branching the processing gas from the processing gas supply means consisting of a gas box equipped with a gas supply source, connecting branch pipes that supply the central chamber and the peripheral chamber respectively, and the flow rate of the processing gas flowing through each branch pipe A device provided with a flow rate adjusting means such as a mass flow controller for adjustment is described. According to this, the processing gas supplied to the central region and the peripheral region of the substrate can be made uniform by adjusting the flow rate adjusting means of each branch pipe.

JP 2007-324331 A

  By the way, since the upper electrode for performing plasma processing on the FPD substrate is large, the length of the branch pipe connected to the central chamber is usually shorter than that of the branch pipe connected to the peripheral chamber. Therefore, there is a problem that the branch pipe connected to the central chamber has a larger conductance (ease of flow) than the branch pipe connected to the peripheral chamber, and the internal pressure of each branch pipe is not uniform. For this reason, the flow rate adjusting means is adjusted so that the conductance of the branch pipe connected to the central chamber is made smaller than the conductance of the branch pipe connected to the peripheral chamber so that the pressure in each pipe is uniform. There is a need. In this regard, it is considered that the flow rate adjusting means of each branch pipe described above may be configured by a mass flow controller to adjust the flow rate of the processing gas flowing through the branch pipe.

  However, when the flow rate adjusting means of each branch pipe is configured by a mass flow controller, generally, the gas box constituting the processing gas supply means is also provided with a mass flow controller, so that the downstream side of the gas box (more than the mass flow controller). The downstream side) exceeds the atmospheric pressure. For this reason, if the piping on the downstream side of the gas box is damaged, there is a risk of gas leaking from the piping into the atmosphere. To prevent this, the piping structure must be devised, for example, by making each piping a double structure. No longer.

  In this regard, by configuring the flow rate adjusting means of each branch pipe with a fixed throttle valve such as a needle valve, the pipe on the downstream side of the gas box can be reduced to atmospheric pressure or lower. Can be prevented from leaking into the atmosphere.

  However, when the flow control means of each branch pipe is configured with a fixed throttle valve, as described above, the conductance of the branch pipe connected to the central chamber is smaller than the conductance of the branch pipe connected to the peripheral chamber. The opening of the fixed throttle valve of the branch pipe connected to the central chamber must be throttled and fixed. In this case, for example, when an FPD substrate is processed by supplying a large flow of processing gas only from the central region of the upper electrode, sufficient conductance cannot be ensured. There is a problem that it becomes impossible to supply.

  Accordingly, the present invention has been made in view of such problems, and the object of the present invention is to branch the processing gas from a processing gas supply means such as a gas box, for example, so that the central region and the peripheral portion of the FPD substrate A plasma processing apparatus capable of supplying an optimum processing gas in accordance with the processing of the FPD substrate while maintaining the inside of the pipe on the downstream side of the processing gas supply means at atmospheric pressure or lower when independently supplying to the region Is to provide etc.

  In order to solve the above-described problems, according to one aspect of the present invention, a first electrode and a second electrode are disposed to face each other in a processing chamber, and on a flat panel display substrate supported by the second electrode. A plasma processing apparatus for performing a predetermined plasma processing on the flat panel display substrate by supplying a high-frequency power to one or both of the electrodes while generating a processing gas to generate plasma. A processing gas supply device is provided for supplying a processing gas to the first electrode, and the first electrode is opposed to the second electrode, and a plurality of gas ejection holes for ejecting the processing gas into the processing chamber are formed. An electrode plate, a support for supporting the electrode plate, a hollow portion formed between the electrode plate and the support plate, into which the processing gas is introduced, and the hollow portion is divided into a central chamber and a peripheral chamber The processing gas supply device includes a processing gas supply means, branch pipes for branching the processing gas from the processing gas supply means, and flow rates through the branch pipes. And a pipe for introducing the processing gas from each branch pipe into the central chamber and the peripheral chamber, respectively. The flow regulators are on-off valves provided in the branch pipes. The branch pipe flow rate adjusting means connected to the central chamber is further provided with a bypass pipe in parallel with the on-off valve and the fixed throttle valve. Is provided with an on-off valve.

  In order to solve the above-described problems, according to another aspect of the present invention, a first electrode and a second electrode are disposed opposite to each other in a processing chamber, and a flat panel display substrate supported by the second electrode is provided. In the plasma processing apparatus for performing a predetermined plasma process on the flat panel display substrate by supplying a high frequency power to one or both of the electrodes while generating a processing gas into the flat panel display substrate, to the first electrode A processing gas supply apparatus for supplying a processing gas, wherein the first electrode is opposed to the second electrode, and a plurality of gas ejection holes for ejecting the processing gas into the processing chamber are formed. An electrode plate, a support that supports the electrode plate, a hollow portion that is formed between the electrode plate and the support plate in which the processing gas is introduced, and the hollow portion is divided into a central chamber and a peripheral chamber. A processing gas supply means, each branch pipe for branching the process gas from the process gas supply means, and a flow rate adjusting means for adjusting a flow rate through each of the branch pipes. And a pipe for introducing the processing gas from each branch pipe into the central chamber and the peripheral chamber, respectively, and each flow rate adjusting means includes an on-off valve and a fixed throttle valve (for example, a needle) provided in each branch pipe. The branch pipe flow rate adjusting means connected to the central chamber is further provided with a bypass pipe in parallel with the on-off valve and the fixed throttle valve, and the bypass pipe is provided with an on-off valve. A processing gas supply device is provided.

  According to the present invention, since the fixed throttle valve is used as the flow rate adjusting means provided in each branch pipe branched from the processing gas supply means, even if a mass flow controller is used as the processing gas supply means, the processing gas The piping on the downstream side of the supply means can be kept below atmospheric pressure. Thereby, even if the piping on the downstream side of the processing gas supply means is damaged, gas can be prevented from leaking from the piping into the atmosphere.

  Furthermore, since the flow rate adjusting means for each branch pipe includes an on-off valve and a fixed throttle valve, the conductance can be adjusted by adjusting the opening of the fixed throttle valve in accordance with the length of each branch pipe. Thus, for example, by reducing the opening of the fixed throttle valve of the branch pipe connected to the central chamber, which is shorter than the branch pipe connected to the peripheral chamber of the first electrode, Therefore, the processing gas can be supplied uniformly from the central chamber and the peripheral chamber of the first electrode.

  Moreover, since the flow rate adjusting means of the branch pipe connected to the central chamber of the first electrode is provided with a bypass pipe, the on-off valve is controlled and supplied to the central chamber through the bypass pipe without passing through the fixed throttle valve. Thus, the flow of the processing gas in the branch pipe can be switched. Thereby, sufficient conductance can be ensured even when the processing gas is supplied only from the central chamber, for example. As described above, according to the present invention, it is possible to supply the optimum processing gas according to the processing of the FPD substrate while keeping the piping on the downstream side of the processing gas supply means at atmospheric pressure or lower.

  Further, in this case, an inert gas supply pipe is connected between the on-off valve and the fixed throttle valve in the flow rate adjusting means of the branch pipe connected to the peripheral chamber. An on-off valve may be provided. According to this, since only the processing gas can be supplied from the central chamber of the first electrode and only the inert gas can be supplied from the peripheral chamber, the processing uniformity of the FPD substrate can be further improved. it can.

  Each of the flow rate adjusting means is provided with a plurality of bypass pipes in parallel with the on-off valve and the fixed throttle valve, and each of the bypass pipes is provided with an on-off valve and a fixed throttle valve. Each of the fixed throttle valves may be adjusted in opening so as to have different conductance ratios. According to this, by controlling the on-off valve of each flow rate adjusting means, the central chamber and the peripheral chamber of the first electrode are connected from each branch pipe by a combination of pipes through which the processing gas passes by passing the processing gas through a desired pipe. A processing gas having a desired flow rate can be supplied. Even in this manner, while the piping on the downstream side of the processing gas supply means is kept below atmospheric pressure, the flow rate of the processing gas supplied to the central region and the peripheral region of the FPD substrate is uniform according to the processing of the FPD substrate. You can control sex.

  Further, a rectifying member that changes the flow of gas discharged into the hollow portion in a horizontal direction is provided at a discharge port that opens into the hollow portion of the gas introduction hole introduced from each branch pipe into the central chamber and the peripheral chamber. You may make it provide. According to this, the inside of the hollow portion can be diffused uniformly over a wider range. Thereby, process gas can be more uniformly ejected from each gas ejection hole.

  According to the present invention, it is possible to supply the optimum processing gas according to the processing of the FPD substrate while maintaining the inside of the piping on the downstream side of the processing gas supply means at the atmospheric pressure or lower.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(Configuration example of plasma processing equipment)
First, a plasma processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of a multi-chamber type plasma processing apparatus. The plasma processing apparatus 100 shown in the figure includes a plurality of (for example, three) processing chambers 200 for performing plasma processing on a flat panel display substrate (FPD substrate) S.

  In the processing chamber 200, for example, a mounting table for mounting the FPD substrate S is provided, and an upper electrode serving also as a shower head for introducing a processing gas (for example, process gas) is provided above the mounting table. It has been. Each processing chamber 200 may perform the same processing (for example, etching processing) or different processing (for example, etching processing and ashing processing). A specific configuration example in the processing chamber 200 will be described later.

  Each processing chamber 200 is connected via a gate valve 102 to a side surface of a transfer chamber 110 having a polygonal cross section (for example, a rectangular cross section). A load lock chamber 120 is further connected to the transfer chamber 110 via a gate valve 104. A substrate carry-in / out mechanism 130 is provided adjacent to the load lock chamber 120 via a gate valve 106.

  Two indexers 140 are provided adjacent to the substrate carry-in / out mechanism 130, respectively. A cassette 142 for storing the FPD substrate S is placed on the indexer 140. The cassette 142 is configured to accommodate a plurality of (for example, 25) FPD substrates S.

  When plasma processing is performed on the FPD substrate S using such a plasma processing apparatus, the substrate loading / unloading mechanism 130 first loads the FPD substrate S in the cassette 142 into the load lock chamber 120. At this time, if there is a processed FPD substrate S in the load lock chamber 120, the processed FPD substrate S is unloaded from the load lock chamber 120 and replaced with an unprocessed FPD substrate S. When the FPD substrate S is carried into the load lock chamber 120, the gate valve 106 is closed.

  Next, after reducing the pressure in the load lock chamber 120 to a predetermined degree of vacuum, the gate valve 104 between the transfer chamber 110 and the load lock chamber 120 is opened. Then, after the FPD substrate S in the load lock chamber 120 is carried into the transfer chamber 110 by a transfer mechanism (not shown) in the transfer chamber 110, the gate valve 104 is closed.

  The pressure in the transfer chamber 110 is further reduced to a vacuum level higher than that in the load lock chamber 120, and then the gate valve 102 is opened. Then, an unprocessed FPD substrate S is carried into the lower electrode that also serves as a mounting table in the processing chamber 200. At this time, if there is a processed FPD substrate S, the processed FPD substrate S is unloaded and replaced with an unprocessed FPD substrate S.

  In the processing chamber 200, plasma is generated between the lower electrode and the upper electrode, and a processing gas is introduced into the processing chamber via the upper electrode, whereby a predetermined plasma processing is performed on the FPD substrate S.

(Configuration example of processing chamber)
Next, a specific configuration example of the processing chamber 200 will be described with reference to the drawings. Here, a configuration example of a processing chamber when the plasma processing apparatus of the present invention is applied to an apparatus for etching a glass substrate for liquid crystal display (hereinafter also simply referred to as “substrate”) as an FPD substrate will be described. FIG. 2 is a cross-sectional view illustrating a schematic configuration of the processing chamber 200.

  The processing chamber 200 shown in FIG. 2 includes a processing container 202 having a substantially rectangular tube shape made of aluminum whose surface is anodized (anodized), for example. The processing vessel 202 is divided into two parts in the vicinity of the upper end so that the upper part of the processing vessel 202 can be opened and closed so that the internal maintenance can be easily performed. Note that the processing container 202 is grounded.

  A mounting table 210 having a lower electrode 212 as an example of a second electrode is disposed in the processing container 202 at the bottom. Above the mounting table 210, an upper electrode 300 as an example of a first electrode that also serves as a gas introduction part is disposed so as to face each other through a gap. The upper electrode 300 is connected to a high frequency power source 208 via a matching unit 206. For example, high frequency power of 13.56 MHz is applied to the upper electrode 300 from the high frequency power source 208.

  A processing gas supply device 400 that supplies a processing gas for performing predetermined processing such as film formation and etching on the substrate S is disposed outside the processing container 202. The processing gas supply device 400 supplies the processing gas from the gas box 410 constituting the processing gas supply means into the processing chamber 200. The gas box 410 includes a processing gas supply source, and an open / close valve and a mass flow controller are provided in the piping of the processing gas supply source. The processing gas from the processing gas supply source is supplied from the gas box 410 after the flow rate is adjusted by the mass flow controller. The gas box 410 may include a plurality of processing gas supply sources. In this case, an on-off valve and a mass flow controller may be provided in the piping of each processing gas supply source, and the processing gas mixed by mixing the downstream sides of these piping may be supplied from the gas box 410. A specific configuration example of the gas box 410 will be described later.

  An exhaust passage 240 is connected to the side wall of the processing vessel 202, and a vacuum exhaust means 242 is connected to the exhaust passage 240. Further, a loading / unloading port 250 for loading / unloading the substrate S to / from the transfer chamber 110 is provided on the side wall of the processing container 202, and the loading / unloading port 250 is opened and closed by the gate valve 102. It has become.

  In such a processing chamber 200, the processing gas is supplied from the processing gas supply device 400 into the processing chamber 200, and high-frequency power is applied to the upper electrode 300, so that the processing gas flows between the lower electrode 212 and the upper electrode 300. Plasma is generated, and plasma processing such as etching, ashing, and film formation can be performed on the substrate S placed on the mounting table 210.

  The lower electrode 212 is supported by the support portion 216 via an insulating material 214. A protective tube 218 that extends downward through the opening 204 formed in the bottom wall of the processing vessel 202 is provided at the center of the lower surface of the support portion 216.

  The lower surface of the protective tube 218 is supported by a conductive support plate 220 having a larger diameter than the protective tube 218. The support plate 220 is attached to the protective tube 218 so as to close the inside of the protective tube 218. A lower end of a conductive bellows body 222 is fixed around the support plate 220. The upper end of the bellows body 222 is fixed to the opening edge of the opening 204 of the processing container 202.

  The bellows body 222 airtightly partitions the internal space where the protective tube 218 is disposed and the atmosphere side space. The support plate 220 is provided with a lifting mechanism (not shown). The mounting table 210 can be raised and lowered by raising and lowering the support plate 220 by this raising and lowering mechanism. The lower electrode 212 is connected to the support plate 220 through the conductive path 213. As a result, the lower electrode 212 is electrically connected to the processing container 202 through the conductive path 213, the support plate 220, and the bellows body 222, and is grounded.

  Note that the lower electrode 212 of the mounting table 210 and the processing container 202 may be electrically connected via an impedance adjustment unit. Specifically, for example, the impedance adjusting unit is connected between the lower electrode 212 and the support plate 220 with a conductive wire. As a result, one end of the impedance adjusting unit is connected to the lower electrode, and the other end is electrically connected to the bottom of the processing vessel 202 via the support plate 220 and the bellows body 222. By adjusting the impedance value by this impedance adjusting unit, it is possible to suppress the generation of plasma between the upper electrode 300 to which the high frequency power source is connected and the side wall of the processing vessel 202.

  On the other hand, the upper electrode 300 is mounted on the upper inner surface of the processing container 202 via a frame 302 made of an insulating member, and is suspended on the upper wall of the processing container 202 via, for example, a plurality of bolts 230. Yes. Specifically, an insulator 232 is attached to a hole formed in the upper wall of the processing container 202, and a bolt 230 is inserted into the insulator 232 to fix the upper electrode 300. Further, a bolt whose surface is insulated may be used.

  Further, the upper electrode 300 also has a function as a gas introduction part for ejecting a predetermined gas toward the surface of the FPD substrate S mounted on the mounting table 210, and constitutes a so-called shower head. As shown in FIG. 2, the upper electrode 300 is formed with a gas diffusion buffer chamber 330 having a rectangular hollow portion. A number of gas ejection holes 312 are uniformly distributed over the entire lower surface of the upper electrode 300 (the surface facing the lower electrode), and the processing gas is supplied from the gas ejection holes 312 to the entire processing chamber 200 in a downward flow.

  Specifically, the upper electrode 300 is formed in a rectangular electrode plate 310 in which the gas ejection holes 312 are formed, and substantially the same shape as the electrode plate 310, and detachably supports the upper surface side of the electrode plate 310. An electrode support 320. The electrode plate 310 and the electrode support 320 are made of aluminum having an anodized surface, for example. The number and arrangement of the gas ejection holes 312 are not limited to those shown in FIG.

  The electrode support 320 is formed with a rectangular space that constitutes the buffer chamber 330. This space portion is formed so as to open at the edge (bottom surface) of the electrode support 320. By attaching the electrode plate 310 to the bottom surface of the electrode support 320, the space portion is closed. Yes.

  In the space where the buffer chamber 330 of the electrode support 320 is formed, the electrode support 320 is suspended on the inner surface of the upper wall of the electrode support 320 via the plurality of suspension members 360. The suspension member 360 is made of, for example, aluminum whose surface is anodized or SUS (Stainless Used Steel). The suspension member 360 is fixed to the upper wall of the electrode support 320 with a fastening member 364 such as a bolt.

  Further, the suspension member 360 may be fixed to the electrode plate 310 by the fastening member 364. A flange portion is provided on the suspension member 360, and the flange portion and the electrode plate are connected to a bolt smaller than the fastening member 364. You may make it fix separately with this fastening member.

  In this way, not only the electrode plate 310 is attached to the edge (bottom surface) of the electrode support 320, but also is suspended in the buffer chamber 330 of the electrode support 320 by the suspension member 360, so that a large electrode plate is obtained. 310 can be attached to the electrode support 320 so as not to be bent or deformed by its own weight.

  The buffer chamber 330 of the electrode support 320 is partitioned into a plurality of chambers (for example, a first chamber 332 at the center and a second chamber 334 at the periphery thereof) by a loop-shaped (frame-shaped) partition wall 350. A plurality of gas introduction holes 326 are provided on the upper wall of the electrode support 320. Branch pipes of the processing gas supply device 400 are connected to the gas introduction holes 326, respectively, so that the processing gas from the processing gas supply device 400 is introduced for each of the chambers 332 and 334 with the flow rate controlled. Yes.

  For example, as shown in FIG. 2, the processing gas from the gas box 410 is introduced into the first chamber 332 via the flow rate adjusting means 420 through one branch pipe 404 branched into two from the gas box 410. The processing gas passing through the other branch pipe 406 is introduced into the second chamber 334 via the flow rate adjusting means 430. The processing gas supplied to the chambers 332 and 334 is controlled in flow rate by the flow rate adjusting means 420 and 430, respectively.

  In this way, by individually controlling the flow rate of the processing gas introduced from the chambers 332 and 334 toward the substrate S, the gas flow rate in the entire region of the substrate S is equalized even if the substrate S has a large area. As a result, the plasma processing can be made uniform.

(Pipe configuration example of processing gas supply device)
Here, an example of the piping configuration of such a processing gas supply apparatus 400 will be described with reference to the drawings. FIG. 3 is a view of the electrode support 320 viewed from below when the electrode plate 310 is removed. FIG. 4 is a schematic view showing the appearance of the processing gas supply apparatus 400. FIG. 5 is a block diagram showing the piping configuration of the processing gas supply apparatus 400. 3 and 5, the piping configuration of the processing gas supply device 400 is conceptually represented by a diagram.

  Here, a case where five gas introduction holes 326 are formed in the electrode support 320 will be described. Specifically, one gas introduction hole 326 is disposed at the center of the electrode support 320 and one gas introduction hole 326 is disposed near each of the four corners. These five gas introduction holes 326 are arranged symmetrically in the vertical and horizontal directions, respectively.

  The partition wall 350 shown in FIG. 3 is a specific example when it is formed in a frame shape similar to the buffer chamber 330. A sealing member such as an O-ring (not shown) is provided on the upper and lower surfaces of the partition wall 350 along the frame portion of the partition wall 350. With such a partition wall 350, the buffer chamber 330 is partitioned into a first chamber 332 in the center and a second chamber 334 in the periphery surrounding the outside of the first chamber 332.

  Such a partition wall 350 is sandwiched and held between the inner surface of the upper wall of the electrode support 320 and the electrode plate 310. Therefore, if the electrode plate 310 is removed from the electrode support 320, the partition walls having different loop shapes can be easily obtained. 350 can be exchanged. The partition wall 350 shown in FIG. 3 is formed in a loop shape such that the area of the first chamber 332 is approximately 25% of the entire area of the buffer chamber 330. In the case of being partitioned by such a partition wall 350, the processing gas is introduced into the first chamber 332 from the central gas introduction hole 326, and the processing gas is introduced into the second chamber 334 from the four gas introduction holes 326 close to the four corners. Is introduced.

  When the processing gas is introduced into the gas introduction hole 326 arranged in this way, the processing gas supply device 400 is configured as shown in FIGS. That is, the processing gas supply pipe 402 shown in FIG. 3 includes a branch pipe 404 that introduces the processing gas into the gas introduction hole 326 of the first chamber 332 and a branch pipe 406 that introduces the processing gas into the gas introduction hole 326 of the second chamber 334. It is branched into two. The branch pipes 404 and 406 are provided with flow rate adjusting means 420 and 430, respectively.

  The branch pipe 404 is connected to the central gas introduction hole 326 via the flow rate adjusting means 420. Further, the branch pipe 406 branches into four on the downstream side of the flow rate adjusting means 430, and each of the branch pipes 406a to 406d is connected to four gas introduction holes 326 that are closer to four corners. Specifically, as shown in FIG. 4, the branch pipe 406 is further branched into two on the downstream side of the on-off valve 432 and the flow rate regulator 434, one of the pipes is branched into branch pipes 406a and 406b, and the other pipe. Is branched into branch pipes 406c and 406d. It is not limited to such a pipe configuration, and the branch pipe 406 may be branched radially into four on the downstream side of the on-off valve 432 and the flow rate regulator 434.

  The flow rate adjusting means 420 and 430 are configured by, for example, on-off valves 422 and 432 provided on the upstream side and flow rate regulators 424 and 434 provided on the downstream side, respectively. The flow rate adjusting means 420 and 430 can separately control the flow rate of the processing gas introduced from the first chamber 332 and the second chamber 334 into the processing chamber 200.

The gas box 410 is configured as shown in FIG. 5, for example. Here, a case where four types of gases (first gas, second gas, third gas, inert gas) can be supplied via the gas supply pipes 510A to 510D is described as an example. Among these gases, the first gas, the second gas, and the third gas are, for example, fluorocarbon fluorine compounds as etching gas, C ₄ such as CF ₄ , C ₄ F ₆ , C ₄ F ₈ , and C ₅ F _{8. X} F _Y gas. Further, these gases may include, for example, O ₂ gas as a gas for controlling the deposition of a CF-based reaction product. Further, the inert gas may be, for example, a rare gas (for example, Ar gas) as a carrier gas, and may be N ₂ gas that is also used as a purge gas, for example. Note that the number of gas supply sources is not limited to the example shown in FIG. 5, and may be one, two, or four or more.

  As described above, the gas supply pipes 510A to 510C of the first gas, the second gas, and the third gas used as the etching gas are similarly configured. That is, each of the gas supply pipes 510A to 510C includes gas supply sources 520A to 520C for the first gas, the second gas, and the third gas, respectively, and each of the gas supply sources 520A to 520C passes through the gas supply pipes 510A to 510C, respectively. Are connected to the processing gas supply pipe 402.

  The gas supply pipes 510A to 510C of the gas supply pipes 510A to 510C are provided with flow controllers, for example, mass flow controllers (MFC) 540A to 540C, for adjusting the flow rate of the gas from the gas supply sources 520A to 520C. The mass flow controllers (MFCs) 540A to 540C here may have different capacities.

  First cutoff valves (upstream cutoff valves) 530A to 530C and second cutoff valves (downstream cutoff valves) 550A to 550C are provided on the upstream side and downstream side of the mass flow controllers (MFCs) 540A to 540C, respectively. Yes. By closing both the first shut-off valves 530A to 530C and the second shut-off valves 550A to 550C, the gas flow in each mass flow controller (MFC) 540A to 540C can be shut off. Thereby, for example, the flow rate of the gas that actually passes through each of the mass flow controllers (MFCs) 540A to 540C can be adjusted to zero.

  5, hand valves 522A to 522C are provided between the gas supply sources 520A to 520C and the first shut-off valves (upstream shut-off valves) 530A to 530C. Although not shown, a pressure reducing valve (regulator) and a pressure gauge (PT) may be provided between the hand valves 522A to 522C and the first shutoff valves (upstream shutoff valves) 530A to 530C. Good.

On the other hand, an inert gas (for example, N ₂ gas) gas supply pipe 510D includes an inert gas supply source 520D, and the inert gas from the gas supply source 520D is supplied to each of the other gas supply pipes 510A to 510C. The gas can be supplied into the processing chamber 200 via mass flow controllers (MFC) 540A to 540C and second cutoff valves 550A to 550C. Accordingly, the mass flow controllers (MFC) 540A to 540C can be used for the N ₂ gas, so that it is not necessary to provide a mass flow controller (MFC) separately. Further, the gas can be supplied to the processing chamber 200 via the processing gas supply pipe 402 without passing through the gas supply pipes 510A to 510C.

  Specifically, the gas supply source 520D of the inert gas is connected to the processing gas supply pipe 402 via the second cutoff valve 550D by the gas supply pipe 510D, and each via the cutoff valves 560A to 560C. The gas supply pipes 510A to 510C are connected between the first cutoff valves 530A to 530C and the mass flow controllers (MFC) 540A to 540C.

  Similarly to the other gas supply pipes 510A to 510C, a hand valve 522D and a first shut-off valve (upstream shut-off valve) 530D are connected to the gas supply pipe 510D. When the flow rate of the inert gas is controlled by the mass flow controllers (MFC) 540A to 540C, the cutoff valves 560A to 560C are first cutoff valves (upstream cutoff valves) provided on the upstream side of the mass flow controller (MFC). ) May be controlled.

  In the processing gas supply apparatus 400 having such a configuration, the processing gas mixed at a predetermined gas flow rate is controlled via the processing gas supply pipe 402 by controlling each valve in the gas box 410 and the MFC. To be supplied. At this time, the flow rate adjusting means 420 and 430 can separately control the flow rate of the processing gas introduced from the first chamber 332 and the second chamber 334 into the processing chamber 200.

  For example, in order to supply gas uniformly from the upper electrode 300 toward the FPD substrate S, a branch pipe 404 connected to the central gas introduction hole 326 and a branch pipe 406 connected to four gas introduction holes 326 near the four corners are provided. It is necessary to make the pressure in the pipe uniform. However, since the upper electrode 300 for performing plasma processing on the FPD substrate S is large, the length of the branch pipe 404 connected to the first chamber 332 in the center is connected to the second chamber 334 in the periphery. Therefore, the conductance (ease of flow) is also increased. For this reason, the flow rate regulators 424 and 434 are adjusted so that the flow rate of the processing gas flowing through the branch pipe 404 is less than the flow rate of the processing gas flowing through the branch pipe 406 so that the internal pressures of the branch pipes 404 and 406 are uniform. Must be.

  Note that the partition wall 350 of the upper electrode 300 is not limited to that shown in FIG. For example, the processing gas supply apparatus 400 may be applied to the upper electrode 300 provided with the partition wall 350 as shown in FIG. The partition wall 350 shown in FIG. 6 has a loop shape so that the area of the first chamber 332 is larger than that of the partition wall 350 shown in FIG. According to the partition wall 350 shown in FIG. 6, the area of the first chamber 332 is approximately 50% of the entire area of the buffer chamber 330.

  Further, like the partition wall 350 shown in FIG. 6, the loop shape is set such that the number of gas introduction holes 326 included in the regions of the compartments 332 and 334 divided is the same as that shown in FIG. Thus, only the partition area of the buffer chamber 330 can be changed without changing the piping configuration of the processing gas supply apparatus 400.

  By the way, the flow rate regulators 424 and 434 described above can be configured by, for example, a mass flow controller. However, if the flow rate regulators 424 and 434 are configured by a mass flow controller, the mass flow controllers 540A to 540C are also provided in the gas box 410, so the downstream side of the gas box 410 (downstream side of the mass flow controllers 540A to 540C). Will exceed atmospheric pressure. For this reason, if the piping on the downstream side of the gas box 410 is damaged, there is a risk of gas leaking from the piping into the atmosphere. To prevent this, the piping structure must be devised, for example, by making each piping a double structure. I will have to.

  Therefore, in the present embodiment, the flow rate regulators 424 and 434 are constituted by fixed throttle valves such as needle valves, for example, so that the downstream side of the gas box 410 is less than the atmospheric pressure, and even if the piping is damaged, the gas Is not leaking into the atmosphere. When the flow rate regulators 424 and 434 are composed of fixed throttle valves, the fixed throttle valve is set so that the flow rate of the processing gas flowing through the branch pipe 404 is smaller than the flow rate of the processing gas flowing through the branch pipe 406 as described above. Fix with the opening of the throttle closed. For example, when the opening of the fixed throttle valve is 0 and the fully open is 10, the flow rate regulators 424 and 424 are controlled so that the conductance ratio between the branch pipe 404 and the branch pipe 406 is 3:10. The opening degree of the fixed throttle valve constituting 434 is adjusted.

  However, if the opening of the fixed throttle valve constituting the flow rate regulator 424 of the branch pipe 404 is reduced and fixed in this way, for example, a large flow rate of processing gas is supplied only from the central region of the upper electrode 300 and the FPD substrate S When processing is desired, there is a problem that it is impossible to supply an optimal processing gas according to the processing of the FPD substrate S, such as a sufficient conductance cannot be ensured. For this reason, for example, a bypass pipe that does not pass through the flow regulator 424 is provided in parallel with the flow regulator 424 so that the flow of the processing gas can be switched to the bypass pipe, thereby supplying a large flow of processing gas through the bypass pipe. It is preferable to be able to do this.

  A specific example of such a pipe configuration will be described in detail with reference to the drawings. FIG. 7 is a diagram illustrating a specific example of a pipe configuration including a bypass pipe. Here, the bypass pipe 404A is provided in parallel with the flow rate regulator 424 of the branch pipe 404. The bypass pipe 404A is provided with an on-off valve 422A, which can be switched between a case where the processing gas passing through the branch pipe 404 flows through the flow rate regulator 424 and a case where the processing gas flows through the bypass pipe 404A.

  In this case, for example, when the opening of the fixed throttle valve is 0 and when it is fully open, the flow rate is adjusted so that the conductance ratio between the branch pipe 404 and the branch pipe 406 is 3:10. The opening degree of the fixed throttle valve constituting the devices 424 and 434 is adjusted and fixed. Note that the opening of the fixed throttle valve is not limited to the above case. A conductance ratio is obtained in advance so that the pressures in the branch pipe 404 and the branch pipe 406 are uniform according to the lengths of the branch pipe 404 and the branch pipe 406, and the opening of the fixed throttle valve is adjusted so that the conductance ratio is obtained. It is preferable to adjust.

  According to the processing gas supply device 400 having such a piping configuration, for example, when it is desired to supply processing gas uniformly from the central region of the upper electrode 300 and its peripheral region, the on-off valve 432 and the on-off valve 422 are opened. By closing the on-off valve 422A, the processing gas may flow into the branch pipe 406 via the flow rate regulator 434, and the processing gas may flow into the branch pipe 404 via the flow rate regulator 424.

  On the other hand, when it is desired to supply a large amount of processing gas only from the central region of the upper electrode 300, the branch pipe 406 is treated by closing the on-off valve 432, closing the on-off valve 422, and opening the on-off valve 422A. What is necessary is just to make it process gas flow from the branch piping 404 via the bypass piping 404A, without flowing gas.

  According to this, even when the opening of the fixed throttle valve constituting the flow rate regulator 424 of the branch pipe 404 is throttled and fixed, a large flow rate of processing gas is supplied from only the central region of the upper electrode 300 via the bypass pipe 404A. Can be made available.

  In the branch pipe 406 in the pipe configuration shown in FIG. 7, for example, as shown in FIG. 8, an inert gas (for example, Ar gas, He gas) is supplied between the on-off valve 432 and the flow rate regulator 434. A gas supply pipe 408 may be further connected. In this case, the inert gas supply pipe 408 is provided with an opening / closing valve 409 so that only the inert gas is supplied from the peripheral region of the upper electrode 300.

  That is, only the inert gas can be supplied from the peripheral region of the upper electrode 300 by closing the on-off valve 432 and opening the on-off valve 409. Accordingly, the processing gas is supplied from the central region of the upper electrode 300 and the inert gas is supplied from the peripheral region, so that the uniformity of processing of the FPD substrate can be improved.

  Such an inert gas may be configured to be directly supplied from, for example, the inert gas supply pipe 510D in the gas box 410 shown in FIG. 5 to the inert gas supply pipe 408 shown in FIG. Further, a gas supply flow path may be provided in a separate system from the gas supply pipes 510 </ b> A to 510 </ b> D shown in FIG. 5 and supplied directly to the inert gas supply pipe 408.

  7 and 8, the case where the bypass pipe 404A is provided only in the branch pipe 404 has been described. However, the present invention is not limited to this, and the bypass pipe is not limited to the branch pipe 404 but also in the branch pipe 406. May be provided.

  In this case, for example, as shown in FIG. 9, the branch pipe 404 is provided with a plurality of (for example, two) bypass pipes 404A and 404B in parallel with the flow rate regulator 424, and the bypass pipes 404A and 404B are opened and closed, respectively. Valves 422A and 422B and flow rate regulators 424A and 424B may be provided. The branch pipe 406 is provided with a plurality of (for example, two) bypass pipes 406A and 406B in parallel with the flow rate regulator 434. The bypass pipes 406A and 406B are respectively provided with on-off valves 432A and 432B and a flow rate regulator 434A. , 434B may be provided.

  Then, by adjusting the conductance ratio by fixing the opening of the fixed throttle valves of the flow regulators 424, 424A, 424B to different opening degrees, a combination of pipes that flow by controlling the on-off valves 422, 422A, 422B. A plurality of types of flow rates can be passed through the branch pipe 404.

  In the same manner, the opening / closing valves 432, 432A, 432B are controlled by adjusting the conductance ratio while fixing the opening of the fixed throttle valves of the flow regulators 434, 434A, 434B to different opening degrees. A plurality of types of flow rates can be caused to flow through the branch pipe 406 by a combination of pipes that flow through.

  Specifically, when the opening degree of the fixed throttle valve is 0 and the full opening degree is 10, the opening degree of the fixed throttle valve of the flow regulators 424, 424A, 424B is, for example, 10: 5: 2. .5. Further, the opening degree of the fixed throttle valve of the flow rate regulators 434, 434A, 434B is also set to 10: 5: 2.5, for example. Thereby, the combination of the conductance ratios of the process gas flowing through the branch pipe 404 and the branch pipe 406 can be increased.

  For example, the on-off valves 422 and 422B are closed and the on-off valve 422A is opened so that the processing gas passes only through the flow regulator 424A in the branch pipe 404, and the processing gas passes only through the flow regulator 434 in the branch pipe 406. If the on-off valves 432A and 432B are closed and the on-off valve 432 is opened as described above, the conductance ratio between the branch pipe 404 and the branch pipe 406 can be 5:10. In this case, the conductance of the branch pipe 404 and the branch pipe 406 is controlled by closing the on-off valve 422 and opening the on-off valves 422A, 422B so that the processing gas passes only through the flow rate regulators 424A, 424B in the branch pipe 404. The ratio can also be 7.5: 10.

  In this way, each on-off valve is controlled so that the processing gas passes through the desired piping, so that the processing gas passes through the combination of the piping through which the branch gas passes from the branch pipe to the first chamber 332 in the center and the second chamber 334 in the periphery. A processing gas having a desired flow rate can be supplied. Thereby, the uniformity of the flow rate of the processing gas supplied to the central region and the peripheral region of the substrate S can be controlled according to the processing of the substrate S.

  Further, each gas introduction hole 326 of the upper electrode 300 may be provided with a rectifying member that changes the flow of the discharged gas in the horizontal direction at the discharge port 327 that opens in the buffer chamber 330. For example, as shown in FIGS. 10A and 10B, the disk-shaped rectifying member 328 is suspended from a plurality of (for example, four) suspension members 329 around the discharge port 327. Further, as shown in FIGS. 11A and 11B, a disc-shaped rectifying member 328 having a plurality of holes extending in the horizontal direction from the center may be attached to the discharge port 327 of each gas introduction hole 326. In addition, in the electrode plate 310 shown to FIG. 10A and FIG. 11A, the gas ejection hole 312 is abbreviate | omitted.

  By doing so, the processing gas introduced from each gas introduction hole 326 is supplied in the horizontal direction by the action of the rectifying member 328, so that the inside of the buffer chamber 330 can be diffused uniformly over a wider range. As a result, the processing gas can be ejected more uniformly from the gas ejection holes 312 of the electrode plate 310.

  In particular, since the rectifying member 328 of this embodiment is so compact that it can be provided for each discharge port 327 of each gas introduction hole 326, the buffer chamber 330 is partitioned into a plurality of chambers 332 and 334 by a partition wall 350. Even in the case, it can be provided without getting in the way. Therefore, regardless of the shape of the partition wall 350 (for example, FIGS. 3 and 6), the rectifying member 328 can be provided at the discharge port 327 of each gas introduction hole 326. In addition, in each of the chambers 332 and 334 of the buffer chamber 330 partitioned by the partition wall 350 as in this embodiment, the processing gas introduced from each gas introduction hole 326 can be diffused in a wider range. The shape and size of the rectifying member 328 are not limited to those described above. For example, the shape and size of the flow regulating member 328 may be determined according to the arrangement of the gas introduction holes 326, the arrangement of the gas ejection holes 312, the shape of the partition wall 350, and the like.

  The partition wall 350 in the present embodiment has been described as being easily replaceable. However, the present invention is not limited to this, and the partition wall 350 is formed on the upper wall of the electrode support 320 with a plurality of bolts and screws. It may be fixed.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the present embodiment, the case where the present invention is applied to a plasma processing apparatus in which the lower electrode is grounded and high-frequency power is applied only to the upper electrode has been described, but the present invention is not necessarily limited thereto. For example, the present invention may be applied to a plasma processing apparatus that applies high-frequency power to both the upper electrode and the lower electrode, or applied to a plasma processing apparatus that applies only two types of high-frequency power having different high frequencies to only the lower electrode. May be.

  The present invention is applicable to a plasma processing apparatus that performs a predetermined process on an FPD substrate and a processing gas supply apparatus used therefor.

1 is an external perspective view of a plasma processing apparatus according to an embodiment of the present invention. It is sectional drawing of the process chamber in the embodiment. It is a figure for demonstrating the piping structural example of a process gas supply apparatus. It is a perspective view which shows the outline of the external appearance of the process gas supply apparatus shown in FIG. It is a block diagram which shows the piping structure shown in FIG. It is a figure for demonstrating the piping structural example of the process gas supply apparatus at the time of applying to an upper electrode provided with another division wall. It is a block diagram which shows the specific example of the flow volume adjustment means which provided the bypass piping in the same embodiment. It is a block diagram which shows the other specific example of the flow volume adjustment means which provided the bypass piping in the same embodiment. It is a block diagram which shows the other specific example of the flow volume adjustment means which provided the bypass piping in the same embodiment. It is a longitudinal cross-sectional view which shows the specific example of the rectification | straightening member attached to each gas introduction hole of an upper electrode. It is AA sectional drawing shown to FIG. 10A. It is a longitudinal cross-sectional view which shows the other specific example of the rectification | straightening member attached to each gas introduction hole of an upper electrode. It is BB sectional drawing shown to FIG. 11A.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Plasma processing apparatus 102 Gate valve 104 Gate valve 106 Gate valve 110 Transfer chamber 120 Load lock chamber 130 Substrate carrying in / out mechanism 140 Indexer 142 Cassette 200 Processing chamber 202 Processing container 204 Opening 206 Matching device 208 High frequency power supply 210 Mounting base 212 Lower electrode 213 Conductive path 214 Insulating material 216 Support portion 218 Protective tube 220 Support plate 222 Bellows body 230 Bolt 232 Insulator 240 Exhaust path 242 Vacuum exhaust means 250 Carry-in / out port 300 Upper electrode 302 Frame body 310 Electrode plate 312 Gas ejection hole 320 Electrode support body 326 Gas introduction hole 327 Discharge port 328 Rectification member 329 Suspension member 330 Buffer chamber 332 First chamber (center chamber)
334 Second room (peripheral room)
350 Partition wall 360 Suspension member 364 Fastening member 400 Processing gas supply device 402 Processing gas supply piping 404, 406 Branch piping 404A, 404B Bypass piping 406a-406d Branch piping 406A, 406B Bypass piping 408 Inert gas supply piping 409 Open / close valve 410 Gas box 420, 430 Flow rate adjusting means 422, 422A, 422B On-off valve 424, 424A, 424B Flow rate regulator (fixed throttle valve)
430 Flow rate adjusting means 432, 432A, 432B On-off valve 434, 434A, 434B Flow rate regulator (fixed throttle valve)
510A to 510D Gas supply piping 520A to 520D Gas supply source 522A to 522D Hand valve 530A to 530D First shutoff valve 540A to 540C Mass flow controller 550A to 550D Second shutoff valve 560A to 560C Shutoff valve S Substrate (FPD substrate)

Claims (7)

A first electrode and a second electrode are disposed opposite to each other in a processing chamber, and high-frequency power is supplied to one or both of the electrodes while introducing a processing gas onto a flat panel display substrate supported by the second electrode. A plasma processing apparatus for performing a predetermined plasma process on the flat panel display substrate by generating plasma,
A processing gas supply device for supplying a processing gas to the first electrode;
The first electrode is opposed to the second electrode, has an electrode plate formed with a plurality of gas ejection holes for ejecting the processing gas into the processing chamber, and a support for supporting the electrode plate; A hollow portion formed between the electrode plate in the support and into which the processing gas is introduced; and a loop-shaped partition wall for partitioning the hollow portion into a central chamber and a peripheral chamber;
The processing gas supply device includes a processing gas supply means, a flow rate controller provided in the processing gas supply means and capable of changing a flow rate setting of the processing gas by control, and a processing gas whose flow rate is adjusted by the flow rate controller. Each branch pipe that branches into two branches, a fixed throttle valve that adjusts a conductance ratio of each branch pipe by fixing an opening and closing valve provided in each branch pipe, and a processing gas from each branch pipe A central chamber and piping to be introduced into each of the peripheral chambers,
Provided with a bypass pipe in parallel to the fixed throttle valve with the on-off valve in the branch pipe connected to said central portion room, providing the opening and closing valve for different said bypass pipe and the on-off valve in the bypass pipe A plasma processing apparatus. Connect the inert gas supply pipe between the front SL-off valve of the branch pipe connected to the peripheral portion room said fixed throttle valve, the on-off valve differ the inert gas supplied to the inert gas supply pipe The plasma processing apparatus according to claim 1, further comprising an on- off valve for piping . Provided with a plurality of bypass pipes in parallel before SL-off valve and the fixed throttle valve, wherein each provided fixed throttle valve off valve in each bypass pipe, respectively before Symbol fixed throttle valve becomes different conductance ratio the plasma processing apparatus according to claim 1 or 2, characterized in that the opening. A rectifying member that changes the flow of gas discharged into the hollow portion in the horizontal direction is provided at a discharge port that opens into the hollow portion of the gas introduction hole that is introduced from each branch pipe into the central chamber and the peripheral chamber. The plasma processing apparatus according to any one of claims 1 to 3. The plasma processing apparatus according to claim 1, wherein the fixed throttle valve is a needle valve. A first electrode and a second electrode are disposed opposite to each other in a processing chamber, and high-frequency power is supplied to one or both of the electrodes while introducing a processing gas onto a flat panel display substrate supported by the second electrode. In the plasma processing apparatus for performing a predetermined plasma processing on the flat panel display substrate by generating plasma, a processing gas supply apparatus for supplying a processing gas to the first electrode,
The first electrode is opposed to the second electrode, has an electrode plate formed with a plurality of gas ejection holes for ejecting the processing gas into the processing chamber, and a support for supporting the electrode plate; A hollow portion formed between the electrode plate in the support and into which the processing gas is introduced; and a loop-shaped partition wall for partitioning the hollow portion into a central chamber and a peripheral chamber;
A processing gas supply means, a flow rate controller provided in the processing gas supply means and capable of changing the flow rate setting of the processing gas by control, and branch pipes for branching the processing gas whose flow rate is adjusted by the flow rate controller into two branches; A fixed throttle valve for adjusting the conductance ratio of each branch pipe by fixing the opening and closing valve provided in each branch pipe, and the central chamber and the peripheral chamber for processing gas from each branch pipe And pipes to be introduced respectively,
Provided with a bypass pipe in parallel to the fixed throttle valve with the on-off valve in the branch pipe connected to said central portion room, providing the opening and closing valve for different said bypass pipe and the on-off valve in the bypass pipe A processing gas supply device characterized by the above. A rectifying member that changes the flow of gas discharged into the hollow portion in the horizontal direction is provided at a discharge port that opens into the hollow portion of the gas introduction hole that is introduced from each branch pipe into the central chamber and the peripheral chamber. The processing gas supply device according to claim 6.

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