Plasma processing device

Abstract

The present invention provides a plasma processing apparatus. The plasma processing apparatus includes a plurality of plasma processing chambers (S2 to S6) for performing plasma processing on a substrate (X), a tray (Y) for holding the substrate (X) in an upright state, and a lifting mechanism (10) for continuously conveying the tray (Y) to the plurality of plasma processing chambers (S2 to S6). The plasma processing apparatus can continuously perform plasma processing even on a substrate that is difficult to wind around a roll.

Description

Technical Field

[0001] The present invention relates to a plasma processing apparatus for manufacturing, for example, separators for fuel cells. Background Art

[0002] As such a plasma processing apparatus, Patent Document 1 discloses a so-called roll-to-roll type apparatus in which a substrate wound around a feed roll is fed out, plasma-treated to form a film, and the film-formed substrate is wound around a take-up roll.

[0003] Such a roll-to-roll type plasma processing apparatus has advantages such as a high processing speed and high manufacturing efficiency because continuous film formation processing can be performed.

[0004] However, when forming a film on a substrate that is difficult to wind around a roll, such as a substrate with unevenness or a thick substrate, it is difficult to apply the above roll-to-roll type apparatus.

[0005] Patent Document 1: Japanese Patent Laid-Open Publication No. 2019-117773. Summary of the Invention

[0006] The present invention has been made to solve the above problems, and its main object is to enable continuous plasma processing even for a substrate that is difficult to wind around a roll.

[0007] That is, the present invention provides a plasma processing apparatus including: a plurality of plasma processing chambers for performing plasma processing on a substrate; a tray for holding the substrate in an upright state; and a lifting mechanism for continuously transporting the tray to the plurality of plasma processing chambers.

[0008] In the plasma processing apparatus configured as described above, since the tray holding the substrate is continuously transported to the plurality of plasma processing chambers by the lifting mechanism, continuous film formation processing can be performed even if the substrate is difficult to wind around a roll.

[0009] Preferably, the plurality of plasma processing chambers communicate with each other, and a differential exhaust chamber is provided between the respective plasma processing chambers.

[0010] With this configuration, by connecting the plurality of plasma processing chambers, continuous transportation of the tray can be achieved, and each plasma processing chamber can be maintained at a desired degree of vacuum.

[0011] In order to simplify the lifting mechanism, preferably, the lifting mechanism has: a rope stretched across the plurality of plasma processing chambers, with the tray hanging on the rope; and a drive source for moving the rope between the plurality of plasma processing chambers.

[0012] Preferably, the plasma processing apparatus further includes a conveying mechanism provided with a plurality of the trays, and the plurality of trays are sequentially conveyed onto the rope.

[0013] With such a configuration, a plurality of trays can be automatically sent out sequentially, and a plurality of substrates held in the trays can be continuously formed into films all at once, thereby further improving the efficiency.

[0014] As a method for realizing the automatic feeding of such trays, examples include: the conveying mechanism has an endless belt for sending the trays to the rope, and the trays fall from the edge portion of the endless belt, and a hook portion provided on the trays is hooked on the rope, and the trays are suspended on the rope.

[0015] Preferably, the plasma processing chamber includes: a plasma cleaning chamber for plasma cleaning the substrate; an ion implantation chamber for implanting carbon ions into the substrate; a first film forming chamber for forming a DLC film on one surface of the substrate; a second film forming chamber for forming a DLC film on the other surface of the substrate; and a hydrophilic treatment chamber for performing hydrophilic treatment on the substrate using oxygen plasma, and the lifting mechanism sequentially conveys the trays to the plasma cleaning chamber, the ion implantation chamber, the first film forming chamber, the second film forming chamber, and the hydrophilic treatment chamber.

[0016] With such a configuration, since the trays holding the substrates in an upright state are conveyed to the plasma cleaning chamber, the ion implantation chamber, the first film forming chamber, the second film forming chamber, and the hydrophilic treatment chamber, plasma treatment can be performed on both sides of the substrate in each chamber, and thus a DLC film can be efficiently formed on the substrate.

[0017] As a more specific embodiment for performing plasma treatment on both sides of the substrate, examples include: the plasma cleaning chamber, the ion implantation chamber, and the hydrophilic treatment chamber are respectively provided with at least a pair of antennas for generating plasma at positions sandwiching the substrate.

[0018] Effects of the Invention

[0019] According to the present invention configured as such, even a substrate that is difficult to be wound around a roller can be continuously subjected to plasma treatment. Brief Description of the Drawings

[0020] Figure 1 It is a schematic diagram showing the configuration of the plasma processing apparatus in this embodiment.

[0021] Figure 2 It is a schematic diagram showing the configuration of the plasma processing apparatus in this embodiment.

[0022] Figure 3 It is a schematic diagram showing the structure of the tray in this embodiment.

[0023] Figure 4 It is a schematic diagram showing the structure of the conveying mechanism in this embodiment.

[0024] Figure 5 It is a schematic diagram showing the structure of the plasma processing apparatus in other embodiments.

[0025] Figure 6 It is a schematic diagram showing the structure of the plasma processing apparatus in other embodiments.

[0026] Explanation of reference numerals

[0027] 100... Plasma processing apparatus

[0028] X... Substrate

[0029] Y... Tray

[0030] Ya... Hook portion

[0031] S1... Tray delivery chamber

[0032] S2... Plasma cleaning chamber

[0033] S3... Ion implantation chamber

[0034] S4... First film formation chamber

[0035] S5... Second film formation chamber

[0036] S6... Hydrophilic treatment chamber

[0037] S7... Tray storage chamber

[0038] S8... Differential exhaust chamber

[0039] 10... Lifting mechanism

[0040] P... Suction mechanism

[0041] 2... Antenna

[0042] 3... Heater

[0043] 11... Rope

[0044] 12... Conveying mechanism

[0045] 121... Endless belt

[0046] 13... Roller Specific embodiments

[0047] Hereinafter, an embodiment of the plasma processing apparatus of the present invention will be described with reference to the drawings.

[0048] The plasma processing apparatus of the present embodiment is a continuous film-forming apparatus capable of continuously forming films on multiple substrates. Hereinafter, an example of forming a gas barrier film having acid and alkali corrosion resistance on a substrate will be described. This gas barrier film is used for manufacturing separators for fuel cells, etc. In addition, the substrate is, for example, an aluminum substrate, etc., and the gas barrier film is, for example, a DLC coating film having conductivity and suppressing the permeation of sulfuric acid water that causes corrosion. However, the substrate and the coating film to be formed on the substrate are not limited to the following embodiments and can be changed according to circumstances.

[0049] As Figure 1 and Figure 2 shown, the plasma processing apparatus 100 holds the substrate in an upright state on the tray Y, and at the same time conveys the substrate X and the tray Y together to a plurality of plasma processing chambers S2 to S6. In addition, the upright state mentioned here is preferably a state along the vertical direction, but is not necessarily limited to this state, and may also be a state inclined from the vertical direction. Furthermore, as Figure 3 shown, the tray Y is in a frame shape, and a plurality of substrates X are hung and held vertically and horizontally in this frame.

[0050] Specifically, as Figure 1 and Figure 2 shown, the plasma processing apparatus 100 includes a tray delivery chamber S1, a plasma cleaning chamber S2, an ion implantation chamber S3, a first film-forming chamber S4, a second film-forming chamber S5, a hydrophilic treatment chamber S6, a tray storage chamber S7, and a lifting mechanism 10 for conveying the substrate X and the tray Y together to each chamber.

[0051] The tray delivery chamber S1 accommodates a plurality of trays Y and is a chamber for sequentially delivering these trays Y to the subsequent processing chambers. This tray delivery chamber S1 is evacuated by an attracting mechanism P such as a vacuum pump and maintained at a specified vacuum degree.

[0052] Together with the tray Y delivered from the tray delivery chamber S1, the substrate X held on the tray Y is sent into the plasma cleaning chamber S2, and the plasma cleaning chamber S2 is a processing chamber for performing plasma cleaning on the substrate X. Specifically, in the plasma cleaning chamber S2, at least a pair of antennas 2 are provided at positions sandwiching the substrate X. In the present embodiment, these pairs of inductively coupled antennas 2 are two groups and are arranged side by side in the conveying direction. And high-frequency power from a high-frequency power source (not shown) is applied to these antennas 2 through an integrator (not shown), and argon gas as a cleaning gas is supplied into the chamber, thereby generating inductively coupled discharge plasma including argon ions near the front and back surfaces of the substrate X. One surface (hereinafter referred to as the front surface) and the other surface (hereinafter referred to as the back surface) of the substrate X are cleaned by this argon plasma.

[0053] Together with the tray Y sent out from the plasma cleaning chamber S2, the substrate X held on the tray Y is fed into the ion implantation chamber S3, which is a processing chamber for implanting carbon ions into the substrate X. This ion implantation forms nuclei (so to speak, like the roots of hair) on the substrate X to improve the adhesion of the DLC coating described later. Specifically, in the ion implantation chamber S3, at least a pair of antennas 2 are provided at positions sandwiching the substrate X. In this embodiment, these pairs of inductively coupled antennas 2 are two groups, arranged side by side in the conveying direction. High-frequency power from a high-frequency power supply (not shown) is applied to these antennas 2 through an integrator (not shown), and a carbon compound gas such as methane as a source gas is supplied into the chamber. Thus, an inductively coupled discharge plasma containing carbon ions is generated near the front and back surfaces of the substrate X. Then, a negative DC voltage or a negative pulsed voltage from a bias power supply (not shown) is applied to the substrate X, and carbon ions are implanted into the front and back surfaces of the substrate X to form nuclei that contribute to improving the adhesion of the DLC coating.

[0054] Together with the tray Y sent out from the ion implantation chamber S3, the substrate X held on the tray Y is fed into the first film formation chamber S4, which is a processing chamber for generating a DLC coating on one surface (front surface) of the substrate X. Specifically, in the first film formation chamber S4, one or more antennas 2 are provided on the front surface side of the substrate X. In this embodiment, five inductively coupled antennas 2 are arranged side by side in the conveying direction. On the other hand, a heater 3 is provided on the back surface of the substrate X.

[0055] And, high-frequency power from a high-frequency power supply (not shown) is applied to the above antennas 2 through an integrator (not shown), and a mixed gas of nitrogen, methane, and acetylene is supplied into the chamber as a source gas. Thus, an inductively coupled discharge plasma including carbon ions is generated near the front surface of the substrate X. At this time, in order to make the DLC coating conductive, the surface of the substrate X substrate is heated to, for example, 150 to 400 °C by the above heater 3. Then, a negative DC voltage or a negative pulsed voltage from a bias power supply (not shown) is applied to the substrate X, and the substrate X is further heated by using the heater 3 or the ion energy in the plasma, and a conductive DLC coating is formed on the front surface of the substrate X.

[0056] Together with the tray Y sent out from the first film formation chamber S4, the substrate X held on the tray Y is fed into the second film formation chamber S5, which is a processing chamber for generating a DLC coating on the other surface (back surface) of the substrate X. Specifically, in the second film formation chamber S5, one or more antennas 2 are provided on the back surface of the substrate X. In this embodiment, five inductively coupled antennas 2 are arranged side by side in the conveying direction. On the other hand, a heater 3 is provided on the front surface side of the substrate X.

[0057] Further, high-frequency power from a high-frequency power supply (not shown) is applied to the above-described antenna 2 by an integrator (not shown), and a mixed gas of, for example, nitrogen, methane, and acetylene is supplied into the chamber as a source gas, whereby an inductively coupled discharge plasma including carbon ions is generated near the back surface of the substrate X. At this time, in order to make the DLC film conductive, the surface of the substrate X base is heated to, for example, 150 to 400°C by the above-described heater 3. Then, a negative DC voltage or a negative pulse voltage from a bias power supply (not shown) is applied to the substrate X, and the substrate X is further heated by the heater 3 or the ion energy in the plasma, and a conductive DLC film is formed on the back surface of the substrate X.

[0058] Together with the tray Y sent out from the second film formation chamber S5, the substrate X held on the tray Y is sent into the hydrophilic treatment chamber S6, which is a treatment chamber for performing a hydrophilic treatment on the substrate X and imparting hydrophilicity to the substrate X. Specifically, in the hydrophilic treatment chamber S6, at least a pair of antennas 2 are provided at positions sandwiching the substrate X. In the present embodiment, a set of these paired inductively coupled antennas 2 is provided. Further, high-frequency power from a high-frequency power supply (not shown) is applied to these antennas 2 by an integrator (not shown), and an inductively coupled discharge plasma including oxygen ions is generated near the front and back surfaces of the substrate X by supplying oxygen gas into the chamber. Through this oxygen plasma, a hydrophilic treatment is performed on one surface and the back surface of the substrate X.

[0059] Together with the tray Y sent out from the hydrophilic treatment chamber S6, the substrate X held on the tray Y is sent into the tray storage chamber S7, which is a chamber for storing and holding them. The tray storage chamber S7 is evacuated by an attracting mechanism P such as a pump, for example, to maintain a predetermined degree of vacuum.

[0060] These tray sending chambers S1, plasma cleaning chamber S2, ion implantation chamber S3, first film formation chamber S4, second film formation chamber S5, hydrophilic treatment chamber S6, and tray storage chamber S7 communicate with each other. Between the plasma cleaning chamber S2 and the ion implantation chamber S3, between the ion implantation chamber S3 and the first film formation chamber S4, and between the second film formation chamber S5 and the hydrophilic treatment chamber S6, there are differential exhaust chambers S8, and the differential exhaust chambers S8 are exhausted by an attracting mechanism P1 such as a common pump. Further, all of these chambers communicate through gaps (not shown) through which the tray Y can pass. Thus, the plasma cleaning chamber S2, ion implantation chamber S3, first film formation chamber S4, second film formation chamber S5, and hydrophilic treatment chamber S6 are differentially exhausted. Therefore, the plasma treatment chambers S2 to S6 can all be maintained at a predetermined degree of vacuum without providing gate valves or the like between the chambers.

[0061] The lifting mechanism 10 continuously conveys the tray Y into a plurality of plasma processing chambers S2 to S6. Here, the lifting mechanism 10 conveys the tray Y in sequence into the plasma cleaning chamber S2, the ion implantation chamber S3, the first film formation chamber S4, the second film formation chamber S5, and the hydrophilic treatment chamber S6. More specifically, it is conveyed from the tray delivery chamber S1 to the tray storage chamber S7.

[0062] Specifically, as Figure 4 shown, the lifting mechanism 10 has a rope 11 spanned across a plurality of plasma processing chambers S1 to S6, and a drive source such as a motor (not shown) that moves the rope 11 between the plurality of plasma processing chambers S2 to S6.

[0063] Here, as Figure 2 and Figure 4 shown, the hook portion Ya of the tray Y in the present embodiment for hooking the rope 11 is provided at, for example, the upper end portion and can be hung on the rope 11.

[0064] The rope 11 is a rope on which the hook portion Ya of the tray Y is hooked, and is made of, for example, metal, glass fiber, carbon fiber, etc. Here, it is a stainless steel rope.

[0065] In the present embodiment, the rope 11 is spanned across each chamber from the tray delivery chamber S1 to the tray storage chamber S7. After moving from the tray delivery chamber S1 to the tray storage chamber S7 above each chamber, it then moves from the tray storage chamber S7 to the tray delivery chamber S1 below each chamber and rotates around these chambers.

[0066] Furthermore, as Figure 4 shown, the plasma processing apparatus 100 in the present embodiment has a conveying mechanism 12, on which a plurality of trays Y are arranged side by side, and these trays Y are sequentially conveyed to the rope 11.

[0067] A plurality of trays Y are placed on the conveying mechanism 12, and at the same time, these trays Y are also sequentially conveyed to the rope 11. Specifically, for example, it has a pair of rollers 13 and an endless belt 121 wound around these rollers 13.

[0068] The relative positional relationship between the conveying mechanism 12 and the above-mentioned rope 11 is set such that by the tray Y falling from the edge of the endless belt 121, the hook portion Ya of the tray Y is hooked on the rope 11, so that the tray Y is hung on the rope 11.

[0069] If described more specifically, when the tray Y placed on the endless belt 121 and facing the rope 11 passes the apex of the front roller 13 around which the endless belt 121 is wound, it starts to gradually descend along the surface of the roller 13 and becomes an inclined state tilted forward. And the rope 11 and the endless belt 121 are arranged such that the hook portion Ya of the tray Y is hooked on the rope 11 before the tray Y falls.

[0070] In addition, the plasma processing apparatus 100 of the present embodiment is further provided with an unloading mechanism (not shown) that sequentially receives the trays Y from the rope after the film forming process.

[0071] This unloading mechanism has the same configuration as Figure 4 the shown conveying mechanism 12, and receives the tray Y by an operation opposite to that of the above-described conveying mechanism 12.

[0072] That is to say, such an unloading mechanism has, for example, a pair of rollers and an endless belt wound around these rollers. And, the tray Y sent by the rope 11 is placed on the endless belt and lifted, so that the hook portion Ya of the tray Y is disengaged from the rope 11, thereby recovering the tray Y.

[0073] With such a configuration, a plurality of trays Y placed on the conveying mechanism 12 are sent out to the rope 11 and automatically sequentially moved onto the rope 11. Thereafter, the rope 11 is moved by a drive source such as a motor (not shown), and is automatically sequentially conveyed to the above-described plasma processing chambers S2 to S6.

[0074] Moreover, a negative DC voltage or a negative pulse voltage (bias voltage) from the above-described bias power supply (not shown) is applied to the rope 11, and this bias voltage is applied to the substrate X through the rope 11 and the tray Y suspended from the rope 11.

[0075] In the plasma processing apparatus 100 of the present embodiment configured as described above, since the tray Y holding the substrate X can be continuously conveyed to the plurality of plasma processing chambers S2 to S6 by the lifting mechanism 10, even if the substrate X is difficult to roll up, continuous film forming processing can be performed. Of course, it goes without saying that the plasma processing apparatus 100 can be applied to a substrate X that is not difficult to roll up.

[0076] In addition, since the plurality of plasma processing chambers S2 to S6 communicate with each other and each processing chamber is differentially evacuated, by making the plurality of plasma processing chambers S2 to S6 communicate, the tray Y can be continuously conveyed, and at the same time, each plasma processing chamber S2 to S6 can be maintained at a desired degree of vacuum.

[0077] Furthermore, since the lifting mechanism 10 is constituted by using a rope 11 stretched across the plurality of plasma processing chambers S2 to S6, and the tray Y can be hung on the rope 11, the lifting mechanism 10 can be made into a simple configuration.

[0078] Moreover, since the conveying mechanism 12 sequentially sends out a plurality of trays Y to the rope 11, the sending out of the plurality of trays Y can be automated, so that a plurality of substrates X held in the plurality of trays Y can be continuously formed into films all at once, further improving the efficiency.

[0079] Moreover, since the conveying mechanism 12 has an endless belt 121 for sending the tray Y to the rope 11, and the tray Y falls from the edge of the endless belt 121, and the hook portion Ya provided on the tray Y is hung on the rope 11, so that the tray Y is suspended on the rope 11. Therefore, the automatic feeding of the tray Y can be realized with a simple structure.

[0080] In addition, the tray Y holding the substrate X in an upright state is conveyed to the plasma cleaning chamber S2, the ion implantation chamber S3, the first film forming chamber S4, the second film forming chamber S5, and the hydrophilic treatment chamber S6. Since a pair of antennas 2 are provided in the plasma cleaning chamber S2, the ion implantation chamber S3, and the hydrophilic treatment chamber S6 in such a manner as to sandwich the substrate X therebetween, plasma treatment can be performed on both sides of the substrate X in each chamber, and a DLC coating can be generated more effectively than before.

[0081] The present invention is not limited to the above-described embodiments.

[0082] For example, in the above-described embodiment, it is described that the rope 11 is a stainless steel rope. However, when the rope 11 is made of a conductive material such as metal or carbon fiber, since a bias voltage is applied to the substrate X through the rope 11, the same magnitude of bias voltage can be simultaneously applied to a plurality of substrates X respectively held in each tray Y.

[0083] On the contrary, the rope 11 can also be made of a non-conductive material such as a glass rope. In this case, as Figure 5 shown, for example, a conductive member D such as a pantograph can be provided in advance in each of the plasma treatment chambers S2 to S6, and a bias voltage can be applied to the substrate X through the conductive member D. In addition, in order to apply the bias voltage to the substrate X at an appropriate timing, as Figure 5 shown, the hook portion Ya can be elongated in the conveying direction.

[0084] With such a configuration, different magnitudes of bias voltage can be applied to the substrate X in each of the plasma treatment chambers S2 to S6. Since a bias voltage suitable for the treatment process in each of the plasma treatment chambers S2 to S6 can be applied to the substrate X, the degree of freedom in the film forming process can be increased, and a film of higher quality can be formed.

[0085] In addition, in the above-described embodiment, the rope 11 is provided so as to pass above and below the plasma treatment chambers S2 to S6. However, the arrangement of the rope 11 is not limited thereto. For example, as Figure 6 shown, the rope 11 can also be arranged to move back and forth between the plasma treatment chambers S2 to S6 above the plasma treatment chambers S2 to S6.

[0086] In addition, the base material X is not limited to aluminum, and may also have at least one metal among alloys such as nickel (Ni), iron (Fe), magnesium (Mg), titanium (Ti), or stainless steel containing these metals.

[0087] In addition, not only the methods described in the above embodiments can be used to form the gas barrier film, but also, for example, plasma CVD method, vacuum evaporation method, sputtering method, ion plating method, etc. can be used.

[0088] Needless to say, the present invention is not limited to the above embodiments, and various other changes are possible within the scope without departing from the object of the invention.

Claims

1. A plasma processing apparatus, characterized in that, Comprising: A plurality of plasma processing chambers for performing plasma processing on a substrate; A tray for holding the substrate in an upright state; A lifting mechanism for continuously transporting the tray to the plurality of plasma processing chambers, The lifting mechanism having: A rope spanned across the plurality of plasma processing chambers, with the tray hanging on the rope; and A drive source for moving the rope between the plurality of plasma processing chambers; and A conveying mechanism that conveys the tray to the lifting mechanism, wherein the conveying mechanism has an endless belt for sending the tray to the rope, By the tray falling from the edge portion of the endless belt, a hook portion provided on the tray is hooked on the rope, and the tray is suspended on the rope.

2. The plasma processing apparatus according to claim 1, wherein The plurality of plasma processing chambers communicate with each other, and a differential exhaust chamber is provided between each of the plasma processing chambers.

3. The plasma processing apparatus according to claim 1, wherein A plurality of the trays are provided on the conveying mechanism, and the plurality of trays are sequentially conveyed onto the rope.

4. The plasma processing apparatus according to claim 1, wherein The plasma processing chamber includes: a plasma cleaning chamber for performing plasma cleaning on the substrate; an ion implantation chamber for implanting carbon ions into the substrate; a first film forming chamber for forming a DLC film on one surface of the substrate; a second film forming chamber for forming a DLC film on the other surface of the substrate; and a hydrophilic treatment chamber for performing hydrophilic treatment on the substrate using oxygen plasma, The lifting mechanism sequentially conveys the tray to the plasma cleaning chamber, the ion implantation chamber, the first film forming chamber, the second film forming chamber, and the hydrophilic treatment chamber.

5. The plasma processing apparatus according to claim 4, wherein The plasma cleaning chamber, the ion implantation chamber, and the hydrophilic treatment chamber are each provided with at least a pair of antennas for generating plasma in the chamber at positions sandwiching the substrate.

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