JP2018028117A - Film deposition apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film deposition apparatus capable of stably depositing a film and suppressing the occurrence of abnormal discharge.SOLUTION: A film deposition apparatus 1 comprises a film deposition chamber 40 grounded and allowing evacuation and a gas supply nozzle 50 for supplying a material gas including the constituent element of a thin film in a base material 60 arranged in the film deposition chamber 40. The gas supply nozzle 50 is branched into a gas flow passage 51 extended along the front surface 61 of a base material 60 from one end side of the front surface 61 to the other end side and for ejecting the material gas on the side of the front surface 61 and a gas flow passage 52 extended along the rear surface 62 of the base material 60 from one end side on the rear surface 62 to the other end side and for ejecting the material gas on the side of the rear surface 62; the gas supply nozzle 50 is penetrated and connected in a hole formed in the side wall part of the film deposition chamber 40; and an insulator 70 is provided in a space between the hole and the gas supply nozzle 50.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a film forming apparatus for forming a thin film on a base material for a separator of a fuel cell.

  A fuel cell is attracting attention as a power generation system that generates electric power through an electrochemical reaction between hydrogen and oxygen. This fuel cell (for example, a polymer electrolyte fuel cell) generally has a stack structure in which a plurality of single cells are stacked.

  A single cell is configured by sandwiching both sides of a membrane electrode assembly with a pair of separators. Since this separator also plays a role of flowing current generated in a single cell to the adjacent single cell, the separator material constituting the separator is not only required to have high conductivity, but also its high conductivity is a fuel. Conductive durability that is maintained for a long time even in a high-temperature acidic atmosphere inside the battery cell is required.

  In view of such circumstances, by using the plasma film forming apparatus described in Patent Document 1 below, by forming a carbon-containing thin film on the surface of a base material for a fuel cell separator, high conductivity and durability are achieved. It is known to produce an applied separator. In the plasma film forming apparatus described in Patent Document 1 below, a raw material gas is turned into plasma by high-frequency power in a processing vessel (vacuum chamber), and a carbon-containing thin film is formed on the substrate by the plasma. In this plasma film forming apparatus, the gas nozzle for supplying the source gas is provided on the side wall surface portion of the vacuum chamber that does not face the cathode electrode and the ground electrode.

JP 2001-284262 A

  By the way, in order to form a uniform film on the entire front and back surfaces of the base material, it is necessary to uniformly supply the gas to the base material. For this purpose, it is desirable to install a gas nozzle near the base material. However, if the gas nozzle is installed near the substrate, the gas nozzle becomes an electrode, plasma is generated between the substrate and the gas nozzle, and a film adheres to the gas nozzle. If a film is deposited on the gas nozzle outlet, abnormal discharge may occur.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a film forming apparatus capable of performing stable plasma film formation while improving the uniformity of the gas supplied to the substrate. There is.

  In order to solve the above-mentioned problems, a film forming apparatus according to the present invention is a film forming apparatus for forming a thin film on a substrate for a fuel cell separator, and a grounded film forming chamber capable of being evacuated, A gas supply nozzle connected to the film formation chamber and configured to supply a source gas containing a constituent element of the thin film to the substrate disposed in the film formation chamber, and the gas supply nozzle An injection nozzle that extends along the surface from one end side to the other end side of the surface and injects the raw material gas to the surface side, and from the one end side of the back surface of the base material to the other end side The gas supply nozzle is penetratingly connected to a hole formed in a side wall portion of the film forming chamber, and is branched to an injection nozzle that extends along the back surface and injects the source gas to the back surface side, and An insulating member is formed in the gap between the hole and the gas supply nozzle. It has been kicked.

  In the present invention, the spray nozzle extending along the surface from one end side to the other end side of the surface of the base material, and extending along the back surface from the one end side of the back surface of the base material toward the other end side. Since the source gas can be supplied uniformly over a wide range of the front and back surfaces of the base material by the gas supply nozzle including the existing injection nozzle, the uniformity of the film formed on the base material can be improved. Further, since the gas supply nozzle is insulated from the film formation chamber by the insulating member provided in the gap between the gas supply nozzle and the hole formed in the side wall portion of the film formation chamber, the discharge between the gas nozzle and the substrate is performed. Stable film formation can be performed even when the gas nozzle is close to the substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the film-forming apparatus which can perform the stable plasma film-forming can be provided, improving the uniformity of the gas supplied to a base material.

It is explanatory drawing which shows schematic structure of the film-forming apparatus in this embodiment. It is explanatory drawing which shows the side surface of the film-forming chamber of FIG. It is explanatory drawing which shows the front of the film-forming chamber of FIG. It is explanatory drawing which shows schematic structure of the gas supply nozzle of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. It should be noted that the following description of the preferred embodiment is merely an example, and is not intended to limit the present invention, its application, or its use. 1 to 4, the X direction and the Y direction indicate directions parallel to the horizontal plane, and the Z direction indicates a direction parallel to the vertical direction.

  FIG. 1 is an explanatory diagram showing a schematic configuration of a film forming apparatus 10 according to the present embodiment. The film deposition apparatus 10 converts one or more source gases of a compound containing constituent elements of a thin film into plasma by plasma CVD, which is a kind of chemical vapor deposition method, and forms carbon on the entire surface of the substrate 60 to be deposited. A containing thin film is formed. The structure of the carbon-containing thin film formed on the substrate 60 may be an amorphous structure, a graphite structure, or another type of structure. In addition, as the base material 60, it can be set as the flat metal plate used as a base material of the separator of a fuel cell, for example.

  The film forming apparatus 10 includes a film forming chamber 40, a preheating chamber 30, and a transport mechanism 20. The film forming chamber 40 forms a carbon-containing thin film on both surfaces of the substrate 60 in the presence of plasma. The preheating chamber 30 preheats both surfaces of the base material 60 uniformly before forming a thin film on the base material 60 in the presence of plasma in the film forming chamber 40. The transport mechanism 20 is a device that transports the substrate 60 between the preheating chamber 30 and the film forming chamber 40.

  The transport mechanism 20 is configured to reciprocately slide the cylinder shaft 22 along the cylinder cylinder 21, the cylinder cylinder 22 disposed so as to be reciprocally slidable along the inner wall of the cylinder cylinder 21, and the cylinder cylinder 21. The sliding mechanism 23 is provided. The sliding mechanism 23 is an annular slider that is slidably fitted along the outer wall of the cylinder cylinder 21, and a magnet 24 is provided therein. A magnet 25 that interacts with the magnet 24 is provided near the end of the cylinder shaft 22, and is linked to the reciprocating motion of the sliding mechanism 23 using the magnetic force acting between the magnets 24 and 25. Thus, the cylinder shaft 22 can be reciprocated. A valve body 26 and a jig 27 connected to the valve body 26 are provided at the tip of the cylinder shaft 22. The jig 27 is a member for holding the base material 60.

  The preheating chamber 30 is installed in the preheating space, a housing 31 that defines the preheating space, a lid 32 that can be opened and closed with respect to the housing 31 in order to carry the base material 60 into the preheating chamber 30. An infrared lamp heater 33 that preheats the base material 60 and a shutter 34 that can be opened and closed to transport the base material 60 between the preheating chamber 30 and the film formation chamber 40 are provided. Although not shown in FIG. 1, the preheating chamber 30 includes a vacuum pump that evacuates the preheating chamber 30 when the substrate 60 is preheated, and sets the temperature of the substrate 60 to the target temperature. And a control unit for controlling the intensity of infrared rays emitted from the infrared lamp heater 33 in order to match.

  The film formation chamber 40 includes a casing 41 (chamber) that defines a plasma generation space, a pair of counter electrodes 42 and 43 that generate a voltage necessary for plasma generation, and a raw material gas containing constituent elements of a thin film. And a gas supply nozzle 50 for spraying on the front surface and the back surface. Although not shown in FIG. 1, the film forming chamber 40 includes a vacuum pump that evacuates the film forming chamber 40 when a thin film is formed on the substrate 60, and a raw material that supplies a raw material gas to the gas supply nozzle 50. A gas supply source, a plasma generating power source for applying a voltage with a base material 60 as a cathode and a pair of counter electrodes 42 and 43 as an anode, and an exhaust gas containing atoms that have not been used for plasma film formation are formed. An exhaust gas treatment unit for exhausting air from the membrane chamber 40. As source gas, pyridine which is 1 type of the amine of a heterocyclic aromatic compound can be used, for example. The source gas may contain nitrogen atoms or silicon atoms in addition to carbon atoms. The cation of the carbon atom of the source gas in the plasma is adsorbed and deposited on the front and back surfaces of the substrate 60 that is the cathode, thereby forming a carbon-containing thin film.

  Note that the control unit (not shown) includes control of the supply amount of the source gas in the film forming chamber 40, control of a vacuum pump that evacuates the film forming chamber 40, heating control in the preheating chamber 30, control of the transfer mechanism 20, and the like. Controlled by

  Next, the configuration of the gas supply nozzle 50 will be described with reference to FIGS. 2 to 4. 2 is an explanatory view showing the side of the film forming chamber 40, FIG. 3 is an explanatory view showing the front of the film forming chamber 40, and FIG. 4 is an explanatory view showing a schematic configuration of the gas supply nozzle 50. Note that, for example, the aspect ratio (shape) of the film formation chamber 40 in FIG. 1 is different from that in the film formation chamber 40 in FIG. 2, but this is for the sake of convenience of the drawing, and the film formation chamber 40 in FIG. This is the same as the film forming chamber 40 of No. 1. The members denoted by the same reference numerals in the respective drawings are the same for other portions having different aspect ratios.

  The gas supply nozzle 50 extends from one end side to the other end side of the surface 61 of the substrate 60 and injects a raw material gas toward the surface 61, and a back surface 62 of the substrate 60. A gas flow path 52 (injection nozzle) that extends from one end side to the other end side and injects the source gas toward the back surface 62, and a branch flow that bifurcates the source gas supplied from the source gas supply source A gas flow path 53 that leads to the gas flow paths 51 and 52 via the path 54 is provided. In the gas channel 51 and the gas channel 52, a plurality of injection holes (not shown) are formed on the surface on the base material 60 side, and the raw material gas is injected from the injection holes toward the base material 60. For example, a metal material is used for the gas supply nozzle 50.

  The gas flow path 51 is bent in a substantially U shape so as to surround the three sides of the substrate 60 in a plane parallel to the surface 61 of the substrate 60. Similarly, the gas flow path 52 is bent in a substantially U shape so as to surround three sides of the substrate 60 in a plane parallel to the back surface 62 of the substrate 60.

  An insulator 70 is provided at the connection between the gas flow path 53 and the film forming chamber 40. Specifically, a hole (a hole larger than the outer diameter of the gas flow channel 53) is formed in one side wall portion of the film forming chamber 40, and the gas flow channel 53 is disposed so as to penetrate the hole. (See FIG. 3), an insulator 70 is provided in the gap between the inner peripheral surface of the hole formed in the side wall portion and the outer peripheral surface of the gas flow path 53. As a result, the gas supply nozzle 50 and the grounded film formation chamber 40 (vacuum chamber) are electrically insulated. Thus, the gas supply nozzle 50 insulated from the film forming chamber 40 is not in the same potential as the ground electrode but in a so-called floating potential, and the ground electrode (0 V) and the electrode of the substrate 60 (−3 kV). An intermediate potential is taken. Thereby, the potential difference between the gas supply nozzle 50 and the substrate 60 can be reduced, and the gas supply nozzle 50 can be brought closer to the substrate 60. In addition, a potential difference (potential difference smaller than the potential difference between the base material 60 and the counter electrodes 42 and 43) is applied only to the portion of the gas supply nozzle 50 facing the counter electrodes 42 and 43. However, the discharge is weaker than that of the base material 60. In addition, since the discharge and the film are formed on the surface (back surface) opposite to the injection hole for ejecting the gas, the formation of the film on the injection hole can be suppressed. Thereby, deposition of a film on the injection hole is suppressed, and abnormal discharge can be suppressed.

  Note that the material used for the insulator 70 is not particularly limited as long as it has an insulating property. For example, alumina can be used.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In other words, those specific examples that have been appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. Each element included in each of the specific examples described above and their arrangement, material, condition, shape, size, and the like are not limited to those illustrated, and can be appropriately changed.

DESCRIPTION OF SYMBOLS 10: Film-forming apparatus 20: Conveying mechanism 21: Cylinder cylinder 22: Cylinder shaft 23: Sliding mechanism 30: Preheating chamber 33: Infrared lamp heater 34: Shutter 40: Film-forming chamber 42, 43: Counter electrode 50: Gas supply nozzle 51, 52: Gas flow path (injection nozzle)
60: Base material 70: Insulator (insulating member)

Claims (1)

A film forming apparatus for forming a thin film on a base material for a fuel cell separator,
A grounded deposition chamber that can be evacuated;
A gas supply nozzle connected to the film formation chamber and configured to supply a source gas containing a constituent element of the thin film to the base material disposed in the film formation chamber;
The gas supply nozzle extends from one end side to the other end side of the surface of the base material so as to follow the surface, and an injection nozzle that injects the source gas to the surface side, and a back surface of the base material Branched from one end side to the other end side along the back surface and branched to an injection nozzle for injecting the raw material gas to the back surface side,
The film forming apparatus, wherein the gas supply nozzle is through-connected to a hole formed in a side wall portion of the film forming chamber, and an insulating member is provided in a gap between the hole and the gas supply nozzle.

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