JP4832046B2 - Continuous thermal CVD equipment - Google Patents

Description

  The present invention relates to a continuous thermal CVD apparatus mainly comprising a belt conveyor used for production of a film or a carbon nanotube.

  A film formation method by chemical vapor deposition (hereinafter referred to as CVD method) is a method in which a substrate is placed in a reaction tube in an inert gas atmosphere, a raw material gas is sent into the reaction tube, and catalyst fine particles provided on the substrate are used as nuclei. In this method, a film or a carbon nanotube is formed on the substrate surface. The CVD method is classified into a thermal CVD method using heat, a plasma CVD method using plasma, and a photo CVD method using light energy. Further, the CVD apparatus is classified into a low pressure CVD apparatus that forms a film in a reduced pressure state and an atmospheric pressure CVD apparatus that performs at atmospheric pressure.

As a thermal CVD apparatus, a batch type apparatus in which one or a plurality of substrates is supplied to a reactor at a time to form a film is generally used. In this apparatus, once a reaction is performed, it is necessary to replace the substrate and gas in the reactor each time. Therefore, the operation time is long, and a large amount of carrier gas and source gas are required. It was difficult to supply the substrate. For this reason, a continuous CVD apparatus has been developed in which a substrate is continuously supplied into a reactor by a conveying means such as a belt conveyor to generate a film (see Patent Document 1).
JP 2000-77340 A

  However, in an atmospheric pressure CVD apparatus in which a substrate is continuously supplied into the reactor to form a film at atmospheric pressure, if the seal between the atmosphere in the reactor and its outside air is insufficient, Impurity gas components and particles are mixed into the substrate, resulting in non-uniform film formation on the substrate surface, and particles adhering to the substrate, resulting in a low product yield. Also, with conventional CVD devices, it is difficult to control the temperature distribution and gas flow of the substrate and gas in the vicinity of the substrate when supplying or heating the source gas in the reactor, regardless of whether it is a batch type or a continuous type. The distribution and the gas flow are likely to be uneven, which has been a factor in reducing the uniformity of the film formed on the substrate.

  In view of the above problems, the present invention has high uniformity because it is easy to control the temperature distribution and gas flow of the substrate and gas in the vicinity of the substrate without the possibility of impurity gas components and particles entering the reactor. It is an object of the present invention to provide a continuous thermal CVD apparatus capable of forming a film.

The present invention relates to a loop belt conveyor arranged horizontally, a substrate supplied on one end of the conveyor, and a substrate preheating provided from the central portion of the length of one side of the conveyor to the arc portion of the other end. A zone, a CVD heating zone provided from the other end to the center of the length on the other side of the conveyor, a carrier gas inlet provided on the other end of the conveyor, and an upper portion in the carrier gas inlet Bei example a feed gas inlet provided in the CVD heating zone facing the extension portion of the raw material gas inlet is led to the top of the other side of the other end arc part of the belt conveyor, the extension portion from the substrate A continuous CVD apparatus having a wide nozzle is provided.

  The continuous CVD apparatus according to the present invention preferably includes an exhaust path for discharging a gas mixture of unreacted raw material gas and carrier gas, and a seal gas supply path provided adjacent to the exhaust path.

  In this specification, the right end of the continuous CVD apparatus shown in FIG. 1 is one end, the left end is the other end, the upper side is one side, and the lower side is the other side.

  The continuous CVD apparatus according to the present invention is provided with a substrate preheating zone provided from the central length of one side of the conveyor to the arc of the other end, and provided from the other end to the central length of the other side of the conveyor. Since only the necessary portions of the conveyor are heated in these zones, energy saving can be achieved as compared with an apparatus for heating the entire conveyor, and the cost of the product can be reduced.

  In addition, since this apparatus is provided with a carrier gas inlet on the other end of the conveyor, by flowing a part of the gas into the preheating zone, the gas preheated in the preheating zone is transferred from the zone to the CVD heating zone. It is possible to prevent the inflow of impurities, thereby reliably preventing impurity gas components and particles contained in the preheating gas from entering the CVD heating zone, and improving the yield of products.

  In addition, according to this apparatus, since the substrate is moved between the substrate preheating zone and the CVD heating zone, the generation area is not limited, and a uniform and large-area film can be generated.

  Furthermore, by providing a seal gas supply passage adjacent to the exhaust passage, it is possible to prevent the outside air from flowing into the CVD heating zone, and impurity gas components and particles contained in the outside air are mixed into the CVD heating zone. Can be surely prevented.

  Next, in order to describe the present invention specifically, an embodiment of the present invention is shown.

  In FIG. 1 and FIG. 2, a loop belt conveyor (1) composed of straight sections on both sides and circular arc sections on both ends is horizontally arranged. On one end of the belt conveyor (1), a silicon substrate (4) carrying a catalyst (not shown) is continuously supplied. An exhaust passage (13) is provided on the top wall of the casing (5) so as to rise in front of the substrate carrying-in portion in the rotational direction, whereby a gas mixture containing a carrier gas and the like is discharged out of the apparatus. The belt conveyor (1) is housed in a casing (5) having a substantially U-shaped horizontal section except for a portion near one end thereof. A preheating zone (9) is provided from the length central portion on one side of the belt conveyor (1) to the arc portion on the other end.

  On the other side of the belt conveyor (1), a CVD heating zone (11) is provided from the other end to the center of the length. The preheating zone (9) and the CVD heating zone (11) in front of the rotation direction are continuous as shown by a one-dot chain line (a) in the figure, and are heated to a required temperature by heating means (not shown).

  On the other end of the casing (5) containing the belt conveyor (1), a carrier gas inlet (2) is provided horizontally on the vertical end wall (12), and the upper part in the inlet (2) The material gas inlet (3) is horizontally provided in the direction of the CVD heating zone (11), and its extension (6) extends to the other side of the other end arc portion of the belt conveyor (1). The extension part (6) of the raw material gas inlet (3) has a flat nozzle (6a) wider than the substrate (4) (width 100 mm × height 5 mm). The lower wall tip (6b) of the flat nozzle (6a) is an inclined wall inclined forward and downward. With such a configuration, the mixed gas of the source gas and the carrier gas is evenly supplied onto the substrate (4) from the flat nozzle (6a), and the carrier gas flows between the flat nozzle (6a) and the substrate (4). . The carrier gas introduces the source gas from the other side of the other end of the casing (5) into the CVD heating zone (11) and passes the inside of the other side of the casing (5). The carrier gas also serves to prevent gas flow from the substrate preheating zone (9) to the CVD heating zone (11), and further prevents the mixed gas of the source gas and carrier gas from flowing backward and completely leaking out. Work as well. Uniform thickness of the film (7) formed on the surface of the substrate (4) by uniformly supplying a mixed gas of source gas and carrier gas from the flat nozzle (6a) onto the substrate (4) Can do. Moreover, a film (7) having a desired uniform thickness can be formed by appropriately controlling the supply amount and / or concentration of the carrier gas as the seal gas and the mixed gas of the source gas and the carrier gas.

  An exhaust passage (8) is provided on the top wall of the casing (5) so as to rise in front of the CVD heating zone (11) in the direction of rotation, so that a gas mixture of unreacted raw material gas and carrier gas is removed from the outside of the apparatus. Is discharged. A seal gas supply passage (10) is provided adjacent to the exhaust passage (8) in front of the rotation direction.

  In the continuous film production apparatus having the above-described configuration, a plurality of substrates (4) are continuously supplied from one end of the belt conveyor (1) onto the conveyor belt. The substrate (4) is then sent to a preheating zone (9) where it is preheated and passes through the other end arc of the belt conveyor (1) to enter the CVD heating zone (11). A part of the carrier gas (inert gas such as helium gas or argon gas) is fed into the preheating zone (9) from the inlet (2). This prevents the gas preheated in the preheating zone (9) from flowing into the CVD heating zone (11) from the zone (9), and the impurity gas components and particles contained in the preheating gas are prevented from flowing into the CVD heating zone. Can be surely prevented.

In the CVD heating zone (11), the raw material gas for film formation from the raw material gas inlet (3) through the raw material gas passage (6) and the remainder of the carrier gas from the carrier gas inlet (2) A gas mixture is supplied. As a result, a film (7) is formed on the surface of the substrate (4). Substrate with membrane (7) (4)
Next, it leaves the casing (5) and is carried out of the apparatus from the belt conveyor (1). A seal gas supply passage (14) having the same structure as the seal gas supply passage (10) is provided at one end of the casing (5) adjacent to the front of the substrate carrying-in portion in the rotation direction.

  The gas mixture of the unreacted material gas and the carrier gas is discharged out of the apparatus through the exhaust path (8). Seal gas is blown into the casing (5) through the air supply passages (10), (14). This prevents outside air from flowing into the CVD heating zone (11) from the front of the casing (5) in the rotation direction and from the substrate carry-in portion, and impurity gas components and particles contained in the outside air are mixed into the CVD heating zone. Can be surely prevented.

It is a top view which shows a film | membrane continuous manufacturing apparatus. It is a vertical longitudinal cross-sectional view which shows a film | membrane continuous manufacturing apparatus.

Explanation of symbols

(1): Loop belt conveyor
(2): Carrier gas inlet
(3): Raw material gas inlet
(4): Board
(5): Casing
(6): Extension
(6a): Flat nozzle
(8) (13): Exhaust passage
(9): Preheating zone
(10) (14): Seal gas supply passage
(11): CVD heating zone
(12): Vertical wall

Claims (2)

Horizontally arranged loop belt conveyor, substrate supplied on one end of the conveyor, substrate preheating zone provided from the center of the length of one side of the conveyor to the arc of the other end, the conveyor A CVD heating zone provided on the other side from the other end to the center of the length, a carrier gas inlet provided on the other side of the other end of the conveyor, and a CVD heating zone on the upper side in the carrier gas inlet e Bei a feed gas inlet provided in the orientation, the extension of the raw material gas inlet is led to the top of the other side of the other end arc part of the belt conveyor, said extension portion is a wider nozzle from the substrate A continuous CVD apparatus.   The continuous CVD apparatus according to claim 1, further comprising: an exhaust path for discharging a gas mixture of unreacted raw material gas and carrier gas; and a seal gas supply path provided adjacent to the exhaust path.

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