JP6717632B2 - Vapor deposition processing equipment - Google Patents

Description

The present invention relates to a vapor deposition processing apparatus suitable for chemical vapor deposition (CVD), particularly counter diffusion CVD.

Chemical vapor deposition (CVD) is known as a technique for forming a thin film or the like by attaching the evaporated substance to the surface of a material to be processed. In particular, counter diffusion CVD is widely used for producing a ceramic-based gas separation material used for separating and purifying a specific gas component such as hydrogen gas from a mixed gas.

FIG. 9 is a schematic diagram illustrating the concept of counter diffusion CVD. In counter-diffusion CVD, a source gas (for example, an organosilicon compound gas) and a counter gas (for example, oxygen gas) that reacts with the source gas are counter-diffused from both ends of the pores of the porous base material, and then inside the pores. React. The reaction product is vapor-deposited on the inner wall of the pore, and when the reaction proceeds, the pore is blocked by the reaction product, so that the reaction ends when the contact of both gases is blocked. As a result, the closed portion F formed in the pores becomes an extremely thin film.

As a ceramic-based gas separation material, a separation active layer made of silica or the like is used because it is possible to perform gas separation by the sub-nano-sized pores of the material itself. To manufacture the silica film used as the separation active layer by counter diffusion CVD, for example, a gas containing tetramethoxysilane and oxygen gas are heated in a state of being counter diffused from both ends of the pores of the porous substrate. As a result, silica is formed so as to close the pores. The formed blocking portion is made of an extremely thin silica film having a thickness of about 50 to 500 nm. Since the gas permeation rate is inversely proportional to the film thickness, it is effective to use an extremely thin silica membrane for the separation active layer because the permeation rate at the time of gas separation is increased and the separation treatment capacity is increased.

Patent Document 1, Patent Document 2 and Patent Document 3 disclose a method for producing a gas separating material using a counter diffusion CVD method. In the counter diffusion CVD method, usually, an oxygen-containing gas as a counter gas is supplied into the cylinder of a cylindrical porous substrate, and an organosilicon compound gas as a source gas is supplied to the outer peripheral surface side at a predetermined temperature. By being heated, a silica film is formed inside the pores of the porous substrate.

JP, 2007-216106, A JP, 2009-202096, A International Publication No. 2014/007140

However, it has been found that in the conventional apparatus disclosed in each of the above patent documents, the vapor deposition process becomes more difficult as the total length of the porous substrate increases, in other words, the processing area increases. At the beginning of film formation, the processing chamber is filled with the source gas and the counter gas. As the vapor deposition process progresses, the raw material gas and the counter gas are consumed and reduced. Therefore, the raw material gas and the counter gas are additionally supplied until the processing is completed. However, when the length of the porous substrate is increased and the treatment area is increased, the phenomenon that silica is deposited in the form of powder on the surface of the porous substrate is observed, and it is found that there is a problem that a good vapor deposition process cannot be performed. .. Further, the generated silica powder also causes the pipe of the vapor deposition processing device to be clogged, and it is difficult to continuously perform the processing.

In view of the above problems, it is an object of the present invention to provide a vapor deposition processing apparatus capable of performing a desired vapor deposition processing even when the processing area is increased due to the lengthening of a substrate. ..

As a result of earnest research to solve this problem, the present inventors have found that the cause of the generation of silica powder is the imbalance of the partial pressures of the source gas and the counter gas in the processing chamber. By developing this result, the invention described below was completed.

That is, the present invention is a vapor deposition process in which a source gas and a counter gas are counter-diffused from both end sides of the pores of a porous portion having a plurality of pores, and chemical vapor deposition is performed on inner walls of the pores. A device,
A processing chamber that contains a material to be processed having the portion to be processed in a position that divides a raw material gas supply side to which the raw material gas is supplied and a counter gas supply side to which the counter gas is supplied,
Source gas supply means for supplying the source gas to the source gas supply side from a plurality of locations,
Counter gas supply means for supplying the counter gas to the counter gas supply side,
Exhaust means for exhausting the processing chamber,
Energy applying means for applying energy to at least the raw material gas supplied to the processing chamber,
Equipped with.

As described above, the inventors of the present application have found out that the cause of the generation of silica powder is the imbalance of the partial pressures of the source gas and the counter gas in the processing chamber. In the conventional vapor deposition processing apparatus, the supply position of the raw material gas is limited to one position with respect to the processing chamber that houses the material to be processed. In the vicinity of the supply position of the source gas, sufficient source gas exists. However, in a location away from the source gas supply position, the partial pressure is imbalanced due to the lack of source gas, and the opposing gas is jetted from the opposing gas supply side to the source gas supply side through the pores of the processed part. However, it is considered that the reaction products are pulverized without being vapor-deposited in the pores due to the reaction of both gases at the position apart from the processed portion on the raw material gas supply side.

In order to suppress such a phenomenon, it was newly conceived to supply the source gas into the processing chamber from a plurality of locations. By supplying the raw material gas into the processing chamber from a plurality of locations, the partial pressure in the processing chamber is balanced even if the vapor deposition process proceeds. Therefore, even when processing a large material to be processed having a large processing area, pulverization of the raw material gas is suppressed, and a desired vapor deposition processing can be performed.

It should be noted that each of the conventional vapor deposition processing apparatuses has only one source gas supply port, and was not aware of the above problems in the first place. Therefore, the present invention is an invention made from a new point of view that has never existed before.

The vapor deposition processing apparatus of the present invention enables favorable vapor deposition to be performed on a large area to be processed, which has been difficult to perform vapor deposition in the past.

It is a schematic diagram for explaining a vapor deposition equipment of the present invention. 3 is a schematic diagram showing a vapor deposition processing apparatus of Example 1. FIG. FIG. 3 is a schematic diagram showing a material to be processed used in the vapor deposition processing apparatus of Example 1. It is a schematic diagram which shows the vapor deposition processing apparatus of Example 2 partially. It is a schematic diagram which shows the vapor deposition processing apparatus of Example 3 partially. It is a schematic diagram which shows the vapor deposition processing apparatus of Example 4 partially. It is a schematic diagram which shows the vapor deposition processing apparatus of Example 5 partially. It is a schematic diagram which shows the vapor deposition processing apparatus of Example 6 partially. It is a schematic diagram explaining the concept of counter diffusion CVD.

Below, the form for implementing the vapor deposition processing equipment of the present invention is explained. The upper limit and the lower limit of the numerical range described in the present specification, and the numerical ranges listed in the examples can be arbitrarily combined to form the numerical range.

The present invention relates to a vapor deposition processing apparatus that performs a chemical vapor deposition on the inner wall of the pores by facing and diffusing a source gas and a counter gas from both ends of the pores of a porous portion having a plurality of pores to be processed. Is. In other words, the vapor deposition processing apparatus is suitable for performing counter diffusion CVD. The vapor deposition processing apparatus mainly includes a processing chamber, a source gas supply unit, a counter gas supply unit, an exhaust unit, and an energy applying unit.

<Processing room>
The processing chamber houses a material to be processed having a portion to be processed in a position that divides a source gas supply side to which a source gas is supplied and a counter gas supply side to which a counter gas is supplied. The treatment chamber is not particularly limited as long as it is a container capable of maintaining the airtightness necessary for vapor deposition treatment. The material of the container is not particularly limited, but a material having low reactivity with the raw material gas, for example, ceramics such as quartz glass and various metals are desired. Further, if the energy applying means described later has a structure of heating from the outside of the processing chamber, it is preferably made of metal having excellent heat conduction. Specific examples thereof include stainless steel, nickel-based alloys such as Inconel (registered trademark) and Hastelloy (registered trademark).

The shape of the container forming the processing chamber is not particularly limited as long as the material to be processed can be stored at a predetermined position, and may be appropriately selected according to the shape of the material to be processed. The number of materials to be treated is not limited, and the inside of the processing chamber is divided into a source gas supply side that contacts one surface of the processing target part and a counter gas supply side that contacts the other surface facing away. It only needs to be partitioned. The direction in which the processing chamber is partitioned is not limited, and may be partitioned in the horizontal direction, the vertical direction, or any other direction. The method for accommodating the material to be treated at a predetermined position is not particularly limited, but at least it is necessary to divide the processing chamber into the source gas supply side and the counter gas supply side while maintaining the airtightness of the processing chamber. It is desired to hold the treated part in a hermetically sealed state. For example, the material to be treated may be held by being sandwiched by seal members. The seal member may be appropriately selected depending on the shape and size of the processing chamber and the material to be processed, but various squeeze type gaskets represented by O-rings may be used. Further, the material of the sealing member may be appropriately selected from inorganic or organic sealing members according to usage conditions. Examples of the organic seal member include various resins, natural rubber, synthetic rubber and the like. Specific examples thereof include fluororubber, nitrile rubber, silicone rubber, ethylene propylene rubber, chloroprene rubber, perfluoroelastomer and polytetrafluoroethylene. Under the use conditions in which the sealing member has a high temperature, it is desirable to use an inorganic sealing member such as ceramics or various metals from the viewpoint of heat resistance. As the inorganic seal member, specifically, a graphite sheet, a hollow O-ring made of a metal such as stainless steel or a nickel-based alloy, a C ring, an E ring, or a U ring can be used.

However, in order to favorably diffuse the source gas and the counter gas in the pores of the processed portion, the portion of the processed material excluding the processed portion, that is, the portion where the vapor deposition process is not performed is the source gas and/or Or do not let the opposite gas pass. Even when the entire material to be processed is porous, by sealing the pores and providing gas sealing properties to the portions where vapor deposition processing is unnecessary, counter diffusion within the pores of the processed portion can be achieved. It is done efficiently. For example, one or more of borosilicate glass, aluminosilicate glass, quartz, glass such as vanadium-based glass, talc, clay such as clay, metal such as titanium and aluminum, ceramics such as alumina, and carbon as main components. It is advisable to seal unnecessary pores with an inorganic sealing material. As with the sealing member, it is desired that the sealing material be appropriately selected according to the usage conditions.

The processing chamber will be described with reference to the drawings. Figure 1 is a schematic view for explaining a vapor deposition equipment of the present invention. The vapor deposition processing apparatus described with reference to FIG. 1 has a processing chamber 1 for performing a vapor deposition process on a porous substrate 1s as a material to be processed. The porous substrate 1s has a circular flat plate shape, and is made of a porous body having a large number of pores penetrating from one surface side opposite to the other surface side. The porous substrate 1s is provided with a seal 1s' made of a carbon-based sealing material on the surface of the peripheral edge portion. The portion of the porous base material 1s that is not covered with the seal 1s' is the portion to be processed. The processing chamber 1 comprises an upper chamber 1A and a lower chamber 1B, both of which are made of stainless steel and have a bottomed cylindrical shape. The porous base material 1s is sandwiched by the open end portions of the upper chamber 1A and the lower chamber 1B with the peripheral edge portion sealed with the seal 1s' via the metal U-rings 1a and 1b. As a result, the upper chamber 1A, the metal U-ring 1a, the porous substrate 1s, the metal U-ring 1b and the lower chamber 1B are coaxially arranged in order, and the upper chamber 1A and the lower chamber are crushed to crush the metal U-rings 1a and 1b. By tightening and fixing the chamber 1B, the inside of the processing chamber 1 is divided into a source gas supply side 2a and a counter gas supply side 3b while maintaining airtightness.

<Source gas supply means>
The raw material gas supply means supplies the raw material gas to the raw material gas supply side of the processing chamber from a plurality of locations. The raw material gas supply means may have a plurality of raw material gas supply ports. The source gas supply port may be a plurality of openings formed in the processing chamber, or may be a plurality of holes or a plurality of nozzles provided in a pipe formed to branch into a plurality of flow paths in the processing chamber. Good. Further, it is desirable that the raw material gas supply means has a raw material gas pipe that connects the raw material gas tank for storing the raw material gas and the processing chamber. A plurality of source gas tanks and source gas pipes may be provided according to the number of source gas supply points, or the source gas tank may be shared by a plurality of source points. When the source gas tank is shared, the source gas pipe may be branched depending on the number of source gas supply ports connected. The material of the pipe is not particularly limited, and the same material as the container forming the processing chamber can be used.

In the case of containing a material to be processed having a long processing target portion in the processing chamber, the raw material gas supply means is composed of a plurality of raw material gas supply ports arranged at intervals in the longitudinal direction of the processing target portion. that it has a. At this time, the adjacent individual source gas supply ports may be arranged on the same straight line in the longitudinal direction, or the positions may be intentionally changed in a direction intersecting with the longitudinal direction. In particular, when accommodating a material to be treated having a cylindrical portion to be treated in the treatment chamber, the individual source gas supply ports adjacent to each other in the longitudinal direction of the portion to be treated are located at different positions in the circumferential direction of the portion to be treated. May be located at. That is, the individual source gas supply ports may be arranged at a predetermined interval in the axial direction and at a predetermined angle in the circumferential direction. Further, it is desirable that the individual source gas supply ports are arranged at least at both ends in the longitudinal direction of the portion to be processed.

As an upper limit of the interval between the center positions of the adjacent source gas supply ports, 200 mm is preferable, 150 mm is more preferable, and 100 mm is particularly preferable. The lower limit of the distance between the center positions of adjacent source gas supply ports is not particularly limited, but is preferably 30 mm, more preferably 40 mm, and particularly preferably 50 mm. The size of the raw material gas supply port is not particularly limited, but the inner diameter is preferably φ3 to 12 mm, more preferably φ6 to 10 mm.

The raw material gas supply hand stage, will be described with reference to FIG. The configuration of the processing chamber 1 is as described above. The raw material gas supply means 2 supplies the raw material gas to the raw material gas supply side 2a. In FIG. 1, the arrow indicating the raw material gas supply means 2 indicates the flow path of the raw material gas, and the raw material gas is supplied from a plurality of locations to the surface of the porous substrate 1s from above the upper chamber 1A. Specifically, the raw material gas supply means 2 has a main pipe that penetrates the raw material gas supply side 2a through an opening formed in the central portion of the bottom wall of the upper chamber 1A and a main pipe that branches off from the main pipe on the raw material gas supply side 2a. And a plurality of nozzles extending radially. Alternatively, the source gas supply means may be configured to supply the source gas to the source gas supply side 2a from a plurality of openings (not shown) provided in the sidewall of the upper chamber 1A at intervals in the circumferential direction. Good.

<Counter gas supply means>
The counter gas supply means supplies the counter gas to the counter gas supply side of the processing chamber. The form of the counter gas supply means is not particularly limited, but the counter gas may be supplied from a plurality of locations as in the case of the source gas supply means, depending on the shapes of the processing chamber and the portion to be processed. The counter gas supply means preferably has a counter gas tank for storing the counter gas. When a material to be processed having a cylindrical portion to be processed is accommodated in the processing chamber, the raw material gas supply means supplies the raw material gas to the outer peripheral side of the target portion, and the counter gas supply means the inner peripheral surface of the target portion. It is desirable to supply opposing gas to the side.

The counter gas supply hand stage, will be described with reference to FIG. The configurations of the processing chamber 1 and the source gas supply means 2 are as described above. The counter gas supply means 3 supplies counter gas to the counter gas supply side 3b. In FIG. 1, the arrow indicating the counter gas supply means 3 indicates the flow path of the counter gas, and the counter gas is supplied from the opening provided in the side wall of the lower chamber 1B. Alternatively, the counter gas supply means 3 may be configured to supply the counter gas to the counter gas supply side 3b from an opening (not shown) provided in the central portion of the bottom wall of the lower chamber 1B.

<Exhaust means>
The exhaust means exhausts the inside of the processing chamber. The exhaust means preferably has a source gas exhaust means for exhausting the source gas supplied to the processing chamber, and may further include a counter gas exhaust means for exhausting the counter gas. The unreacted source gas and the counter gas are exhausted from the processing chamber by the exhaust means. The evacuation unit preferably has a general vacuum pump such as a rotary pump, a turbo molecular pump, a mechanical booster pump, a cryopump, and a diaphragm pump. The vacuum pump may be provided with an opening serving as an exhaust port in the processing chamber, and may be connected to the opening via a pipe.

When the material to be treated having the elongated portion to be treated is accommodated in the treatment chamber, the source gas exhausting means is located at least at one end in the longitudinal direction of the portion to be treated and is mainly supplied to the treatment chamber. It is desirable to have a source gas exhaust port for exhausting gas. In particular, if the raw material gas exhaust port is composed of a plurality of, even if the powdered reaction product is exhausted together with the raw material gas, the powder deposited on the pipe is distributed to multiple, and the pipe is clogged by the powder. Is reduced and the partial pressure in the processing chamber is balanced, which is desirable. It is desirable that the plurality of source gas exhaust ports be located at both ends in the longitudinal direction of the portion to be processed with the source gas supply port interposed therebetween. The size of the raw material gas exhaust port is not particularly limited, but the inner diameter is preferably φ3 to 12 mm, more preferably φ6 to 10 mm.

The exhaust hand stage, will be described with reference to FIG. The configurations of the processing chamber 1, the source gas supply means 2 and the counter gas supply means 3 are as described above. The exhaust means 4 exhausts the source gas from the source gas supply side 2a and the counter gas from the counter gas supply side 3b, respectively. In FIG. 1, the exhaust means 4 is shown at one place, but it may be provided at a plurality of places.

<Energy application means>
The energy applying means applies energy to at least the raw material gas supplied to the processing chamber. The means is not particularly limited as long as energy for chemical reaction is applied to at least the source gas, but at least heating means for heating the source gas supplied to the processing chamber is preferable. For example, a method of heating the processing chamber from the outside using a heater or the like is convenient. Other methods include radio wave irradiation such as high frequency and microwave, light irradiation such as ultraviolet ray, electromagnetic wave such as laser irradiation, and plasma irradiation. A tubular furnace may be used when a material to be processed having a long portion to be processed is housed in the processing chamber.

The energy imparted hand stage, will be described with reference to FIG. The configurations of the processing chamber 1, the source gas supply unit 2, the counter gas supply unit 3, and the exhaust unit 4 are as described above. The energy applying unit 5 applies energy to at least the source gas supplied to the source gas supply side 2a from the outside of the processing chamber 1 to cause the source gas and the counter gas to react with each other.

<Treatment method using vapor deposition treatment equipment>
Below, the processing method of the to-be-processed part using the vapor deposition processing apparatus of this invention is demonstrated.

The material to be treated is not particularly limited as long as it has a treated portion made of a porous material having a plurality of pores. The treated portion is preferably a porous body having pores penetrating linearly or in a mesh shape, in other words, having communicating pores, in order to cause the source gas and the counter gas to diffuse oppositely. However, in chemical vapor deposition, the temperature around the material to be treated may also become high when the source gas and the counter gas are reacted, so it is preferable to use a thermally stable inorganic porous material. Examples of the inorganic porous material include α-alumina, mullite, cordierite, and silicon carbide. Since these inorganic porous materials usually have an average pore diameter of the communicating pores of 50 to 1000 nm, it is necessary to form a thin film inside the pores by blocking the pores with a reaction product by using counter diffusion CVD. Not suitable. When forming a thin film inside the pores, it is preferable to use an inorganic porous membrane having an average pore diameter of about 4 to 8 nm as the intermediate layer. In particular, when a separation active layer containing silica as a main component is formed, an intermediate layer made of γ-alumina having pores with an average pore diameter of preferably 10 nm or less, more preferably 8 nm or less, and particularly preferably 6 nm or less. It is preferable to use a material to be treated having a treated portion formed on the surface of the treated portion. Among them, the γ-alumina intermediate layer containing a nickel (Ni) element is suitable from the viewpoint of the moisture resistance required for the gas separating material. When defining the lower limit of the average pore size of the pores in the γ-alumina intermediate layer, it is preferably 1 nm, more preferably 2 nm, and particularly preferably 3 nm. Such a γ-alumina intermediate layer is preferably formed on the surface of an inorganic porous material having pores having an average pore diameter of preferably 40 to 200 nm, more preferably 60 to 150 nm. The thickness of the intermediate layer is not limited, but is preferably 1 to 6 μm, more preferably 2 to 5 μm.

In the present specification, the average pore diameter of the inorganic porous material is the 50% permeation flux diameter in the pore distribution measured by the bubble point method and the half dry method using a commercially available pore distribution measuring device. .. Further, the average pore diameter of the intermediate layer is a 50% permeation flux diameter in the pore distribution measured by a pore size distribution measuring device “Nano Palm Porometer” manufactured by Seika Sangyo Co., Ltd.

The shape of the portion to be processed is selected according to the purpose and application, but may be plate-like, columnar, tubular, semi-cylindrical, rod-shaped, lump-shaped or the like. The size of the portion to be processed is also selected according to the purpose and application, but in particular, it is a tubular shape such as a square tube or a cylinder, a plate shape such as a curved plate or a flat plate, and includes a long portion of 200 mm or more. A material to be processed having a processing portion is preferable because the effect of using the vapor deposition processing device of the present invention is remarkable. Moreover, when the shape of the to-be-processed part is a cylindrical shape suitable for the gas separating material, the outer diameter thereof is preferably φ3 to 16 mm, and more preferably φ6 to 12 mm.

The types of the raw material gas and the counter gas are determined according to the material (that is, the reaction product) deposited on the processed portion. The reaction product is not limited, and any material that can be deposited by a conventional chemical vapor deposition method can be deposited. As the raw material gas, a gas containing a metal compound that is generally used may be used, and a counter gas containing an element that reacts with the metal compound may be used depending on the target reaction product. Examples of the metal compound include organic metal compounds, metal halides, metal hydrides and the like. As the counter gas, oxygen gas, ozone gas, hydrogen gas, ammonia gas, hydrocarbon gas or the like may be used depending on the purpose. The raw material gas may further contain, as a carrier gas together with the metal compound, one or more selected from inert gases such as nitrogen gas, helium gas, argon gas, krypton gas, and xenon gas. It is practical that the carrier gas is contained in an amount of 30% or less, and further 10 to 20% when the entire raw material gas is 100% by volume. The material gas and counter gas suitable for depositing silica will be described in detail below.

When silica is vapor-deposited on the inner walls of the pores, it is preferable to use a source gas containing at least a silica precursor and a counter gas containing an oxygen element. As the silica precursor, either an organic silicon compound or an inorganic silicon compound can be used, but an organic silicon compound is particularly preferable. Examples of the inorganic silicon compound include inorganic silane compounds such as monosilane, disilane, SiH ₂ Cl ₂ and SiF ₄ . Examples of the organic silicon compound include silane compounds such as CH ₃ SiH ₃ , dimethylsilane, tripropylsilane, tetramethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, and diphenyldimethoxysilane, tetraethylsiloxane, hexamethyldisiloxane, tetramethylcyclo. Examples thereof include siloxane compounds such as tetrasiloxane and trimethyldisiloxane. It is desirable to use one or more of these in the gaseous state. Since many of the above compounds are liquid at room temperature, it is advisable to gasify the liquid by using a bubbling method in which the liquid is contained in a bubbler kept at a constant temperature and the liquid is vaporized by acting a carrier gas. Further, a gas mixer may be used to mix a plurality of kinds of gases or a gas containing an additive element. Examples of the gas containing oxygen element include oxygen gas and ozone gas. The reaction temperature is preferably 200 to 700°C, more preferably 500 to 650°C.

The formation position of the reaction product depends on the flow rate balance of the source gas and the counter gas. When the reaction product is desired to be vapor-deposited on the surface layer on the side of the source gas supply of the portion to be processed, the ratio of the flow rate (sccm) of the source gas and the counter gas is preferably 1:1 to 1:6. It is more preferable that the ratio is from 2 to 1:5. The raw material gas may be retained in the vicinity of the surface of the portion to be treated on the raw material gas supply side of the processing chamber, or may be continuously or intermittently flowed so that a constant amount is present. Further, the counter gas may be continuously fed to the counter gas supply side, or may be intermittently fed. In any case, since the raw material gas sufficient for the vapor deposition process is present on the raw material gas side, the good vapor deposition process is continuously performed. The volume ratio of the source gas and the counter gas in contact with each other in the pores of the portion to be treated is such that the volume% of the source gas is 20 to 80 volume%, further 30 to 70 volume, when the total of the two is 100 volume %. % Is desirable.

Although the embodiment of the vapor deposition processing apparatus of the present invention has been described above, the present invention is not limited to the above embodiment. Which embodiment is the best depends on the required performance, the object of use, etc., but it should be carried out in various forms with modifications and improvements that can be made by those skilled in the art without departing from the scope of the present invention. You can

Hereinafter, the present invention will be specifically described with reference to examples of the vapor deposition processing apparatus of the present invention. The vapor deposition processing apparatus of Example 1 is schematically shown in FIG. Further, FIG. 3 schematically shows the material to be processed used in the vapor deposition processing apparatus of the first embodiment.

<Example 1>
(1) Vapor Deposition Processing Apparatus The vapor deposition processing apparatus of Example 1 includes a processing chamber 10, a source gas supply means 20, a counter gas supply means 30, an exhaust means 40, and an energy applying means 50.
The processing chamber 10 is composed of a stainless steel reactor 11 that is cylindrical and has both axial ends that can be connected to piping via vacuum joints 16 and 17. The reactor 11 includes a large-diameter portion that accommodates the material S to be treated, and small-diameter portions that are integrally formed at both ends of the large diameter portion and that retain the material S to be treated. The large-diameter portion has an outer diameter of 30 mm, an inner diameter of 26 m, and a total length of 700 mm, and ten openings 110 to 119 are formed on the outer peripheral surface. The openings 110 to 119 have an inner diameter of 6 mm, a distance between adjacent openings (distance between centers) of 50 mm, and are located at equal intervals in the axial direction of the reactor 11. The small diameter portion has open ends 18 and 19, and vacuum fittings 16 and 17 using Swagelok Ultra Tall (registered trademark) are screwed.

The raw material gas supply means 20 includes raw material gas supply pipes 201 to 208, a raw material gas pipe 21, a bubbler 22, a mass flow controller (hereinafter abbreviated as “MFC”) 23, and a gas cylinder 24. The raw material gas supply pipes 201 to 208 are made of stainless steel, and are welded to the openings 111 to 118 so as to extend from the openings 111 to 118 to the radially outer side of the reactor 11. Therefore, the openings 111 to 118 serve as raw material gas supply ports. The source gas pipe 21 is a pipe made of stainless steel including a pipe branched in a comb shape, and connects the source gas supply pipes 201 to 208 and the bubbler 22. The gas cylinder 24 is connected to the bubbler 22, and an MFC 23 that controls the flow rate of the gas supplied from the gas cylinder 24 to the bubbler 22 is attached to the pipe connecting the both. The mantle heater 26 maintains the bubbler 22 in a constant temperature state.

The counter gas supply means 30 is composed of a counter gas pipe 31, an MFC 32, and a gas cylinder 33. The opposing gas pipe 31 is a stainless steel pipe, and connects one end of the reactor 11 and the gas cylinder 33 via the vacuum joint 17. Therefore, the open end 19 on one end side (the right end side in FIG. 2) of the reactor 11 serves as a counter gas supply port. The MFC 32 controls the flow rate of the gas flowing into the reactor 11 between the reactor 11 and the gas cylinder 33.

The exhaust means 40 is composed of exhaust pipes 401 and 409, exhaust pipes 41 and 46, and an exhaust pipe 49 for evacuating the inside of the reactor. The exhaust pipes 401 and 409 are made of stainless steel, and are welded to the openings 110 and 119 so as to extend from the openings 110 and 119 to the outside in the radial direction of the reactor 11, respectively. Therefore, the openings 110 and 119 serve as source gas exhaust ports. Exhaust pipes 41 and 46 connect exhaust pipes 401 and 409 to cold traps 42 and 47, respectively. The pressure gauges 41g and 46g and the flow rate control valves 41b and 46b are attached between the exhaust pipes 401 and 409 and the cold traps 42 and 47, respectively. The exhaust pipe 49 is a pipe made of stainless steel, and connects the other end of the reactor 11 and the rotary pump 48 via the vacuum joint 16. Therefore, the open end 18 on the other end side (the left end side in FIG. 2) of the reactor 11 serves as a counter gas exhaust port. The pressure gauge 49g and the flow rate control valve 49b are attached between the reactor 11 and the rotary pump 48.

The energy applying means 50 is an electric tube having a total length of 500 mm, in which a heating element 51 made of a cylindrical module heater and an insulating material 52 made of Al ₂ O ₃ —SiO ₂ ceramics fiber are housed in a casing 53 made of aluminum. Use a furnace. The electric tubular furnace is configured such that it can be opened and closed in two in the axial direction, and has 10 sets of semicircular grooves that sandwich the source gas supply pipes 201 to 208 and the exhaust pipes 401 and 409 in the cross section. Further, spacers 54 and 55 made of ring-type refractory bricks are placed on both ends of the heating element 51, and the reaction tubes 11 are housed in the hollow portion of the heating element 51 so as to be coaxial with each other. Since the total length of the heating element 51 is shorter than the total length of the large diameter portion of the reactor 11, both ends of the reactor 11 project from the electric tubular furnace. Cooling fans (not shown) are attached to the outer sides of both ends of the energy applying means 50 for the purpose of cooling the rubber O-rings 14 and 15 used for the vacuum joints 16 and 17, respectively.

(2) Material to be treated As shown in FIG. 3, the material S to be treated is an α-alumina tubular length having an outer diameter of 12 mm, a length of 750 mm, a thickness of 1.6 mm, and communication holes with an average pore diameter of 150 nm. The γ-alumina intermediate layer S1 and the glass seal S2 are formed on the outer surface of the length base material S0. Of the material to be processed S, the central portion in the longitudinal direction of the member to be processed S on which the γ-alumina intermediate layer S1 is formed corresponds to the portion to be processed Ps.
Specifically, the material S to be processed is such that after coating glass powder with a width of 175 mm from both ends of the long base material S0, and melting and solidifying the glass powder, both end surfaces of the long base material S0 are completely glass. And the communication holes that do not require vapor deposition were blocked with glass. A γ-alumina intermediate layer S1 containing a Ni element was formed by applying a Ni-added boehmite-based mixed liquid to the central portion of the long base material S0 having a width of 400 mm and baking the applied mixture. The intermediate layer S1 had a thickness of 3 μm and an average pore diameter of 5 nm.

(3) Vapor Deposition of Silica Film Using the vapor deposition processing apparatus of Example 1, a silica film was formed on the treated portion Ps of the treated material S as described above.

First, the material S to be processed was inserted from one end to the other end of the processing chamber 10. Then, both ends of the material S to be processed were fixed by the vacuum joints 16 and 17. By interposing a pair of O-rings 14 and 15 at both ends of the metal ring in the vacuum joint 16 and the vacuum joint 17, respectively, the inside of the reactor 11 was made airtight. Since the reactor 11 and the material S to be processed are coaxially arranged, the openings 110 to 119 formed in the reactor 11 are located at equal intervals in the axial direction of the material S to be processed. Further, the inside of the reactor 11 was partitioned by the material S to be processed into a raw material gas supply side 12 located on the outer peripheral surface side and a counter gas supply side 13 located on the inner peripheral surface side. Note that among the openings 110 to 119, the central openings 111 to 118 are located at equal intervals in the axial direction of the processed portion Ps, and the openings 110 and 119 at both ends are located at the glass seal S2.

Next, the reaction vessel 11 was housed in the heating element 51 of the electric tubular furnace. The processing chamber 10 was placed on the spacers 54 and 55 so that the axial direction of the reaction vessel 11 was horizontal, and the source gas supply pipes 201 to 208 and the exhaust pipes 401 and 409 were extended horizontally. In this state, the vacuum joint 16 and the exhaust pipe 49, the vacuum joint 17 and the counter gas pipe 31, the source gas supply pipes 201 to 208 and the source gas pipe 21, and the exhaust pipes 401 and 409 and the exhaust pipes 41 and 46 were connected. A ribbon heater 25 was wound around the source gas pipe 21 in order to prevent the source gas from condensing in the pipe.

Hexamethyldisiloxane (HMDS) as a silica precursor was prepared for the bubbler 22. Further, nitrogen gas as a carrier gas was prepared for the gas cylinder 24, and oxygen gas was prepared for the gas cylinder 33.

First, the pressure inside the reactor 11 was reduced by the rotary pump 48. When the pressure in the reactor 11 reached 50 Pa, the heating element 51 was operated to raise the temperature in the reactor 11 to 600°C. At this time, both ends of the reactor 11 were cooled by a cooling fan (not shown). Further, the ribbon heater 25 was set to 70° C. and the mantle heater 26 was set to 45° C. to heat the raw material gas pipe 21 and the bubbler 22. Next, the rotary pump 48 was stopped, nitrogen gas was introduced into the reactor 11 from a gas cylinder (not shown), and the inside of the reactor 11 was replaced with nitrogen gas. When the temperature in the reactor 11 became stable, HMDS in the bubbler 22 was bubbled with nitrogen gas to be vaporized, and the HMDS gas was introduced into the raw material gas supply side 12 of the reactor 11. The flow rate control valves 41b and 46b of the exhaust means 40 were adjusted so that the differential pressure was 5 Pa as indicated by the pressure gauges 41g and 46g. Next, oxygen gas was introduced from the gas cylinder 33 to the opposing gas supply side 13 (inner peripheral side of the material S to be processed) of the reactor 11 to start the vapor deposition process. The gas flow rate ratio (sccm) of the source gas and the counter gas at this time was 1:4. The processing time was 5 minutes. During the vapor deposition process, the differential pressure indicated by the pressure gauges 41 g and 46 g once increased and then decreased due to the clogging of the pores by the reaction product (silica).

<Comparative Example 1>
A silica film was formed on the treated portion Ps of the treated material S in the same manner as in Example 1 except that the openings 110 and 112 to 118 of the reactor 11 were closed. That is, in Comparative Example 1, only one source gas supply port 111 is in a functioning state.
When the vapor deposition processing apparatus of Comparative Example 1 was used, silica powder adhered to the surface of the processed material S after processing. The differential pressure indicated by the pressure gauge 46g continued to rise and exceeded 0.1 MPa. This is because the supply of the HMDS gas is non-uniform in the longitudinal direction of the processed portion Ps. At a location where the HMDS gas is not sufficient, the pores of the target portion Ps are not blocked by the silica film, and oxygen gas is ejected from the pores that are not blocked. The oxygen gas ejected from the pores reacts with the HMDS gas at a position away from the surface of the portion to be processed Ps to generate silica powder. Further, it is considered that the generated silica powder was exhausted together with the carrier gas from the raw material gas supply side 12 of the processing chamber 10, causing the exhaust pipe 46 to be clogged in the vicinity of the valve 46b, which hindered the progress of the vapor deposition process. Silica powder was attached to the surface of the material S to be treated after the treatment.

On the other hand, when the vapor deposition processing apparatus of Example 1 is used, only a small amount of silica powder adheres to the surface of the processed material S after processing, and the silica powder is not attached to the exhaust pipe 41 and the exhaust pipe 46. Was hardly confirmed. That is, by using the vapor deposition processing apparatus of Example 1, generation of silica powder was suppressed, and the pores of the processed portion Ps could be closed with the silica film.

<Example 2>
The vapor deposition processing apparatus of the second embodiment is different from the vapor deposition processing apparatus of the first embodiment except that raw material gas pipes connected to raw material gas supply pipes 201 to 208 having raw material gas supply ports 111 to 118 are independently arranged. Is the same as. FIG. 4 schematically shows the main part of the vapor deposition processing apparatus of the second embodiment.

That is, independent gas cylinders 124, 224, 324, 424, 524, 624, 724, and 824 are connected to the source gas supply pipes 201 to 208, respectively. Bubblers 122, 222, 322, 422, 522, 622, 722 and 822 and MFCs 123, 223, 323, 423, 523, 623, 723 and 823 are installed between the individual gas cylinders and the source gas supply pipe, respectively. To be done.

According to the vapor deposition processing apparatus of the second embodiment, since the plurality of bubblers are provided, it is possible to suppress variations in the source gas concentration in the processing chamber 10 in the longitudinal direction of the material S to be processed.

<Example 3>
In the vapor deposition processing apparatus of Example 3, the raw material gas pipes connected to the raw material gas supply pipes 201 to 208 having the raw material gas supply ports 111 to 118 were pipes branched in a comb shape and a tournament shape. It is the same as that of the vapor deposition processing apparatus No. 1. FIG. 5 schematically shows the main part of the vapor deposition processing apparatus of the third embodiment.

That is, the source gas supply pipes 201 to 208 are connected to the first source gas pipe 271 branched in a comb shape. The second raw material gas pipe 272 branched in a comb shape is connected to the first raw material gas pipe 271 at seven locations so as to straddle the branched portion of the first raw material gas pipe 271. Furthermore, the third raw material gas pipe 273 is arranged in a tournament shape at six locations so as to straddle the branched portion of the second raw material gas pipe 272, and independent gas cylinders 214, 234 and 254 are connected to each other. Bubblers 212, 232 and 252 and MFCs 213, 233 and 253 are installed between the individual gas cylinders and the source gas supply pipe, respectively.

According to the vapor deposition processing apparatus of Example 3, since a plurality of bubblers are connected in a tournament shape, even if a smaller number of bubblers than those of Example 2 are used, the raw material in the longitudinal direction of the processing target material S in the processing chamber 10 is used. It is possible to suppress variations in gas concentration.

<Example 4>
The vapor deposition processing apparatus of Example 4 is similar to the vapor deposition processing apparatus of Example 2 except that a plurality of openings formed on the outer peripheral surface of the reactor are arranged on different collinear lines extending in the axial direction of the reactor. is there. FIG. 6 schematically shows the main part of the vapor deposition processing apparatus of Example 4.

That is, the processing chamber 60 has openings 610, 612, 614, 616, and 618 arranged at equal intervals in the axial direction of the cylindrical reactor 61 and arranged on the same straight line. Further, it has openings 611, 613, 615, 617 and 619 which are arranged at equal intervals on the same straight line which is shifted by 180° in the circumferential direction with respect to the central axis of the cylindrical reactor 61. In other words, the openings 610 to 619 are formed at predetermined intervals in the axial direction and the circumferential direction. The openings 610, 612, 614, 616 and 618 and the openings 611, 613, 615, 617 and 619 are formed in the reactor 61 at positions that do not face each other.

According to the vapor deposition processing apparatus of Example 4, the raw material gas is supplied to the material to be processed from two different radial directions. Therefore, the material gas and the counter gas are distributed over the entire periphery of the portion to be processed Ps. Good balance of pressure is maintained.

<Example 5>
The vapor deposition treatment apparatus of Example 5 is similar to the vapor deposition treatment apparatus of Example 2 except that a plurality of openings formed on the outer peripheral surface of the reactor are arranged on different collinear lines extending in the axial direction of the reactor. is there. FIG. 7 schematically shows a radial cross section of the main part of the vapor deposition processing apparatus of Example 5.

That is, the processing chamber 70 has a plurality of openings formed at predetermined intervals in the axial direction and the circumferential direction of the cylindrical reactor 71. Specifically, an opening 711 is formed at a position offset by 120° in the circumferential direction and at a predetermined interval in the axial direction with respect to the opening 710 formed on one end side of the reactor 71 among the plurality of openings. There is. Further, an opening 712 is formed at a position offset by 120° in the circumferential direction and at a predetermined interval in the axial direction with respect to the opening 711. The processing chamber 70 has a total of 10 openings on the outer peripheral surface of the reactor 71 at positions displaced by a predetermined interval in the circumferential direction and the axial direction, but the openings are displaced by 120°, and therefore, in FIG. The opening is formed at a position overlapping with the opening 710, 711, or 712.

According to the vapor deposition processing apparatus of Example 5, the raw material gas is supplied to the material to be processed from a plurality of radial directions, so that the material gas and the counter gas are distributed over the entire periphery of the portion to be processed Ps. The pressure balance is better maintained.

<Example 6>
The vapor deposition processing apparatus of Example 6 is the same as the vapor deposition processing apparatus of Example 1 except that it has a source gas supply pipe 900 composed of a plurality of nozzles having source gas supply ports 911 to 918. FIG. 8 schematically shows the main part of the vapor deposition processing apparatus of Example 6.

That is, the processing chamber 80 has an opening at the center of the outer peripheral surface of the cylindrical reactor 81, and the source gas supply pipe 900 is inserted through this opening. The raw material gas supply pipe 900 is branched into a T shape, and eight nozzles are branched from a pipe extending in the axial direction. Raw material gas is supplied into the reactor 81 from the raw material gas supply ports 911 to 918 at the tip of the nozzle. Further, the reactor 81 has openings 810 and 819 at both ends, and exhaust pipes 401 and 409 are welded to these openings.

1, 10 Processing chamber 2, 20 Raw material gas supply means 3, 30 Counter gas supply means 4, 40 Exhaust means 5, 50 Energy applying means 2a, 12 Raw material gas supply side 3b, 13 Counter gas supply side,
111-118 Raw material gas supply port (opening)
110,119 Raw material gas exhaust port (opening)
18 Opposing gas exhaust port (open end)
19 Opposing gas supply port (open end)

Claims (8)

A vapor deposition processing apparatus for performing chemical vapor deposition on the inner wall of the pores by facing and diffusing the source gas and the counter gas from both ends of the pores of the portion to be treated made of a porous material having a plurality of pores,
A processing chamber that stores a material to be processed having the elongated portion to be processed in a position that divides the raw material gas supply side to which the raw material gas is supplied and the counter gas supply side to which the counter gas is supplied,
Source gas supply means for supplying the source gas to the source gas supply side from a plurality of locations, the source gas supply port having a plurality of source gas supply ports arranged at intervals in the longitudinal direction of the portion to be processed ,
Counter gas supply means for supplying the counter gas to the counter gas supply side,
Exhaust means for exhausting the processing chamber,
Energy applying means for applying energy to at least the raw material gas supplied to the processing chamber,
A vapor deposition processing apparatus comprising. The processing chamber accommodates the material to be processed having the tubular portion to be processed,
The vapor deposition process according to claim 1, wherein the source gas supply unit supplies the source gas to the outer peripheral side of the processing target portion, and the counter gas supply unit supplies the counter gas to the inner peripheral side of the processing target unit. apparatus. The vapor deposition processing apparatus according to claim 1 or 2 , wherein the source gas supply port is an opening formed in the processing chamber. The exhaust means, according to claim 1 having at least the positioned longitudinal end of the treatment section, mainly raw material gas outlet for exhausting the supplied the raw material gas into the processing chamber Vapor deposition processing equipment. The vapor deposition processing apparatus according to claim 4 , wherein the raw material gas exhaust port is composed of a plurality of raw material gas exhaust ports, which are located at both ends of the processing target portion in the longitudinal direction with the raw material gas supply port interposed therebetween. The processing chamber accommodates the material to be processed having the tubular portion to be processed,
Wherein each of the raw material gas supply port adjacent in the longitudinal direction of the processing unit, the vapor deposition apparatus according to any one of claims 1 to 5 arranged in different positions in the circumferential direction of該被processing unit to each other. It said energy applying means, vapor deposition apparatus according to any one of claims 1 to 6 which is a heating means for heating the raw material gas supplied to at least the processing chamber. The raw material gas comprises silica precursor, the counter gas comprises oxygen element, vapor deposition apparatus according to any one of claims 1 to 7 for depositing a silica on the inner wall of the pores.

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