JPH112384A - Piping system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piping system wherein occupied area of assembled piping is small, replacement of a functional part of valve, filter, etc., is facilitated, and conveyed gas can be uniformly heated. SOLUTION: In a piping system integrating a filter, air operated valve 21, etc., fixed able to be mounted/demounted, connecting an integrated block 31 formed with a gas flow path 37 in the inside, and assembling piping, in a groove formed in a side surface part of a body almost in parallel, to the gas flow path 37 of the integrated block 31, a tape heater 41 is inserted, the tape heater 41 is connected to a temperature control device 47, by carrying a current, the integrated block 31 is heated, to be held at a prescribed temperature, gas conveyed in the gas flow path 37 via the air operated valve 21 or the like is uniformly heated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piping system, and more particularly, to a small occupation area when assembled, easy replacement of functional parts such as valves and filters, and uniform distribution of gas to be conveyed. The present invention relates to a piping system that can be heated to a high temperature.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, as is well known, a wafer is loaded into a CVD furnace maintained at a predetermined temperature in the range of 500 to 1000 ° C., and a raw material gas such as silane (SiH ₄ ) Dichlorosilane (Si
H ₂ Cl ₂ ) or the like is introduced and thermally decomposed to form a thin film on a wafer. Also, in order to thermally diffuse donors and acceptors into the formed thin film, the wafer on which the thin film is formed is loaded into a diffusion furnace maintained at a predetermined temperature, and a dopant gas containing an element serving as a donor or an acceptor is introduced. That is being done. Phosphine (PH) is added to phosphorus (P) and arsenic (As) serving as donors.
₃ ), phosphorus trichloride (PCO ₃ ), arsine (As
For boron (B) serving as an acceptor, such as H ₃ ) and arsenic trichloride (AsCl ₃ ), boron trichloride (BCl ₃ ) and boron hydride (B ₂ H ₆ ) are used as dopant gases.

Some of these gases are in a liquid state, and are heated and vaporized when introduced into a CVD furnace or a diffusion furnace, and are sent together with an inert carrier gas. However, depending on the type of gas, it may be cooled while being sent to a CVD furnace or diffusion furnace and a part of the gas may be condensed or liquefied. It can also cause

FIG. 9 is a plan view showing a part of a pipe for carrying such a gas, and includes a filter, a mass flow controller, an air operated valve (an air pressure control valve opened and closed by a diaphragm), etc. Are functional components) are connected by a SUS pipe. That is, in this pipe 3, a nitrogen (N ₂₎ gas filter (F) 11 ₁ from the mass flow controller is introduced via (MFC) 15 _1, dichlorosilane (SiH ₂ Cl ₂₎ gas filter (F) 1
Are introduced via a mass flow controller MFC) 15 ₂ 1 _2, Anmoniya (NH ₃₎ gas filter (F) 11 ₃ from a mass flow controller (MFC) 1
5 ₃ are introduced via their gas CVD
Is conveyed to the furnace A or CVD furnace B, to its pipe 3 from eleven air operate valve (AV) 21 ₁ 21
₁₁ and check valves (CV) 22 ₁ , 22 ₂ . In FIG. 9, regions surrounded by alternate long and short dash lines excluding the N ₂ gas line are a line of SiH ₂ Cl ₂ gas and a line of NH ₃ gas. In this region, a ribbon heater is spirally provided outside the pipeline. And the whole is covered with a heat insulating material, and an aluminum tape is further wound thereon to heat and keep the temperature, so that dew condensation and liquefaction of the SiH ₂ Cl ₂ gas and the NH ₃ gas are prevented.

However, it is difficult to uniformly wind the above-described ribbon heater around a functional part having a complicated shape and its joints 8 and 9, and there is a space where the ribbon heater overlaps and there is a space between the ribbon heaters. However, there is a difference in heating between the region immediately below the overlapping ribbon heater and the blank region between the ribbon heaters, and it is not always possible to say that the temperature distribution is uniform. In addition, since the ribbon heater is wound around the joints 8 and 9 connecting the functional components and the SUS pipe, replacement of the failed functional component and the SUS pipe is a complicated operation. Furthermore, since the functional components are all connected by SUS pipes, the overall piping length is large, and the occupied area of the assembled piping is large.

As a prior art, a heating pipe for transporting gas is disclosed in "Processing Apparatus and Processing Gas Transport Pipe" in Japanese Patent Application Laid-Open No. 7-183246.
As shown in FIG. 7, an inner tube member 91a substantially forming a gas flow path 93, a heating element 91b covering the entire outer periphery of the inner tube member 91a, and an outer tube member 91 covering the entire outer periphery of the heating element 91b
The inner pipe member 91a and the outer pipe member 91c are made of ethylene tetrafluoride resin, and the heating element 91b is made of tetrafluoroethylene resin in which conductive fine particles such as carbon are dispersed and mixed in large amounts. The molded processing gas conveying pipe 91 is illustrated. Note that the heating element 91b is connected to a power supply 96 by an electric wire 92. However, even when such a processing gas transfer pipe 91 is used, functional components such as a filter, a mass flow controller, and an air operated valve remain without being heated, and generally, a functional component having a complicated flow path is exemplified. It is difficult to mold with a tetrafluoroethylene resin like the processing gas transfer pipe 91. Furthermore, since the piping connects many functional components with the processing gas transfer pipe 91, it is inevitable that the overall piping length becomes large.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and the assembled pipe occupies a small area, and when necessary, it is easy to replace functional parts such as filters and valves, and to carry the pipe. It is an object to provide a piping system capable of uniformly heating a gas.

[0008]

Means for Solving the Problems The above object is solved by the structure of claim 1, but the piping system of the present invention is:
Filters, valves, and other functional components are integrated and fixed, and a heater is attached to the body of the integrated block in which the gas flow path is formed to enable heating, and the number of pipe connections is reduced as much as possible. I have. The piping assembled by such a piping system occupies a small area, facilitates replacement of functional parts, and uniformly transports the gas so that dew or liquefaction does not occur.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The piping by the piping system of the present invention is constructed by connecting an integrated block in which functional parts such as a filter, a mass flow controller, and an air operated valve are detachably fixed and a gas flow passage is formed inside. Although assembled, the integrated block is heated by inserting a tape-shaped or rod-shaped resistance heating element into a heater attached to the body, for example, a groove or a long hole formed along a gas flow path in the body. .

[0010] The integrated block may have a heater alone and be heated independently, or may have a heater alone and when the integrated block is connected, the heaters are also connected at the same time to connect a plurality of connected integrated blocks. The blocks may be integrally heated, or a plurality of connected integrated blocks may be provided with a common heater to integrally heat the integrated blocks.

[0011] The heating temperature is controlled in units of a single integrated block or a plurality of connected integrated blocks in a pipe in which the integrated blocks are assembled.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a piping system according to the present invention.

(Example 1) FIG. 1 is a plan view of a pipe 1 according to a piping system of an embodiment, and FIG. 2 is a pipe 1 of FIG.
It is a perspective view of a part of. That is, the pipe 1 shown in FIG.
It is constructed similarly to the conventional example of pipe 3 shown in FIG. 9, N ₂ gas, SiH ₂ Cl ₂ gas, NH ₃ gas CV
It is a part of a pipe that is transported to the D furnace A or the CVD furnace B.
That is, the filters (F) 11 ₁ , 11 ₂ , 11 ₃ , the mass flow controllers (MFC) 15 ₁ , 15 ₂ , 15
₃ and 11 air operated valves (AV) 21
To ₁ to 21 ₁₁ are assembled is fixed to the integrated block several units. The length and width of the pipe 1 are 60 to 70 compared to the conventional pipe 3.
%, And the area occupied by the pipe 1 is small. In addition,
Check valves 22 ₁ and 22 ₂ in the conventional piping 3
Has been omitted.

Referring to FIG. 2, the inlet 15E of the mass flow controller 15 through which gas flows in the direction of the arrow is connected to a bolt 3
Is fixed to the downstream end portion 31B of the stacking blocks 31 ₁ through 1b, also the outlet portion 15U is fixed to the integrated block 31 ₂ of the upstream end portion 31F with bolts 32 b, 3 pieces of the upper surface side of the integrated block 31 ₁ air operated valve 21 _{2-21 4} is detachably fixed, integrated block 31 into _two upper surface side three air operate valve 21 ₅
To 21 ₇ are detachably fixed. Further, the lower surface side of the integrated block 31 _first pipe 53 for introducing the N ₂ gas
Is attached, also connected to the integrated block 31 ₁ and the integrated block 31 ₂ and the vacuum exhaust vent common exhaust passage 54 from the lower surface side pipe is taken out is formed.

The SiH ₂ introduced from the pipe 53
Cl ₃ gas through the air operate valve 21 ₂ for example, the inlet portion 1 of the mass flow controller 15 from its downstream end 31B through the gas flow path of the stacking blocks 31 in ₁
It is led to the mass flow controller 15 via 5E. The integrated block 31 ₁ of N ₂ gas introduced from the upstream end through the air operated valve 21 _3, for example, SiH ₂ Cl ₂ gas as well as the mass flow controller 15 through the gas flow path of the stacking blocks 31 in ₁ Is to be led to. The flow of gas from the mass flow controller 15 to the downstream side is also the same as described above. In addition, as will be described later, the side surface portions of the integrated block 31 ₁ of the body is inserted the tape heater 41 _1, the tape heater 41 ₂ is inserted also in the integrated block 31 _2. Incidentally, in the following, for example, when describing the integrated block 31 _1, 31 ₂ generally subscript numerals are omitted, an integrated block 31.

FIG. 3 is an exploded sectional view showing a method of fixing the air operated valve 21 to the integrated block 31.
An insertion hole 36 into which the insertion portion 23 of the air operated valve 21 is inserted is formed in the fixed portion 35 on the upper surface of the integrated block 31, and the gas flow path 3 on the introduction side and the discharge side is formed on the bottom surface.
7 is opened and communicated. A male screw 39 is formed on the outer peripheral surface of the fixing portion 35. On the other hand, a flange portion 24 having a large outer diameter is formed at the upper end of the insertion portion 23 of the air operated valve 21, and a perforated cap nut 27 having a female screw 29 on the inner surface is formed on the outer peripheral side of the insertion portion 23. The upper end of the insertion portion 23 is loosely fitted into the hole 28 of the perforated cap nut 27 and is engaged with the perforated cap nut 27 via the flange portion 24.

In the air operated valve 21, the insertion portion 23 is inserted into the insertion hole 36 of the fixing portion 35 of the integrated block 31, and the female screw 29 of the perforated cap nut 27 and the male screw 39 of the fixing portion 35 are screwed. Then, the bottom surface of the insertion portion 23 and the bottom surface of the insertion hole 36 are pressed against each other via a metal gasket 34 provided with a gas passage, and are fixed leak-free. As described above, since the air operated valve 21 and the integrated block 31 are in contact with each other with good heat transfer properties, when the integrated block 31 is heated by a tape heater not shown in FIG. The power is transmitted to the air operated valve 21. Accordingly, since it is not necessary to attach a heater to the air operated valve 21 itself, it is extremely easy to replace the air operated valve 21 in the event of failure, in combination with the above-described fixing method. The left end of the integrated block 31 is a male screw 3
3 is formed as a connecting portion 32 to which a pipe or other integrated block having a joint portion with a perforated cap nut similar to the perforated cap nut 27 of the air operated valve 21 is connected. Therefore, these exchanges are also easy.

A heater is attached to such an integrated block. FIG. 4 shows a tape heater 41 in which a resistance heating element 43 is insulated and covered with an epoxy resin impregnated glass cloth 44.
Is inserted into a groove provided on the side surface of the body of the integrated block 31 so that the integrated block 31 can be heated. 4A is a perspective view of the integrated block 31, and FIG. 4B is a sectional view thereof. Both ends of the inserted tape heater 41 are connected to a temperature controller 47 with a power supply via an electric wire 46 to supply an AC or DC current to the tape heater 41.
1 generates heat and the integrated block 31 is heated and maintained at a predetermined temperature, and the gas flowing through the gas flow path 37 is heated. Note that a rod-shaped molded product made of, for example, a fluororesin may be fitted as a sealing material to the outside of the inserted tape heater 41.

[0019] FIG 5 is placed across the two integrated blocks 31 ₁ and 31 ₂ and the mass flow controller 15, is a side view showing a case where not in direct contact with,
In such a case, as shown in A of FIG. 5, the tape heater 41 ₁ in the integrated block 31 _1, the stacking blocks 31
The ₂ by inserting the tape heater 41 _2, may be heated independently, and as shown in B of FIG. 5, the stacking blocks 31 ₁ and the integrated block 31 ₂ Common tape heaters 41 ₃ and It may be inserted and heated.

In the piping 1 shown in FIG. 1, a tape heater is inserted into each integrated block in the region of the SiH ₂ Cl ₂ gas and the NH ₃ gas surrounded by the dashed line, excluding the N ₂ gas line, and heating is performed. It is possible. In addition, a flexible and easily attachable and detachable heat-resistant rubber or other heat insulating material is applied to an integrated block or the like whose temperature is increased by heating to suppress heat loss.

The structure of the pipe 1 of the first embodiment is as described above. Next, its operation will be described. In the pipe 1 configured as described above, the flow path between the SiH ₂ Cl ₂ gas and the NH ₃ gas is heated to a predetermined temperature. That is, SiH ₂
For example, an alternating current is applied to the tape heater inserted in each integrated block in the region of the Cl ₂ gas and the NH ₃ gas, and the integrated block is maintained at a temperature of 100 to 150 ° C. Further, as described above, with reference to FIG. 3, the air operated valve 21 is in contact with the integrated block 31 and the metal, so that the heat of the heated integrated block 31 is immediately transmitted to the air operated valve 21. You. Similarly, the mass flow controller 15 also with reference to FIGS. 2, 5, the inlet side is directly fixed by bolts 31b in the integrated block 31 _1, the outlet side is directly fixed by bolts 32b in the stacking blocks 31 ₂ because there, the heated stacking blocks 31 _1, 31 ₂ of the heat is immediately transmitted to the mass flow controller 15. The same applies to other air operated valves, mass flow controllers, or other functional components.

Accordingly, SiH ₂ Cl ₂ gas, N ₂ gas heated and vaporized from each liquid supply source and sent to the pipe 1
Since the H ₃ gas is not liquefied in the gas flow path inside the integrated block, the gas flow path inside the mass flow controller, the air operated valve, or the like, the transfer of the gas is hindered or the gas liquefied inside the pipe 1 Does not cause corrosion. Further, the integrated block and the like are heated evenly as a whole by a tape heater inserted substantially parallel along the gas flow path, and the temperature is controlled by a temperature control device. It is heated and transported to a CVD furnace, and contributes to the formation of a uniform thin film.

Furthermore, since the tape heater is inserted into the groove on the side surface of the integrated block, the assembling work of the piping is significantly simplified as compared with the case where the ribbon heater is wound. In addition, it is easy to replace the air operated valve, other functional parts, pipes, or integrated blocks, and the time and labor required for the replacement are greatly reduced.

(Embodiment 2) FIG. 6 is a side view of a pipe 2 according to the piping system of the present invention, although the functional parts and the shape of the integrated block are slightly different from those of the pipe 1 shown in FIGS. . In other words, six stacking blocks from the integrated block 51 ₁ to the integrated block 51 ₆ are connected by the joint portions 55 to each other, the integrated block 51 ₁
To the stacking blocks 51 ₆ mass flow controller 16 which is fixed to, in addition to different from the shape of the air operated valve 22 is used in the pipe 1, the filter 12 did not show a shape in the pipe 1, not shown in the pipe 1 Manual valve 14, check valve 1
7, a regulator 18, and a pressure gauge 19 are fixed. The joint 55 is formed by the same method as the method in which the air operated valve 21 is fixed to the integrated block 31 in FIG.

[0025] sometimes have to be connected by the joint 55, but by inserting the tape heater 61 ₁ until the tape heater 61 ₆ in each of the body of the stacking blocks from the integrated block 51 ₁ to 51 _6, each tape Heater 61
And a _{1-61 6} is connected to the temperature controller 67. Thus by controlling the current value for each tape heater 61 _{1-61 6,} it is possible to control the heating temperature for each integrated block. Further, in addition to easily removing each functional component from the integrated block and replacing it with a new one, it is also easy to replace the integrated block unit, and it is possible to greatly reduce the number of maintenance steps as in the first embodiment. .

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited to these, and various modifications can be made based on the technical concept of the present invention.

For example, in this embodiment, the heater is mounted on the integrated block by inserting a tape heater into a longitudinal groove formed on the side surface of the integrated block, but the groove is not formed. The tape heater may be mechanically closely attached to the body of the integrated block with a jig and fixed. Further, as shown in the sectional view of the integrated block 32 in FIG.
The sheath heater 42 (the resistance heating body 45 covered with the insulator magnetism 48 in the outer stainless steel tube 49) may be inserted into the through hole formed in parallel with 8.

FIG. 5B of this embodiment shows a case where a common tape heater is inserted into a plurality of integrated blocks. However, since the combination of the integrated blocks is generally not fixed, the common tape heater is inserted. When the tape heater is inserted, it is performed after the assembly block and the like are assembled to complete the piping. On the other hand, by using an integrated block having a built-in heater in advance and connecting the heaters simultaneously when connecting the integrated block, the connected integrated block can be heated integrally. For example, FIG. 8 is a side view of an integrated block 71 having a built-in heater 81, and the integrated blocks 71 are connected by a joint (not shown). At both ends of the groove 72 formed on the side surface of the integrated block 71, the heater 81 is held between the metal members 74 supported by the insulator 73, and the metal members 7.
4, a terminal 77 is attached via a coil spring 76. The terminal 77 which is a free end on the left side of the integrated block 71 protrudes from the left end face of the integrated block 71, but the terminal 77 connected on the right side is pushed down to the right end face of the integrated block 71,
A contact pressure due to the bias of the coil spring 76 is secured to the connected terminal 77, and poor contact can be prevented. As described above, by directly connecting the integrated blocks having the built-in heaters, the assembly of the piping is remarkably simplified, and the removal of the integrated block from the piping in the unit of the integrated block and the subsequent mounting are extremely simplified.

In the drawings showing the present embodiment,
Although only one gas flow channel 37 is shown in the integrated block 31, it goes without saying that two or more gas flow channels may be formed in some cases.

In this embodiment, an example has been described in which the tape heater is inserted by forming a groove only on one side of the integrated block. However, the tape heater may be inserted into both sides. Good.

In this embodiment, the case where the piping system of the present invention is applied to a piping for supplying gas to a CVD furnace has been described. However, the piping system of the present invention is applicable to a thermal diffusion furnace other than the CVD furnace or a thermal oxidation furnace. Also applies to piping to furnaces. In addition, the piping system of the present invention is also applied to piping for transporting other easily liquefied organic compounds, for example, vapors such as ethane chloride.

[0032]

The present invention is embodied in the form described above, and has the following effects.

In a pipe for transporting a gas which is easily liquefied, the pipe is easy to assemble, occupies a small area, and it is easy to mount a heater and replace functional parts such as a filter, a mass flow controller, and an air operated valve.
The gas to be conveyed can be heated uniformly.

[Brief description of the drawings]

FIG. 1 is a plan view of a pipe according to a first embodiment.

FIG. 2 is a perspective view of a part of FIG.

FIG. 3 is an exploded cross-sectional view showing a method of fixing an air operated valve to an integrated block.

FIG. 4 shows a heatable integrated block in which a tape heater is inserted, where A is a perspective view and B is a cross-sectional view.

FIG. 5 shows the insertion of a tape heater when two integrated blocks are connected apart from each other; FIG. 5A shows a case where a tape heater is divided and inserted; and FIG. 5B shows a case where a common tape heater is inserted.

FIG. 6 is a side view of a pipe according to a second embodiment, showing a case where the temperature of each integrated block is independently controlled.

FIG. 7 is a cross-sectional view showing a modified example of attachment of a heater.

FIG. 8 is a side view of an integrated block incorporating a heater.

FIG. 9 is a plan view of a conventional pipe corresponding to the pipe of the first embodiment.

FIG. 10 is a perspective view of a prior art process gas carrying pipe.

[Explanation of symbols]

1 ... Piping of Example 1, 2 ... Piping of Example 2, 3 ...
Conventional pipe, 11 ... Filter, 15 ... Mass flow controller, 21 ... Air operated valve, 31 ...
... Integrated block, 41 ... Tape heater.

Claims (6)

[Claims] 1. A piping system in which functional parts such as a filter, a mass flow controller, and an air pressure control valve are integrated and fixed, and a piping is assembled by connecting an integrated block having a gas flow path formed therein. A piping system, wherein a heater is attached to the body, and the gas can be heated in the gas flow path. 2. The tape-shaped or rod-shaped resistance heating element inserted into a groove or a long hole formed substantially parallel to the gas flow path of the body of the integrated block. 2. The piping system according to 1. 3. The piping system according to claim 1, wherein each of the integrated blocks is independently mounted with the heater, and is heated independently. 4. The piping system according to claim 1, wherein each of the integrated blocks individually mounts the heater, and the heater is connected at the same time when the integrated block is connected. . 5. The apparatus according to claim 1, wherein the plurality of connected integrated blocks have a common heater.
Or the piping system according to claim 2. 6. The heating temperature of the connected integrated block is controlled in units of a single integrated block and / or a plurality of connected integrated blocks. The piping system according to any one of the above.