JP2011029211A - Heating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating unit that can be easily repaired and maintained. <P>SOLUTION: In the heating unit 101, outer shells 121a and 121b are removably bonded to an inner shell 111 by a screw 151, and planar heat generating bodies 131a and 131b are arranged between the inner shell 111 and outer shells 121a and 121b. On the circumferences of the planar heat generating bodies 131a and 131b, O-rings 141a and 141b are arranged, and the planar heat generating bodies 131a and 131b are prevented from being exposed to an external gas. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention is a heating apparatus suitable for use in heating a chamber or a wall of a semiconductor manufacturing apparatus such as a CVD apparatus or an etching apparatus, a transfer path of an object to be processed such as a wafer, a supply / exhaust pipe for a processing gas, or the like. About.

For example, in a semiconductor manufacturing apparatus such as a CVD apparatus or an etching apparatus, a wafer is placed in a processing chamber, and the wafer is exposed to a reactive gas or plasma in a high-temperature atmosphere, whereby a desired film forming process or etching process is performed on the wafer. Apply. During such processing, the processing gas and reaction by-products flowing in the chamber undergo sublimation changes in both the gas and solid phases depending on the relationship between pressure and temperature (sublimation curve), but the sublimation changes from gas to solid. In such a case, the by-product is deposited as a solid and adheres to the wall surface below the sublimation temperature such as in the chamber or the exhaust pipe. As a result, piping and the like may be blocked by by-products, which is not preferable.
In order to avoid or suppress such deposition and deposition of by-products, and to uniformly perform film formation processing and etching processing on the wafer, the temperature of the chamber and piping is set to a relatively uniform high temperature state. It is necessary to maintain and manage this accurately.

Conventionally, in order to maintain the inside of a chamber or the like at a high temperature, measures such as mounting a heater on the outside of the chamber or the like have been taken (see, for example, Patent Document 1). However, in the conventional method in which the heater is disposed outside the chamber, it is difficult to uniformly heat the inner wall of the chamber, and it is difficult to accurately maintain and manage the temperature inside or inside the chamber.
Therefore, a method has been proposed in which a cylindrical, disk, or rectangular heating unit is disposed along the inner wall of the chamber or piping, whereby the temperature in the chamber is controlled and managed uniformly, efficiently, and accurately (patent) Reference 2). According to this apparatus, the temperature of the chamber, piping, etc. can be maintained and controlled at a high temperature and in a uniform state, and by-product precipitation and deposition can be suppressed with high accuracy compared to previous apparatuses. it can.
JP 2003-27240 A WO2004 / 105103 publication

  For example, in a conventional apparatus as disclosed in Patent Document 2, in a heating apparatus that heats the inside of a chamber or the like, a heating element is embedded in the heating structure by joining the surface structure members of the heating apparatus by welding. Yes.

However, in such a welded structure, when a failure such as a disconnection occurs in the heating element, it is difficult to repair or repair it, and it is necessary to discard the heating device itself and replace it with a new one. As a result, there is a problem that the cost of the apparatus or the operation cost of the apparatus becomes high.
Further, it takes time to disassemble the failed heating device that has been taken out, and there is a possibility that it may become an obstacle to separating and disposing of the heating device.

  This invention is made | formed in view of such a subject, The objective is to provide the heating apparatus which can perform arrangement | positioning replacement | exchange and repair of a heat generating body easily.

  In order to solve the above-described problem, a heating apparatus according to a first aspect of the present invention relates to a processing chamber for performing a desired process on an object to be processed, a conveyance path for the object to be processed, or the desired process. A heating device disposed inside a gas supply / exhaust pipe, which is an outer wall portion formed by joining a planar heating element and a plurality of members, wherein the plurality of members are joined. The sheet heating element is formed in the outer wall portion so as to cover the sheet heating element and accommodate the sheet heating element, and at least a part of the plurality of members is separated. An outer wall portion in which the body is detachable, a sealing material disposed at a joint portion of the plurality of members around the heating element housing portion of the outer wall portion, and a joining means for joining the plurality of members It is characterized by having.

  Further, in the heating device of the present invention according to claim 2, the outer wall portion includes a cylindrical inner member, and one or a plurality of outer members disposed along the outer surface of the inner member, The heating element accommodating portion that accommodates the planar heating element is formed by a recess formed on one or both of the outer surface of the inner member and the inner surface of the outer member.

  In the heating device of the present invention according to claim 3, a flange is formed on the inner member and the outer member in the cylindrical core direction of the cylindrical member, and the flanges are joined to each other by the flange. And

  Further, in the heating device of the present invention according to claim 4, the outer wall portion has two plate-like members joined to face each other, and either one of the opposing surfaces of the two plate-like members or The heating element accommodating portion for accommodating the planar heating element is formed by recesses formed on both sides.

  According to a fifth aspect of the present invention, there is provided the heating device according to the present invention, wherein the outer wall portion has a slit formed with a slit into which the planar heating element can be inserted and which has an opening having a width substantially equal to the thickness of the planar heating element. And a lid member that closes the opening.

Further, in the heating device of the present invention according to claim 6, the outer wall portion includes a cylindrical inner tube member and a plurality of outer wall portions that are connected to the outside of the inner tube member in the length direction of the inner tube member. An outer cylinder member,
A flange projecting in the radial direction along the outer periphery is formed at a location connected to each other outer cylinder member of each of the plurality of outer cylinder members, and the plurality of outer cylinder members are joined by joining the flanges. Are connected to each other, and outer peripheral surfaces of both end portions of the inner cylindrical member are joined to inner peripheral surfaces of the outer cylindrical member disposed on the outer side, and the planar heat generation is performed between the inner cylindrical member and the outer cylindrical member. The body is clamped.

  The heating device of the present invention according to claim 7 is characterized in that the joining means joins the plurality of members by any one of a screw, a magnetic force, a clamp, and a mechanical latching means.

  In addition, the heating device of the present invention according to claim 8 further includes a lead wire lead-out portion for leading a lead wire for supplying electric power to the planar heating element to the outside, and the heating element housing portion of the outer wall portion includes The lead wire lead-out portion is open to the atmosphere.

  The heating device of the present invention according to claim 9 is characterized in that the member forming the outer wall portion is a metal member.

  According to the heating device of the present invention according to claim 1, even when a failure such as disconnection occurs in the heating element, the heating element can be easily replaced and repaired.

  Further, according to the heating device of the present invention according to claim 2, the heating device is a cylindrical heating device that can easily replace and repair the heating element, and is disposed inside the processing chamber. A heating device suitable for appropriately heating the chamber internal space to a desired temperature can be provided.

  According to the heating device of the present invention according to claim 3, in the cylindrical heating device in which the heating element can be easily replaced and repaired, the inner member and the outer member are firmly joined by the flange. Therefore, it is possible to increase the arrangement area (heater area) of the planar heating element, and the temperature distribution along the cylindrical circumferential direction can be made more appropriate.

  According to the fourth aspect of the present invention, there is provided a plate-like heating device capable of easily replacing and repairing the heating element, along the upper surface or the lower surface of the processing chamber. It is possible to provide a heating device suitable for disposing and heating the chamber internal space appropriately to a desired temperature.

  Further, according to the heating device of the present invention according to claim 5, the heating device can be replaced and replaced by removing the lid member, and the heating device can be replaced more easily. Can be provided.

  Further, according to the heating device of the present invention according to claim 6, the heating device is a tubular heating device that can easily replace and repair the heating element. It is possible to provide a heating device that is disposed inside an exhaust pipe or the like and is suitable for appropriately heating the inside of the pipe to a desired temperature.

  Further, according to the heating device of the present invention according to claim 7, any one of a screw, a magnetic force, a clamp, and a mechanical latching means is used as a joining means of a plurality of members constituting the outer wall portion of the heating device. These members can be reliably and easily joined.

  Further, according to the heating device of the present invention according to claim 8, since it is not necessary to seal and seal the heating element housing portion of the outer wall portion in which the planar heating element is accommodated, the configuration of the heating device is simplified. In addition, the replacement arrangement of the planar heating element can be further facilitated. In addition, since the outside air can be introduced into the heat generating portion (the heat generating member housing portion of the outer wall portion) and the sheet heating element can be cooled quickly, replacement of the sheet heating element can be performed more efficiently and quickly. Can do. Furthermore, by setting the heating element housing part to atmospheric pressure, the amount of heat generated by the heating element is converted into natural convection heat transfer in the heating element housing part space and heat conduction at the contact part between the heating element and the outer wall part. The two heat transfer modes can be efficiently transmitted to the heat consuming part.

  In addition, according to the heating device of the present invention according to claim 9, it is possible to provide a heating device that can efficiently transmit the heat generated by the planar heating element to the outside and perform heating efficiently.

An embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, the present invention will be described by exemplifying a substrate processing apparatus that includes the heating apparatus according to the present invention and is used for processing such as CVD (Chemical Vapor Deposition).
FIG. 1 is a cross-sectional view of a main part of the substrate processing apparatus.

  As shown in FIG. 1, a substrate processing apparatus 1 accommodates a semiconductor wafer W to be processed in an internal space (chamber internal space) 13, provides a desired environment, and performs a desired process. In order to supply the chamber internal space 13 with a susceptor 20 on which the wafer W to be processed is placed in the space 13, a wafer transfer pipe 30 for carrying the wafer W to be processed into and out of the chamber internal space 13, and a processing gas. And a heating unit 101, 201, 202, 301, 401 and 501 according to the present invention for heating the chamber inner space 13 and the like.

The processing chamber 10 includes a chamber body 11 that is a bottomed cylindrical container having an upper opening, and a lid 12 that closes the upper opening.
The lid portion 12 is connected to the upper portion of the chamber body 11 by a connecting portion (not shown) so that the upper opening thereof can be opened and closed. The lid 12 is placed on the upper edge surface of the chamber body 11 with an O-ring 19 interposed therebetween, and is fastened to the chamber body 11 by fastening means (not shown) so that the upper opening of the chamber body 11 is closed. The chamber inner space 13 is a sealed space.

  A susceptor 20 on which a wafer W to be processed is placed is installed in the approximate center of the inside of the processing chamber 10 (chamber internal space 13). The susceptor 20 is supported by a support shaft 21 that has passed through the opening 14 at the bottom of the processing chamber 10 such that the susceptor 20 can move up and down and rotate. The support shaft 21 is connected to an external drive mechanism (not shown), and is moved up and down and rotated. The bottom opening 14 of the processing chamber 10 through which the support shaft 21 passes is provided with a not-shown magnetic fluid sealing device or the like, for example, so that the inside of the processing chamber 10 (chamber internal space 13) and the outside are blocked from vacuum. It is sealed.

  An opening 15 having a rectangular cross section for loading and unloading the wafer W into and from the chamber internal space 13 is formed on the side wall of the chamber body 11. A rectangular cylindrical wafer transfer tube 30 is connected to the wafer transfer opening 15 with an O-ring 31 interposed outside the chamber body 11.

  An air supply port 16 having a circular cross section for introducing a processing gas into the chamber internal space 13 is formed at the center of the lid 12. An annular air supply pipe 40 is connected to the air supply port 16 with an O-ring 41 interposed outside the processing chamber 10. A shower head 42 is disposed inside the air supply port 16 so that the target gas is uniformly supplied to the entire wafer W placed on the susceptor 20. On the surface of the shower head 42 on the susceptor 20 side, an opening 241 for allowing gas to flow uniformly over the upper surface of the wafer W placed on the susceptor 20 is formed.

  Further, an exhaust port 17 for exhausting the gas in the chamber internal space 13 is formed on the side wall of the chamber body 11. An annular exhaust pipe 50 is connected to the exhaust port 17 outside the processing chamber 10 with an O-ring 51 interposed. The end of the exhaust pipe 50 that is not connected to the exhaust port 17 is connected to exhaust means such as a turbo molecular pump (TMP) (not shown), and when the chamber internal space 13 is evacuated or inside the chamber When a desired reaction gas is circulated in the space 13 to perform a desired process, the gas in the chamber internal space 13 is exhausted.

Inside the processing chamber 10, heating units 101, 201, and 202 according to the present invention for maintaining the chamber internal space 13 at a desired temperature are disposed along the inner peripheral surface of the side wall thereof. In addition, heating units 301, 401, and 501 for maintaining the inside of each tube at a desired temperature are arranged along the inner peripheral surface of the wafer transfer tube 30, the supply tube 40, and the exhaust tube 50, respectively. It is installed.
Hereinafter, these heating units according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, the heating unit 101 is a device disposed along the inner peripheral surface of the chamber body 11 of the processing chamber 10, and heats the chamber internal space 13 of the processing chamber 10 to a desired temperature. .
2 to 4 are diagrams showing a configuration of the heating unit 101, FIG. 2 is a perspective view showing a schematic configuration of the heating unit 101, and FIG. 3 (A) is a cross-sectional view taken along line AA of FIG. 3B is a cross-sectional view of the inner shell 111 of the heating unit 101 at the same location (AA), and FIG. 4 is a cross-sectional view taken along the line BB of FIG.

As shown in FIG. 2, the heating unit 101 is a cylindrical device in which both upper and lower ends are opened.
As shown in FIGS. 2 and 3A, the heating unit 101 includes an inner shell 111, outer shells 121a and 121b, planar heating elements 131a and 131b, O-rings 141a and 141b, and a plurality of screws 151.
The member in which the inner shell 111 and the outer shells 121a and 121b are joined corresponds to the outer wall portion according to the present invention, and the inner shell (inner member) 111, the outer shell (outer member) 121a and 121b, It corresponds to a plurality of members constituting the outer wall portion according to the present invention.

  The inner shell 111 is a single cylindrical metal member having a cross-sectional shape as shown in FIG. On the outer peripheral surface of the inner shell 111, two concave portions 112a and 112b that are recessed (notched) along the circumferential direction are formed. The recesses 112a and 112b are formed in a back-to-back state as shown in the drawing over substantially a half of the outer circumferential surface of the inner shell 111, that is, on the outer circumferential surface of the inner shell 111.

  The recesses 112a and 112b are each formed in a two-step recess as shown in the figure. The recesses 112a and 112b are a first-stage recess 113a and 113b formed on the outer peripheral surface side, and a second-stage recess in a form that is further deeply cut out in the inner circumferential direction from the first-stage recesses 113a and 113b. 114a and 114b.

  The first-stage recesses 113a and 113b are outer shell recesses in which the outer shells 121a and 121b are disposed. The first-stage recesses 113a and 113b are recesses formed in a predetermined range in the circumferential direction of the inner shell 111, and are completely cut out from the upper edge to the lower edge in the vertical direction. It is a recess.

  On the other hand, the recesses 114a and 114b in the second stage are heater recesses in which the planar heating elements 113a and 113b are disposed. That is, it is a recess for forming the heating element housing portion according to the present invention. The second-stage recesses 114a and 114b are recesses further recessed from the bottom surfaces of the first-stage recesses 113a and 113b of the inner shell 111, and are configured to be recessed within a predetermined range in both the circumferential direction and the vertical direction. That is, in the circumferential direction of the inner shell 111, the second-stage recesses 114a and 114b are side walls formed in four directions to define the range thereof, and are recesses that are open only in the outer diameter direction. The recesses 114a and 114b are formed in a shape and size that match the shape and size of the planar heating elements 113a and 113b so that the planar heating elements 113a and 113b can be accommodated.

  The outer shells 121 a and 121 b are desirably plate members made of the same metal as the inner shell 111, and are members in a form in which a metal plate is bent into an arc shape along the surfaces of the recesses 112 a and 112 b of the inner shell 111.

  The planar heating elements 131a and 131b are resistance heating elements. The planar heating elements 131a and 131b are accommodated in the second-stage recesses 114a and 114b of the recesses 112a and 112b of the inner shell 111, respectively, so that the space between the inner shell 111 and the outer shells 121a and 121b is finally reached. Sandwiched between. Therefore, the planar heating elements 131a and 131b are plate-like members that are bent into an arc shape along these peripheral curved surfaces.

  In this embodiment, as shown in FIGS. 3A, 3B, and 4, recesses 121a and 121b in which planar heating elements 131a and 131b are disposed on the outer peripheral surface of the inner shell 111 are provided. Was assumed to be formed. However, the concave portions for accommodating the planar heating elements 131a and 131b may be provided on the outer shells 121a and 121b side. Further, a configuration may be adopted in which concave portions are provided on both opposing surfaces of the inner shell 111 and the outer shells 121a and 121b, and the planar heating elements 131a and 131b are sandwiched between the opposing concave portions.

  As shown in FIGS. 2 and 3A, the O-rings 141a and 141b surround the planar heating elements 131a and 131b on the joint surface between the inner shell 111 and the outer shells 121a and 121b, respectively. It is arranged. Similarly to the planar heating elements 131a and 131b, the O-rings 141a and 141b are also formed on one or both of the surfaces of the concave portions 112a and 112b of the inner shell 111 and the inner peripheral surfaces of the outer shells 121a and 121b. It arrange | positions along the recessed part which is not shown in figure, and is finally clamped between the inner shell 111 and the outer shells 121a and 121b.

  The screws 151 are screwed into the inner shell 111 from the outer peripheral surfaces of the outer shells 121a and 121b, and the outer shells 121a and 121b are firmly joined to the inner shell 111 with sufficient and appropriate pressure. As shown in the figure, the screws 151 are used at predetermined appropriate intervals on the upper and lower sides of the outer shells 121a and 121b and on the peripheral edges at both ends in the circumferential direction.

In the heating unit 101 having such members, the planar heating elements 131a and 131b are accommodated in the second-stage recesses 114a and 114b of the inner shell 111, and the first-stage recesses 113a and 113b of the inner shell 111 are accommodated. The outer shells 121 a and 121 b are fitted with the O-rings 141 a and 141 b interposed therebetween, and the outer shells 121 a and 121 b are joined to the inner shell 111 with screws 151.
Thus, the planar heating elements 131a and 131b are completely covered by the inner shell 111 and the outer shells 121a and 121b and are accommodated in the heating element accommodating portion in the outer wall portion of the heating unit 101, in other words, the heating unit. Even when the heating unit 101 is installed in the chamber internal space 13, the planar heating elements 131 a and 131 b are exposed to the processing gas supplied to the chamber internal space 13. Is prevented.

  As shown in FIGS. 2 and 4, a pair of lead wires 132a and 132b for supplying power to the sheet heating elements 131a and 131b are connected to the sheet heating elements 131a and 131b. The lead wires 132a and 132b are connected to the resistance heating circuit inside the planar heating elements 131a and 131b at the upper edges of the planar heating elements 131a and 131b, and are connected to the outside from the upper edges of the planar heating elements 131a and 131b. To the outside of the heating unit 101 via lead wire outlet pipes (lead wire outlet portions) 133a and 133b attached to the upper edge of the main body of the heating unit 101 (inner shell 111 and outer shells 121a and 121b). Has been derived.

In the substrate processing apparatus 1, the heating unit 101 having such a configuration is disposed in the chamber internal space 13 of the processing chamber 10 as shown in FIG. 1.
At that time, the lead wire outlet pipes 133 a and 133 b of the heating unit 101 pass through the lead wire outlet pipe passage openings 18 a and 18 b provided in the lid portion 12 of the processing chamber 10 and are drawn out of the processing chamber 10. Thereby, the lead wires 132a and 132b passing through the inside of the lead wire outlet tubes 133a and 133b are also led out to the outside of the processing chamber 10.

  Further, the processing chamber 10 is provided with a wafer transfer opening 15 and a wafer transfer pipe 30 for taking in and out the wafer. The wafer is transferred to the susceptor 20 inside the heating unit 101 through this transfer path. The heating unit 101 is also provided with an opening 115 at a position corresponding to the wafer transfer opening 15 in the processing chamber 10 so as to be appropriately loaded and unloaded.

  Similarly, the processing chamber 10 is provided with an exhaust port 17 and an exhaust pipe 50 for exhausting the gas in the chamber internal space 13, and the gas in the chamber internal space 13 is appropriately disposed through these. As described above, the heating unit 101 is also provided with an opening 116 at a position corresponding to the exhaust port 17 of the processing chamber 10.

Note that the inner shell 111 and the outer shells 121a and 121b are formed of a material having high heat transfer efficiency and corrosion resistance to the processing gas. Specifically, for example, a stainless steel material (for example, SUS316) or an aluminum plate material (for example, A5052) is suitable, but titanium, aluminum alloy, nickel cobalt alloy, or aluminum oxide, silicon carbide, aluminum nitride, silicon nitride, oxide Ceramics made of any of silicon may be used. Corrosion resistance can be ensured by coating. In this case, the coating material is preferably alumina (Al ₂ O ₃ ), SiC, AlN, Si ₃ N _4, Y ₂ O ₃ or the like.

Further, the planar heating elements 131a and 131b are constituted by a resistance heating element such as a silicon rubber heater, a mica heater, a ceramic heater or a polyimide heater.
Moreover, in this embodiment, the plate | board thickness of the planar heating elements 131a and 131b is 0.1 mm-2 mm.

The heating unit 201 is a heating unit disposed so as to close the upper opening of the heating unit 101, in other words, a disc-shaped heating unit disposed along the inner surface of the lid portion 12. Together with the heating unit 202 described later, the chamber internal space 13 of the processing chamber 10 is heated to a desired temperature.
FIG. 5 is a cross-sectional view showing the configuration of the heating unit 201.

The heating unit 201 is a disc-shaped heating unit as a whole, but its basic configuration is the same as the heating unit 101 described above.
As shown in FIG. 1, the heating unit 201 is a member disposed along the inner surface of the lid 12 inside the lid 12 at the top of the chamber internal space 13. Therefore, an opening 261 is formed in the central portion for allowing the gas released from the shower head 42 to flow in the direction of the wafer W placed on the susceptor 20. Accordingly, the heating unit 201 is strictly an annular heating means.

The heating unit 201 includes an inner shell 211, an outer shell 221, a planar heating element 231, an outer diameter side O-ring 241, an inner diameter side O-ring 242, and a plurality of screws 251.
The inner shell 211 and the outer shell 221 are made of metal and are ring-shaped members having openings 212 and 222 formed at the center, and the material and the like thereof are the inner shell 111 and the outer shell of the heating unit 101 described above. It is the same as 121a and 121b. A concave portion 213 for arranging the planar heating element 231 is formed on the outer surface (upper surface) of the inner shell 211, and an outer diameter side O-ring 241 and an outer diameter side and an inner diameter side thereof are provided. Grooves 214 and 215 for arranging the inner diameter side O-ring 242 are formed.

The planar heating element 231 is an annular resistance heating element, and the material thereof is the same as the planar heating elements 131a and 131b of the heating unit 101 described above.
As shown in FIG. 5, the outer diameter side O-ring 241 and the inner diameter side O-ring 242 are arranged between the inner shell 211 and the outer shell 221 so as to sandwich the planar heating element 231 from inside and outside in the radial direction. .

In the heating unit 201, such a planar heating element 231, an outer diameter side O-ring 241 and an inner diameter side O-ring 242 are arranged between the inner shell 211 and the outer shell 221 as illustrated, and the inner shell 211 and the outer shell 221 are arranged. The shell 221 is joined with the screw 251. At this time, the central opening 212 of the inner shell 211 and the central opening 222 of the outer shell 221 are connected to form one opening 261 as a whole.
The screw 251 is screwed in from the outer surface (upper surface) of the outer shell 221 in the direction of the inner shell 211 to join the outer shell 221 firmly to the inner shell 211 with sufficient and appropriate pressure. The screws 251 are respectively used at predetermined appropriate intervals along the inner peripheral edge and the outer peripheral edge of the annular heating unit 201.

  With such a configuration, in the heating unit 201 as well as the heating unit 101, the planar heating element 231 is completely covered with the inner shell 211 and the outer shell 221, and the heating element accommodating portion on the outer wall portion of the heating unit 201. In other words, when the heating unit 201 is installed in the chamber internal space 13, the planar heating element 231 is supplied to the chamber internal space 13. Exposure to the treated gas or the like is prevented.

  The planar heating element 231 is connected to a pair of lead wires 232 that supply power to the planar heating element 231. The lead wire 232 is connected to a resistance heating circuit (not shown) inside the planar heating element 231 on the outer shell 221 side (upper surface side) of the planar heating element 231, and is connected to the outside from the outer surface side of the planar heating element 231. The lead is led out to the outside of the heating unit 201 via a lead wire lead pipe (lead wire lead-out portion) 233 attached to the outer shell 221.

In the substrate processing apparatus 1, as shown in FIG. 1, the heating unit 201 having such a configuration is disposed in the upper opening of the heating unit 101 in the chamber internal space 13 of the processing chamber 10.
At that time, the lead wire outlet tube 233 of the heating unit 201 is pulled out of the processing chamber 10 through the lead wire outlet tube passage 18 c provided in the lid 12. As a result, the lead wire 232 passing through the inside of the lead wire outlet tube 233 is also led out of the processing chamber 10.

As shown in FIG. 1, a disk-shaped heating unit 202 is disposed below the heating unit 101 inside the processing chamber 10.
The heating unit 202 is a disk-shaped heating unit disposed along the bottom surface of the chamber body 11 so as to close the lower opening of the heating unit 101, and together with the heating unit 101 and the heating unit 201, The chamber internal space 13 is heated to a desired temperature.

Since the configuration of the heating unit 202 is substantially the same as that of the heating unit 201 described above, a detailed description thereof is omitted.
The heating unit 202 is different from the heating unit 201 described above in the size of the opening formed in the central portion.
Since the heating unit 201 is disposed above the heating unit 101, an opening 261 is formed in the center of the heating unit 201 to allow the gas released from the shower head 42 to flow in the direction of the wafer W placed on the susceptor 20. It was. On the other hand, since the heating unit 202 is disposed below the heating unit 101, an opening 262 for allowing the support shaft 21 of the susceptor 20 to pass therethrough is formed at the center thereof. Therefore, the opening 262 at the center of the heating unit 202 is very small compared to the opening 261 at the center of the heating unit 201, and is formed to have a diameter sufficient to allow the support shaft 21 to pass therethrough. .

  From the heating unit 202 installed under the heating unit 101 inside the processing chamber 10 (chamber internal space 13), lead wires 234 connected to a planar heating element inside the heating unit 202 pass. A tube (lead wire lead-out portion) 235 is mounted toward the bottom of the processing chamber 10, and the lead wire lead-out tube 235 is connected to a lead wire lead-out tube passage port 18 d formed at the bottom of the chamber body 11. To the outside of the processing chamber 10. As a result, the lead wire 234 passing through the inside of the lead wire outlet tube 235 is also led out of the processing chamber 10.

In addition, heating units 301, 401, and 501 for maintaining the inside of each tube at a desired temperature are arranged along the inner peripheral surface of the wafer transfer tube 30, the supply tube 40, and the exhaust tube 50, respectively. It is installed.
As these heating units 301, 401, and 501, a heating unit having substantially the same configuration as the cylindrical heating unit 101 for the chamber described above with reference to FIGS. 2 to 4 can be used. That is, with respect to the cylindrical (in the above example, cylindrical) heating unit 101 described above with reference to FIGS. The wafer transfer pipe 30 and the air supply pipe have a size that can be installed inside, the length in the extending direction of the cylinder is the length of the heating target area of the pipe, and a configuration suitable for the pipe in which the lead wire is led out. The heating units 301, 401, and 501 are configured to heat the 40 and the exhaust pipe 50, respectively.

  As an example, a heating unit 401 for heating the air supply pipe 40 is shown in FIG. In FIG. 6, the same reference numerals are used for the same components as those of the heating unit 101 shown in FIG. 2, and description thereof is omitted. As shown in the figure, the heating unit 401 is also sandwiched between the inner shell 111 and the outer shells 121a and 121b by the O-rings 141a and 141b so that the sheet heating elements 131a and 131b are sandwiched between the inner shell 111 and the outer shells 121a and 121b. Thus, the inner shell 111 and the outer shells 121a and 121b are joined together by screws 151.

  The heating unit 401 is different from the heating unit 101 described above in the form of lead wires for supplying power to the planar heating elements 131a and 131b. In the heating unit 101, the lead wire is led out further upward from the upper edge (inner shell 111) of the main body of the cylindrical heating unit 101. In the heating unit 401, the outer periphery of the main body of the cylindrical heating unit 401 is drawn. Lead wires are led out from the surface in the outer diameter direction. That is, the pair of lead wires 432a and 432b for supplying power to the sheet heating elements 131a and 131b are connected to the sheet heating elements 131a and 131b on the outer peripheral surface of the substantially central portion of the sheet heating elements 131a and 131b. The lead wires are led out of the heating unit 401 via lead wire lead pipes (lead wire lead portions) 433a and 433b attached to the central portions of the outer peripheral surfaces of the outer shells 121a and 121b.

In the substrate processing apparatus 1, the heating unit 401 having such a configuration is disposed inside the air supply pipe 40 as shown in FIG. 1.
At that time, the lead wire outlet pipes 433a and 433b of the heating unit 401 are drawn out of the air supply pipe 40 through lead wire outlet pipe passage ports 43a and 43b formed on the side wall of the air supply pipe 40. Thereby, the lead wires 432a and 432b passing through the inside of the lead wire outlet tubes 433a and 433b are also led out to the outside of the air supply tube 40.

The heating unit 301 for heating the wafer transfer tube 30 preferably has a rectangular cross-sectional shape because the cross-sectional shape of the wafer transfer tube 30 is rectangular. Even when the cross section is rectangular, the configuration is basically the same as that of the heating unit 401 with reference to FIG.
As shown in FIG. 1, the heating unit 301 is disposed inside the wafer transfer tube 30, and the front end on the chamber internal space 13 side passes through the wafer transfer opening 15 of the chamber body 11 and is heated. It reaches the opening 115 formed on the peripheral surface.
Lead wire outlet tubes (lead wire outlet portions) 333a and 333b through which the lead wires 332a and 332b connected to the planar heating element of the heating unit 301 pass are lead wire outlet tube passage ports 33a formed in the wafer transfer tube 30. And 33b to the outside of the wafer transfer tube 30. As a result, the lead wires 332a and 332b passing through the lead wire outlet tubes 333a and 333b are also led out of the wafer transfer tube 30.

The heating unit 501 for heating the exhaust pipe 50 is basically the same as the heating unit 401 with reference to FIG.
As shown in FIG. 1, the heating unit 501 is disposed inside the exhaust pipe 50, and the front end on the chamber internal space 13 side passes through the exhaust port 17 of the chamber body 11 and the peripheral surface of the heating unit 101. The opening 116 is formed.
Lead wire outlet tubes (lead wire outlet portions) 533a and 533b through which the lead wires 532a and 532b connected to the planar heating element of the heating unit 501 pass are lead wire outlet tube passage ports 53a and 53a formed in the exhaust pipe 50, respectively. It is drawn out of the exhaust pipe 50 through 53b. Thereby, the lead wires 532a and 532b passing through the inside of the lead wire outlet pipes 533a and 533b are also led out to the outside of the exhaust pipe 50.

  In the substrate processing apparatus 1 having such a configuration, for example, after the chamber internal space 13 is evacuated through the exhaust pipe 50, the heating units 101, 201, 202, 301, 401, and 501 are energized. The interior of the chamber internal space 13, the wafer transfer pipe 30, the air supply pipe 40, and the exhaust pipe 50 are heated. Thus, by directly heating the chamber internal space 13, the wafer transfer pipe 30, the supply pipe 40 and the exhaust pipe 50 by the heating units 101, 201, 202, 301, 401 and 501, these spaces are rapidly heated. The chamber internal space 13 can be quickly brought to the target temperature. Further, the chamber internal space 13 can be heated uniformly, and temperature management can be performed appropriately.

  When the inside of the chamber internal space 13, the wafer transfer pipe 30, the air supply pipe 40, and the exhaust pipe 50 reach a desired high temperature state, the wafer to be processed is put into the chamber internal space 13 through the wafer transfer pipe 30, and the air supply pipe A desired reaction gas is introduced into the chamber internal space 13 through 40, and the gas is discharged from the exhaust pipe 50 as necessary to perform a process such as film formation by CVD. At this time, in the substrate processing apparatus 1 of the present embodiment, the inner surface temperature of the chamber inner space 13 is kept uniform and high by the heating units 101, 201, and 202, thereby preventing deposition of by-products. In addition, the generation of particles due to the accumulation of by-products can be prevented. In addition, it is possible to simultaneously improve the film forming speed, the reaction speed, and the film thickness uniformity.

Further, in the substrate processing apparatus 1, the heating units 301, 401, and 501 appropriately heat the wafer transfer pipe 30, the air supply pipe 40, and the exhaust pipe 50. It is possible to prevent the gas component from being sublimated. That is, it is possible to prevent or suppress by-products from generating, adhering to and accumulating in these piping portions.
As a result, for example, the exhaust pipe 50 can be prevented from being clogged with by-products, or the time until the exhaust pipe 50 can be clogged can be made sufficiently long, and the MTBF (Mean Time Between Failure) of the apparatus can be extended. Mean Time To Repair) can be shortened and the operating rate of the device can be improved.

In the substrate processing apparatus 1 according to the present embodiment, the heating units 101, 201, 202, 301, 401, and 501 each have an inner shell and an outer shell that sandwich the planar heating element are easily removed by screws. Joined freely.
Therefore, if a disconnection failure occurs in the planar heating element, loosen the screw, separate the outer shell and inner shell, take out the defective planar heating element, set a new planar heating element, By repairing the outer shell with the inner shell again and joining them with screws, the repair can be performed.
That is, in the heating unit of the present embodiment, it is possible to easily perform repair / repair when a failure occurs.
As a result, even when a disconnection failure occurs in the heating unit of the substrate processing apparatus in the semiconductor manufacturing process, the heating unit can be repaired only by replacing parts, and the cost can be reduced.
In addition, since a broken heating unit can be easily disassembled, it can be easily separated and discarded for each material.

  The above-described embodiments are described for facilitating understanding of the present invention, and do not limit the present invention. Each element disclosed in the present embodiment includes all design changes and equivalents belonging to the technical scope of the present invention, and various suitable modifications can be made.

For example, the form of the heating unit according to the present invention is not limited to the above-described examples. For example, the cylindrical heating unit may be a heating unit 102 having a configuration as shown in FIG.
The heating unit 102 shown in FIG. 7 is provided with flanges 117a and 117b, 161a and 161b, and 162a and 162b in the cylindrical cylindrical core direction on the inner shell 112 and the outer shells 122a and 122b, respectively. By joining, the inner shell and the outer shell are firmly joined. By joining the inner shell 112 and the outer shells 122a and 122b by such a method, it becomes possible to increase the arrangement area (heater area) of the planar heating element as compared with the example shown in FIG. It is possible to improve the temperature distribution.
In the heating unit 102 shown in FIG. 7, the configuration of the planar heating elements 134a and 134b, the O-rings 142a and 142b, etc. is substantially the same as the planar heating elements 131a and 131b and the O-rings 141a and 141b of the heating unit 101 described above. Are the same.

In the heating unit 102 shown in FIG. 7, the lead wires 135a and 135b connected to the planar heating elements 134a and 134b are lead wire outlet pipes (lead wire derivation tubes) installed on the outer peripheral surface of the cylindrical heating unit 102. Part) It is led out through 136a and 136b. The connection position and the lead-out form of the lead wire for supplying power to the planar heating element may be arbitrary. In the cylindrical heating unit installed inside the processing chamber 10 as well, from the outer periphery of the heating unit main body in this way, You may make it pull out outside from the outer shells 122a and 122b.
In the heating unit 102 shown in FIG. 7 as well, as with the heating unit 101 shown in FIG. 2, the lead wires 135a and 135b may be led out from the upper edge of the heating unit.

Moreover, as a heating unit which heats such an internal space, the cross-sectional shape is not limited to a circle, but may be a rectangle. The heating unit having such a configuration is shown in FIGS.
The heating unit 103 shown in FIG. 8 is different from the heating unit 101 shown in FIG. 1 in that its cross-sectional shape is rectangular. However, the basic configuration is the same as that of the heating unit 101 described above with reference to FIG. That is, planar heating elements 137a and 137b and O-rings 143a and 143b are interposed between the inner shell 113 and the outer shells 123a and 123b, and the inner shell 113 and the outer shells 123a and 123b are joined by the screws 153. ing. Lead wires 172a and 172b connected to the planar heating elements 137a and 137b are connected to the heating unit via lead wire outlet pipes (lead wire outlet portions) 173a and 173b installed in the outer shells 123a and 123b of the heating unit 103. 103 is led out from the side wall 103.

The heating unit 103 having such a configuration also has exactly the same function and effect as the above-described heating unit 101 of the present invention.
In the heating unit 103 shown in FIG. 8, the lead wires 172a and 172b may be led out from the upper edge portion of the heating unit, similarly to the heating unit 101 shown in FIG.

Further, the heating unit 104 shown in FIG. 9 has a rectangular cross section, and is formed as a shell 114 in which an inner shell and an outer shell are integrated, and a slit formed in a side wall of the shell 114. Is a heating unit configured to be a heater accommodating portion (planar heating element accommodating portion) 118a and 118b for accommodating the planar heating elements 138a and 138b.
The heater accommodating portions (slits) 118a and 118b have openings having a width substantially the same as or slightly wider than the thickness of the planar heating elements 138a and 138b into which the planar heating elements 138a and 138b can be inserted. Through these openings, the planar heating elements 138a and 138b are inserted into and removed from the heater accommodating portions (slits) 118a and 118b.

  Lid members 176a and 176b are attached to the heater accommodating portions 118a and 118b so as to cover the openings. The lid members 176a and 176b are installed by screws 154 with O-rings 144a and 144b interposed between the cover members 176a and 176b. The lid members 176a and 176b are provided with lead wire outlet tubes (lead wire outlet portions) 175a and 175b. The lead wires 174a and 174b of the sheet heating elements 138a and 138b are connected to the lead wire outlet tubes 175a and 175b. It is derived to the outside through. Accordingly, in the heating unit 104, the two sets of lead wires 174 a and 174 b are led out from one side surface of the shell 114.

The heating unit 104 having such a configuration also has exactly the same function and effect as the heating unit 101 of the present invention described above.
In addition, in the heating units 103 and 104 having a rectangular cross section shown in FIG. 8 and FIG. 9, the planar heating elements are arranged on two opposing surfaces, but these are arranged on the entire four surrounding surfaces. Also good.

FIG. 10 is a diagram showing a modification of the disc-shaped heating units 201 and 202 described above with reference to FIG. 5 and showing another example of a method for joining the inner shell and the outer shell.
The heating unit 203 shown in FIG. 10A has a configuration in which the outer shell 226 is fitted into the recess formed in the inner shell 216, and the screw 271 and the outer circumferential surface of the inner shell 216 and the outer shell 226 are fitted. 272 is formed so that the inner shell 216 and the outer shell 226 are fitted to each other.
The inner shell 216 and the outer shell 226 can be detached and firmly joined also by such mechanical latching means.

A heating unit 204 shown in FIG. 10B has magnets 273 and 274 embedded in an inner shell 217 and an outer shell 227, thereby joining the inner shell 217 and the outer shell 227 together.
In the heating unit 204 having such a configuration, it is preferable to remove the inner shell 217 and the outer shell 227 by, for example, weakening the magnetic force with a demagnetizer. Even in such a configuration, the inner shell 217 and the outer shell 227 can be detached and firmly joined.

A heating unit 205 shown in FIG. 10C is obtained by joining an inner shell 218 and an outer shell 228 with a clamp 275.
In the heating unit 205 having such a configuration, it is preferable that the inner shell 218 and the outer shell 228 can be easily detached by loosening the clamp 275. Even in such a configuration, the inner shell 218 and the outer shell 228 can be detached and firmly joined.

FIGS. 11-14 is a modification of the heating unit 401 for piping mentioned above with reference to FIG. 6, FIG. 11 is a perspective view which shows schematic structure of the heating unit 601 for piping, FIG. It is sectional drawing for demonstrating the structure in detail, Comprising: It is sectional drawing in CC of FIG.
13 and 14 are views showing another example of the method of joining the inner shell and the outer shell, and are the same sectional views as FIG.
As shown in FIGS. 11 and 12, the heating unit 601 has one inner shell (inner cylinder member) 611 and two outer shells (outer cylinder members) 621a and 621b.

  When the inner shell 611 and the outer shells 621a and 621b are joined as shown in the figure, a gap is formed between them as shown in FIG. 12, and the planar heating element 631 is accommodated in this space. O-rings 641 and 642 are provided between the inner shell 611 and the outer shell 621a at both ends in the longitudinal direction (the length direction of the cylinder) of the heating unit 601 and between the inner shell 611 and the outer shell 621b, respectively. Is intervened. Thereby, the space in which the sheet heating element 631 is accommodated and the inside of the pipe are sealed, and the sheet heating element 631 can be prevented from being exposed to the gas atmosphere in the pipe.

  One end portions of the outer shells 621a and 621b are formed in flanges 622a and 622b, respectively. By joining the flange 622a of the outer shell 621a and the flange 622b of the outer shell 621b with a screw 651, the outer shells 621a and 621b are integrated with one outer shell, and O-rings 641 and 642 are interposed. The inner shell 611 is sandwiched from both ends, and thereby the heating unit 601 is integrally configured.

  Further, when the flange 622a of the outer shell 621a and the flange 622b of the outer shell 621b are joined, a lead wire lead-out opening (lead wire lead-out portion) 633 for leading the lead wire 632 to the outside at a predetermined position of the boundary. Is formed. The lead wire 632 connected to the substantially central portion of the sheet heating element 631 is led out of the pipe through the lead wire lead-out opening 633.

  When this heating unit 601 is arranged in a pipe, as shown in FIG. 12, the lead wire lead-out opening 633 is exposed to the outside from the joint or opening of the pipe 60, and the lead wire 632 is led out to the outside. Just keep it.

In addition, in such a heating unit 601 for piping, the method for joining the inner shell and the outer shell is not limited to the method shown in FIG. Another example is shown in FIGS.
In the heating unit 602 shown in FIG. 13, the inner shell 614 and the outer shells 624 a and 624 b are joined by screws 652. In this case, the inner shell 614 and the outer shells 624a and 624b are preferably joined by screws 652 outside the O-rings 641 and 642.

In addition, in the heating unit 603 shown in FIG. 14, screws (threads or thread grooves) 616a and 616b are formed at both ends of the inner shell 615, and screws (screw grooves or screws) are formed at each end of the outer shells 625a and 625b. Mountain) 626a and 626b are formed and the inner shell 615 and the outer shells 625a and 625b are joined by engaging them. Further, the flange portions 627a and 627b of the outer shells 625a and 625b are locked by a locking pin or a screw 653.
Any of these types of heating units 601 to 603 has exactly the same function and effect as the heating unit 401 described above with reference to FIG. The heating unit may be implemented in such various forms.

In any of the cases described above, as a sealing material between the inner shell and the outer shell, a metal gasket, a metal O ring, a C seal, an E seal, or the like may be used in addition to the O ring.
In addition, it is preferable to select the material of these sealing materials according to the pressure, operating temperature, atmospheric gas, and the like.

  The heating apparatus of the present invention can be applied to semiconductor manufacturing apparatuses such as a substrate processing apparatus and an etching apparatus. Moreover, as long as it is necessary to heat the inner wall surface defining the flow path or space directly from the inside, it can also be used in other devices.

FIG. 1 is a cross-sectional view of an essential part of a substrate processing apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing a schematic configuration of a cylindrical heating unit of the substrate processing apparatus shown in FIG. FIG. 3 is a cross-sectional view of the cylindrical heating unit shown in FIG. 2 and a cross-sectional view of its inner shell. FIG. 4 is a cross-sectional view of the side wall of the cylindrical heating unit shown in FIG. FIG. 5 is a diagram showing a configuration of the disc-shaped heating unit of the substrate processing apparatus shown in FIG. 6 is a diagram showing a configuration of a cylindrical heating unit for piping of the substrate processing apparatus shown in FIG. FIG. 7 is a diagram showing another example of a cylindrical heating unit according to the present invention. FIG. 8 is a diagram showing an example of a cylindrical heating unit having a rectangular cross section according to the present invention. FIG. 9 is a view showing still another example of a cylindrical heating unit having a rectangular cross section according to the present invention. FIG. 10 is a view showing another example of the disc-shaped heating unit according to the present invention. FIG. 11 is a perspective view showing another example of the heating unit for piping according to the present invention. 12 is a cross-sectional view of the heating unit shown in FIG. FIG. 13 is a diagram showing another example of the heating unit for piping according to the present invention. FIG. 14 is a diagram showing still another example of the heating unit for piping according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate processing apparatus 10 ... Processing chamber 11 ... Chamber main body 12 ... Cover part 13 ... Chamber internal space 14 ... Bottom part opening 15 ... Wafer loading / unloading opening 16 ... Air supply port 17 ... Exhaust port 18a, 18b, 18c, 18d, 33a, 33b,
43a, 43b, 53a, 53b ... Lead wire outlet pipe passage port 19 ... O-ring 20 ... susceptor 21 ... support shaft 30 ... wafer transfer pipe 31 ... O-ring 40 ... air supply pipe 41 ... O-ring 42 ... shower head 241 ... opening 50 ... Exhaust pipe 51 ... O-ring 101, 102, 201, 202, 203, 204, 205, 301, 401,
501, 601, 602, 603... Heating unit 111, 112, 113, 114, 211, 216, 217, 218, 611,
614, 615 ... Inner shell 112a, 112b ... Recess 113a, 113b, 118a, 118b, 213 ... Heater recess (heater housing)
114a, 114b ... outer shell recesses 212, 222, 261 ... central opening 214, 215 ... O-ring recesses 115, 116 ... opening 117a, 117b, 161a, 161b, 162a, 162b, 622a,
622b, 627a, 627b ... flanges 121a, 121b, 122a, 122b, 123a, 123b, 221;
226, 227, 228, 621a, 621b, 624a, 624b,
625a, 625b ... outer shell 131a, 131b, 134a, 134b, 137a, 137b, 138a,
138b, 231, 631 ... planar heating elements 132a, 132b, 135a, 135b, 172a, 172b, 174a,
174b, 232, 332a, 332b, 432a, 432b,
532a, 532b, 632 ... lead wires 133a, 133b, 136a, 136b, 173a, 173b, 175a,
175b, 233, 235, 333a, 333b, 433a, 433b,
533a, 533b ... Lead wire outlet tube (lead wire outlet portion)
141a, 141b, 142a, 142b, 143a, 143b, 144a,
144b, 241, 242, 641, 642 ... O-rings 151, 152, 153, 154, 251, 651, 652, 653 ... screws 176a, 176b ... lid members 271, 272, 616a, 616b, 626a, 626b ... screw grooves ( Thread)
273, 274 ... Magnet 275 ... Clamp 633 ... Opening for lead wire extraction (lead wire lead-out portion)

Claims (9)

A heating apparatus disposed in a processing chamber for performing a desired process on the object to be processed, a transfer path of the object to be processed, or a gas supply / exhaust pipe for the desired process,
A planar heating element;
An outer wall portion formed by joining a plurality of members, and in a state where the plurality of members are joined, a heating element accommodating portion that covers the periphery of the planar heating element and accommodates the planar heating element Is formed on the outer wall portion, and in a state where at least some of the plurality of members are separated, the outer wall portion in which the planar heating element is detachable,
A sealing material disposed at a joint location of the plurality of members around the heating element housing portion of the outer wall portion;
A heating apparatus comprising: a joining unit that joins the plurality of members.   The outer wall portion includes a cylindrical inner member and one or more outer members disposed along the outer surface of the inner member, and either the outer surface of the inner member or the inner surface of the outer member. The heating device according to claim 1, wherein the heating element accommodating portion that accommodates the planar heating element is formed by a recess formed in both.   The heating device according to claim 2, wherein a flange is formed on the inner member and the outer member in a tube core direction of the tubular member, and the flange is joined to each other by the flange.   The outer wall portion includes two plate-like members joined to face each other, and the planar heating element is accommodated by a recess formed on one or both of the opposing surfaces of the two plate-like members. The heating device according to claim 1, wherein the heating element housing portion is formed.   The outer wall includes a main body member in which a slit having an opening having a width substantially equal to the thickness of the planar heating element can be inserted, and a lid member that closes the opening. The heating apparatus according to claim 1. The outer wall portion includes a cylindrical inner cylinder member, and a plurality of outer cylinder members that are installed outside the inner cylinder member in a length direction of the inner cylinder member,
A flange projecting in the radial direction along the outer periphery is formed at a location connected to each other outer cylinder member of each of the plurality of outer cylinder members, and the plurality of outer cylinder members are joined by joining the flanges. Are connected,
The outer peripheral surfaces of both end portions of the inner cylindrical member are joined to the inner peripheral surface of the outer cylindrical member disposed on the outside,
The heating apparatus according to claim 1, wherein the planar heating element is sandwiched between the inner cylinder member and the outer cylinder member.   The heating device according to claim 1, wherein the joining unit joins the plurality of members by any one of a screw, a magnetic force, a clamp, and a mechanical hooking unit. A lead wire lead-out portion for leading the lead wire for supplying power to the planar heating element to the outside;
The heating device according to any one of claims 1 to 7, wherein the heating element housing portion of the outer wall portion is open to the atmosphere through the lead wire lead-out portion.   The heating device according to claim 1, wherein the member forming the outer wall portion is a metal member.

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