WO2008029595A1

WO2008029595A1 - Temperature measuring device

Info

Publication number: WO2008029595A1
Application number: PCT/JP2007/065854
Authority: WO
Inventors: Kentaro Asakura
Original assignee: Tokyo Electron Limited
Priority date: 2006-09-06
Filing date: 2007-08-14
Publication date: 2008-03-13
Also published as: TW200823439A; CN101421599A; KR20080109747A; TWI403702B; JP2008064551A; JP4803596B2; CN101421599B

Abstract

A temperature measuring device (5) is provided with a sheathed thermocouple (50). The sheathed thermocouple has a leading end section (50a) movable in an advancing/retracing direction by following a susceptor (4), and a buffer section (50b) extending to the outside of a chamber (1) to allow movement of the leading end section (50a). The temperature measuring device is also provided with a compression coil spring (53) for urging the leading end section (50a) in a direction to press the leading end section to the susceptor (4). A hermetically sealing member (51) storing the compression coil spring (53) and the buffer section (50b) is adhered to the bottom wall (19) of the chamber (1) so that inside the hermetically sealed member communicates with the inside of the chamber (1). The end portion of the buffer section (50b) extends to the external of the hermetically sealed member (51), and a connecting section (55) is formed by being welded to a part where the end portion of the buffer section (50b) of the hermetically sealed member (51) extends.

Description

Specification

Temperature measuring device

Technical field

The present invention relates to a temperature measuring device that measures the temperature of a temperature-measuring object arranged in a container.

Background art

In a semiconductor manufacturing process, a semiconductor substrate is placed on a mounting table in a processing container, and a processing gas is supplied into the processing container, and a semiconductor is heated by a heating mechanism such as a heater built in the mounting table. A predetermined process is performed on the semiconductor substrate by heating the substrate. In such a process, since the heating temperature greatly affects the quality of the semiconductor substrate, it is necessary to accurately measure the temperature of the mounting table or the heating mechanism. For this reason, thermocouples with excellent thermal responsiveness are often used to measure the temperature of the mounting table. Among them, a sheath made of a metal having heat resistance and a thermocouple element disposed in the sheath are used. Many sheathed thermocouples with wires are used! (See, for example, Patent Documents 1 and 2).

Patent Document 1: Japanese Patent Laid-Open No. 4 63281

Patent Document 2: JP-A-6 176855

[0003] Sheath thermocouples are generally long enough to be hermetically attached to the wall of the processing vessel so that the tip is in contact with the mounting table. In addition, when the processing gas is supplied into the processing container, the mounting table moves a little due to a change in pressure in the processing container, and therefore, the distal end portion of the sheath thermocouple tends to be out of contact with the mounting table. If the tip is not in contact with the mounting table, the temperature of the mounting table cannot be measured accurately. For this reason, since the sheath thermocouple absorbs attachment errors and follows the movement of the mounting table, the sheath thermocouple uses a bellows on the wall of the processing container so as to have a degree of freedom in the advancing and retreating direction relative to the mounting table, that is, in the length direction. It is considered to be attached.

[0004] However, when the sheath thermocouple is attached to the wall of the processing container using the bellows, when the inside of the processing container is depressurized, the inside of the bellows is also depressurized, and the sheath thermocouple is pressed toward the mounting table, and the sheath The thermocouple may be damaged.

Disclosure of the invention [0005] The present invention has been made in view of the force and the circumstances, and is a temperature measuring device using a sheathed thermocouple, in which a sheathed thermocouple or a temperature-measured body is damaged due to decompression in the container. An object of the present invention is to provide a temperature measuring device capable of accurately measuring the temperature of the temperature measuring object while preventing the above.

[0006] Further, the present invention is a temperature measuring device using a sheath thermocouple, and the temperature of the temperature-measured body is prevented while preventing damage to the sheath thermocouple or the temperature-measured body due to decompression in the container. In addition to accurately measuring the temperature, a temperature measuring device capable of preventing corrosion caused by the corrosive gas in the container is provided.

aimed to.

[0007] The present invention relates to a temperature measuring device for measuring the temperature of a temperature-measured body arranged in a processing container, and comprises a sheath and a thermocouple wire arranged in the sheath, A tip that extends inward of the processing container and abuts the temperature-measured body and moves in the forward / backward direction following the temperature-measured body, and a buffer that extends outward from the process container and allows movement of the tip A sheathed thermocouple, a sealing member that is fixed to the outer surface of the processing container and that houses the buffer portion of the sheathed thermocouple, and a spring member that is disposed in the sealing member and biases the distal end of the sheathed thermocouple toward the temperature-measured body The end portion of the buffer portion of the sheath thermocouple extends further outward through the sealing member force welded portion or the brazed portion.

[0008] In the present invention, the inside of the processing vessel has a corrosive gas atmosphere, and the sheath, the sealing member, and the spring member are made of a material having corrosion resistance against corrosive gas. It is a temperature device.

[0009] In the present invention, the spring member comprises a coil spring, and the sealing member moves in the advancing and retreating direction with respect to the temperature-measured body as the coil spring expands and contracts. The temperature measuring device is characterized in that a piston made of a material having the above is housed, and the sheath thermocouple is fixed to the piston.

[0010] The present invention provides the temperature measuring device, wherein the corrosive gas is a gas containing halogen, and the material having corrosion resistance to the corrosive gas is nickel (Ni) or a nickel alloy. is there.

[0011] In the present invention, the temperature measuring device is characterized in that the spring member is made of Inconel (registered trademark). It is a position.

[0012] The present invention is the temperature measuring device, wherein the buffer portion is bent so as to expand and contract in the advancing and retreating direction with respect to the temperature measuring object!

[0013] The present invention is the temperature measuring device, wherein the buffer portion is bent in a spiral shape.

[0014] The present invention is the temperature measuring device, wherein the buffer portion is bent in a waveform.

[0015] According to the present invention, the sheath thermocouple is provided in the container so as to be positioned in the container and movable in the advancing and retreating direction following the temperature measurement object, and to extend out of the container. This is composed of a buffer part that allows movement of the tip part, and is provided with a spring member that urges the tip part of the sheath thermocouple in the direction to press against the body to be measured. The tip of the sheathed thermocouple without using rose can be brought into contact with the object to be measured reliably. Therefore, it is possible to accurately measure the temperature of the temperature-measured body while preventing damage to the sheath thermocouple or the temperature-measured body due to the reduced pressure in the container.

[0016] Further, according to the present invention, the sheath thermocouple is provided so as to be positioned inside the container and move in the advancing and retreating direction following the temperature measurement object, and to extend outside the container. And a spring member that urges the tip of the sheath thermocouple in the direction of pressing the temperature-measured body, which greatly affects the pressure difference inside and outside the container. The tip of the sheath thermocouple, which uses the received bellows or peels off part of the sheath that causes a decrease in corrosion resistance, can be reliably brought into contact with the object to be measured. In addition, the sheath, sealing member, and spring member that are exposed to the corrosive gas atmosphere in the container are all formed of a corrosion-resistant material against the corrosive gas, and the joint between the sealing member and the sheath is formed by welding or brazing. Therefore, corrosion by corrosive gas can be prevented. Therefore, it is possible to accurately measure the temperature of the temperature-measured body while preventing damage to the sheathed thermocouple or temperature-measured body due to the decompression of the container and corrosion caused by the corrosive gas in the container. It becomes.

Brief Description of Drawings

FIG. 1 is a cross-sectional view schematically showing a wafer processing apparatus provided with a temperature measuring device as one embodiment according to the present invention.

[FIG. 2] FIG. 2 (a) is a cross-sectional view of a temperature measuring device, and FIG. 2 (b) is a cross-sectional view showing a sheath thermocouple. FIG. 3 is a view showing a modification of the buffer portion provided in the temperature measuring device.

[FIG. 4] FIG. 4 is a view showing another manner of attaching the temperature measuring device to the processing container.

FIG. 5 is a view showing a modification of the sealing member provided in the temperature measuring device.

[Fig. 6] Fig. 6 is a view showing an aspect of attachment of a sheathed thermocouple as a comparative example to a processing vessel. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

The wafer processing apparatus 100 is a chamber 11 as a processing container capable of accommodating a wafer W, which is a semiconductor substrate, and is disposed in the chamber 11, and the temperature of the wafer W is set by placing the wafer W thereon. A susceptor 4 as a temperature control unit to be adjusted, a temperature measuring device 5 for measuring the temperature of the susceptor 4 (temperature measurement object), and a processing gas containing a corrosive gas for performing predetermined processing on the wafer W are provided in a chamber. A processing gas supply mechanism 2 for supplying the inside of the chamber 1 and a decompression mechanism 3 for reducing the pressure inside the chamber 1 are provided.

The chamber 11 is formed in a substantially cylindrical shape having an upper opening, and a loading / unloading port 13 for loading and unloading the wafer W is formed on the side wall of the chamber 11. A gate valve 14 for opening and closing the loading / unloading port 13 is provided. The susceptor 4 is provided on the bottom wall 19 of the chamber 1 through a column member 11 extending in the height direction, and a heater 40 is embedded therein, and the heater 40 is connected to a heater power supply 41. . The heater power source 41, that is, the heater 40, is controlled by a controller 90 described later based on the measured temperature of the temperature measuring device 5, and thereby the temperature of the wafer W placed on the susceptor 4 is adjusted.

A shower head 15 is provided on the upper portion of the chamber 11 so as to close the opening and to face the susceptor 4. The shower head 15 has a diffusion space 16 for diffusing the processing gas by the processing gas supply mechanism 2 inside, and a plurality or many of the processing gas discharges by the processing gas supply mechanism 2 on the surface facing the susceptor 4. The discharge hole 17 is formed.

An exhaust port 18 is formed in the lower part of the side wall of the chamber 11. Pressure reducing mechanism 3 is exhaust An exhaust pipe 31 connected to the port 18 and an exhaust device 32 for exhausting the inside of the chamber 11 through the exhaust pipe 31 are provided.

[0023] The processing gas supply mechanism 2 includes a processing gas storage unit 21 in which a processing gas containing a corrosive gas such as a halogen-based gas (a gas containing gas or rhogen) is stored, and a processing gas from the processing gas storage unit 21. A conduit 22 led into the diffusion space 16 of the shower head 15, and a mass flow controller 23 and a valve 24 as a flow rate adjusting mechanism for adjusting the flow rate of the processing gas flowing through the conduit 22 are provided. In the case where a plurality of types of different processing gases are supplied into the chamber 11, for example, a plurality of processing gas supply mechanisms 2 are provided.

[0024] Next, the temperature measuring device 5 will be described in detail.

2 (a) is a cross-sectional view of the temperature measuring device 5, and FIG. 2 (b) is a cross-sectional view of the sheath thermocouple 50.

[0025] The temperature measuring device 5 extends inward of the chamber 1 and contacts the susceptor 4, and moves in the forward and backward direction following the susceptor 4 (one axial side) 50a and the chamber 1 A sheath thermocouple 50 having a buffer portion (the other side in the axial direction) 50b extending outward and allowing the tip portion 50a to move, and a buffer portion 50b of the sheath thermocouple 50 fixed to the outer surface of the chamber 1 are accommodated. And a sealing member 51. Also, in the sealing member 51, there is a compression as a spring member that biases the piston 54 attached to the sheath thermocouple 50 and the tip 50a of the sheath thermocouple 50 attached to the piston 54 in a direction to press against the susceptor 4. The coil spring 53 is housed. The sealing member 51 that accommodates the piston 54, the compression coil spring 53, and the buffer portion 50b is connected to the wall portion of the chamber 11 such as the bottom wall 19 so that the inside thereof communicates with the inside of the chamber 11. It is provided in close airtight contact. The end portion of the buffer portion 50b extends to the outside of the sealing member 51, and the joint portion 55 is formed in the portion of the sealing member 51 where the end portion of the buffer portion 50b extends to the outside (atmosphere side outside the chamber 1). It is airtight.

[0026] As shown in Fig. 2 (b), the sheath thermocouple 50 includes a thermocouple wire 50c, a hollow sheath 50d covering the thermocouple wire 50c, and magnesia filled in the sheath 50d. Insulation material 50e. The sheath 50d of the sheath thermocouple 50 is made of a material having corrosion resistance to a halogen-based gas, for example, a nickel alloy such as pure nickel (Ni) or nickel 'chromium' molybdenum iCrMo) or hastelloy. Note that the sheath 50d and the insulating material 50e do not necessarily have to be provided in a portion extending from the sealing member 51 to the outside. Good.

[0027] The distal end portion 50a of the sheath thermocouple 50 is in contact with the susceptor 4 by being inserted into, for example, a insertion hole 4a formed in the lower surface of the susceptor 4. The buffer portion 50b of the sheath thermocouple 50 is bent or curved, for example, spirally so that it can expand and contract in the advancing and retracting direction with respect to the susceptor 4. The end portion of the sheathed thermocouple 50 is connected to the signal transmission unit 52, and the signal transmission unit 52 transmits a measurement temperature signal from the sheath thermocouple 50 to the controller 90 described later, and the controller based on the measurement temperature signal 90 is configured to control the temperature of the heater power supply 41, namely the heater 40.

[0028] The sealing member 51 is made of a material having corrosion resistance to a halogen-based gas, for example, pure nickel or a nickel alloy, which is the same kind of metal as the sheath 50d of the sheath thermocouple 50, and has a cylindrical shape. Yes. The sealing member 51 is a cylinder portion 51b that houses a compression coil spring 53 and a piston 54 that can move in the forward and backward direction relative to the susceptor 4 as the compression coil spring 53 expands and contracts in order from one side to the other side in the axial direction. And a buffer housing portion 51c for housing the buffer portion 50b of the sheath thermocouple 50. A flange 51a is formed at one end in the axial direction of the sealing member 51, and the sealing member 51 is attached by one end surface of the flange 51a being in airtight contact with the outer surface (bottom surface) of the bottom wall 19 of the chamber 1. It has been. The above-mentioned joint portion 55 is provided on the wall portion on the other axial side of the sealing member 51, and the joint portion 55 is formed by welding or brazing. Here, the sealing member 51 is made of the same type of metal as the sheath 50d of the sheath thermocouple 50, so that the welding or brazing of both is good, and the sheath 50d is securely fixed to the sealing member 51 by the joint portion 55. can do.

[0029] The compression coil spring 53 is formed of a material that has corrosion resistance against halogen-based gas and has an elastic force, such as SUS316L containing Inconel (registered trademark), nickel, and molybdenum. It is made of a material having corrosion resistance to the system gas, for example, pure nickel or nickel alloy which is the same kind of metal as the sheath of the sheath thermocouple 50. The piston 54 is provided with a through-hole through which the sheath of the sheath thermocouple 50 penetrates, and both of them are fixed by welding, brazing, caulking, or the like. 50a is the pressure through piston 54 It is urged so as to be pressed against the susceptor 4 by the repulsive force of the compression coil spring 53 (in the direction of arrow F in FIG. 2 (a)). Here, when the piston 54 is made of the same kind of metal as the sheath 50d of the sheath thermocouple 50, the welding or brazing of both is improved, and the piston 54 can be reliably fixed to the sheath 50d.

Each component of the wafer processing apparatus 100 is connected to and controlled by a controller 90 (control unit) that includes a microprocessor (computer). The controller 90 includes a keyboard that performs command input operations to manage each component of the wafer processing apparatus 100, a user interface that includes a display that visualizes and displays the operating status of the wafer processing system 1, and the like. A control program for realizing processing executed by the wafer processing apparatus 100 by control of the controller 90 and a storage unit storing a recipe including processing condition data are connected. If necessary, an arbitrary recipe is called from the storage unit by an instruction from the user interface and the controller 90 executes the recipe, so that a desired process is performed in the wafer processing apparatus 100 under the control of the controller 90. .

In wafer processing apparatus 100 configured as described above, processing of wafer W is performed as follows. First, in a state where the loading / unloading port 13 is opened by the gate valve 14, the wafer W is loaded into the chamber 11 from the loading / unloading port 13 and placed on the susceptor 4, and the loading / unloading port 13 is closed by the gate valve 14.

[0032] Next, the exhaust device 32 of the decompression mechanism 3 is operated to decompress the interior of the chamber 1 to a predetermined pressure, for example, a vacuum pressure, and the interior of the chamber 1 through the shower head 15 by the processing gas supply mechanism 2 The wafer W is heated by the heater 40 via the susceptor 4 while supplying a predetermined flow rate of the processing gas. During heating by the heater 40, as described above, the sheath thermocouple 50 measures the temperature of the susceptor 4, and the signal transmission unit 52 transmits the measured temperature signal of the susceptor 4 by the sheath thermocouple 50 to the controller 90. Based on this measured temperature signal, the controller 90 controls the temperature of the heater 40, so that the wafer W on the susceptor 4 is adjusted to a predetermined temperature. Thereby, the wafer W is subjected to predetermined processing.

Here, when the processing gas is supplied into the chamber 11 by the processing gas supply mechanism 2 and / or the pressure in the chamber 1 is reduced by the pressure reducing mechanism 3, the pressure in the chamber 11 changes. As a result, the susceptor 4 slightly moves. Sheath thermocouple Since 50 buffer portions 50b expand and contract in the forward and backward direction with respect to the susceptor 4, and the distal end portion 50a of the sheath thermocouple 50 is biased to be pressed against the susceptor 4 by the compression coil spring 53, the distal end of the sheath thermocouple 50 The part 50a moves following the movement of the susceptor 4 so that the contact with the susceptor 4 is maintained. Therefore, the temperature of the susceptor 4 can be accurately measured, and thereby the temperature of the heater 40 can be accurately controlled to improve the processing quality of the wafer W.

[0034] Further, the spring member, for example, the compression coil spring 53, biases the distal end portion 50a of the sheath thermocouple 50 against the susceptor 4, so that it is significantly increased by the pressure difference between the atmosphere and vacuum as in the prior art. Since it is not necessary to use a bellows that exerts a pressing force, it is possible to prevent the sheath thermocouple 50 from being strongly pressed against the susceptor 4 due to the reduced pressure in the chamber 1. In addition, it is possible to prevent damage to the susceptor 4 and increase the durability of the device.

[0035] Further, since the sheath thermocouple 50 is bent together with the sheath 50d, for example, in a spiral shape to form the buffer portion 50b, there is no need to peel off a part of the sheath and expose the thermocouple wire as in the conventional case. Therefore, heat resistance is ensured, which makes it possible to cope with the case where the inside of the chamber 11 is kept at a high temperature.

[0036] It should be noted that the buffer 50b preferably has a curvature S that is as small as possible so that the load during expansion and contraction is reduced, and the susceptor 4b is distributed so that the load during expansion and contraction is distributed. It is preferable that the shape has a certain regularity in the advancing and retreating direction. Examples of the shape of the buffer portion 52b include a waveform as shown in FIG. 3 in addition to the spiral shape shown in FIG. 2 (a).

[0037] Further, each member of the temperature measuring device 5 exposed to an atmosphere of a processing gas in the chamber 11, for example, a corrosive gas such as a halogen-based gas, that is, the sheath 50d of the sheath thermocouple 50, the sealing member 51, and the compression coil Both the spring 53 and the piston 54 are made of a material having corrosion resistance against the processing gas, for example, nickel or a nickel alloy. Further, the joint 55 that hermetically joins the sheath 50d of the sheath thermocouple 50 and the sealing member 51 is formed by welding or brazing. For this reason, it is possible to prevent organic contamination by preventing corrosion of the temperature measuring device 5 due to processing gas that does not require the use of any organic material such as resin. it can.

Next, the decompression mechanism 3 depressurizes the chamber 11, the processing gas supply mechanism 2 supplies the processing gas into the chamber 11, and the heater 40 heats the wafer W for a predetermined time. After the wafer W has been subjected to a predetermined process, supply of the processing gas into the chamber 1 by the processing gas supply mechanism 2 and heating of the wafer W by the heater 40 are stopped, and the loading / unloading port 13 is opened by the gate valve 14. Then, the wafer W is transferred out of the chamber 11 through the loading / unloading port 13.

Next, a comparative example of the present invention will be described with reference to FIG.

As shown in FIG. 6, one end and the other end of the bellows C in a slightly expanded / contracted state here are hermetically sealed to the sheath thermocouple A and the wall of the processing vessel, for example, the bottom wall D. It is also conceivable that the sheath thermocouple A is pressed weakly against the mounting table B in advance by attaching it, and the sheath thermocouple A follows the movement of the mounting table by the expansion and contraction of the bellows C.

[0040] However, in the semiconductor manufacturing process, in general, when a processing gas is supplied, the inside of the processing container is reduced to, for example, a vacuum pressure, and in addition, the bellows is generally used. Because of the manufacturing process, it has a certain diameter R. For this reason, in the above-described manner of attaching the sheath thermocouple using the bellows C, the pressure difference between the atmosphere and the vacuum corresponding to the diameter R is applied to the bellows C by reducing the inside of the processing container to a vacuum pressure, for example. An extremely large pressing force against the mounting base B (see arrow E in Fig. 6) acts on the sheath thermocouple A. As a result, the sheath thermocouple A is strongly pressed against the mounting table B, and the sheath thermocouple A or the mounting table B may be damaged.

[0041] On the other hand, according to the present invention, it is not necessary to use a bellows as described above, so that the sheath thermocouple 50 is strongly pressed against the susceptor 4 due to the reduced pressure in the chamber 11, without the force S. Damage to the sheath thermocouple 50 and the susceptor 4 can be prevented.

The present invention is not limited to the above embodiment, and various modifications can be made. In the above embodiment, the temperature measuring device 5 is arranged so that the sheath thermocouple 50 is exposed in the chamber 11. However, as shown in FIG. 4, for example, the sheath thermocouple 50 is placed in the cylindrical column member 11. Measured to fit A warming device 5 may be arranged.

[0042] In the above embodiment, the buffer housing 51c for housing the buffer 50b, the cylinder 51b for housing the compression coil spring 53 and the piston 54, and the flange 51a protruding from one end of the cylinder 51b. The sealing member 51 is integrally formed with the sealing member 51, and the sealing member 51 is attached so that one end surface of the flange 51a is in close contact with the outer surface of the bottom wall 19 of the chamber 11. However, for example, as shown in FIG. 5, the sealing member 51 is attached to the outer member 51d attached to the outer surface (bottom surface) of the bottom wall 19 of the chamber 11 and the inner surface (upper surface) of the bottom wall 19 of the chamber 11. In this case, the buffer portion 50b, the compression coil spring 53, and the piston 54 are disposed between the outer member 51d and the inner member 51e. In FIG. 5, the outer member 51d is formed in a container shape that accommodates the buffer portion 50b, the inner member 51e is formed in a ring shape surrounding the sheath thermocouple 50, and the compression coil spring 53 and the piston 54 are It is disposed in the bottom wall 19 of the chamber 1 so as to be sandwiched between the outer member 5 Id and the inner member 51 e. In this case, the portion surrounding the compression coil spring 53 and the piston 54 on the bottom wall 19 of the chamber 11 also functions as a part of the sealing member 51. With such a configuration, the sealing member 51 (the portion of the sealing member 51 protruding from the bottom wall 19 of the chamber 11) can be reduced in size. Instead of using the inner member 50e, the compression coil spring 53 and the piston 54 may be disposed so as to be sandwiched between the outer member 51d and the bottom wall 19 of the chamber 11, or the outer member may be used. Instead, the inner member 50e may be formed in a container shape, and the buffer portion 50b, the compression coil spring 53, and the piston 54 may be accommodated in the inner member 50e.

[0043] In the above embodiment, the force S using a compression coil spring as a spring member is not limited to this, and other springs such as a tension coil spring may be used.

Furthermore, in the above embodiment, the force described in the application example in which the temperature of the semiconductor wafer is adjusted by heating the heater is not limited to this. For example, when the temperature of the wafer is adjusted by cooling the cooling plate It can also be applied to. Further, the object to be processed is not limited to a semiconductor wafer but may be a glass substrate for FPD.

Industrial applicability

The present invention relates to a CVD (Chemical Vapor Deposition) that performs a film forming process on a semiconductor substrate. Applicable to all types of applications that measure the temperature of a temperature sensing object such as a susceptor placed in a vessel in a corrosive gas atmosphere, such as a post-heat device that heat-treats semiconductor substrates after COR (Chemical Oxide Removal) processing. is there.

Claims

The scope of the claims

[1] A temperature measuring device that measures the temperature of the temperature-measuring object placed in the processing container!

A sheath and a thermocouple wire disposed in the sheath, extending inward of the processing container and abutting against the measured object and moving in the forward and backward direction following the measured object, and a treatment A sheath thermocouple having a buffer portion extending outward from the treatment container and permitting movement of the tip, a sealing member fixed to the outer surface of the processing container and housing the buffer portion of the sheath thermocouple, and disposed in the sealing member A spring member that biases the distal end of the sheath thermocouple toward the temperature-measured body,

The temperature measuring device, wherein the end portion of the buffer portion of the sheath thermocouple extends further outward through the sealing member welded portion or the brazed portion.

[2] The inside of the processing vessel has a corrosive gas atmosphere.

2. The temperature measuring device according to claim 1, wherein each of the sheath, the sealing member, and the spring member is made of a material having corrosion resistance against a corrosive gas.

[3] The spring member comprises a coil spring,

In the sealing member, a piston made of a material resistant to the corrosive gas, which moves in the forward / backward direction with respect to the temperature-measured body as the coil spring expands / contracts, is accommodated.

The temperature measuring device according to claim 2, wherein the sheath thermocouple is fixed to the piston.

[4] The corrosive gas is a gas containing halogen,

4. The temperature measuring device according to claim 2, wherein the material having corrosion resistance against the corrosive gas is nickel or nickel alloy.

5. The temperature measuring device according to claim 1, wherein the spring member is made of Inconel (registered trademark).

6. The temperature measuring device according to claim 1, wherein the buffer portion is bent so as to be extendable and retractable in a forward / backward direction with respect to the temperature measuring object.

7. The temperature measuring device according to claim 6, wherein the buffer portion is bent in a spiral shape. 8. The temperature measuring device according to claim 6, wherein the buffer portion is bent in a waveform.