Temperature measurement assembly, substrate processing device, substrate processing method, manufacturing method for semiconductor device, and program

Abstract

Provided is a technology with which temperatures can be measured in a stable manner over a long period under a high-temperature environment.　The present invention comprises: (a) an insulating tube having two through-holes into which two conductive wires of a temperature sensor are respectively inserted; (b) a first protective tube through which the insulating tube is inserted from a first end on the inner side; (c) a cylindrical sleeve that is connected to the first end of the first protective tube in an airtight manner and is attached to an attachment port in an airtight manner from the outside of a furnace; and (d) a second protective tube that is attached to the attachment port from the inside of the furnace and covers the entire first protective tube inside the furnace.

Description

Temperature measurement assembly, substrate processing apparatus, substrate processing method, semiconductor device manufacturing method and program

[0001] The present disclosure relates to a temperature measurement assembly, a substrate processing apparatus, a substrate processing method, a method for manufacturing a semiconductor device, and a program.

[0002] In semiconductor device manufacturing methods, a vertical substrate processing apparatus may be used to form an oxide film or anneal a substrate (hereinafter referred to as a wafer). When performing these processes on a wafer, a processing chamber is heated to a predetermined temperature while a processing gas is supplied into the processing chamber. To maintain the predetermined temperature, a temperature sensor, such as a thermocouple, may be installed in the processing chamber to detect the temperature.

[0003] JP 2009-117798 A JP 2013-036977 A JP 2014-067766 A

[0004] Deterioration of the metal protective tube or seal in which the thermocouple is inserted in a high-temperature environment can lead to destruction when the inside of the metal protective tube is completely filled with an inert atmosphere, causing a decrease in the electromotive force of the thermocouple or the thermocouple to break, making it impossible to measure the temperature correctly.

[0005] The present disclosure provides a technology that enables stable temperature measurement for a long period of time in a high-temperature environment.

[0006] According to one aspect of the present disclosure, there is provided a technology including: (a) an insulating tube having two through holes through which two conducting wires of a temperature sensor are respectively inserted; (b) a first protective tube into which the insulating tube is inserted from a first end; (c) a cylindrical sleeve that is airtightly connected to the first end of the first protective tube and airtightly attached to an attachment port from outside the furnace; and (d) a second protective tube that is attached to the attachment port from inside the furnace and covers the entire first protective tube inside the furnace.

[0007] According to the present disclosure, stable temperature measurement is possible for a long period of time in a high-temperature environment.

[0008] FIG. 1 is a vertical cross-sectional view of a process furnace according to one embodiment of the present disclosure. FIG. 2 is a cross-sectional view along the central axis of an installed temperature measurement assembly according to one embodiment. FIG. 3 is a bottom view of a horizontal cross-section of a temperature measurement assembly according to one embodiment within a process furnace 2. FIG. 4 is a bottom view of a first insulating tube according to one embodiment. FIG. 5 is a perspective view of a vertical cross-section near a T-joint of a temperature measurement assembly according to one embodiment, viewed from the bottom left. FIG. 6 is a flowchart illustrating a substrate processing method according to one embodiment. FIG. 7(a) is a cross-sectional view along the central axis of a temperature measurement assembly according to a modified example of the present disclosure, and FIG. 7(b) is a bottom view of a sleeve of the temperature measurement assembly of FIG. 7(a).

[0009] Hereinafter, one embodiment of the present disclosure will be described mainly with reference to FIGS. 1 to 5. It should be noted that all drawings used in the following description are schematic, and the dimensional relationships and ratios of elements shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships and ratios of elements between multiple drawings do not necessarily correspond to the actual ones. Furthermore, elements that are substantially the same as those described in FIGS. 1 and 2 are denoted by the same reference numerals, and their description will be omitted. Furthermore, unless otherwise specified in the specification, each element is not limited to one, and multiple elements may be present.

[0010] 1 shows a vertical cross-sectional view of a processing furnace 2 in a substrate processing apparatus 1 according to this embodiment. The substrate processing apparatus 1 is configured as a batch-type vertical annealing apparatus that performs annealing on a plurality of silicon carbide (SiC) substrates aligned vertically. By configuring the apparatus as a batch-type processing apparatus, it becomes possible to process a large number of substrates at once, thereby improving productivity.

[0011] The substrate processing apparatus 1 has a configuration similar to that shown in Fig. 1 of International Publication No. 12 / 115170. The substrate processing apparatus 1 has a processing furnace 2, and a boat 3 serving as a substrate holder is configured to be insertable into and detachable from the processing furnace 2. The boat 3 is made of a heat-resistant material such as carbon graphite or SiC. The boat 3 is configured to hold a plurality of wafers 4 serving as substrates made of SiC or the like, stacked vertically in a horizontal position with their centers aligned.

[0012] An insulating part 5 made of a heat-resistant material such as SiC is disposed below the boat 3. The insulating part 5 supports the boat 3 from below and is configured to make it difficult for heat from a heating element 6 (described later) to be transmitted to the lower side of the processing furnace 2. The boat 3 loaded with a plurality of wafers 4 is carried into the processing furnace 2, whereupon heat processing is performed.

[0013] 1, the processing furnace 2 is made of a heat-resistant material such as quartz or SiC and includes a cylindrical reaction tube 7 that is closed at the top and open at the bottom. A reaction chamber 8 serving as a processing chamber is formed in the hollow cylindrical portion of the reaction tube 7. The reaction chamber 8 is configured to accommodate the boat 3 described above that holds wafers 4 serving as substrates made of SiC or the like.

[0014] A manifold 11 is disposed concentrically with the reaction tube 7 below the reaction tube 7. The manifold 11 is made of, for example, metal, and is formed in a cylindrical shape with open upper and lower ends. The manifold 11 is provided to support the reaction tube 7 from below. An O-ring (not shown) is provided as a sealing member between the manifold 11 and the reaction tube 7. The reaction tube 7 and the manifold 11 form a reaction vessel.

[0015] The processing furnace 2 includes a heating element 6 as a heated object to be heated by induction heating, and an induction coil 12 as an induction heating unit, i.e., a magnetic field generator. The heating element 6 is formed into a cylindrical shape from a conductive heat-resistant material such as carbon, and is provided to surround the boat 3 housed in the reaction chamber 8, i.e., to surround the area where the wafers 4 are housed. The heating element 6 is formed into a cylindrical shape with open top and bottom ends, or a cylindrical shape with a closed top end and an open bottom end. The induction coil 12 is supported by a coil support 12a made of an insulating heat-resistant material and is provided to surround the outer periphery of the reaction tube 7. The induction coil 12 is supplied with AC power of, for example, 10 to 450 kHz and 10 to 200 kW from an AC power source 13. An AC magnetic field generated by passing an AC current through the induction coil 12 causes an induced current to flow through the heating element 6, which generates heat due to Joule heat. When the heating element 6 generates heat, the wafers 4 held in the boat 3 are heated to a predetermined processing temperature, for example, 1500° C. to 2000° C., by radiant heat emitted from the heating element 6. At this time, in order to prevent thermal damage, it is preferable to maintain the temperature of the components below the processing furnace 2 at a temperature of, for example, 200° C. or less.

[0016] A heat insulator 14 is provided between the reaction tube 7 and the heating element 6. The heat insulator 14 is formed in a cylindrical shape with a closed upper end and an open lower end.

[0017] A temperature measurement assembly 15 for detecting the processing temperature is provided between the boat 3 holding the wafers 4 and the heating element 6. The temperature measurement assembly 15 passes through the manifold 11 and extends vertically to near the upper end of the boat 3. The temperature measurement assembly 15 is electrically connected to a temperature control unit (not shown). The temperature control unit adjusts the power supplied from the AC power supply 13 to the induction coil 12 based on temperature information detected by the temperature measurement assembly 15, thereby controlling the processing temperature of the wafers 4 to a desired temperature. The heating element 6, induction coil 12, AC power supply 13, and temperature measurement assembly 15 mainly constitute the heating unit according to this embodiment.

[0018] An outer heat insulating wall 16, for example, of a water-cooled structure, is provided outside the induction coil 12 to surround the reaction chamber 8 and suppress the transfer of heat from inside the reaction chamber 8 to the outside. Furthermore, a magnetic shield 17 is provided outside the outer heat insulating wall 16 to prevent the magnetic field generated by the induction coil 12 from leaking to the outside.

[0019] The processing furnace 2 is provided with a first gas nozzle 18 having a first gas supply port 18a at its upper end. The first gas nozzle 18 is disposed inside the heating element 6, vertically disposed between the wafer 4 accommodation area and the heating element 6. The first gas nozzle 18 is connected to a first gas supply pipe 19 provided to penetrate the manifold 11. A gas supply unit 21 is connected to the upstream end of the first gas supply pipe 19.

[0020] A second gas supply pipe 22 is disposed in the vertical direction outside the heating element 6, between the heat insulator 14 and the reaction tube 7. A second gas supply port 23 is provided at the downstream end of the second gas supply pipe 22. The second gas supply pipe 22 is disposed so as to penetrate the manifold 11. A gas supply unit 21 is connected to the upstream end of the second gas supply pipe 22.

[0021] A first exhaust port 24 is provided in the side wall of the manifold 11 facing the first gas supply port 18a, below the heat insulating unit 5, i.e., the wafer 4 accommodation area. A second exhaust port 25 is provided in the wall of the manifold 11 between the heat insulating body 14 and the reaction tube 7, on which the reaction tube 7 is mounted. The first exhaust port 24 and the second exhaust port 25 are connected to the upstream ends of branched exhaust pipes 26, respectively. The exhaust pipe 26 is provided with, in order from the upstream side, a pressure sensor 27 as a pressure detector, an APC (Auto Pressure Controller) valve 28 as a pressure regulator, and a vacuum pump 29 as a vacuum exhaust device. The pressure sensor 27, the APC valve 28, and the vacuum pump 29 are electrically connected to a pressure control unit (not shown). The pressure control unit controls the opening of the APC valve 28 based on the pressure information measured by the pressure sensor 27 in a feedback manner, thereby controlling the pressure inside the reaction chamber 8 to a predetermined pressure.

[0022] Furthermore, by providing the second exhaust port 25 as described above, the purge gas, which is an inert gas such as nitrogen, supplied into the reaction chamber 8 from the second gas supply port 23 purges the space between the reaction tube 7 and the heat insulator 14 and is exhausted from the second exhaust port 25.

[0023] Furthermore, the boat 3 can be carried into the reaction chamber 8 (i.e., boat loading) and carried out (i.e., boat unloading) by an elevator mechanism (not shown). When the boat 3 is carried into the reaction chamber 8, the opening of the processing furnace 2 (i.e., the furnace port) is airtightly closed by a seal cap 31 via a sealing member such as an O-ring. Furthermore, the heat insulating part 5 can be rotatably supported by a boat support mechanism 30 provided on the seal cap 31.

[0024] The controller 50 controls each part of the substrate processing apparatus 1 and includes a central processing unit (CPU) 51, a main memory device 52, and an auxiliary memory device 53. The auxiliary memory device 53 stores recipe information that defines a series of operations for causing the substrate processing apparatus 1 to perform an annealing process and the like, and a program that is executed by the CPU 51 to actually control the substrate processing apparatus 1 based on the recipe information. The auxiliary memory device 53 may include a recording medium such as an optical disk.

[0025] 2 to 4, the temperature measurement assembly 15 will be described in detail. The temperature measurement assembly 15 has a thermocouple 32, a first protective tube 33, a second protective tube 34, a sleeve 35, a first insulating tube 37, and a second insulating tube 38. The temperature measurement assembly 15 may also include a sealing portion 36 and a T-joint 39 as a purge gas supply portion. The assembly including the thermocouple 32, the first protective tube 33, the sleeve 35, the sealing portion 36, the first insulating tube 37, and the second insulating tube 38 is referred to as a thermocouple unit to distinguish it from the temperature measurement assembly 15.

[0026] The thermocouple 32 is a temperature sensor for measuring temperature, and may be, for example, a tungsten-rhenium thermocouple or an iridium-rhodium thermocouple. To prevent oxidation degradation, such thermocouples are preferably used in a vacuum, an inert atmosphere, or a hydrogen atmosphere when used at high temperatures. The thermocouple has a pair of wires, a positive wire and a negative wire, extending along the central axis of the temperature measurement assembly 15. For convenience of illustration, only one wire is shown in FIG. 2 . Near the junction (i.e., the temperature measurement point) at the tip of the thermocouple 32, the pair of wires may be twisted together to protect the junction from mechanical loads. The pair of wires of the thermocouple 32 may be connected to a corresponding pair of compensation wires 32a outside the process furnace 2, where the temperature is sufficiently low. The wires and compensation wires are collectively referred to as wires.

[0027] The first protective tube 33 is cylindrical, with a closed upper end and an open lower end, and covers at least the portion of the thermocouple 32 inserted into the process furnace 2. In other words, the insulating tube is inserted into the first protective tube 33 from its lower end (first end). The first protective tube 33 may be made of a high-melting-point metal such as tantalum (Ta), molybdenum (Mo), or iridium (Ir). Because such metals may oxidize at high temperatures, they are preferably used in a vacuum or inert atmosphere. The upper end (second end) of the first protective tube 33 may be closed by welding a cover made of the same high-melting-point metal as the cylindrical portion or a high-melting-point metal that can be welded to the cylindrical portion to the cylindrical portion. The first protective tube 33 has one or more first emission holes 33a that communicate between the inside and outside of the first protective tube 33 at a height between the upper end and the tip of the thermocouple 32.

[0028] The second protective tube 34 is formed in a cylindrical shape with a closed upper end and an open lower end, and is attached to the attachment port from inside the furnace, covering at least the portion of the first protective tube 33 that is inserted into the processing furnace 2. The material of the second protective tube 34 is, for example, graphite, carbides such as tantalum carbide (TaC), titanium carbide (TiC), and SiC, nitrides such as boron nitride (BN) and aluminum nitride (AlN), aluminum oxide (Al ２ O ３The second protective tube 34 may be made of various high-temperature ceramics or metal materials, such as silicon dioxide (SiO 2 ) or oxides such as magnesium oxide (MgO), and may be appropriately selected from various high-temperature ceramics or metal materials depending on conditions such as the processing temperature. The second protective tube 34 is provided with one or more second release holes 34 a that communicate the inside and outside at a low position within the processing furnace 2. The outer diameter of the portion of the second protective tube 34 that is inserted into an attachment port 41 (described later) can be made smaller than the outer diameter of the remaining portion.

[0029] The sleeve 35 is formed into a cylindrical shape from metal, and its upper end is airtightly connected to the lower end of the first protective tube 33. The sleeve 35 is airtightly attached to the mounting port 41 from outside the furnace. Specifically, the sleeve 35 has a central hole whose inner diameter changes stepwise. After the first protective tube 33 is inserted into the larger diameter side of the central hole, the upper end of the sleeve 35 is connected to the side of the first protective tube 33 by welding or brazing. Meanwhile, the smaller diameter side of the central hole, i.e., the side opposite to the side connected to the first protective tube 33, is sealed with a sealing portion 36, through which the wires of the thermocouple 32 or the compensating wire 32a are routed. The sealing portion 36 is made of an electrically insulating material with low gas permeability, such as glass, cement, heat-resistant adhesive, or synthetic resin. In this example, the wires of the thermocouple 32 and the compensating wire 32a are connected within the sealing portion 36. The sleeve 35 also has a side surface whose outer diameter changes stepwise and a hole 35a in the side surface as a second flow path connecting the inside and outside of the sleeve 35. At least a portion of the side surface of the sleeve 35 can be mirror-polished to improve the sealing performance between the sleeve 35 and an O-ring, which will be described later.

[0030] The first insulating tube 37 is formed in the shape of an elongated round rod having two through holes 37a aligned along the central axis of the temperature measurement assembly, and is mainly disposed outside the processing furnace 2. A pair of wires of the thermocouple 32 is inserted into each of the two through holes 37a. The first insulating tube 37 is made of, for example, Al ２ O ３ , zirconium oxide (ZrO ２The first insulating tube 37 is made of a heat-resistant insulating material such as quartz or other ceramics, and electrically insulates the wires of the thermocouple 32 from each other and from the first protective tube 33, while maintaining the upright position of the thermocouple 32. The lower end of the first insulating tube 37 is supported by a sealing portion 36. The first insulating tube 37 may have three or more through holes 37a, two of which are used as the through holes 37a.

[0031] 4, a groove 37b extending through the two through-holes 37a in a direction perpendicular to the central axis is formed at the lower end of the first insulating tube 37. The groove 37b functions as a third flow path that guides a purge gas (described later) to the two through-holes 37a.

[0032] 3, the second insulating tube 38 is formed in a round rod shape having two through holes 38a aligned along the central axis of the temperature measurement assembly, and is disposed mainly in the portion of the thermocouple 32 inside the process furnace 2. The second insulating tube 38 is made of, for example, MgO or hafnia (HfO ２ The insulating tube beads may be made of a plurality of insulating tube beads made of a heat-resistant insulating material such as PTFE. The insulating tube beads are shortened insulating tubes, each having a length of, for example, about 3 to 5 mm, and are stacked in multiple stages on the first insulating tube 37.

[0033] A pair of wires of the thermocouple 32 is inserted into each of the through holes 38a. The wires of the thermocouple 32 are also inserted into the first insulating tube 37 in a similar manner. A thermocouple unit with this structure is called an "insulating tube type." A gap is provided between the first insulating tube 37 and the second insulating tube 38 so that they can be easily inserted into the first protective tube 33 and so that differences in thermal expansion can be released.

[0034] As shown in FIG. 2 , the thermocouple unit is attached to a mounting port 41 that penetrates the seal cap 31 in the vertical direction. The mounting port 41 is formed of metal and has a cylindrical shape that extends vertically downward, and the sleeve 35 is inserted with a clearance fit from the lower end that is outside the process furnace 2. The mounting port 41 further has an O-ring 41 a and a nut (not shown) that presses the O-ring 41 a against the sleeve 35 and the mounting port 41. By tightening the nut, the thermocouple unit is fixed and a vacuum seal is achieved. A ferrule (not shown) may be interposed between the nut and the O-ring 41 a.

[0035] The second protective tube 34 is attached with a clearance fit from the upper end of the attachment port 41, which is located inside the process furnace 2. The second protective tube 34 is separate from the thermocouple unit and can be replaced independently of the thermocouple unit. Typically, the second protective tube 34 is installed in the reaction chamber 8 when the process furnace 2 is assembled. That is, the second protective tube 34 may be provided by forming a lower end portion (adapter) 34b attached to the attachment port 41 and the remaining cylindrical portion separately and then joining them. In this case, the adapter 34b may have an enlarged diameter portion to ensure a strong connection with the cylindrical portion, and the enlarged diameter portion may be partially cut out to avoid interference with the heat insulating portion 5 and the heating element 6.

[0036] The T-joint 39 has a detachable metal cylindrical portion attached to the outer periphery of the sleeve 35 and is attached from the lower end of the sleeve 35. The cylindrical portion has an inner circumferential surface whose inner diameter changes stepwise in response to changes in the outer shape of the sleeve 35. The step prevents the sleeve 35 from entering the step on the outer periphery, determining its installation position. The T-joint 39 includes an O-ring 39a as a first seal, an O-ring 39b as a second seal, and two nuts that press the O-rings 39a and 39b against the sleeve 35 and the T-joint 39, respectively. This structure can be similar to that of the mounting port 41. The T-joint 39 further includes a hole in the airtight section between the O-rings 39a and 39b that communicates with the hole 35a in the side of the sleeve 35, and a purge gas inlet pipe 39c is connected to the hole. At least one of the communication hole and the purge gas inlet pipe 39c constitutes a first flow path.

[0037] 5, the first flow path of the T-joint 39 desirably opens to face the hole 35a (i.e., the second flow path) of the sleeve 35. Furthermore, the hole 35a desirably opens to face the groove 37b of the first insulating tube 37 on an extension of the groove 37b, in other words, in the same direction as the arrangement of the two through-holes 37a. The depth of the groove 37b is desirably set so that the upper end of the groove 37b coincides with the upper end of the hole 35a. Furthermore, the lower end of the first insulating tube 37 is desirably set to coincide with or lower than the bottom of the hole 35a.

[0038] Purging the temperature measurement assembly 15 with an inert gas will now be described.

[0039] The purge gas inlet pipe 39c is supplied with Ar or N as a purge gas. ２ A purge gas supply source (not shown) that supplies an inert gas such as toluene, toluene, toluene HCl, toluene HCl, toluene HCl, toluene HCl ...

[0040] As described above, the first insulating tube 37 has a groove (i.e., a notch) 37b, into which the purge gas enters. The lower part of the sleeve 35 below the first insulating tube 37 is sealed with the sealing part 36, so that the purge gas that flows into the sleeve 35 flows upward through the gap between the sleeve 35 or the first protective tube 33 and the first insulating tube 37, and the gap between the through-hole 37a and the wires. This allows the purge gas supplied from the purge gas inlet tube 39c (i.e., the first flow path) to purge both the first space 60 between the two wires and the two through-holes, and the second space 61 between the first insulating tube 37 and the first protective tube 33.

[0041] At the transition point from the first insulating tube 37 to the second insulating tube 38, the through-hole 37a and the through-hole 38a are continuous, allowing the purge gas to flow through the through-hole 38a. Even if gas leaks from the joints between the insulating tube beads, some of the purge gas flows through the through-hole 38a to the upper end of the second insulating tube 38, merges with the purge gas that has flowed between the outside of the second insulating tube 38 and the first protective tube 33, and passes through the tip of the thermocouple 32. If the purge gas is low in temperature at this time, there is a concern that the temperature detected by the thermocouple 32 may be low. However, in this embodiment, the purge gas can be heated to a temperature close to the temperature inside the reaction chamber 8 by heat transfer from the first protective tube 33, the first insulating tube 37, and the second insulating tube 38 while rising through the first insulating tube 37 and the second insulating tube 38. Furthermore, when the temperature inside the reaction chamber 8 reaches 1500°C or higher, heat radiation is more dominant than heat conduction or heat transfer, so sufficient thermal response can be obtained even if the first protective tube 33 is not in contact with the second protective tube 34.

[0042] As described above, the first release hole 33a is opened near the tip of the first protective tube 33, and allows the inert gas that has flowed from below the thermocouple 32 to escape. In the present embodiment, the tip of the first protective tube 33 is described as being sealed, and the first release hole 33a is opened on the side surface of the first protective tube 33. The sealing portion at the tip of the first protective tube 33 may be open, or a hole may be opened in the sealing portion, allowing the purge gas to escape.

[0043] The purge gas that has escaped to the outside of the first protective pipe 33 flows downward between the first protective pipe 33 and the second protective pipe 34. A second discharge hole 34a is opened at the bottom of the second protective pipe 34, and the purge gas is discharged into the reaction chamber 8. The second discharge hole 34a is closer to the first exhaust port 24 than the wafers 4 and opens downstream of the processing gas flowing in the reaction chamber 8, so that the effect of the purge gas on the wafers 4 is limited. Furthermore, the temperature of the wafers 4 passing near the second discharge hole 34a during loading and unloading of the boat 3 is sufficiently lower than the temperature at which the wafers 4 are heat-treated.

[0044] According to this embodiment, one or more of the following effects can be obtained.

[0045] Inert gas can be introduced from the T-joint, and flows into the first protective tube through the hole in the sleeve. Furthermore, the cut (groove) in the insulating tube allows the inert gas to flow into the through-hole through which the thermocouple wire passes. Furthermore, the inert gas that has flowed to the top end of the first protective tube flows between the first and second protective tubes and is released into the furnace through the release hole in the second protective tube.

[0046] By adopting such a non-sealed structure, the pressure inside the first protective tube does not increase at high temperatures, and as a result, no stress is applied to the sealed portion, thereby suppressing deterioration of the seal.

[0047] One type of thermocouple that can be used in high-temperature environments is the sheathed thermocouple, which consists of a thermocouple and insulator inserted into a metal sheath tube, which is then filled with an inert gas and sealed at the end to isolate the thermocouple from the oxidizing atmosphere. In this sheathed thermocouple structure, impurities contained in the protective tube are released at high temperatures, especially when the sheath tube is covered with a protective tube. This released gas has no escape route and remains inside the protective tube. Long-term exposure of the sheath tube to this released gas can cause deterioration of the sheath tube. Furthermore, evaporation and gas release from the sheath tube itself can cause deterioration of the thermocouple and protective tube and contamination of the processing chamber. Oxygen, in particular, accelerates oxidation of the materials, and metal components can change the electromotive force of the thermocouple wire.

[0048] In this embodiment, by employing a structure in which an inert gas is continuously flowed through the first protective tube, it is possible to push out oxygen and impurities that cause deterioration of the thermocouple wire and the protective tube. Since the through-hole through which the thermocouple wire passes is forcibly purged, the atmosphere in contact with the surface of the thermocouple wire is always maintained as a fresh inert atmosphere, and deterioration of the thermocouple can be effectively suppressed.

[0049] Furthermore, even if impurities precipitate or evaporate from the second protective tube, they are washed away by the inert gas, preventing deterioration of the thermocouple and the first protective tube. Even if the seal is broken, the air that flows in is diluted with the inert gas, preventing the progression of deterioration of the thermocouple inside the first protective tube.

[0050] In this embodiment, the thermocouple unit is attached to the mounting port using a strong sleeve instead of a protective tube, so that even if a strong force is applied from the purge gas introduction tube, etc., the force is not applied to the protective tube, and damage can be prevented. In addition, since the seal is made between the mounting port and a metal sleeve rather than a heat-resistant material such as graphite, high airtightness can be easily obtained.

[0051] In addition, since the second protective tube is detachable, if the thermocouple breaks, only the thermocouple unit can be replaced, which is economical.Furthermore, since the purge gas supply section can be separated from the long thermocouple unit, the thermocouple unit can be easily replaced.

[0052] Next, substrate processing using the above-described substrate processing apparatus 1 will be described with reference to the flowchart in Figure 6. In this processing, as one step in the manufacture of a semiconductor device, a SiC wafer 4 is annealed in a reaction chamber 8 in an argon (Ar) atmosphere. In this specification, the processing temperature refers to the temperature of the wafer 4 or the temperature of the reaction chamber 8, and the processing pressure refers to the pressure within the reaction chamber 8. In the following description, the operation of each component of the substrate processing apparatus 1 is controlled by a controller 50.

[0053] First, a plurality of wafers 4 are loaded (that is, charged) into the boat 3 that has been lowered outside the reaction chamber 8 (STEP 01).

[0054] Next, the boat 3 is raised and loaded into the reaction chamber 8, and the wafers 4 are carried in (prepared). The lower opening of the reaction tube 7 is closed (i.e., sealed) by the seal cap 31. The reaction chamber 8 is then evacuated once by the vacuum pump 29, and then Ar gas is supplied from the gas supply unit 21, and the pressure is adjusted to a predetermined level by the APC valve 28. At this time, N is introduced into the thermocouple unit via the purge gas introduction pipe 39c. ２ Gas is supplied, and the temperature of the wafer 4 is raised to a predetermined temperature at a predetermined rate by adjusting the AC power applied to the induction coil 12 based on the temperature information detected by the thermocouple 32 so that the wafer 4 reaches a predetermined processing temperature (STEP 02).

[0055] Next, the wafer 4 is exposed to an Ar atmosphere at a predetermined temperature and pressure for a predetermined time, thereby activating the implanted impurities and removing oxygen from the surface, thereby producing an annealed wafer (STEP 03).

[0056] The processing conditions for the activation annealing of the wafer 4 are, for example, as follows: processing temperature (wafer temperature): 1500° C. to 1900° C., processing pressure (pressure inside the processing chamber): 1 Pa to atmospheric pressure, Ar gas: 1 sccm to 5 SLM, N ２ Gas: 1 sccm to 5 SLM. By setting each processing condition within the respective range, the film formation process can be carried out appropriately. Note that the notation of a numerical range such as "1500°C to 1900°C" above means that the lower limit and upper limit are included in the range. For example, "1500°C to 1900°C" means "1500°C or higher and 1900°C or lower." The same applies to other numerical ranges.

[0057] Next, the power supplied to the induction coil 12 is adjusted to lower the temperature of the wafers 4 to a predetermined temperature, and the APC valve 28 is closed to return the pressure inside the reaction chamber 8 to atmospheric pressure. Thereafter, the seal cap 31 is lowered, and the boat 3 is removed (i.e., unloaded) from the reaction tube 7 (STEP 04).

[0058] Next, after the boat 3 is removed, the wafers 4 are further cooled until they reach a temperature at which they can be transported (STEP 05).

[0059] Finally, the processed wafers 4 are stored in a cassette from the boat 3 by a transfer machine (not shown) (STEP 06).

[0060] A temperature measurement assembly according to a modified example will be described with reference to FIGS. 7( a) and 7(b). This modified example differs from the previous embodiment in that the mounting port 41 and the T-joint 39 are integrated and the adapter 34b is eliminated. The mounting port 141 in this example is cylindrical, with its inner diameter varying in two stages. The larger diameter side is connected to the seal cap 31, and the smaller diameter side is provided with an O-ring 41a and a nut (not shown) that presses the O-ring 41a against the sleeve 135 and the mounting port 141. The inner diameter of the larger diameter side corresponds to the second protective tube 34, and the inner diameter of the smaller diameter side corresponds to the outer diameter of the sleeve 135. A hole communicating with the hole 135a in the side of the sleeve 135 is provided on the inner side surface of the smaller diameter side, and a purge gas introduction pipe 141c corresponding to the purge gas introduction pipe 39c is connected to the hole.

[0061] The sleeve 135 is formed in a tubular shape with an outer diameter smaller than that of the seal cap 31, and has a stepped protrusion 135b at its lower end. The sleeve 135 is loosely fitted into the small-diameter end of the mounting port 141, and its installation position is determined by abutting this stepped protrusion against the nut end face of the mounting port 141. Therefore, the sleeve 135 does not need a step that changes its outer diameter. In other respects, it is similar to the sleeve 35. The stepped protrusion 135b is provided in the same direction as the hole 135a when viewed from the center axis of the sleeve 135, and serves to align the hole 135a with the purge gas introduction pipe 141c.

[0062] In the above-described embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied, for example, to a case where a film is formed using a single-wafer substrate processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace.

[0063] When using these substrate processing apparatuses, each process can be performed using the same processing procedures and conditions as in the above-described embodiments and modifications, and the same effects as in the above-described embodiments and modifications can be obtained.

[0064] 32: Thermocouple 33: First protective tube 34: Second protective tube 35: Sleeve 37: First insulating tube 41: Mounting port

Claims

1. A temperature measurement assembly comprising: (a) an insulating tube having two through holes through which two conducting wires of a temperature sensor are respectively inserted; (b) a first protective tube into which the insulating tube is inserted from a first end; (c) a cylindrical sleeve that is airtightly connected to the first end of the first protective tube and airtightly attached to an installation port from outside the furnace; and (d) a second protective tube that is attached to the installation port from inside the furnace and covers the entire first protective tube inside the furnace.

2. A temperature measuring assembly as described in claim 1, further comprising a fitting attached to the outer periphery of the sleeve and providing a first flow path communicating with a side of the sleeve, the sleeve having a second flow path connecting the first flow path to the inside of the sleeve, and the insulating tube having a third flow path connecting the second flow path to the two through holes, and configured such that purge gas supplied from the first flow path purges both a first space between the two conducting wires and the two through holes and a second space between the insulating tube and the first protective tube.

3. A temperature measuring assembly as described in claim 1, wherein the sleeve has a flow path that connects purge gas to the inside of the sleeve, and the first protective tube has a first release hole at a second end opposite the first end that connects the inside and outside of the first protective tube, and the purge gas flows from the first end side to the second end side inside the first protective tube and then flows through the gap between the first protective tube and the second protective tube from the second end side to the first end side.

4. A temperature measuring assembly as described in claim 2, wherein the second protective tube has a second discharge hole communicating the inside and outside of the second protective tube on the inside of the furnace near the mounting port, and the purge gas is configured to be discharged into the furnace.

5. A temperature measuring assembly according to claim 1, wherein said sleeve has an opening on the side opposite to the side to which said first protective tube is connected, through which said conductor wire is drawn out, said opening being sealed by a sealing portion.

6. A temperature measuring assembly according to claim 2, wherein said third flow passage is formed by penetrating said insulating tube from the side facing said second flow passage to the opposite side.

7. A temperature measuring assembly as claimed in claim 6, wherein one end of said insulating tube is arranged at a position corresponding to said second flow path of said sleeve, and said third flow path is formed as a groove penetrating said two through holes at said one end of said insulating tube, said groove facing said second flow path.

8. A temperature measuring assembly as described in claim 2, comprising: a first seal pressed against the outer periphery of the sleeve and the fitting at a position closer to the first protective tube than the first flow path, thereby forming a seal between them; and a second seal pressed against the outer periphery of the sleeve and the fitting at a position farther from the first protective tube than the first flow path, thereby forming a seal between them.

9. A temperature measuring assembly as described in claim 2, wherein the sleeve is arranged so that its central axis is the same as that of the first protective tube, the outer diameter at a position closer to the first protective tube is larger than the outer diameter at a position farther from the first protective tube, and the joint has an inner diameter that changes in accordance with the change in the outer diameter of the sleeve.

10. A temperature measuring assembly as described in claim 2, wherein the sleeve is formed so that the outer diameter at a position closer to the first protective tube is larger than the outer diameter at a position farther from the first protective tube, and the fitting is removably attached to the sleeve and has an inner diameter that changes in accordance with the change in the outer diameter of the sleeve.

11. The temperature measuring assembly according to claim 3, further comprising a plurality of insulating tube beads having the two through holes through which the two conducting wires are inserted, on the second end side of the insulating tube.

12. A substrate processing apparatus comprising: a processing furnace for thermally processing a substrate; the temperature measurement assembly according to claim 1; and said mounting port for vertically mounting said temperature measurement assembly for measuring a temperature within said processing furnace.

13. A substrate processing apparatus according to claim 12, wherein the processing furnace comprises an airtight container, a cylindrical heating element that is inductively heated and disposed inside the container to surround the substrate, and a thermal insulator disposed between the container and the heating element, and the temperature measuring assembly is disposed extending vertically through the space between the heating element and the substrate.

14. A method for processing a substrate, comprising the steps of: preparing a substrate in a processing furnace in which the temperature measurement assembly according to claim 1 is mounted vertically with a second end opposite the first end facing up; and raising the temperature of the processing furnace while measuring the temperature within the processing furnace, and heat-processing the substrate.

15. A method for manufacturing a semiconductor device, comprising the substrate processing method according to claim 14.

16. A program for causing a substrate processing apparatus to execute, by a computer, the steps of: preparing a substrate in a processing furnace in which the temperature measurement assembly according to claim 1 is vertically mounted with a second end opposite the first end facing up; and raising the temperature of the processing furnace while measuring the temperature within the processing furnace, and heat-processing the substrate.

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