Temperature control system, temperature control method, semiconductor device manufacturing method, and substrate processing device

Abstract

Provided is technology capable of suppressing an increase in the wire temperature of an auxiliary heater and ensuring the service life of the auxiliary heater.　The present invention comprises: a first heater that is provided so as to be divided into zones and heats a processing container in which a substrate is disposed; a second heater that assists with heating by the first heater corresponding to a specific zone among the zones; a temperature sensor that detects the temperature of the second heater; and a control unit that is configured to be capable of setting the temperature inside the processing container to a target temperature by limiting the output of the second heater when the temperature detected by the temperature sensor is at or above a prescribed temperature that is lower than the target temperature.

Description

Temperature control system, temperature control method, semiconductor device manufacturing method, and substrate processing apparatus

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

[0002] As one step in the manufacturing process of a semiconductor device, a predetermined process may be performed on a wafer (hereinafter also referred to as a substrate) (see, for example, Patent Documents 1 to 6). These documents describe a technique for controlling the temperature of a process chamber using an auxiliary heater that assists in heating a specific zone.

[0003] International Publication No. WO 2016 / 135876 International Publication No. WO 2020 / 261466 International Publication No. WO 2019 / 053807 JP 2016-157923 A International Publication No. WO 2020 / 026445 JP 2020-057796 A

[0004] The present disclosure provides a technique that can suppress an increase in the wire temperature of an auxiliary heater and ensure the life of the auxiliary heater.

[0005] According to one aspect of the present disclosure, there is provided a technology comprising: a first heater that is arranged to be divided into zones and heats a processing vessel in which a substrate is placed; a second heater that assists the first heater in heating a specific zone among the zones; a temperature sensor that detects the temperature of the second heater; and a control unit configured to limit the output of the second heater when the temperature detected by the temperature sensor is equal to or higher than a predetermined temperature that is lower than a target temperature, thereby enabling the temperature inside the processing vessel to be set to the target temperature.

[0006] According to the present disclosure, it is possible to suppress an increase in the wire temperature of the auxiliary heater and ensure the life of the auxiliary heater.

[0007] FIG. 1 is a schematic diagram of a processing furnace of a substrate processing apparatus according to an embodiment of the present disclosure. FIG. 2 is a front cross-sectional view showing a sub-heater and its surroundings of the substrate processing apparatus according to an embodiment of the present disclosure. FIG. 3(A) is a top view of the sub-heater of the substrate processing apparatus according to an embodiment of the present disclosure. FIG. 3(B) is a partial vertical cross-sectional view of the sub-heater shown in FIG. 3(A). FIG. 4 is a schematic configuration diagram of a controller in a substrate processing apparatus according to an embodiment of the present disclosure, and is a block diagram of a control system of the controller. FIG. 5(A) is a diagram showing a first mode of temperature control by a temperature control system according to an embodiment of the present disclosure. FIG. 5(B) is a diagram showing a second mode of temperature control by a temperature control system according to an embodiment of the present disclosure. FIG. 5(C) is a diagram showing a third mode of temperature control by a temperature control system according to an embodiment of the present disclosure. FIG. 6 is a block diagram of a temperature control system in a substrate processing apparatus according to an embodiment of the present disclosure. FIG. 7(A) is a diagram for explaining a substrate processing sequence performed in a substrate processing apparatus according to an embodiment of the present disclosure. FIG. 7(B) is a diagram for explaining a substrate processing sequence performed in a substrate processing apparatus according to an embodiment of the present disclosure, and is a graph showing temperatures at each step of the substrate processing sequence.

[0008] (1) Configuration of the Substrate Processing Apparatus One embodiment of the present disclosure will now be described, primarily with reference to FIGS. 1 to 7. It should be noted that the drawings used in the following description are all schematic, and the dimensional relationships, ratios, and the like of the elements shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships, ratios, and the like of the elements do not necessarily correspond between multiple drawings. Furthermore, substantially identical elements are assigned the same reference numerals between multiple drawings, and each element is described in the drawing in which it first appears, and its description is omitted in subsequent drawings unless specifically required.

[0009] 1, in this embodiment, a substrate processing apparatus 10 is configured as a processing apparatus (batch processing apparatus) that performs processing steps in an IC manufacturing method. The processing furnace 12 is a heating unit (heating mechanism) and has a heater 14 as a first heater. The heater 14 is cylindrical and installed vertically.

[0010] A reaction tube 16 constituting a reaction vessel (processing vessel) is disposed inside the heater 14 concentrically with the heater 14. The reaction tube 16 is made of, for example, quartz (SiO ２ The reaction tube 16 is made of a heat-resistant material such as silicon carbide (SiC) or silicon dioxide (SiO2), and is formed in a cylindrical shape with a closed upper end and an open lower end. A processing chamber 18 is formed in the hollow cylindrical portion of the reaction tube 16. The processing chamber 18 is configured to accommodate wafers 2 as substrates in a boat 20 (described later) in a horizontal position and aligned vertically in multiple stages.

[0011] A nozzle 22 is provided in the processing chamber 18 so as to penetrate the lower part of the reaction tube 16. The nozzle 22 is made of a heat-resistant material such as quartz or SiC. A gas supply pipe 24a is connected to the nozzle 22. A mass flow controller (MFC) 26a, which is a flow rate controller (flow rate control unit), and a valve 28a, which is an on-off valve, are provided in the gas supply pipe 24a, in this order from upstream to downstream of the valve 28a. A gas supply pipe 24b, which supplies an inert gas, is connected to the gas supply pipe 24a downstream of the valve 28a. The gas supply pipe 24b is provided with an MFC 26b and a valve 28b, in this order from upstream to downstream. The gas supply pipe 24a, the MFC 26a, and the valve 28a mainly constitute a processing gas supply unit, which is a processing gas supply system. The gas supply pipe 24b, the MFC 26b, and the valve 28b mainly constitute an inert gas supply unit, which is an inert gas supply system.

[0012] The nozzle 22 is provided in the annular space between the inner wall of the reaction tube 16 and the wafers 2, extending from the bottom to the top of the inner wall of the reaction tube 16 and rising upward in the arrangement direction of the wafers 2. That is, the nozzle 22 is provided in a region horizontally surrounding the wafer arrangement region on the side of the wafer arrangement region where the wafers 2 are arranged, and extending along the wafer arrangement region. The nozzle 22 is configured as an L-shaped long nozzle, with its horizontal portion penetrating the lower sidewall of the reaction tube 16 and its vertical portion rising at least from one end of the wafer arrangement region to the other end. Gas supply holes 30 for supplying gas are provided on the side of the nozzle 22. Each gas supply hole 30 opens toward the center of the reaction tube 16 and is configured to be able to supply gas toward the wafers 2. A plurality of gas supply holes 30 are provided from the bottom to the top of the reaction tube 16, each with the same opening area and arranged at the same opening pitch.

[0013] However, the processing furnace 12 of this embodiment is not limited to the above embodiment. For example, a metal manifold supporting the reaction tube 16 may be provided below the reaction tube 16, and a nozzle may be provided to penetrate the side wall of the manifold. In this case, the manifold may further be provided with an exhaust pipe 120, which will be described later. Even in this case, the exhaust pipe 120 may be provided below the reaction tube 16, rather than in the manifold. In this way, the furnace opening of the processing furnace 12 may be made of metal, and a nozzle or the like may be attached to this metal furnace opening. Furthermore, a plurality of nozzles may be provided.

[0014] The reaction tube 16 is provided with an exhaust pipe 120 for exhausting the atmosphere in the processing chamber 18. A vacuum pump 36 serving as a vacuum exhaust device is connected to the exhaust pipe 120 via a pressure sensor 32 serving as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 18 and an APC (Auto Pressure Controller) valve 34 serving as a pressure regulator (pressure adjustment unit). The APC valve 34 opens and closes the valve while the vacuum pump 36 is operating, thereby evacuating and stopping the vacuum evacuation of the processing chamber 18. Furthermore, the APC valve 34 is configured to adjust the pressure in the processing chamber 18 by adjusting its valve opening based on pressure information detected by the pressure sensor 32 while the vacuum pump 36 is operating. The exhaust pipe 120, the APC valve 34, and the pressure sensor 32 primarily constitute an exhaust system. The vacuum pump 36 may be considered to be included in the exhaust system.

[0015] A seal cap 38 is provided below the reaction tube 16 as a furnace port cover capable of airtightly closing the lower end opening of the reaction tube 16. The seal cap 38 is made of a metal such as SUS or stainless steel and is formed in a disk shape. An O-ring 40 is provided on the upper surface of the seal cap 38 as a sealing member that abuts against the lower end of the reaction tube 16. When a manifold is provided below the reaction tube 16, O-rings 40 are provided between the reaction tube 16 and the manifold and between the manifold and the seal cap 38, and the reaction tube 16, the manifold, and the seal cap 38 form a processing chamber 18.

[0016] The seal cap 38 is configured to abut against the lower end of the reaction tube 16 from below in the vertical direction, and is configured to be raised and lowered in the vertical direction by a boat elevator 46, which serves as an elevating mechanism installed vertically outside the reaction tube 16. That is, the boat elevator 46 is configured to be able to load and unload the boat 20 into and out of the processing chamber 18 by raising and lowering the seal cap 38. In other words, the boat elevator 46 is configured as a transfer device (transfer mechanism) that transfers the boat 20, i.e., the wafers 2, into and out of the processing chamber 18.

[0017] The boat 20, serving as a substrate support, is configured to support multiple wafers 2 (e.g., 25 to 200 wafers 2) in a horizontal position, aligned vertically with their centers aligned, and arranged in multiple stages. The boat 20 is made of a heat-resistant material, such as quartz or SiC. A heat insulating plate 48, formed in a disk shape with an outer diameter substantially equal to that of the wafer 2, is supported in a horizontal position and in multiple stages below the lowest wafer 2 among the wafers 2 placed on the boat 20. The heat insulating plate 48 is formed of a material with low thermal capacity and high emissivity, such as quartz, silicon (Si), or SiC. This configuration facilitates absorption of radiant heat from the sub-heater 50, described in detail below, thereby improving the temperature response of the wafers 2 during temperature recovery and shortening the recovery time. Note that a numerical range, such as "25 to 200 wafers," used in this specification means that the lower and upper limits are included within the range. Therefore, for example, "25 to 200 sheets" means "25 sheets or more and 200 sheets or less." The same applies to other numerical ranges.

[0018] A rotation mechanism 42 for rotating the boat 20 is installed on the opposite side of the seal cap 38 from the processing chamber 18. The rotation mechanism 42 includes a housing 56 formed in a generally cylindrical shape with an open upper end and a closed lower end. The housing 56 is concentrically arranged and fixed to the underside of the seal cap 38. An elongated cylindrical inner shaft 58 is disposed vertically within the housing 56 and is fixedly supported by the closing wall of the housing 56. A hollow disk-shaped outer shaft 60 is disposed concentrically within the housing 56. The outer shaft 60 has a cylindrical shape with a diameter larger than the outer diameter of the inner shaft 58 and a central through-hole through which the sub-heater 50 is inserted at the upper end of the cylindrical shape. The outer shaft 60 is rotatably supported by a pair of upper and lower inner bearings 62, 64 interposed between the inner shaft 58 and the outer shaft 60, and a pair of upper and lower outer bearings 66, 68 interposed between the outer shaft 60 and the housing 56. The sub-heater 50, which will be described in detail later, is inserted vertically inside the inner shaft 58.

[0019] A substantially cylindrical rotating shaft 54 ​​is fixed to the upper surface of the outer shaft 60. The rotating shaft 54 ​​has an outward flange-shaped lower end and a through-hole formed in the center for passing the sub-heater 50 through. A substantially cylindrical base 96 is fixed to the upper end of the rotating shaft 54, on the upper surface of the seal cap 38, and has an outward flange-shaped lower end and a through-hole formed in the center for passing the sub-heater 50 through. The base 96 is made of a heat-resistant material such as quartz or SiC.

[0020] An insulator holder 110 is fixed to the upper surface of the seal cap 38. The insulator holder 110 is composed of a disk-shaped upper plate 112, a hollow disk-shaped lower plate 114 having an outer diameter the same as that of the upper plate 112 and an inner diameter larger than that of the base 96, and three holding posts 116 bridging the upper and lower plates 112 and 114. A sub-heater (also referred to as a cap heater) 50, which serves as an auxiliary heating unit (also referred to as an auxiliary heating mechanism or auxiliary heater) and a second heater, is disposed below the upper plate 112. Below the sub-heater 50, quartz insulators 108 are arranged at equal intervals in holding grooves formed in each of the three holding posts 116.

[0021] The boat 20 is connected above the thermal insulator holding part 110 via a support 99. That is, the upper plate 112 and a disk-shaped boat plate 98 provided at the lower end of the boat 20 are connected by the support 99 provided coaxially.

[0022] The heater 14 is divided into, for example, five control zones U, CU, C, CL, and L from the top to the bottom. The heater 14 is configured to heat each zone in the processing vessel to a target temperature. The sub-heater 50 is configured to assist in heating a specific zone among the zones, for example, the lowest zone L. In other words, zone L is the zone in which the temperature detected by the temperature sensor 52 fluctuates most significantly, for example, the zone most likely to become coldest. This allows the wafers 2 placed at the bottom of the boat 20 to be heated and raised to a predetermined temperature (a temperature-raising step) within a predetermined time. In this way, by using the sub-heater 50 in addition to the heater 14 to heat the wafers 2 placed in a zone (e.g., zone L) where the temperature is less likely to rise, the wafers 2 can be heated to a target temperature without delay. This allows the temperature-raising time (temperature-raising step) to be shortened without being extended.

[0023] Here, when the lowermost wafer 2 among the wafers 2 placed on the boat 20 is located in zone CU, the sub-heater 50 (described later) is configured to be provided near the wafer 2 located below the boat 20. That is, the sub-heater 50 (described later) is preferably installed in the zone where the wafers 2 located below the boat 20 are located, near the lower side of the wafer 2. By heating the wafers 2 with the sub-heater 50 in addition to the heater 14, the wafers 2 located at the bottom of the boat 20 can be heated and raised to a predetermined temperature (a temperature-raising step can be executed) in a predetermined time. Here, the "lowest" refers to several to a dozen or so wafers 2 counting from the bottom (the first wafer 2 from the bottom) of the wafers 2 held in the boat 20.

[0024] Thermocouples 302 are provided on the inner wall of the heater 14 at positions corresponding to each zone. The thermocouples 302 are heater thermocouples that detect the temperature of the heater 14 in each zone. Hereinafter, the temperature detected by the thermocouples 302 will be referred to as the heater TC detected temperature. Hereinafter, this will be referred to as the heater temperature.

[0025] A temperature sensor 52 serving as a first temperature sensor is provided in the annular space between the inner wall of the reaction tube 16 and the wafer 2. The temperature sensor 52 is configured in an L-shape similar to the nozzle 22, and is provided along the inner wall of the reaction tube 16. Thermocouples 303 are provided at positions corresponding to each zone of the temperature sensor 52. The thermocouples 303 are cascade thermocouples, and detect the temperature of the processing chamber 18 formed within the reaction tube 16 in each zone. Hereinafter, the temperature detected by the thermocouple 303 will be referred to as the in-furnace TC detected temperature (in-furnace temperature).

[0026] More specifically, the controller 200 as a control unit, which will be described later, is configured to adjust the power supply to each zone of the heater 14 and the power supply to the sub-heater 50 based on the temperature information detected by the thermocouples 302, 303, and 304 in each zone, and to control the temperature of the processing chamber 18 (furnace temperature) to a target temperature.

[0027] Next, the details of the sub-heater 50 in this embodiment will be described with reference to FIGS.

[0028] The sub-heater 50 has a support column 82 extending vertically and a heat generating section 84 disposed approximately horizontally relative to the support column 82 .

[0029] The heating portion 84 is formed in a generally annular shape with a diameter smaller than the outer diameter of the wafer 2, and is configured to be supported horizontally relative to the support portion 82 at the upper end of the support portion 82. In other words, the heating portion 84 is supported so as to be parallel to the wafer 2. A heater wire 88, which is a resistance heating wire that constitutes a resistance heating element 146, which is a heating element formed in a coil shape, is enclosed inside the heating portion 84. The resistance heating element 146 is made of, for example, an Fe-Cr-Al alloy, molybdenum disilicide, or the like. Both ends of the heater wire 88 are bent vertically downward at the connection between the support portion 82 and the heating portion 84 and drawn into the interior of the support portion 82.

[0030] A bulge 128 is formed at the upper end of the support column 82, having a cross-sectional area greater than the cross-sectional area of ​​the lower portion, i.e., the cross-sectional area of ​​the support column 82, and the heat generating section 84 is connected to the upper surface of the bulge 128. The heat generating section 84 is configured in a ring shape with the upper surface of the bulge 128 as its start and end points.

[0031] A temperature sensor 150 serving as a second temperature sensor for detecting the temperature of the sub-heater 50 is installed in the sub-heater 50 so as to penetrate the support portion 82. The temperature sensor 150 is curved horizontally at the top and has a generally L-shaped cross section. The temperature sensor 150 is formed from a tubular member, and a thermocouple 304 is attached to its internal tip. The temperature sensor 150 bends and extends horizontally above the bulge 128, i.e., at the center of the annular portion 130, and is connected to the outer wall of the annular portion 130. The horizontal portion of the temperature sensor 150 is formed parallel to the heat-generating portion 84. The horizontal height position of the temperature sensor 150 is configured to be the height of the center of the diameter of the annular portion 130 when viewed in vertical cross section of the sub-heater 50. Here, the horizontal height position refers to the center of the diameter of the horizontal portion when the temperature sensor 150 is viewed in vertical cross section. The thermocouple 304 of the temperature sensor 150 is installed so as to be located near the outer wall of the annular portion 130 and is configured to detect the temperature of the sub-heater 50 .

[0032] 4, the controller 200, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 212, a RAM (Random Access Memory) 214, a storage device 216, and an I / O port 218. The RAM 214, the storage device 216, and the I / O port 218 are configured to be able to exchange data with the CPU 212 via an internal bus 220. An input / output device 222 configured as, for example, a touch panel is connected to the controller 200.

[0033] The storage device 216 includes, for example, a flash memory, a hard disk drive (HDD), etc. The storage device 216 readably stores a control program for controlling the operation of the substrate processing apparatus 10, a process recipe describing the procedures and conditions for substrate processing (described later), and other data. The process recipe is a combination of procedures in the substrate processing process (described later) that are executed by the controller 200 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, control program, etc. are collectively referred to simply as a program (program product). In this specification, the term "program" refers to a program recorded on a computer-readable recording medium, and may include only a process recipe, only a control program, or both. The RAM 214 is configured as a memory area (work area) for temporarily storing programs, data, etc. read by the CPU 212.

[0034] The I / O port 218 is connected to the above-mentioned MFCs 26a, 26b, valves 28a, 28b, pressure sensor 32, APC valve 34, vacuum pump 36, heater 14, sub-heater 50, temperature sensors 52, 150, rotation mechanism 42, boat elevator 46, etc.

[0035] The CPU 212 is configured to read and execute a control program from the storage device 216, and also to read a process recipe from the storage device 216 in response to input of an operation command from the input / output device 222. The CPU 212 is configured to control, in accordance with the contents of the read process recipe, the flow rate adjustment operation of various gases by the MFCs 26a and 26b, the opening and closing operation of the valves 28a and 28b, the opening and closing operation of the APC valve 34 and the pressure adjustment operation by the APC valve 34 based on the pressure sensor 32, the start and stop of the vacuum pump 36, the temperature adjustment operation of the heater 14 and the sub-heater 50 based on the temperature sensors 52 and 150, the rotation and rotation speed adjustment operation of the boat 20 by the rotation mechanism 42, the raising and lowering operation of the boat 20 by the boat elevator 46, and the like.

[0036] The controller 200 can be configured by installing the above-described program stored in an external storage device 224 (e.g., a magnetic tape, a magnetic disk such as a flexible disk or a hard disk, an optical disk such as a CD or a DVD, or a semiconductor memory such as a USB memory or a memory card) into a computer. The storage device 216 and the external storage device 224 are configured as computer-readable recording media on which the program is recorded. Hereinafter, these will be collectively referred to as simply a recording medium. When the term recording medium is used in this specification, it may include only the storage device 216, only the external storage device 224, or both. Note that the program may be provided to the computer using a communication means such as the Internet or a dedicated line, without using the external storage device 224.

[0037] (2) Substrate Processing Step Next, an example of a substrate processing sequence will be described, in which a film is formed on a wafer 2 (hereinafter also referred to as a film formation process) and the formed film is annealed (hereinafter also referred to as an annealing process) as one step in the manufacturing process of a semiconductor device using the above-described substrate processing apparatus 10. Note that in the following description, the operation of each part constituting the substrate processing apparatus 10 is controlled by the controller 200.

[0038] The term "wafer" used in this specification may refer to the wafer itself or to a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may refer to the surface of the wafer itself or to the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0039] (Wafer Charging and Boat Loading) When a plurality of wafers 2 are loaded into the boat 20 (wafer charging), the boat 20 is carried into the processing chamber 18 (boat loading) by the boat elevator 46. At this time, the seal cap 38 airtightly closes (seals) the lower end of the reaction tube 16 via the O-ring 40.

[0040] (Pressure and Temperature Regulation) The processing chamber 18, i.e., the space in which the wafer 2 is present, is evacuated (reduced pressure exhausted) by the vacuum pump 36 so that it reaches a predetermined pressure (vacuum level). At this time, the pressure in the processing chamber 18 is measured by the pressure sensor 32, and the APC valve 34 is feedback-controlled based on this measured pressure information. The vacuum pump 36 is kept in a constantly operating state at least until processing of the wafer 2 is completed.

[0041] The processing chamber 18 is heated by the heater 14 and the sub-heater 50 so that its temperature is maintained at a predetermined temperature. At this time, the amount of power supplied to the heater 14 is feedback-controlled based on temperature information detected by the temperature sensor 52 so that the processing chamber 18 has a predetermined temperature distribution. In a specific zone only, the amount of power supplied to the heater 14 is feedback-controlled based on temperature information detected by the temperature sensors 52 and 150. At the same time, the amount of power supplied to the sub-heater 50 may be feedback-controlled based on temperature information detected by the temperature sensor 150. Heating of the processing chamber 18 by the heater 14 and the sub-heater 50 continues at least until processing of the wafer 2 is completed. At this time, heating by the sub-heater 50 may be stopped. Since the sub-heater 50 is controlled independently of the heater 14, heating by the sub-heater 50 may be disabled, and the wafer 2 in the processing chamber 18 may be heated solely by the heater 14.

[0042] Furthermore, the rotation mechanism 42 starts to rotate the boat 20 and the wafers 2. The rotation mechanism 42 rotates the boat 20, thereby rotating the wafers 2. At this time, the insulator 108 and the sub-heater 50 are not rotated. The rotation mechanism 42 continues to rotate the boat 20 and the wafers 2 at least until the processing of the wafers 2 is completed. In this embodiment, the insulator holder 110 including the insulator 108 is fixed, but the rotation mechanism 42 may be configured to rotate the insulator holder 110 including the insulator 108 in the same manner as the boat 20.

[0043] (Film Formation Process) When the temperature of the processing chamber 18 stabilizes at a preset processing temperature, a source gas is supplied to the wafers 2 in the processing chamber 18. Here, the processing temperature in this specification means the temperature inside the furnace or the temperature inside the processing vessel (the temperature of the processing chamber 18).

[0044] Specifically, valve 28a is opened to allow the source gas to flow into gas supply pipe 24a. The flow rate of the source gas is adjusted by MFC 26a, supplied to processing chamber 18 via nozzle 22, and exhausted from exhaust pipe 120. At this time, the source gas is supplied to wafer 2. At this time, valve 28b may be opened at the same time to allow an inert gas to flow into gas supply pipe 24b. In this case, the flow rate of the inert gas is adjusted by MFC 26b, supplied to processing chamber 18 together with the source gas, and exhausted from exhaust pipe 120.

[0045] After a predetermined film containing the source element is formed on the wafer 2, the valve 28a is closed to stop the supply of the source gas. At this time, the APC valve 34 is left open, and the processing chamber 18 is evacuated by the vacuum pump 36 to discharge the source gas remaining in the processing chamber 18, either unreacted or having contributed to the formation of the film, from the processing chamber 18. At this time, the valve 28b may be opened to supply an inert gas into the processing chamber 18. This can enhance the effectiveness of discharging the gas remaining in the processing chamber 18 from the processing chamber 18.

[0046] As described above, in this embodiment, an example is shown in which a film is formed by simply supplying a source gas, but the film formation process is not limited to this. For example, the source gas and a reactive gas (not shown) may be supplied simultaneously, or the source gas and the reactive gas (not shown) may be supplied cyclically. For example, a container (not shown) may be provided for temporarily storing gas, and a predetermined amount of source gas may be stored in this container and released all at once to supply the source gas to the processing chamber 18.

[0047] During the above-described film formation process, the controller 200 may control the power supply to the sub-heater 50, which will be described later.

[0048] (Heating Up) After the film formation process is completed, i.e., after a predetermined film has been formed on the wafer 2, the wafer 2 in the processing chamber 18 is heated by the heater 14 and the sub-heater 50 to a target temperature, which is an annealing temperature higher than the processing temperature in the above-mentioned film formation process. At this time, the valve 28b is opened, and an inert gas is supplied to the processing chamber 18 via the nozzle 22 and exhausted through the exhaust pipe 120 to purge the processing chamber 18.

[0049] (Annealing Treatment) When the temperature of the processing chamber 18 reaches the target temperature and stabilizes, the wafer 2 in the processing chamber 18, that is, the predetermined film formed on the wafer 2, is subjected to heat treatment (annealing).

[0050] (Purge and Return to Atmospheric Pressure) After the annealing process is completed, the valve 28b is opened, and an inert gas is supplied to the process chamber 18 through the gas supply pipe 24b and exhausted through the exhaust pipe 120. The inert gas acts as a purge gas. This purges the process chamber 18, and gases and reaction by-products remaining in the process chamber 18 are removed from the process chamber 18 (purge). Thereafter, the atmosphere in the process chamber 18 is replaced with the inert gas (inert gas replacement), and the pressure in the process chamber 18 is returned to normal pressure (return to atmospheric pressure).

[0051] (Boat Unloading and Wafer Discharge) The seal cap 38 is lowered by the boat elevator 46, and the bottom end of the reaction tube 16 is opened. Then, the processed wafers 2 supported by the boat 20 are unloaded from the bottom end of the reaction tube 16 to the outside of the reaction tube 16 (boat unloading). The processed wafers 2 are removed from the boat 20 (wafer discharging).

[0052] Here, as in the substrate processing process described above, an annealing process may be performed in the same processing furnace 12 (or processing chamber 18) following the film formation process. In this case, if the temperature during the film formation process is, for example, 500 to 700°C, the target temperature during the annealing process may be 800°C or higher. In such a substrate processing process, the target temperature during the annealing process may have to be set higher than the specified temperature of the sub-heater 50. Furthermore, because the sub-heater 50 uses a wire with a smaller wire diameter than the heater 14, the temperature at which the sub-heater 50 can be controlled (the specified temperature) is lower than that of the heater 14. Therefore, if the sub-heater 50 is used at a temperature higher than the specified controllable temperature, the wire temperature of the sub-heater 50 will rise significantly, accelerating deterioration of the wire of the sub-heater 50. As a result, the life of the sub-heater 50 will be shortened. Furthermore, since the sub-heater 50 is installed at the bottom of the process furnace 12 (or process chamber 18), modifying the wire diameter to a larger (thicker) wire may require a change in the design of the components around the furnace throat. Furthermore, if the wire temperature is suppressed by limiting the maximum output of the heater 14 simply to extend the life of the sub-heater 50, the temperature rise time will be longer and throughput will be reduced.

[0053] In the aspects of the present disclosure, the controller 200 is configured to be able to execute temperature control in a temperature range higher than the specification temperature of the sub-heater 50 by selecting at least one of the temperature control methods shown in the following first to third aspects, or by combining the temperature control methods shown in the first to third aspects. Furthermore, it goes without saying that the controller 200 is configured to be able to control the heater 14 that heats the interior of the process vessel in which the wafer 2 is placed, and the sub-heater 50 that assists in heating a specific zone. This makes it possible to suppress an increase in the wire temperature of the sub-heater 50 and suppress deterioration of the wire of the sub-heater 50.

[0054] Furthermore, the controller 200 is configured to be able to heat the temperature of each zone to the target temperature at each step by appropriately combining heating by both the heater 14 and the sub-heater 50, or heating by the heater 14 alone.

[0055] FIG. 5A shows a case in which the output of the sub-heater 50 is limited when the wire temperature of the sub-heater 50 is equal to or higher than a predetermined temperature. FIG. 5B shows a case in which the temperature rise rate of the sub-heater 50 is reduced when the wire temperature of the sub-heater 50 is equal to or higher than a predetermined temperature. FIG. 5C shows a case in which the start of output of the sub-heater 50 is delayed until the wire temperature of the sub-heater 50 reaches or exceeds the predetermined temperature. In FIGS. 5A to 5C, the thin dashed lines indicate the furnace temperature in the comparative example, and the thick dashed lines indicate the wire temperature in the comparative example. These figures show a case in which the output of the sub-heater 50 is increased to 100%, which is the maximum output, in addition to the heater 14, during the temperature rise step of the substrate processing process described above. The thin solid lines indicate the furnace temperature in the first to third embodiments, respectively, and the thick solid lines indicate the wire temperature of the sub-heater 50 in the first to third embodiments, respectively.

[0056] 5A to 5C, when the output of the sub-heater 50 in addition to the heater 14 is set to 100%, the wire temperature of the sub-heater 50 may temporarily exceed the temperature controllable by the sub-heater 50 before the furnace temperature reaches the target temperature T1 and becomes constant. For example, when raising the temperature of zone L to the target temperature T1, the controller 200 controls the sub-heater 50 to perform at least one of the following first to third modes. Note that at least two of the following first to third modes may be used in combination.

[0057] (First Aspect) In the first aspect, the controller 200 freely controls the output of the sub-heater 50, keeping it constant or varying it, without any particular restrictions, until the wire temperature detected by the temperature sensor 150 reaches a predetermined temperature T2 that is lower than the target temperature T1. Then, the controller 200 limits the output of the sub-heater 50 when the wire temperature of the sub-heater 50 reaches or exceeds the predetermined temperature T2. That is, the controller 200 controls the heater 14 and the sub-heater 50 so that the temperature inside the process vessel (the furnace temperature detected in each zone by the temperature sensor 52) becomes the target temperature T1, and limits the output of the sub-heater 50 when the temperature of the sub-heater 50 detected by the temperature sensor 150 reaches the predetermined temperature T2. Specifically, for example, the controller 200 controls the output of the sub-heater 50 so as to limit it to, for example, 0 to 30% of the maximum output (100%) when the wire temperature is equal to or higher than the predetermined temperature T2 that is lower than the target temperature T1. The heater temperature of zone L, the output value of the sub-heater 50, and the wire temperature of the sub-heater 50 have a predetermined relationship, which makes it possible to control the wire temperature of the sub-heater 50. As a result, as shown in Fig. 5A, the peak value of the wire temperature of the sub-heater 50 can be made lower than the peak value of the wire temperature of the sub-heater 50 in the comparative example, thereby suppressing an increase in the wire temperature of the sub-heater 50 and suppressing deterioration of the wire of the sub-heater 50.

[0058] Here, when the temperature of the sub-heater 50, i.e., the temperature detected by the temperature sensor 150, is equal to or higher than a predetermined temperature T2 that is lower than the target temperature T1, an output limit value that limits the output of the sub-heater 50 is stored and maintained in advance in a storage device 216 or the like.

[0059] Furthermore, when the temperature detected by the temperature sensor 150 reaches the predetermined temperature T2, if the output of the sub-heater 50 exceeds a preset output limit value, the controller 200 is configured to be able to control the output of the sub-heater 50 to be changed to or below the output limit value. This makes it possible to suppress an increase in the wire temperature of the sub-heater 50 and reduce wear and tear of the wire of the sub-heater 50.

[0060] Furthermore, the controller 200 may vary the output of the sub-heater 50 from 0 or more within a range not exceeding a preset output limit value until the temperature detected by the temperature sensor 150 reaches the predetermined temperature T2 and the temperature of each zone detected by the temperature sensor 52 reaches the target temperature T1, or may keep the output of the sub-heater 50 constant at a preset output not exceeding the preset output limit value. This makes it possible to suppress an increase in the wire temperature of the sub-heater 50 and reduce wear and tear of the wire of the sub-heater 50.

[0061] Furthermore, the controller 200 may set the output of the sub-heater 50 to 0 after the temperature detected by the temperature sensor 150 reaches the predetermined temperature T2 and until the temperature of each zone detected by the temperature sensor 52 reaches the target temperature T1, or may vary the output of the sub-heater 50 in a pulsed manner between 0 and a preset output that is greater than 0 and equal to or less than the output limit value. Even with this configuration, it is possible to suppress an increase in the wire temperature of the sub-heater 50 and reduce wear and tear of the wire of the sub-heater 50.

[0062] Furthermore, when the temperature detected by the temperature sensor 150 reaches the predetermined temperature T2, if the output of the sub-heater 50 does not exceed a preset output limit value, the controller 200 may control the output of the sub-heater 50 to fluctuate at or below the output when the predetermined temperature T2 is reached, until the temperature of each zone detected by the temperature sensor 52 reaches the target temperature T1. Even with this configuration, it is possible to suppress an increase in the wire temperature of the sub-heater 50 and reduce wear and tear of the wire of the sub-heater 50.

[0063] In this way, when the temperature detected by the temperature sensor 150 is equal to or higher than the predetermined temperature T2, the controller 200 can heat using both the heater 14 and the sub-heater 50 as long as the output of the sub-heater 50 is equal to or lower than a preset output limit value. Therefore, according to the first aspect, it is possible to suppress an increase in the wire temperature of the sub-heater 50 and reduce wear and tear of the wire of the sub-heater 50, thereby extending the life of the sub-heater 50. Furthermore, by limiting the output of the sub-heater 50, it is expected that the effect of suppressing the power load on the entire heater can be achieved.

[0064] (Second Aspect) In the second aspect, the controller 200 sets the temperature rise rate of the sub-heater 50 lower than the temperature rise rate of the heater 14 in accordance with the wire temperature and the furnace temperature. The controller 200 keeps the output of the sub-heater 50 constant until the wire temperature of the sub-heater 50 detected by the temperature sensor 150 reaches a predetermined temperature T2 that is lower than the target temperature T1. Then, when the wire temperature of the sub-heater 50 reaches or exceeds the predetermined temperature T2, the controller 200 sets the temperature rise rate of the sub-heater 50 lower than the temperature rise rate of the heater 14. As a result, as shown in FIG. 5B , the peak value of the wire temperature of the sub-heater 50 can be made lower than the peak value of the wire temperature in the comparative example, thereby suppressing an increase in the wire temperature of the sub-heater 50 and suppressing deterioration of the wire of the sub-heater 50.

[0065] In the second embodiment, the rate of temperature rise of the sub-heater 50 may be set lower than the rate of temperature rise of the heater 14 from the start of temperature rise to the target temperature T1. Furthermore, since it is sufficient to suppress the rise in the wire temperature of the sub-heater 50, it is not necessary to set an output limit value at or above the predetermined temperature T2, as in the first embodiment.

[0066] (Third Aspect) In the third aspect, the controller 200 delays the start of output of the sub-heater 50 from the start of output of the heater 14, depending on the wire temperature and the furnace temperature. As an example, the controller 200 is configured to start output of the sub-heater 50 when the temperature of zone L detected by the temperature sensor 52 reaches a predetermined temperature T2. For example, the controller 200 is configured to fluctuate the output of the sub-heater 50 at an output equal to or less than a preset output limit value. In this manner, the time for turning off (zeroing) the output of the sub-heater 50 can be set. As a result, as shown in FIG. 5C , the peak value of the wire temperature of the sub-heater 50 can be made lower than the peak value of the wire temperature in the comparative example, suppressing an increase in the wire temperature of the sub-heater 50 and suppressing deterioration of the wire of the sub-heater 50. Furthermore, limiting the time for output of the sub-heater 50 can be expected to reduce the overall power load on the heater.

[0067] In this case, the controller 200 may keep the output of the sub-heater 50 constant at an output equal to or lower than a preset output limit value. Also, since it is sufficient to suppress an increase in the wire temperature of the sub-heater 50, the output limit value does not have to be the same as the output limit value in the first mode.

[0068] Next, an example of a block diagram of temperature control in this embodiment will be described with reference to FIG.

[0069] 6, "target temperature" indicates the target temperature T1 in each zone of the heater 14. The target temperature T1 is input to the positive input terminal of the first subtractor.

[0070] "Detected TC temperature inside the furnace" indicates the temperature inside the furnace measured by the temperature sensor 52 using the thermocouple 303 corresponding to each zone. The temperature inside the furnace detected by the temperature sensor 52 is input to the negative input terminal of the first subtractor. This controls the temperature inside the furnace to the corresponding target temperature T1.

[0071] The first subtractor calculates the deviation between the target temperature T1 and the furnace temperature, and outputs the result to the PID calculation unit 1.

[0072] The deviation from the first subtractor is input to the PID calculation unit 1, which performs a known PID calculation. The result of the PID calculation is input to the positive input terminal of the second subtractor.

[0073] Furthermore, "heater TC detection temperature" indicates the heater temperature measured by the thermocouple 302 corresponding to each zone. The heater temperature detected by the thermocouple 302 corresponding to each zone is input to the negative input terminal of the second subtractor. Note that for a specific zone among the zones, the temperature of the sub-heater 50 detected by the thermocouple 304 may be input to the negative input terminal of the second subtractor.

[0074] The second subtractor calculates the deviation between the calculation result of the PID calculation unit 1 and the heater temperature, and outputs the deviation to the PID calculation unit 2 .

[0075] The deviation from the second subtractor is input to the PID calculation unit 2, which performs a known PID calculation. The PID parameters used in the PID calculation unit 2 are different from those used in the PID calculation unit 1. The PID calculation result is output as a "manipulated variable."

[0076] It is desirable that the PID parameters used when PID calculations are performed in PID calculation unit 1 and PID calculation unit 2 are adjustable. The PID parameters are an example of "control parameters of the heating unit" in the technology of the present disclosure. PID calculation unit 1 and PID calculation unit 2 are configured to allow the PID parameters to be set arbitrarily. The PID parameters, like the "target temperature," are recorded in controller 200 as a recipe or a table associated with the recipe.

[0077] The "manipulated variable" indicates a value that is output as a control calculation result corresponding to the zone to be controlled. This value is converted into a control signal for heating the zone to be controlled by the heater 14 and is output. When the output limit value of the sub-heater 50 is set as described above, the maximum value of this "manipulated variable" is set in advance, so the maximum value of the control signal for the sub-heater 50 may be limited.

[0078] As described above, the controller 200 that operates the temperature control system of the present disclosure is configured to perform control calculations in accordance with a control algorithm known as cascade control, and to control the furnace temperature so that it coincides with the corresponding target temperature T1.

[0079] Next, an example of a substrate processing sequence performed in the substrate processing apparatus 10 will be described with reference to FIGS.

[0080] In step S101 (standby step), the wafer 2 is maintained at a temperature (standby temperature) at which it is waiting before being loaded into the processing furnace 12 (or processing chamber 18). For example, in this embodiment, this standby temperature is the same as the target temperature T0 as the film formation temperature. Note that in step S101, for example, the wafer 2 may be transported to the boat 20.

[0081] Step S102 (boat loading step) is a step in which wafers 2 are loaded into the processing furnace 12 (or processing chamber 18). For example, in this embodiment, the wafers 2 are loaded into the processing furnace 12 (or processing chamber 18) while held in the boat 20. At this time, the temperatures of the boat 20 and the wafers 2 are lower than the target temperature T0. Furthermore, as a result of loading the wafers 2 into the processing furnace 12 (or processing chamber 18), the atmosphere (room temperature) outside the processing furnace 12 is introduced into the processing furnace 12 (or processing chamber 18). Therefore, the temperature inside the processing furnace 12 (or processing chamber 18) temporarily drops below the target temperature T0. Thereafter, under control of the controller 200, the temperature inside the furnace stabilizes at the target temperature T0 after a certain period of time. In this figure, the target temperature T0 after loading the processing substrates into the processing furnace 12 (or processing chamber 18) and in the next step S103 are illustrated as being the same as in step S101. However, the target temperature after loading may differ depending on the requirements of step S103.

[0082] Step S103 (film formation step) is a step in which the temperature inside the furnace is maintained at the target temperature T0 to perform a predetermined film formation process on the wafer 2.

[0083] Step S104 (heating step) is a step of raising the temperature inside the furnace from the target temperature T0 to an annealing temperature at which annealing is performed. In order to perform annealing on the wafer 2 that has been subjected to film formation processing, the controller 200 controls the heater 14 and the sub-heater 50 so that the temperature inside the furnace reaches a target temperature T1, which is an annealing temperature higher than the target temperature T0. At this time, the controller 200 limits the output of the sub-heater 50 when the wire temperature of the sub-heater 50 detected by the temperature sensor 150 is equal to or higher than a predetermined temperature T2 that is lower than the target temperature T1.

[0084] Step S105 (annealing step) is a step in which the temperature inside the furnace is maintained at a target temperature T1 to perform the annealing process on the wafer 2.

[0085] Step S106 (boat unloading step) is a step in which the annealed wafers 2 are unloaded together with the boat 20 from the processing furnace 12 (or the processing chamber 18).

[0086] If unprocessed wafers 2 remain to be processed, the processed wafers 2 are evacuated from the boat 20 and replaced with unprocessed wafers 2, and the series of steps S101 to S106 is repeated one or more times.

[0087] <Effects> According to this aspect, one or more of the following effects can be obtained.

[0088] Both the heater 14 and the sub-heater 50 heat the substrate without any restrictions up to a predetermined temperature T2, which is lower than the target temperature T1, and the output of the sub-heater 50 is limited during high-temperature processing above the predetermined temperature T2, thereby preventing an excessive rise in the wire temperature of the sub-heater 50 and reducing wear and tear of the wire of the sub-heater 50. This ensures the life of the sub-heater 50.

[0089] Furthermore, by allowing both the heater 14 and the sub-heater 50 to heat without any restrictions up to a predetermined temperature T2 that is lower than the target temperature T1, and restricting the output of the sub-heater 50 during high-temperature processing that is higher than the predetermined temperature T2, even if the output of the sub-heater 50 exceeds the output limit value at the predetermined temperature T2, an excessive rise in the wire temperature of the sub-heater 50 can be suppressed, and wear and tear of the wire of the sub-heater 50 can be reduced, thereby ensuring the life of the sub-heater 50.

[0090] Furthermore, by limiting the output of the sub-heater 50, it is possible to expect the effect of suppressing the power load of the heater as a whole.

[0091] Furthermore, since the sub-heater 50 assists the heater 14 corresponding to a specific zone with large temperature fluctuations, it is expected that the in-plane temperature uniformity of the wafers 2 arranged in each zone, including the specific zone, will be improved. Temperature uniformity between each zone can also be ensured.

[0092] Furthermore, since a specific portion of the zones is assisted in heating by the sub-heater 50, the temperature inside the processing vessel corresponding to each zone can be raised to the target temperature T1 without delay, without extending the temperature rise time (temperature rise step).

[0093] Furthermore, when the temperature is raised to the target temperature T1, the temperature rise rate of the sub-heater 50 can be made smaller than the temperature rise rate of the heater 14, so that even during high-temperature processing at temperatures higher than the predetermined temperature T2, an excessive rise in the wire temperature of the sub-heater 50 can be suppressed, reducing wear and tear on the wire of the sub-heater 50. Therefore, the life of the sub-heater 50 can be secured.

[0094] Furthermore, when the temperature is raised to the target temperature T1, heating by the sub-heater 50 can be started later than that by the heater 14, so that even during high-temperature processing at temperatures higher than the predetermined temperature T2, an excessive rise in the wire temperature of the sub-heater 50 can be suppressed, and wear and deterioration of the wire of the sub-heater 50 can be reduced, thereby ensuring the life of the sub-heater 50.

[0095] The above-described embodiments and modifications can be used in appropriate combination. The processing procedures and processing conditions in such cases can be, for example, the same as those of the above-described embodiments and modifications. Furthermore, unless otherwise specified in the specification, each element is not limited to one, and multiple elements may be present.

[0096] Other Aspects The above describes the aspects of the present disclosure. However, the present disclosure is not limited to the above aspects and can be modified in various ways without departing from the spirit of the present disclosure.

[0097] For example, in the above embodiment, an example has been described in which this embodiment is applied during the temperature rise from the film formation process to the annealing process, but the present disclosure is not limited to this, and can also be suitably applied to a case in which this embodiment is applied simply during the temperature rise from the film formation process to the annealing process, or a case in which this embodiment is applied simply during the temperature rise from the film formation process to the annealing process.

[0098] In the above-described embodiment, an example of performing a predetermined process using a substrate processing apparatus that is a batch-type vertical 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 predetermined process is performed using a single-wafer substrate processing apparatus that processes one or several substrates at a time. In the above-described embodiment, an example of performing a predetermined process 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 predetermined process is performed using a substrate processing apparatus having a cold-wall processing furnace.

[0099] 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.

[0100] Furthermore, the substrate processing apparatus according to the present disclosure can be applied not only to semiconductor manufacturing apparatuses that manufacture semiconductors, but also to apparatuses that process glass substrates, such as LCD (Liquid Crystal Display) apparatuses. The substrate processing includes, for example, CVD, PVD, processes for forming oxide films and nitride films, processes for forming metal-containing films, annealing, oxidation, nitriding, and diffusion. It goes without saying that the present disclosure can also be applied to various substrate processing apparatuses, such as exposure apparatuses, coating apparatuses, drying apparatuses, and heating apparatuses.

[0101] 14 Heater (first heater) 50 Sub-heater (second heater) 52 Temperature sensor (first temperature sensor) 150 Temperature sensor (second temperature sensor) 200 Controller (control unit)

Claims

1. A temperature control system comprising: a first heater configured to heat a processing container provided to be divided into zones and having a substrate disposed therein; a second heater configured to assist the heating of the first heater corresponding to a specific zone among the zones; a temperature sensor configured to detect the temperature of the second heater; and a control unit configured to set the temperature inside the processing container to the target temperature by restricting the output of the second heater when the temperature detected by the temperature sensor is equal to or higher than a predetermined temperature lower than the target temperature.

2. The temperature control system according to claim 1, wherein the control unit is configured to change the output of the second heater to be equal to or lower than a preset output limit value when the output of the second heater exceeds the preset output limit value when the temperature detected by the temperature sensor reaches the predetermined temperature.

3. The temperature control system according to claim 1, wherein the control unit is configured to vary the output of the second heater from 0 or more to an output equal to or lower than a preset output limit value until the temperature inside the processing container reaches the target temperature after the temperature detected by the temperature sensor reaches the predetermined temperature.

4. The temperature control system according to claim 1, wherein the control unit is configured to keep the output of the second heater constant at a preset output from 0 or more to an output equal to or lower than a preset output limit value until the temperature inside the processing container reaches the target temperature after the temperature detected by the temperature sensor reaches the predetermined temperature.

5. The temperature control system according to claim 4, wherein the control unit is configured to set the output of the second heater to 0 until the temperature inside the processing container reaches the target temperature after the temperature detected by the temperature sensor reaches the predetermined temperature.

6. The temperature control system according to claim 3, wherein the control unit is configured to vary the output of the second heater with a pulse output between a preset output greater than 0 and equal to or lower than the output limit value and 0 output until the temperature inside the processing container reaches the target temperature after the temperature detected by the temperature sensor reaches the predetermined temperature.

7. When the temperature detected by the temperature sensor reaches the predetermined temperature, if the output of the second heater does not exceed a preset output limit value, the control unit is configured to vary the output of the second heater below the output when the predetermined temperature is reached until the temperature in the processing vessel reaches the target temperature. The temperature control system according to claim 1.

8. When the temperature detected by the temperature sensor is equal to or higher than the predetermined temperature, if the output of the second heater is equal to or lower than a preset output limit value, the control unit is configured to be able to heat by both the first heater and the second heater. The temperature control system according to any one of claims 1 to 7.

9. The control unit is configured to keep the output of the second heater constant until the temperature detected by the temperature sensor reaches the predetermined temperature. The temperature control system according to claim 1.

10. The control unit is configured to be able to heat the temperature in the processing vessel facing each zone to the target temperature by combining heating by both the first heater and the second heater or heating by the first heater alone. The temperature control system according to claim 1.

11. The control unit is configured to start the output of the second heater after starting the output of the first heater. The temperature control system according to claim 10.

12. When the temperature detected by the temperature sensor reaches the predetermined temperature, the control unit is configured to output the second heater. The temperature control system according to claim 11.

13. The control unit is configured to vary the output of the second heater with an output equal to or lower than a preset output limit value. The temperature control system according to claim 12.

14. The control unit is configured to keep the output of the second heater constant with an output equal to or lower than a preset output limit value. The temperature control system according to claim 12.

15. The control unit is configured to be able to make the temperature rise rate by the second heater lower than the temperature rise rate by the first heater. The temperature control system according to claim 1.

16. The target temperature is set higher than the temperature controllable by the second heater. The temperature control system according to claim 15.

17. A temperature control system according to claim 1, further comprising a first temperature sensor configured to detect the temperature within the processing container, wherein the specific zone is a zone among the zones where the temperature variation detected by the first temperature sensor is large.

18. A temperature control method, comprising a step of setting the temperature within the processing container to a target temperature by the temperature control system according to claim 1.

19. A method for manufacturing a semiconductor device, comprising a step of processing the substrate while maintaining the target temperature by the temperature control method according to claim 18.

20. A substrate processing apparatus, comprising: a first heater configured to heat a processing container provided to be divided into zones and having a substrate disposed therein; a second heater configured to assist heating of the first heater corresponding to a specific zone among the zones; a temperature sensor configured to detect the temperature of the second heater; and a control unit configured to set the temperature within the processing container to the target temperature by restricting the output of the second heater when the temperature detected by the temperature sensor is equal to or higher than a predetermined temperature lower than the target temperature.

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