Vertical heat treatment apparatus and heat treatment method

Abstract

This technology provides the ability to appropriately control the temperature according to the number of substrates. [Solution] The vertical heat treatment apparatus comprises a processing container capable of accommodating a plurality of substrates arranged vertically, and a substrate holder capable of holding the plurality of substrates arranged vertically inside the processing container. The vertical heat treatment apparatus also comprises a bottom heater positioned inside the substrate holder and capable of heating the plurality of substrates held by the substrate holder from the vertically lower side, and a lifting mechanism capable of raising and lowering the bottom heater relative to the substrate holder.

Description

Technical Field

[0001] The present disclosure relates to a vertical heat treatment apparatus and a heat treatment method.

Background Art

[0002] Patent Document 1 discloses a vertical heat treatment apparatus (heat treatment apparatus) that arranges a plurality of substrates vertically inside a processing container, supplies a processing gas, and performs heating. In this type of vertical heat treatment apparatus, substrate processing may be performed in a state where the maximum number of substrates is not held in a wafer boat that holds a plurality of substrates. The internal environment of the processing container when the maximum number of substrates is held is different from the internal environment of the processing container when a smaller number of substrates is held. Therefore, in a vertical heat treatment apparatus, temperature control corresponding to the number of substrates is desired.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of appropriately performing temperature control according to the number of substrates.

Means for Solving the Problems

[0005] According to one aspect of the present disclosure, there is provided a vertical heat treatment apparatus including a processing container capable of accommodating a plurality of substrates arranged vertically, a substrate holder capable of holding the plurality of substrates arranged vertically inside the processing container, a bottom heater disposed inside the substrate holder and capable of heating the plurality of substrates from the lower side in the vertical direction of the plurality of substrates held by the substrate holder, and a lifting mechanism capable of relatively lifting and lowering the bottom heater with respect to the substrate holder. [Effects of the Invention]

[0006] According to one embodiment, temperature control can be appropriately performed according to the number of substrates. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic cross-sectional view showing a heat treatment apparatus according to an embodiment. [Figure 2] Figure 2(A) is a longitudinal cross-sectional view showing the substrate holder without any substrates inside. Figure 2(B) is a longitudinal cross-sectional view showing the substrate holder with a small number of substrates inside. [Figure 3] Figure 3(A) is a schematic side view showing the lifting mechanism in the raised position. Figure 3(B) is a schematic top view showing the lifting mechanism. Figure 3(C) is a schematic side view showing the lifting mechanism in the lowered position. [Figure 4] This is a side view showing an enlarged view of the specific configuration of the drive transmission unit. [Figure 5] This is a flowchart showing the heat treatment method according to the embodiment. [Figure 6] Figure 6(A) shows the heating of each heater and the bottom heater in a temperature-controlled furnace with substrates contained throughout the substrate holder. Figure 6(B) shows the heating of each heater and the bottom heater in a temperature-controlled furnace with a small number of substrates contained in the substrate holder. [Figure 7] Figure 7(A) is a plan view showing the lifting mechanism according to the first modified example. Figure 7(B) is a plan view showing the lifting mechanism according to the second modified example. [Figure 8] This is a side view showing a substrate holder having a lifting mechanism according to a third modified example. [Modes for carrying out the invention]

[0008] The following describes embodiments for implementing this disclosure with reference to the drawings. In each drawing, the same reference numerals are used for identical components, and redundant explanations may be omitted.

[0009] Figure 1 is a schematic cross-sectional view of a vertical heat treatment apparatus 1 according to an embodiment. As shown in Figure 1, the vertical heat treatment apparatus 1 according to the embodiment is a semiconductor manufacturing system that arranges a plurality of substrates W in the vertical direction (up and down direction) and performs a film deposition process to deposit a desired film on the surface of the substrates W. Examples of substrates W include semiconductor substrates such as silicon wafers or compound semiconductor wafers, or glass substrates.

[0010] The vertical heat treatment apparatus 1 comprises a processing container 10 for housing multiple substrates W, and a temperature control furnace 50 arranged around the processing container 10. The vertical heat treatment apparatus 1 also includes a control unit 90 for controlling the operation of each component of the vertical heat treatment apparatus 1.

[0011] The processing container 10 is formed in a cylindrical shape that extends vertically. Inside the processing container 10, there is an internal space IS in which multiple substrates W can be arranged vertically. The processing container 10 includes, for example, a cylindrical inner cylinder 11 with an open upper end (ceiling) and lower end, and a cylindrical outer cylinder 12 that is located outside the inner cylinder 11 and has a ceiling but an open lower end. The inner cylinder 11 and the outer cylinder 12 are made of a heat-resistant material such as quartz and exhibit a double-cylinder structure arranged coaxially with each other. The processing container 10 is not limited to a double-cylinder structure; it may also be a single-cylinder structure or a multi-cylinder structure consisting of three or more cylinders.

[0012] The inner cylinder 11 has a diameter larger than the diameter of each substrate W, and an axial length (for example, greater than or equal to the height of each substrate W) that can accommodate each substrate W. Inside the inner cylinder 11, a processing space IS1 (part of the internal space IS) is formed for performing film deposition by discharging gas onto each contained substrate W. At the upper end of the inner cylinder 11, an opening 15 is provided that communicates with the processing space IS1 and allows gas to flow out into the flow space IS2 (another part of the internal space IS) between the inner cylinder 11 and the outer cylinder 12.

[0013] Furthermore, a housing portion 13 for accommodating the gas nozzle 31 is formed along the vertical direction in a part of the circumferential direction of the inner cylinder 11. As an example, the housing portion 13 is provided inside a convex portion 14 formed by protruding a part of the side wall of the inner cylinder 11 radially outward. Note that, instead of the upper end opening 15, the inner cylinder 11 may be provided with a vertically long opening (not shown) at an appropriate position on the circumferential wall (for example, on the opposite side of the housing portion 13 across the central axis).

[0014] The outer cylinder 12 has a diameter larger than that of the inner cylinder 11 and covers the inner cylinder 11 in a non-contact manner, constituting the outer shape of the processing container 10. The flow space IS2 between the inner cylinder 11 and the outer cylinder 12 is formed above and on the side of the inner cylinder 11, and allows the gas that has moved upward to flow vertically downward.

[0015] The lower end of the processing container 10 is supported by a cylindrical manifold 17 made of stainless steel. For example, the manifold 17 has a manifold-side flange 17f at its upper end. The manifold-side flange 17f fixes and supports an outer-cylinder-side flange 12f formed at the lower end of the outer cylinder 12. A seal member 19 for hermetically sealing the outer cylinder 12 and the manifold 17 is provided between the outer-cylinder-side flange 12f and the manifold-side flange 17f.

[0016] In addition, the manifold 17 has an annular support portion 20 on the inner wall of the upper part. The support portion 20 protrudes radially inward and fixes and supports the lower end of the inner cylinder 11. A lid body 21 is detachably attached to the lower end opening 17o of the manifold 17.

[0017] The lid body 21 is part of a substrate arrangement unit 22 that arranges a substrate holder 70 for holding each substrate W inside the processing container 10. The lid body 21 is formed of, for example, stainless steel and has a disc shape. The lid body 21 hermetically closes the lower end opening 17o of the manifold 17 through a seal member 18 provided at the lower end of the manifold 17 with each substrate W arranged in the internal space IS.

[0018] At the center of the lid 21, a rotary shaft 24a that rotatably supports the substrate holder 70 via a magnetic fluid seal portion 23 penetrates therethrough. The rotary shaft 24a is rotated about its axis by a rotation mechanism 24 supported by an arm 25A of a boat elevator 25 constituted by a boat elevator or the like. Further, the boat elevator 25 can move up and down integrally with the lid 21 and the substrate holder 70 by raising and lowering the arm 25A, and insert and remove the substrate holder 70 into and from the processing container 10.

[0019] At the upper end of the rotary shaft 24a, a rotary plate 26 that rotates by the rotation mechanism 24 is provided. The substrate holder 70 that holds each substrate W is fixed and supported on this rotary plate 26. The substrate holder 70 is a wafer boat having a shelf structure capable of holding disk-shaped substrates W at regular intervals along the vertical direction. In the state where each substrate W is held by the substrate holder 70, the surfaces of the substrates W extend horizontally with respect to each other. The configuration of this substrate holder 70 will be described in detail later.

[0020] The gas supply unit 30 is inserted into the processing container 10 via the manifold 17. The gas supply unit 30 introduces gases such as a processing gas, a purge gas, and a cleaning gas into the processing space IS1 of the inner cylinder 11. The gas supply unit 30 has a gas nozzle 31 for introducing a processing gas, a purge gas, a cleaning gas, etc. Although only one gas nozzle 31 is shown in FIG. 1, the gas supply unit 30 may include a plurality of gas nozzles 31. For example, the plurality of gas nozzles 31 may be provided for each type of processing gas, purge gas, cleaning gas, etc. Alternatively, the plurality of gas nozzles 31 may be provided such that the height positions of the gas holes 31h are different from each other, and the height position and discharge amount of the gas discharged can be adjusted individually.

[0021] The gas nozzle 31 is a quartz injector tube that extends vertically through the inner cylinder 11 and is bent in an L-shape at its lower end to penetrate the inside and outside of the manifold 17. The gas nozzle 31 is fixed and supported by the manifold 17. The gas nozzle 31 has multiple gas holes 31h at regular intervals along the vertical direction, and discharges gas horizontally through each gas hole 31h. The spacing between each gas hole 31h is set to be the same as, for example, the spacing between each substrate W supported by the substrate holder 70. In addition, the vertical position of each gas hole 31h is set to be located midway between adjacent substrates W in the vertical direction. This allows each gas hole 31h to smoothly circulate gas through the gaps between each substrate W.

[0022] The gas supply unit 30 supplies processing gas, purging gas, cleaning gas, etc., to the gas nozzle 31 inside the processing container 10 while controlling the flow rate outside the processing container 10. The processing gas should be selected appropriately depending on the type of film to be deposited on the substrate W. For example, when forming a silicon oxide film, the processing gas can be, for example, a silicon-containing gas such as dichlorosilane (DCS) gas, which is the raw material gas, and an oxidizing gas such as ozone (O3) gas, which is the reaction gas. For the purging gas, for example, nitrogen (N2) gas or argon (Ar) gas can be used.

[0023] The gas exhaust unit 40 exhausts the gas inside the processing container 10 to the outside. The gas supplied by the gas supply unit 30 moves from the processing space IS1 of the inner cylinder 11 to the flow space IS2, and then is exhausted through the gas outlet 41. The gas outlet 41 is formed above the support unit 20 in the manifold 17. The exhaust passage 42 of the gas exhaust unit 40 is connected to the gas outlet 41. The gas exhaust unit 40 is equipped with a pressure regulating valve 43 and a vacuum pump 44 in order from upstream to downstream of the exhaust passage 42. The gas exhaust unit 40 adjusts the pressure inside the processing container 10 by sucking the gas inside the processing container 10 with the vacuum pump 44 and adjusting the flow rate of the exhausted gas with the pressure regulating valve 43.

[0024] Furthermore, a temperature sensor 80 for detecting the temperature inside the processing container 10 is provided in the internal space IS (for example, the processing space IS1 of the inner cylinder 11). The temperature sensor 80 has a plurality (five in this embodiment) of thermometers 81 to 85 at different positions in the vertical direction. Thermocouples, resistance thermometers, etc., can be used for the plurality of thermometers 81 to 85. Each thermometer 81 to 85 is provided at a position corresponding to one of the plurality of zones described below, which are set along the vertical direction of the processing container 10. The temperature sensor 80 transmits the temperature detected by each of the plurality of thermometers 81 to 85 to the control unit 90.

[0025] On the other hand, the temperature control furnace 50 is formed in a cylindrical shape that covers the entire processing container 10 and heats and cools each substrate W housed in the processing container 10. Specifically, the temperature control furnace 50 has a cylindrical housing 51 with a ceiling and a heater 52 provided inside the housing 51.

[0026] The housing 51 is formed to be larger than the processing container 10, and its central axis is positioned approximately at the same location as the central axis of the processing container 10. For example, the housing 51 is attached to the upper surface of the base plate 54 to which the outer cylinder side flange 12f is fixed. The housing 51 is installed with a gap between it and the outer circumferential surface of the processing container 10, thereby forming a temperature-controlled space 53 between the outer circumferential surface of the processing container 10 and the inner circumferential surface of the housing 51. The temperature-controlled space 53 is provided to be continuous with the sides and top of the processing container 10.

[0027] The housing 51 includes an insulating section 51a with a ceiling that covers the entire processing container 10, and a reinforcing section 51b that reinforces the insulating section 51a on its outer periphery. That is, the side walls of the housing 51 have a laminated structure of the insulating section 51a and the reinforcing section 51b. The insulating section 51a is formed mainly from silica, alumina, etc., and suppresses heat transfer within the insulating section 51a. The reinforcing section 51b is formed from a metal such as stainless steel. In addition, in order to suppress the heat influence of the temperature control furnace 50 to the outside, the outer periphery of the reinforcing section 51b is covered with a water-cooling jacket (not shown).

[0028] The heater 52 of the temperature-controlled furnace 50 may be configured to heat multiple substrates W inside the processing container 10. For example, an infrared heater that emits infrared rays to heat the processing container 10 can be used as the heater 52.

[0029] The heater 52 is divided into multiple sections (five in this embodiment) along the vertical direction of the temperature-controlled furnace 50, and a temperature control driver 55 is connected to each section. The temperature control driver 55 is connected to the control unit 90, and based on the control of the control unit 90, it supplies power adjusted to the connected heater 52 to heat the heater 52. As a result, the vertical heat treatment apparatus 1 can independently adjust the temperature of the processing vessel 10 for each of the multiple zones where the divided heaters 52 are provided.

[0030] Furthermore, the temperature-controlled furnace 50 is equipped with an external circulation section 60 for circulating a cooling gas (air, inert gas) into the temperature-controlled space 53 in order to cool the processing container 10 during the film formation process. Specifically, the external circulation section 60 includes an external supply path 61 and a flow rate regulator 62 provided outside the temperature-controlled furnace 50, a supply path 63 provided in the reinforcement section 51b, and a supply hole 64 provided in the heat-insulating section 51a. In addition, the external supply path 61 may be equipped with a temperature control section (heat exchanger, radiator, etc.) to adjust the temperature of the air flowing into the temperature-controlled space 53.

[0031] Furthermore, the external circulation unit 60 is provided with an exhaust port 65 on the ceiling of the housing 51 for discharging the air supplied into the temperature-controlled space 53. The exhaust port 65 is connected to an external exhaust path 66 provided outside the housing 51. The external exhaust path 66 exhausts the air from the temperature-controlled space 53 towards an appropriate waste disposal area. Alternatively, the external circulation unit 60 may be configured to circulate the air used in the temperature-controlled space 53 by connecting the external exhaust path 66 to an external supply path 61.

[0032] The control unit 90 of the vertical heat treatment apparatus 1 can be a computer having a processor 91, memory 92, input / output interfaces (not shown), communication interfaces, etc. The processor 91 is a combination of one or more of the following: CPU (Central Processing Unit), GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), circuits consisting of multiple discrete semiconductors, etc. The memory 92 includes a main memory device consisting of semiconductor memory, etc., and an auxiliary memory device consisting of disks or semiconductor memory (flash memory), etc. The memory 92 may be configured by appropriately combining volatile memory and non-volatile memory (e.g., compact discs, DVDs (Digital Versatile Discs), hard disks, flash memory, etc.).

[0033] Memory 92 stores a program for operating the vertical heat treatment apparatus 1 and a recipe for process conditions such as those for the film deposition process (substrate processing). The processor 91 controls each component of the vertical heat treatment apparatus 1 by reading and executing the program from memory 92. In other words, the control unit 90 is an electronic circuit having a CPU, GPU, ASIC, FPGA, etc., and performs the various control operations described in this specification by executing instruction codes stored in memory 92 or by designing the circuit for special applications. The control unit 90 may be composed of a host computer or multiple client computers that communicate information via a network.

[0034] Furthermore, a user interface 95 is connected to the control unit 90 via an input / output interface. The user interface 95 can include a touch panel (input / output device), monitor, speaker, keyboard, mouse, microphone, etc. The control unit 90 receives a recipe for the vertical heat treatment apparatus 1 entered by the user via the user interface 95 and controls each component of the vertical heat treatment apparatus 1 based on this recipe. In addition, when the control unit 90 receives information from each component during the film deposition process, it appropriately notifies the user interface 95 of the film deposition process information (status, errors, etc.).

[0035] The vertical heat treatment apparatus 1 described above houses multiple substrates W in the vertical direction within the processing container 10 and performs a film deposition process (substrate processing including heat treatment) by supplying processing gas from the gas supply unit 30, exhausting the gas from the gas exhaust unit 40, and heating from the temperature control furnace 50. As a result, an appropriate film based on the processing gas is deposited on each substrate W.

[0036] In this process, the vertical heat treatment apparatus 1 individually controls each heater 52 in each zone of the temperature control furnace 50 based on a pre-set recipe or thermal model, thereby aiming to equalize the in-plane temperature distribution within each substrate W, as well as the inter-plane temperature distribution between each substrate W. As a result, the uniformity of the film thickness deposited on each substrate W is increased within each substrate W, and the uniformity between each substrate W is also increased. For example, in the film deposition process, the vertical heat treatment apparatus 1 sets the temperature of the lower vertical zone, which is prone to temperature drops, higher than the temperature of the upper vertical zone. Furthermore, the vertical heat treatment apparatus 1 adjusts the temperature of each zone according to the thermal model over time during the film deposition process, thereby equalizing the in-plane and inter-plane temperature distributions of each substrate W.

[0037] Here, the temperature control recipe and thermal model are basically created assuming that the maximum number of substrates W are accommodated in the processing container 10. On the other hand, as previously mentioned, the vertical heat treatment apparatus 1 may perform film deposition with fewer substrates W than the maximum number accommodated in the processing container 10. For example, when performing film deposition on a small number of substrates W, the amount of heat in each zone of the temperature control furnace 50 will change. Alternatively, it is conceivable to hold multiple dummy substrates in the substrate holder 70 in addition to the substrates W to be processed. However, in this case, disadvantages such as the use of extra heat and waste due to the dummy substrates arise.

[0038] Therefore, the vertical heat treatment apparatus 1 according to this embodiment is equipped with a bottom heater 75 on the substrate holder 70, and is configured to raise and lower the bottom heater 75 vertically according to the number of substrates W to be housed in the substrate holder 70. When a small number of substrates W are housed in the substrate holder 70 for substrate processing, the substrates W are housed sequentially from the upper vertical side, leaving the lower vertical area empty (unhoused). The vertical heat treatment apparatus 1 maintains a constant distance of the bottom heater 75 to the substrate W located at the bottom of the substrate holder 70, thereby ensuring uniformity of the in-plane temperature distribution or inter-plane temperature distribution of each substrate W during the film deposition process.

[0039] Next, the specific configuration of the substrate holder 70 according to the embodiment will be described with reference to Figure 2. Figure 2(A) is a longitudinal cross-sectional view showing the substrate holder 70 in a state without substrates W. Figure 2(B) is a longitudinal cross-sectional view showing the substrate holder 70 in a state with a small number of substrates W.

[0040] As shown in Figure 2(A), the substrate holder 70 extends vertically to support multiple substrates W (for example, 50 to 250). The substrate holder 70 includes a bottom frame 71 provided on the lower vertical side, a plurality of shelf frames 72 extending upward from the bottom frame 71 to directly hold each substrate W, and a ceiling frame 73 bridging the upper parts of each shelf frame 72.

[0041] The bottom frame 71 is formed in a cylindrical shape with an internal space on the inside, and supports a plurality of shelf frames 72 at its outer edge. The bottom frame 71 also houses a bottom heater 75 capable of heating the substrate W, and a lifting mechanism 76 for raising and lowering the bottom heater 75 within its internal space. For example, the bottom frame 71 has an opening at its lowest end, and the lifting mechanism 76 is fixed to a closing member 74 that closes this opening.

[0042] Multiple shelf frames 72 extend vertically upward from the bottom frame 71 to hold each substrate W along the vertical direction. Multiple protrusions 721 are provided on the inner wall side of each shelf frame 72 to individually hold multiple substrates W. Due to the multiple protrusions 721, the inner wall of each shelf frame 72 has a shape with repeated protrusions and indentations in the vertical direction. Each protrusion 721 supports the outer edge side of the lower surface of the substrate W. The spacing between each protrusion 721 along the vertical direction is set to be the same. As a result, the substrate holder 70 can hold each substrate W at a constant interval.

[0043] Although Figures 2(A) and 2(B) show two shelf frames 72 (as a pair), the substrate holder 70 may be configured to hold each substrate W using, for example, three shelf frames 72 extending vertically. For example, the three shelf frames 72 are installed at 90° intervals around the bottom frame 71, allowing each substrate W to be loaded and unloaded through the open areas where the shelf frames 72 are not installed. Each shelf frame 72 has the same height for all of its protrusions 721, enabling it to hold the inserted substrate W horizontally.

[0044] Furthermore, the ceiling frame 73 constitutes the uppermost stage of the substrate holder 70 and works in cooperation with the bottom frame 71 to maintain the extended position of each shelf frame 72. The ceiling frame 73 may be a rod-shaped frame connecting the upper ends of each shelf frame 72, or it may be a disc-shaped frame slightly larger than the substrate W.

[0045] The bottom heater 75 is capable of heating each substrate W located vertically above its position. The bottom heater 75 is disc-shaped and has a diameter that creates a clearance that prevents it from contacting the inside of the bottom frame 71 and each shelf frame 72. As a result, the bottom heater 75 can be raised and lowered vertically by the lifting mechanism 76 without contacting each shelf frame 72. Furthermore, the disc-shaped bottom heater 75 can suppress the flow of processing gas vertically downward in the processing space IS1.

[0046] The bottom heater 75 has a heating element, such as a sheet heater or electric heating wire, on its top surface or inside. The bottom heater 75 is equipped with a pair of electrode members 751 on its bottom surface that can supply power to the heating element. Each electrode member 751 protrudes a short distance vertically downward from the bottom heater 75 and is fixed to a connecting member 752 that connects the bottom heater 75 and the lifting mechanism 76. A harness 753 capable of supplying power to the bottom heater 75 is connected to each electrode member 751. Each harness 753 is wired inside the substrate holder 70 with a length corresponding to the upper limit position of the bottom heater 75 which is raised and lowered by the lifting mechanism 76. In addition, each harness 753 is connected to external wiring via a slip ring provided on the closing member 74 and is connected to an external temperature module (not shown). The temperature module adjusts the temperature of the bottom heater 75 to a target temperature by adjusting the power supplied to the bottom heater 75 under the control of the control unit 90.

[0047] Furthermore, the upper end of the cylindrical body 762 of the lifting mechanism 76 is connected to the center of the connecting member 752. In addition, a bellows 77 is provided on the outer circumference of the lower surface of the connecting member 752 so as to surround the lifting mechanism 76.

[0048] The bellows 77 allows the bottom heater 75 to move vertically up and down while preventing the lifting mechanism 76 from being exposed to the processing gas inside the processing container 10. Examples of materials for the bellows 77 include stainless steel (SUS316L) and Inconel. This provides the bellows 77 with temperature resistance, chemical resistance, and increased resistance to repeated expansion and contraction. Furthermore, the outer surface of the bellows 77 exposed to the processing space IS1 may be coated with a CleanS® or similar material to reduce the effects of film deposition.

[0049] Figure 3(A) is a schematic side view showing the lifting mechanism 76 in the raised position. Figure 3(B) is a schematic top view showing the lifting mechanism 76. Figure 3(C) is a schematic side view showing the lifting mechanism 76 in the lowered position. As shown in Figures 2(A) to 3(C), the lifting mechanism 76 according to this embodiment is configured as a telescopic type that can extend and retract in the vertical direction, and raises and lowers the bottom heater 75 at the upper end.

[0050] Specifically, the lifting mechanism 76 includes a motor 761 which is a drive source, a plurality of cylindrical bodies 762 provided on the upper part of the motor 761, and a plurality of drive transmission units 763 which transmit the rotational driving force of the motor 761 to each cylindrical body 762.

[0051] The motor 761 is fixed to, for example, the closing member 74 (see Figure 2) and installed outside the bottom frame 71. This motor 761 is connected to the control unit 90 via a drive driver (not shown) and rotates based on the control of the control unit 90. The motor 761 can be a stepping motor or servo motor that can switch between forward and reverse rotation. The motor 761 may also be equipped with an encoder capable of detecting the rotation speed and rotation angle of the rotation shaft. The control unit 90 can calculate the current height position of the bottom heater 75 based on the detection result of the encoder. Alternatively, the height position of the bottom heater 75 can be determined by measuring it, for example, by installing a laser displacement meter on the closing member 74.

[0052] Multiple cylindrical bodies 762 are rectangular tubes with a square shape in plan view. Furthermore, the lifting mechanism 76 according to this embodiment has five cylindrical bodies 762 (first cylindrical body 762a, second cylindrical body 762b, third cylindrical body 762c, fourth cylindrical body 762d, and fifth cylindrical body 762e) arranged coaxially. The first cylindrical body 762a is formed to be the widest and is capable of housing the other cylindrical bodies 762 inside. The lowest end of this first cylindrical body 762a is connected to, for example, a closing member 74. As a result, the first cylindrical body 762a is a fixed cylinder that does not move among the multiple cylindrical bodies 762.

[0053] The second cylinder 762b is formed as a rectangular tube that is slightly smaller than the first cylinder 762a, and moves up and down inside the first cylinder 762a relative to the first cylinder 762a. Similarly, the third cylinder 762c is formed as a rectangular tube that is slightly smaller than the second cylinder 762b, and moves up and down inside the second cylinder 762b relative to the second cylinder 762b. The fourth cylinder 762d is formed as a rectangular tube that is slightly smaller than the third cylinder 762c, and moves up and down inside the third cylinder 762c relative to the third cylinder 762c. The fifth cylinder 762e is formed as a rectangular tube that is slightly smaller than the fourth cylinder 762d, and moves up and down inside the fourth cylinder 762d relative to the fourth cylinder 762d.

[0054] Furthermore, a connecting member 752 is installed at the upper end of the fifth cylindrical body 762e (see also Figure 2(a)). The connecting member 752 is connected to the bottom heater 75 via the electrode member 751 as described above. Therefore, the lifting mechanism 76 supports the bottom heater 75 with the fifth cylindrical body 762e and can displace the bottom heater 75 based on the lifting and lowering of each cylindrical body 762.

[0055] Multiple drive transmission units 763 transmit the rotational driving force of the motor 761 to raise and lower each of the individual cylinders (second cylinder 762b, third cylinder 762c, fourth cylinder 762d, and fifth cylinder 762e). Specifically, the multiple drive transmission units 763 include a first drive transmission unit 763A that moves the second cylinder 762b relative to the first cylinder 762a, a second drive transmission unit 763B that moves the third cylinder 762c relative to the second cylinder 762b, a third drive transmission unit 763C that moves the fourth cylinder 762d relative to the third cylinder 762c, and a fourth drive transmission unit 763D that moves the fifth cylinder 762e relative to the fourth cylinder 762d.

[0056] Figure 4 is an enlarged side view showing the specific configuration of the drive transmission unit 763. In the following description, the configuration of the drive transmission unit 763 will be explained using the first drive transmission unit 763A and the second drive transmission unit 763B as examples, and detailed explanations of the third drive transmission unit 763C and the fourth drive transmission unit 763D, which are configured similarly, will be omitted.

[0057] Each of the drive transmission units 763 (first drive transmission unit 763A to fourth drive transmission unit 763D) employs a ball screw mechanism. Specifically, each drive transmission unit 763 comprises a screw shaft 764 extending in the vertical direction, a movable body 765 attached to the screw shaft 764, and a rotation transmission unit 766 provided on the movable body 765.

[0058] The screw shaft 764a of the first drive transmission unit 763A is connected to the rotating shaft of the motor 761 and extends vertically upward from the motor 761. A groove is formed on the outer circumferential surface of the screw shaft 764a, on which multiple balls 765a1 of the movable body 765 can roll. As the motor 761 rotates, the screw shaft 764a rotates around its axis, thereby raising and lowering the attached movable body 765. For example, rotating the screw shaft 764a clockwise raises the movable body 765, while rotating it counterclockwise lowers the movable body 765.

[0059] The movable body 765 of the first drive transmission unit 763A has a conversion unit 765a that is mounted on the screw shaft 764a and converts the rotational driving force of the screw shaft 764a into linear motion, and a protruding part 765b that is attached to the end (lower end) of the conversion unit 765a and protrudes horizontally.

[0060] The conversion section 765a has a through hole through which the screw shaft 764a is positioned. The inner circumferential surface of this through hole is provided with a plurality of balls 765a1 that are inserted into the groove of the screw shaft 764a and roll around. The conversion section 765a is displaced vertically in accordance with the rolling of each ball 765a1 due to the rotation of the screw shaft 764a around its axis.

[0061] The protruding portion 765b is connected to the conversion portion 765a and therefore displaces integrally with the conversion portion 765a. The protruding portion 765b of the first drive transmission portion 763A protrudes from the conversion portion 765a in a first direction. The portion of this protruding portion 765b that protrudes a predetermined distance from the conversion portion 765a supports the screw shaft 764b of the second drive transmission portion 763B. For example, a bearing 765b1 that rotatably supports the screw shaft 764b is provided on the upper part of the protruding portion 765b.

[0062] Furthermore, the first drive transmission unit 763A has a rotation transmission unit 766 connected to the end (upper end) of the conversion unit 765a, which transmits the rotational driving force of the screw shaft 764a of the first drive transmission unit 763A to the screw shaft 764b of the second drive transmission unit 763B. The rotation transmission unit 766 includes a connecting unit 766a connected to the conversion unit 765a, and a drive-side pulley unit 766b rotatably supported on the connecting unit 766a.

[0063] The drive-side pulley portion 766b has a through hole in its center through which the screw shaft 764a is inserted. Multiple balls 766b1 are provided on the inner circumferential surface of this through hole, which are inserted into the groove of the screw shaft 764a. A belt 767 is wrapped around the outer circumferential surface of the drive-side pulley portion 766b. The drive-side pulley portion 766b receives the rotational driving force of the screw shaft 764a via the multiple balls, causing the drive-side pulley portion 766b itself to rotate along with the screw shaft 764a. The belt 767 transmits this rotational driving force of the drive-side pulley portion 766b to the adjacent second drive transmission portion 763B.

[0064] On the other hand, the second drive transmission unit 763B, like the first drive transmission unit 763A, includes a screw shaft 764b, a movable body 765, and a rotation transmission unit 766. As described above, the screw shaft 764b is rotatably supported in the bearing 765b1 of the protruding portion 765b of the first drive transmission unit 763A and extends vertically upward.

[0065] Furthermore, the second drive transmission unit 763B includes a driven pulley unit 768 fixed to the outer circumferential surface of the screw shaft 764b, around which the belt 767 is wound. That is, the belt 767 endlessly circulates between the drive pulley unit 766b and the driven pulley unit 768. The driven pulley unit 768 rotates the screw shaft 764b as a whole when the rotational driving force of the belt 767 is transmitted to it. As a result, the screw shaft 764b can rotate around an axis in the same direction as the screw shaft 764a.

[0066] The movable body 765 of the second drive transmission unit 763B includes a conversion unit 765a and a protruding portion 765b, similar to the first drive transmission unit 763A. The protruding portion 765b of the second drive transmission unit 763B protrudes in a second direction perpendicular to the protruding direction (first direction) of the protruding portion 765b of the first drive transmission unit 763A.

[0067] Furthermore, as shown in Figure 3(B), the protrusion 765b of the third drive transmission unit 763C protrudes in a third direction perpendicular to the second direction of the protrusion 765b of the second drive transmission unit 763B. In addition, the protrusion 765b of the fourth drive transmission unit 763D protrudes in a fourth direction perpendicular to the fourth direction of the protrusion 765b of the third drive transmission unit 763C. As a result, each drive transmission unit 763 is arranged to circulate inside a rectangular cylindrical body 762 in plan view. The movable body 765 of each drive transmission unit 763 supports the lower end of the corresponding cylindrical body 762, thereby allowing the supported cylindrical body 762 to be raised and lowered.

[0068] Specifically, the first drive transmission unit 763A supports the second cylindrical body 762b with the movable body 765, allowing the second cylindrical body 762b to be raised and lowered in conjunction with the movable body 765. The second drive transmission unit 763B supports the third cylindrical body 762c with the movable body 765, allowing the third cylindrical body 762c to be raised and lowered in conjunction with the movable body 765. The third drive transmission unit 763C supports the fourth cylindrical body 762d with the movable body 765, allowing the fourth cylindrical body 762d to be raised and lowered in conjunction with the movable body 765. The fourth drive transmission unit 763D supports the fifth cylindrical body 762e with the movable body 765, allowing the fifth cylindrical body 762e to be raised and lowered in conjunction with the movable body 765.

[0069] As a result, the lifting mechanism 76 can be displaced to any height position and maintain that position within a range from the shortest configuration shown in Figure 3(C) to the most extended configuration shown in Figure 3(A). Consequently, the lifting mechanism 76 can adjust the height position of the bottom heater 75 installed at the upper end of the fifth cylindrical body 762e.

[0070] By adopting the above configuration, the lifting mechanism 76 can achieve a long lifting stroke while reducing its footprint. Furthermore, the lifting mechanism 76 can precisely position the height of the bottom heater 75 through motor control by the control unit 90. For example, the lifting mechanism 76 employing the ball screw mechanism described above can control the height of the bottom heater 75 with an error of less than 0.5 mm.

[0071] The vertical heat treatment apparatus 1 according to this embodiment is basically configured as described above, and its operation (heat treatment method) will be specifically explained below with reference to Figure 5. Figure 5 is a flowchart of the heat treatment method according to this embodiment.

[0072] The vertical heat treatment apparatus 1 performs a heat treatment method when depositing film (substrate processing) on ​​multiple substrates W. In the heat treatment method, the control unit 90 controls each component of the vertical heat treatment apparatus 1 and sequentially executes the processing flow of steps S101 to S106 shown in Figure 5.

[0073] Specifically, the vertical heat treatment apparatus 1 first accommodates multiple substrates W in a substrate holder 70 waiting below the processing container 10 (step S101). At this time, the control unit 90 transports the multiple substrates W using a transport device (not shown) and accommodates the multiple substrates W from the upper end of the substrate holder 70 downwards in the vertical direction. The control unit 90 also counts the number of substrates W to be accommodated in the substrate holder 70 when the substrates W are transported by the transport device.

[0074] Therefore, once the transport device has finished transporting the substrates W, the control unit 90 can recognize the number of substrates W housed in the substrate holder 70 (step S102). This allows the control unit 90 to properly set the height position (target position) of the bottom heater 75.

[0075] Subsequently, the vertical heat treatment apparatus 1 raises the substrate holder 70 using the boat elevator 25, thereby bringing the substrate holder 70 into the processing container 10 (step S103). The lower end of the manifold 17 supporting the processing container 10 is closed by the lid 21 as the substrate holder 70 is brought in.

[0076] Then, the control unit 90 controls the lifting mechanism 76 of the substrate holder 70 to raise the bottom heater 75 and positions the bottom heater 75 at a target position corresponding to the number of substrates W in the recognized substrate holder 70 (step S104). This allows the vertical heat treatment apparatus 1 to maintain a constant distance between the bottommost substrate W of the substrate holder 70 and the bottom heater 75, even if the number of substrates W differs between substrate processing operations.

[0077] Subsequently, the control unit 90 controls the temperature modules of each temperature control driver 55 and bottom heater 75 of the temperature control furnace 50 to adjust the temperature of each substrate W in the processing container 10 (step S105). Each heater 52 of the temperature control furnace 50 and the bottom heater 75 are heated to the target temperature, allowing each substrate W in the processing container 10 to be heated. The control unit 90 also rotates the substrate W using the rotation mechanism 24 during heating and subsequent substrate processing.

[0078] When the temperature of the substrate W reaches the target temperature, the control unit 90 controls the gas supply unit 30 and the gas exhaust unit 40 to supply processing gas into the processing container 10 and exhaust the gas from the processing container 10, thereby performing substrate processing (step S106).

[0079] Figure 6(A) shows the heating of each heater 52 and the bottom heater 75 of the temperature-controlled furnace 50 with substrates W contained throughout the substrate holder 70. Figure 6(B) shows the heating of each heater 52 and the bottom heater 75 of the temperature-controlled furnace 50 with a small number of substrates W contained in the substrate holder 70. In Figures 6(A) and 6(B), cross-hatching of the heater 52 indicates a high temperature state, single-hatching of the heater 52 indicates a low temperature state, and white outlines of the heater 52 indicate a stopped state.

[0080] As shown in Figures 6(A) and 6(B), the vertical heat treatment apparatus 1 can control the operation of each heater 52 and the bottom heater 75 of the temperature control furnace 50 according to the number of substrates W housed in the substrate holder 70. Specifically, even if the number of substrates W housed in the substrate holder 70 differs, the vertical heat treatment apparatus 1 basically positions the bottom heater 75 at the same distance from the lowest substrate W.

[0081] Furthermore, by positioning the bottom heater 75 at a height corresponding to the number of substrates W, the heating amount of each heater 52 in the temperature-controlled furnace 50 can be reduced or its operation stopped. For example, the example in Figure 6 shows an example in which heating is performed by all the heaters 52 and the bottom heater 75 of the temperature-controlled furnace 50. However, taking into account the heating of the bottom heater 75, the temperature of the heater 52 closer to the bottom heater 75 is lowered compared to the other heaters 52. On the other hand, the example in Figure 6(B) shows an example in which the temperature of each substrate W is adjusted by reducing the temperature of the heaters 52 in the zone adjacent to the raised bottom heater 75, while stopping the operation of the heaters 52 below this zone. In addition, the temperature of the heaters 52 adjacent to the bottom heater 75 is reduced. In this way, the vertical heat treatment apparatus 1 can adjust the driving state of each heater 52 and the bottom heater 75 of the temperature control furnace 50, thereby achieving uniformity of the in-plane temperature distribution and inter-plane temperature distribution even for a small number of substrates W.

[0082] As an example, the control unit 90 selects an optimized recipe based on the number of substrates W to be processed and executes temperature control for the substrate processing. For example, the vertical heat treatment apparatus 1 has optimized recipes for 200, 175, 150, 125, 100, 75, and 50 substrates. Each recipe is set with parameters such as the temperature of each heater 52 of the temperature control furnace 50, the temperature of the bottom heater 75, the flow rate of the processing gas, and the pressure inside the processing container 10. The control unit 90 selects an appropriate recipe based on the recognized number of substrates W (or the height position of the bottom heater 75). In addition to the optimized recipes, the control unit 90 may also have a thermal model and a physical model of the processing gas during substrate processing. The thermal model and the physical model of the processing gas may be calculated by conducting experiments or simulations based on the heat, processing gas, pressure inside the processing container 10, and reaction model of the processing gas for each number of substrates W. Furthermore, the optimized recipe, thermal model, and physical model of the processing gas may be calculated by machine learning using experimental film deposition results or actual film deposition results.

[0083] Furthermore, in substrate processing, the control unit 90 may set the temperature change rate and processing period to be the same in order to match the thermal history when the maximum number of substrates W are housed in the substrate holder 70 with the thermal history when a small number of substrates W are housed. In other words, in the substrate processing configuration of Figure 6(A) and each configuration of Figure 6(B), the control unit 90 performs substrate processing with the same temperature change rate and processing period. As a result, the thermal history when the maximum number of substrates W are housed with the thermal history when a small number of substrates W are housed becomes approximately the same, and the in-plane temperature distribution or the inter-plane temperature distribution of each substrate W can be made uniform.

[0084] Furthermore, the vertical heat treatment apparatus 1 may be configured to adjust the supply amount of processing gas for each of the multiple zones by installing multiple gas nozzles 31 at different heights within the processing container 10. For example, when the bottom heater 75 is raised, processing gas is discharged from the gas nozzles 31 higher than the bottom heater 75, while the supply of processing gas from the gas nozzles 31 lower than the bottom heater 75 is stopped. This reduces the consumption of processing gas.

[0085] The vertical heat treatment apparatus 1 described above reduces the energy consumption of each heater 52 by raising and lowering the bottom heater 75 according to the number of substrates W when processing a small number of substrates W. Moreover, the bottom heater 75 can effectively adjust the temperature of each substrate W on the bottom side, where the temperature tends to be lower. Furthermore, the vertical heat treatment apparatus 1 prevents heat from escaping from the processing area of ​​the substrate W to the bottom by using the bottom heater 75, which is close to the substrate W of the substrate holder 70. In addition, the vertical heat treatment apparatus 1 makes it possible to allocate the area that previously housed dummy substrates to substrates W that can be processed, dramatically reducing the amount of dummy substrates. For example, if dummy substrates were housed in 1 / 4 of the substrate holder 70, the productivity of substrate processing can be improved by 25%.

[0086] The vertical heat treatment apparatus 1 according to this disclosure is not limited to the above configuration and can take various modifications. For example, in the above embodiment, the vertical heat treatment apparatus 1 adjusts the height position of the bottom heater 75 so that the distance between the substrate W at the lowest end of the substrate holder 70 and the bottom heater 75 is the same. However, the vertical heat treatment apparatus 1 may change the distance between the substrate W at the lowest end of the substrate holder 70 and the bottom heater 75 based on the content (recipe) of the substrate processing and the number of substrates W.

[0087] Furthermore, in the above embodiment, since the substrate holder 70 is placed on the rotating plate 26, the vertical heat treatment apparatus 1 can rotate the entire substrate holder 70, including the bottom heater 75, by the rotating mechanism 24 during substrate processing. However, the vertical heat treatment apparatus 1 may also be configured such that each shelf frame 72 (each substrate W) of the substrate holder 70 is rotated by the rotating mechanism 24, while the bottom heater 75 and bellows 77 fixed to the closing member 74 are fixed (not rotated). This eliminates the need to apply slip rings or the like to connectors such as harnesses 753, simplifies wiring, and promotes uniformity of the in-plane temperature of each substrate W on the bottom side.

[0088] Furthermore, for example, the vertical heat treatment apparatus 1 may be connected to a cooling mechanism for cooling the lifting mechanism 76 and other components inside the bellows 77. As an example, the vertical heat treatment apparatus 1 actively circulates an inert gas, such as nitrogen gas, inside the bellows 77 by supplying and discharging it from a cooling mechanism connected to the occlusion member 74. This allows the lifting mechanism 76 to be cooled by smoothly discharging the gas heated during substrate processing from inside the bellows 77. In this case, the cooling mechanism may also draw inert gas from a gas nozzle 31 supplied by a pump or fan. Alternatively, the cooling mechanism may be configured to supply air instead of inert gas.

[0089] In addition, the substrate holder 70 may also be configured such that, for example, a Peltier element is installed on the bellows 77, and power is generated by utilizing the temperature difference between the inside of the bellows 77 and the processing space IS1, while actively dissipating heat by applying a heat sink or the like to the processing space IS1 side.

[0090] Figure 7(A) is a plan view showing a lifting mechanism 76A according to a first modified example. Figure 7(B) is a plan view showing a lifting mechanism 76B according to a second modified example. The lifting mechanism 76A according to the first modified example shown in Figure 7(A) comprises a plurality (six) of cylindrical bodies 762, which are pentagonal rectangular tubes in plan view. The lifting mechanism 76A also comprises five drive transmission units 763 that raise and lower each cylindrical body 762 separately. Each drive transmission unit 763 can have the same configuration as the lifting mechanism 76 according to the embodiment. As a result, the lifting mechanism 76A can increase the number of cylindrical bodies 762 that move up and down compared to the lifting mechanism 76 described above, which is formed in a square shape and moves up and down four cylindrical bodies 762, making it possible to extend the stroke of the height position of the bottom heater 75.

[0091] The second modified lifting mechanism 76B shown in Figure 7(B) comprises a plurality (seven) of cylindrical bodies 762, which are hexagonal rectangular tubes in plan view. The lifting mechanism 76B also comprises six drive transmission units 763 that raise and lower each cylindrical body 762 separately. This allows the lifting mechanism 76B to further increase the number of cylindrical bodies 762 that can be raised and lowered, thereby extending the height stroke of the bottom heater 75. In other words, the number and shape of the cylindrical bodies 762 of the lifting mechanism 76 may be appropriately designed according to the range in which the bottom heater 75 is raised and lowered.

[0092] Figure 8 is a side view showing a substrate holder 70 having a lifting mechanism 78 according to a third modified example. In the third modified example, a cylinder mechanism is used instead of the ball screw mechanism described above as the lifting mechanism 78 for raising and lowering the bottom heater 75. For example, the lifting mechanism 78 is installed on the closing member 74 and is in a waiting position at the upper end of the fixed cylinder due to the weight of the bottom heater 75. When processing a small number of substrates W, the lifting mechanism 78 levitates the bottom heater 75 from the waiting position based on the control of the control unit 90.

[0093] Furthermore, the lifting mechanism 78 can be equipped with limit switches at the extension and retraction positions during lifting and lowering, making it possible to recognize when the bottom heater 75 has reached its target position. In this way, even when a cylinder mechanism is used in the lifting mechanism 78, the bottom heater 75 can be raised and lowered to a desired height position. In short, the lifting mechanisms 76 and 78 are not particularly limited, and various structures capable of appropriately raising and lowering the bottom heater 75 can be employed.

[0094] <Note> The technical concept and effects of this disclosure, as described in the embodiments above, are described below.

[0095] A vertical heat treatment apparatus 1 according to a first aspect of the present disclosure comprises a processing container 10 capable of accommodating a plurality of substrates W arranged vertically, a substrate holder 70 capable of holding a plurality of substrates W arranged vertically inside the processing container 10, a bottom heater 75 disposed inside the substrate holder 70 and capable of heating the plurality of substrates W held by the substrate holder 70 from the vertically lower side, and lifting mechanisms 76, 78 that can raise and lower the bottom heater 75 relative to the substrate holder 70.

[0096] As described above, the vertical heat treatment apparatus 1 is equipped with a bottom heater 75 that can be raised and lowered within the substrate holder 70, thereby enabling appropriate temperature control according to the number of substrates W. Specifically, the vertical heat treatment apparatus 1 can position the bottom heater 75 using the lifting mechanisms 76 and 78 to match the number of substrates W, thereby suppressing the heat generated by the bottom heater 75 when heating multiple substrates W from moving vertically downwards. As a result, the vertical heat treatment apparatus 1 can stably heat-treat multiple substrates W, thereby improving the quality of substrate processing, such as achieving uniform film thickness on the substrates W.

[0097] Furthermore, the vertical heat treatment apparatus 1 includes a control unit 90 that controls the lifting mechanism 76. The control unit 90 sets the height position of the bottom heater 75 based on the number of substrates W held by the substrate holder 70, and operates the lifting mechanism 76 to position the bottom heater 75 at the set height. As a result, the vertical heat treatment apparatus 1 can automatically position the bottom heater 75 in the appropriate position according to the number of substrates W, enabling more precise temperature control.

[0098] Furthermore, the control unit 90 positions the bottom heater 75 at a location where the distance between the bottommost substrate W and the bottom heater 75 is the same, even if the number of substrates W held in the substrate holder 70 is different. As a result, the vertical heat treatment apparatus 1 can perform stable substrate processing by controlling the temperature of the substrates W on the lower vertical side substantially the same, even if the number of substrates W is different.

[0099] Furthermore, the vertical heat treatment apparatus 1 is equipped with multiple heaters 52 capable of heating the substrates W inside the processing container 10 in each of the multiple zones vertically divided around the processing container 10, and the control unit 90 changes the driving state of the multiple heaters 52 according to the height position of the bottom heater 75. As a result, when the number of substrates W is small, the vertical heat treatment apparatus 1 can suppress the thermal energy of some of the multiple heaters 52, thereby reducing the cost of substrate processing.

[0100] Furthermore, a bellows 77 is provided between the member supporting the lifting mechanisms 76 and 78 (connecting member 752) and the bottom heater 75, which covers the lifting mechanism 76 and is expandable and contractible together with the bottom heater 75. This allows the vertical heat treatment apparatus 1 to protect the lifting mechanisms 76 and 78 from the processing space IS1 within the processing container 10, and to operate the lifting mechanisms 76 and 78 stably.

[0101] Furthermore, the lifting mechanism 76 is a ball screw mechanism that converts the rotational driving force of the motor 761 into linear motion. As a result, even with a configuration in which the lifting mechanism 76 is located inside the substrate holder 70, the vertical heat treatment apparatus 1 can easily raise and lower the bottom heater 75.

[0102] Furthermore, the lifting mechanism 76 comprises a plurality of cylindrical bodies 762 arranged coaxially, and a plurality of drive transmission units 763 that move each of the plurality of cylindrical bodies 762 up and down relative to each other. As a result, the lifting mechanism 76 can extend and retract the plurality of cylindrical bodies 762 in the vertical direction using the plurality of drive transmission units 763.

[0103] Furthermore, each of the multiple drive transmission units 763 includes a screw shaft 764 extending in the vertical direction, a movable body 765 externally mounted on the screw shaft 764 and displaced vertically as the screw shaft 764 rotates around its axis, and a rotational transmission unit 766 capable of transmitting rotational driving force from one screw shaft 764 to another between adjacent drive transmission units 763. As a result, the lifting mechanism 76 can smoothly transmit rotational driving force between the multiple drive transmission units 763.

[0104] Furthermore, the lifting mechanism 78 is a cylinder mechanism. Even in this case, the vertical heat treatment apparatus 1 can easily raise and lower the bottom heater 75.

[0105] Furthermore, a second aspect of the present disclosure is a heat treatment method for a vertical heat treatment apparatus 1 comprising: a processing container 10 capable of accommodating a plurality of substrates W arranged vertically; a substrate holder 70 capable of holding the plurality of substrates W arranged vertically inside the processing container 10; a bottom heater 75 disposed inside the substrate holder 70 and capable of heating the plurality of substrates W held by the substrate holder 70 from the vertically lower side; and lifting mechanisms 76, 78 capable of raising and lowering the bottom heater 75 relative to the substrate holder 70, the method comprising: a step of obtaining the number of plurality of substrates W held by the substrate holder 70; a step of adjusting the height position of the bottom heater 75 using the lifting mechanism 76 based on the obtained number of plurality of substrates W; and a step of heating the bottom heater 75 to a target temperature at the adjusted height position. Even in this case, the heat treatment method can appropriately control the temperature according to the number of substrates.

[0106] The vertical heat treatment apparatus 1 and heat treatment method according to the embodiments disclosed herein are illustrative and not restrictive in all respects. The embodiments can be modified and improved in various ways without departing from the scope and spirit of the appended claims. The matters described in the above embodiments can be otherwise configured and combined in a non-consistent manner. [Explanation of symbols]

[0107] 1. Vertical heat treatment apparatus 10 Processing containers 70 Substrate holder 75 Bottom heater 76, 78 Lifting mechanism W board

Claims

1. A processing container capable of accommodating multiple substrates arranged vertically, A substrate holder capable of holding the plurality of substrates arranged in the vertical direction inside the processing container, A bottom heater is provided, which is positioned inside the substrate holder and capable of heating the plurality of substrates held by the substrate holder from the vertically lower side of the plurality of substrates. The system includes a lifting mechanism that allows the bottom heater to be raised and lowered relative to the substrate holder. Vertical heat treatment apparatus.

2. The system includes a control unit that controls the lifting mechanism, The control unit sets the height position of the bottom heater based on the number of substrates held by the substrate holder, and operates the lifting mechanism to position the bottom heater at the set height position. The vertical heat treatment apparatus according to claim 1.

3. The control unit positions the bottom heater at a position where the distance between the bottommost substrate and the bottom heater is the same, regardless of the number of substrates held in the substrate holder. The vertical heat treatment apparatus according to claim 2.

4. The processing container is provided with a plurality of heaters capable of heating the substrate inside the processing container in each of the plurality of vertically divided zones around the processing container. The control unit changes the driving state of the plurality of heaters according to the height position of the bottom heater. The vertical heat treatment apparatus according to claim 2.

5. Between the member supporting the lifting mechanism and the bottom heater, there is a bellows that covers the lifting mechanism and is expandable and contractible together with the bottom heater. A vertical heat treatment apparatus according to any one of claims 1 to 4.

6. The aforementioned lifting mechanism is a ball screw mechanism that converts the rotational driving force of the motor into linear motion. A vertical heat treatment apparatus according to any one of claims 1 to 4.

7. The lifting mechanism comprises a plurality of cylindrical bodies arranged coaxially, and a plurality of drive transmission units that move each of the plurality of cylindrical bodies up and down relative to each other. The vertical heat treatment apparatus according to claim 6.

8. Each of the aforementioned plurality of drive transmission units comprises a screw shaft extending in the vertical direction, a movable body mounted on the screw shaft and displaced in the vertical direction as the screw shaft rotates around its axis, and a rotation transmission unit capable of transmitting rotational driving force from one screw shaft to another between adjacent drive transmission units. The vertical heat treatment apparatus according to claim 7.

9. The aforementioned lifting mechanism is a cylinder mechanism. A vertical heat treatment apparatus according to any one of claims 1 to 4.

10. A processing container capable of accommodating multiple substrates arranged vertically, A substrate holder capable of holding the plurality of substrates arranged in the vertical direction inside the processing container, A bottom heater is provided, which is positioned inside the substrate holder and capable of heating the plurality of substrates held by the substrate holder from the vertically lower side of the substrates. A heat treatment method for a vertical heat treatment apparatus comprising a lifting mechanism that allows the bottom heater to be raised and lowered relative to the substrate holder, A step of obtaining the number of the plurality of substrates held by the substrate holder, A step of adjusting the height position of the bottom heater using the lifting mechanism based on the number of substrates obtained, The process includes heating the bottom heater to a target temperature at the adjusted height position, Heat treatment method.

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