Control valve structure, substrate processing device, and manufacturing method for semiconductor device

Abstract

Provided is a control valve structure comprising a plurality of valves, wherein: the plurality of valves are provided in an exhaust pipe that exhausts the atmosphere of a processing chamber; each of the plurality of valves is configured such that the flow path cross-sectional area thereof is smaller than the flow path cross-sectional area of the exhaust pipe; and the sum of the flow path cross-sectional areas of the plurality of valves is larger than the flow path cross-sectional area of the exhaust pipe.

Description

Control valve structure, substrate processing apparatus, and method of manufacturing semiconductor device

[0001] The present disclosure relates to a control valve structure, a substrate processing apparatus, and a method of manufacturing a semiconductor device.

[0002] Currently, in a substrate processing apparatus (hereinafter also referred to as a semiconductor manufacturing apparatus) used in a manufacturing process of a semiconductor device, a film may be formed on a substrate as a processing target (for example, see Patent Document 1). At this time, the pressure in the processing chamber during film formation is adjusted by the opening degree of an exhaust main valve. In recent film formation processes, in order to improve the exhaust speed and gas replacement efficiency, an increase in the diameter of the piping in the exhaust system is required.

[0003] International Publication No. 2021-156934

[0004] The present disclosure provides a technique capable of adjusting the pressure in a processing chamber according to the diameter of a pipe in an exhaust system.

[0005] According to one aspect of the present disclosure, there is provided a control valve structure including a plurality of valves, the plurality of valves being provided in an exhaust pipe that discharges the atmosphere in a processing chamber, each flow path cross-sectional area of the plurality of valves being configured to be smaller than the flow path cross-sectional area of the exhaust pipe, and the sum of the flow path cross-sectional areas of the plurality of valves being configured to be larger than the flow path cross-sectional area of the exhaust pipe.

[0006] According to the present disclosure, the pressure in the processing chamber can be adjusted according to the diameter of the pipe in the exhaust system.

[0007] This is a schematic diagram showing the overall configuration of a substrate processing apparatus according to one embodiment of the present disclosure. This is a front view showing an exhaust system according to one embodiment of the present disclosure. This is a block diagram showing an exhaust system according to one embodiment of the present disclosure. This is a diagram showing the state of a control valve structure provided in an exhaust system according to one embodiment of the present disclosure. This is a diagram showing the state of a control valve structure provided in an exhaust system according to one embodiment of the present disclosure. This is a diagram showing the state of a control valve structure provided in an exhaust system according to one embodiment of the present disclosure. This is a diagram showing the configuration of a control valve structure provided in an exhaust system according to one embodiment of the present disclosure. Figure 6(a) is a cross-sectional view of Figure 5(a), Figure 6(b) is a cross-sectional view of Figure 5(b), and Figure 6(c) is a cross-sectional view of Figure 5(c). This is a diagram showing the arrangement of a heating unit and a temperature measuring unit attached to a control valve structure provided in an exhaust system according to one embodiment of the present disclosure. This is a diagram showing an example of the assignment of an opening degree by an opening degree command calculation unit in the operation of a control valve structure provided in an exhaust system according to one embodiment of the present disclosure. This is a diagram showing a modified example 1 of the configuration of a control valve structure provided in an exhaust system according to one embodiment of the present disclosure. This figure shows a modified example 2 of the configuration of a control valve structure provided in an exhaust system according to one embodiment of the present disclosure. This figure shows an example of the assignment of the opening degree by the opening degree command calculation unit in the operation the configuration of a control valve structure provided in an exhaust system according to another embodiment of the present disclosure. This figure shows the configuration of a control valve structure provided in an exhaust system according to another embodiment of the present disclosure.

[0008] An embodiment of this disclosure will be described below with reference to the drawings. Note that the drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings do not necessarily correspond to reality. Furthermore, the dimensional relationships and ratios of the elements do not necessarily correspond between multiple drawings. Also, the upward direction in the drawings will be described as "up" or "upper part," and the downward direction as "down" or "lower part." In this embodiment, all pressures mentioned refer to atmospheric pressure.

[0009] <Overall configuration of the substrate processing apparatus> As shown in Figure 1, the substrate processing apparatus 100 includes a reactor 10 having a processing chamber 20 for processing a wafer 30 as an example of a substrate containing a semiconductor, a spare chamber 22 for storing a boat 26 for holding the substrate 30, a gas introduction line 40 for introducing gas into the processing chamber 20, an exhaust system 50 for discharging the gas from the processing chamber 20, and a main control unit 70 for controlling the operation of the substrate processing apparatus 100.

[0010] [Reactor] As shown in Figure 1, a processing chamber 20 is formed inside the reactor 10, which includes a reaction tube 12 and a furnace mouth flange 14. The reaction tube 12 is formed in a cylindrical shape with an axis in the vertical direction. The furnace mouth flange 14 is connected to the lower part of the reaction tube 12 with an airtight member 12A in between, and is also formed in a cylindrical shape with an axis in the vertical direction. In addition, an inner tube 16 is supported inside the reaction tube 12 concentrically with the reaction tube 12. A heater 18 is provided on the outer circumference of the reaction tube 12, concentric with the axis of the reaction tube 12, and spaced apart from the outer surface of the reaction tube 12. The heater 18 receives a signal from the main control unit 70, which will be described later, and generates heat to heat the reaction tube 12. Thus, the reactor 10 has a reaction tube 12, a furnace mouth flange 14, an inner tube 16, a heater 18, and a processing chamber 20. A substrate 30 is also placed in the processing chamber 20.

[0011] [Prepared Chamber] As shown in Figure 1, the prepared chamber 22 is composed of a transport housing 24. The transport housing 24 is connected to the lower part of the furnace opening flange 14. Inside the transport housing 24 is a boat 26 on which the substrate 30 is placed and which is transported to the processing chamber 20 for insertion. The furnace opening cover 28 is provided to be movable in the vertical direction and hermetically closes the transport housing 24 when it reaches the upper end. The boat 26 is placed on the furnace opening cover 28 and is introduced into the reactor 10 in accordance with the movement of the furnace opening cover 28. In addition, a second gas introduction line 44, which has the same configuration as the gas introduction line 40 described later, is connected to the lower part of the transport housing 24. This makes it possible to fill the prepared chamber 22 with an atmosphere in which it is difficult for a natural oxide film or the like to form on the substrate 30.

[0012] [Gas Inlet Line] As shown in Figure 1, the gas inlet line 40 includes a gas inlet pipe 40A connecting a gas supply source (not shown) and the furnace mouth flange 14, and a flow rate controller 42 installed between the gas supply source and the furnace mouth flange 14. The flow rate controller 42 has the function of controlling the amount of gas introduced by opening and closing a valve (not shown) installed inside it in response to a signal from the main control unit 70, which will be described later. The second gas inlet line 44 has the same configuration as the gas inlet line 40, except that it connects the gas supply unit and the lower part of the transport housing 24. The gas used here is an inert gas, specifically nitrogen.

[0013] [Main Control Unit] The main control unit 70 is a controller that controls the overall operation of the substrate processing apparatus 100. Although not shown in the diagram, it has a CPU, ROM, RAM, storage, input unit, display unit, communication interface, etc., and each of these has a built-in computer connected to a bus. The communication interface can acquire pressure information from the pressure sensor group 62, which will be described later, and transmit the target pressure value to the valve controller 53, which acts as a valve control unit (valve drive controller). Based on the input information from the input unit, the main control unit 70 executes a substrate processing program for performing various processes in the substrate processing apparatus 100. For example, the main control unit 70 executes a process recipe, which is one of the substrate processing programs, to control the substrate processing process, which is one of the processes for manufacturing semiconductor devices. At this time, the main control unit 70 controls the opening and closing of the on-off valves 56 and 58 of the exhaust system 50 via the valve controller 53, and also adjusts the opening degree of the on-off valve 56 to control the pressure in the processing chamber 20.

[0014] <Configuration of the main parts> [Exhaust system] As shown in Figures 1 to 3, the exhaust system 50 has an exhaust line 52 which comprises at least a large-diameter exhaust pipe 52A as a first pipe for discharging gas from the processing chamber 20, a pressure sensor group 62 provided in the pipe 52A for detecting the pressure in the processing chamber 20, and a control valve structure (hereinafter sometimes referred to as a valve assembly) 55 provided in the middle of the pipe 52A. As shown in Figures 1 to 4, the pipe 52A is a large-diameter pipe that connects the processing chamber 20 to the vacuum pump 60 and constitutes a vacuum exhaust passage. In this embodiment, the diameter of the pipe 52A is α, and as an example, it is 200 mm. That is, the nominal diameter of the pipe 52A is, for example, 200A. Here, in this specification, large diameter means a diameter of 200 mm or more.

[0015] The end of the exhaust line 52 opposite to the processing chamber 20 is connected to the suction side of the vacuum pump 60. The exhaust line 52 is configured to exhaust the gas from the processing chamber 20 by the suction operation of the vacuum pump 60 when the control valve structure 55 is open. The vacuum pump 60 has an ultimate vacuum of a low pressure range of several Pas and is operated continuously to maintain a vacuum downstream of the exhaust line 52. The vacuum pump 60 and valve controller 53 may be included in the exhaust system 50.

[0016] [Control Valve] As shown in Figures 3, 4, 5, and 6, the control valve structure 55 includes two on-off valves 56 and 58 that are configured to be driven independently of each other. The two on-off valves 56 and 58 are electrically connected to a valve controller 53, and opening and closing operations are performed based on signals from the valve controller 53. This control valve structure 55 can vary the conductance of the exhaust line 52, which serves as a vacuum exhaust passage, and within its variable range, it can substantially reduce the conductance to 0, i.e., completely close, thereby blocking the vacuum exhaust passage.

[0017] Each of the on-off valves 56 and 58 includes a retractable rod 78A, 78B as an example of a drive member, actuators 80A, 80B, seal rings 82A, 82B, and plate portions (valve bodies) 77A, 77B that close the valve openings 76A, 76B, respectively, which are arranged perpendicular to the flow path direction. Furthermore, it is equipped with retractable members 75A, 75B (e.g., bellows) that can be extended and retracted by the actuators 80A, 80B, thereby preventing the rods 78A, 78B from coming into contact with the controlled fluid. This suppresses the adhesion of particles. The controlled fluid can be any gaseous fluid, for example, a gas. Naturally, the controlled fluid may be any gas used for substrate processing in the processing chamber 20 (processing gas) or a gas used for purging the processing chamber 20 (purging gas), regardless of the type of gas.

[0018] The valve housing 76, which serves as the enclosure of the control valve structure 55, is a component that forms a flow path for the controlled fluid between the two on-off valves 56 and 58, as part of the vacuum exhaust flow path. In other words, the valve housing 76 has an inlet portion 76EN connected to the inlet-side piping 52A of the control valve structure 55, and an outlet portion 76EX connected to the outlet-side piping 52A, and is configured to form a flow path for the controlled fluid. The valve housing 76 is divided into an upstream space 76IN and a downstream space 76OUT, with the valve openings 76A and 76B of the on-off valves 56 and 58 in between. The upstream space 76IN is in communication with the inlet portion 76EN, and the downstream space 76OUT is in communication with the outlet portion 76EX.

[0019] The valve openings 76A and 76B, which can be considered part of the flow path, open perpendicular to the direction of gas flow through the pipe 52A. The diameters of the valve openings 76A and 76B are β and γ, respectively, for example, 100 mm and 150 mm. Each of the valve openings 76A and 76B is smaller than the inner diameter α of the pipe 52A, for example, with a nominal diameter of 200 A. Specifically, the flow path cross-sectional areas of the valve openings 76A and 76B of the on-off valves 56 and 58 are smaller than the flow path cross-sectional area of ​​the pipe 52A. On the other hand, the sum of the flow path cross-sectional areas β + γ of the valve openings 76A and 76B of the on-off valves 56 and 58 is larger than the flow path cross-sectional area α of the pipe 52A. This makes it possible to handle a range from atmospheric pressure to low pressure with a single pipe, without having to provide multiple pipes in the exhaust system and use different pipes depending on the pressure range.

[0020] The control valve structure 55 is composed of a combination of multiple on-off valves 56 and 58 having a flow path cross-sectional area smaller than that of the pipe 52A. As a result, the flow path formed within the valve housing 76 can have an area equal to or greater than the cross-sectional area of, for example, the pipe 52A with a nominal diameter of 200A. Furthermore, in this embodiment, the control valve structure 55 has an inlet section 76EN connected to the pipe 52A that constitutes the inlet section, and an outlet section 76EX connected to the pipe 52A that constitutes the outlet section, which are arranged to open in the same direction, and are positioned so that they are substantially the same in the direction of gas flow through the flow path (the outlet section 76EX is located on the extension of the flow direction from the inlet section 76EN).

[0021] The valve bodies 77A and 77B are members that move in a straight line between an open position, which creates a flow path by opening the valve openings 76A and 76B, and a closed position, which seals the valve openings 76A and 76B. The valve bodies 77A and 77B are formed to be larger than the valve openings 76A and 76B, and close the valve openings 76A and 76B in the closed position.

[0022] One or more rods 78A and 78B are provided on the valve bodies 77A and 77B, and are movable or extendable in the direction of movement of the valve bodies 77A and 77B together with the valve bodies 77A and 77B. The valve housing 76 facing the valve openings 76A and 76B in the upstream space 76IN is a cover member 79. In this embodiment, the rods 78A and 78B extend out of the valve housing 76 parallel to the direction of movement, passing through the cover member 79. Furthermore, the rods 78A and 78B have strength and rigidity (second moment of area) in order to receive some or all of the flow direction load applied to the valve bodies 77A and 77B and transmit it to the actuators 80A and 80B. Note that the drive member is not limited to the rods 78A and 78B, but can be any member that moves the valve bodies 77A and 77B to open and close the on-off valves 56 and 58. Therefore, the drive member may be, for example, an arm or a ball screw (not shown).

[0023] In particular, the on-off valve 56 is provided with tapered portions 77T and 76T on the valve body 77A and the valve seat portion 76C of the valve housing 76, respectively, allowing for fine adjustment of the flow path cross-sectional area between the valve body 77A and the valve opening 76A. This configuration provides a flow rate adjustment function and a pressure adjustment function. This enables pressure control in the low-pressure range, which will be described later. On the other hand, the on-off valve 58 does not have a pressure adjustment function but functions as a gate valve. Note that the on-off valve 58 can also be provided with a pressure adjustment function in the same configuration as the on-off valve 56.

[0024] Actuators 80A and 80B are drive sources that drive rods 78A and 78B in the direction of movement of valve bodies 77A and 77B. Actuators 80A and 80B are fixed to the cover member 79 and are allowed to be displaced only in the direction of movement of rods 78A and 78B, and can withstand loads in other directions (e.g., the flow direction). Examples of actuators 80A and 80B include cylinder devices, rack and pinion systems, and linear motors.

[0025] The seal rings 82A and 82B are positioned on the surfaces of the valve bodies 77A and 77B facing the valve seats 76C and 76D of the valve housing 76, and are elastic. In the illustrated example, the seal rings 82A and 82B are mounted on the flow path end faces of the valve bodies 77A and 77B and move together with the valve bodies 77A and 77B when the on / off valves 56 and 58 are opened and closed. For example, the seal rings 82A and 82B are fitted into an annular groove (not shown) formed on the flow path end face of the valve bodies 77A and 77B.

[0026] In the control valve structure 55, the on-off valves 56 and 58 are opened when the opening of the flow path is relatively large (conductance or flow rate of the controlled fluid is large), and the on-off valve 58 is closed when the opening of the flow path is relatively small (conductance or flow rate of the controlled fluid is small) or when adjusting the pressure under predetermined conditions, and the on-off valve 56 adjusts the flow rate or regulates the pressure.

[0027] The control valve structure 55 shown in Figures 5 and 6 shows the configuration when both valve openings 76A and 76B are open. As shown in Figures 5, 6(a), (b), and (c), the controlled fluid introduced from the inlet 76EN is configured to pass through at least one of the valve openings 76A and 76B and move to the outlet 76EX. Furthermore, as shown in Figures 6(a), (b), and (c), it can be seen that the cross-sectional area of ​​the flow path facing the outlet 76EX created within the on-off valves 56 and 58 is approximately the same as the cross-sectional area of ​​the flow path of the piping 52A.

[0028] Furthermore, the valve openings 76A and 76B are positioned perpendicular to the flow direction of the piping 52A. This allows the outlets of the on-off valves 56 and 58 to align with the flow direction of the piping 52A. This configuration also allows for a more compact design.

[0029] As shown in Figure 7, the valve bodies 77A and 77B are provided with heaters 90A and 90B as a heating mechanism and thermocouples 92A and 92B as temperature detection units, through rods 78A and 78B, so that the valve bodies 77A and 77B are heated and their temperature can be detected. This prevents by-products from the controlled fluid flowing through the valve openings 76A and 76B from adhering to the valve bodies 77A and 77B.

[0030] More specifically, the wires 90AL and 90BL of heaters 90A and 90B, and the wires 92AL and 92BL of thermocouples 92A and 92B are introduced via the same path from outside the on-off valves 56 and 58 to their respective valve bodies 77A and 77B. The wires 90AL of heater 90A and 92AL of thermocouple 92A in on-off valve 56 pass through the rod 78A, and are configured to move up and down in accordance with the movement of on-off valve 56.

[0031] The wires 90BL of the heater 90B and the wires 92BL of the thermocouple 92B of the on-off valve 58 are spirally wound around the rod 78B. This configuration allows them to expand and contract in accordance with the movement of the on-off valve 58.

[0032] [Pressure Sensor Group] As shown in Figure 1, the pressure sensor group 62 is installed in communication with the processing chamber 20 side from the mounting positions of the on-off valves 56 and 58 by piping 52A. The pressure sensor group 62 is electrically connected to the main control unit 70 and has the function of transmitting pressure information of the processing chamber 20. Also, as shown in Figure 2, the pressure sensor group 62 is composed of an atmospheric pressure sensor 64, a first vacuum sensor 66, and a second vacuum sensor 68, which will be described later. The atmospheric pressure sensor 64, the first vacuum sensor 66, and the second vacuum sensor 68 are installed in order from the side closer to the processing chamber 20 to the side further away, and are each connected to piping 52A by piping 62A. Here, the atmospheric pressure sensor 64, the first vacuum sensor 66, and the second vacuum sensor 68 are each examples of pressure sensors.

[0033] (Atmospheric pressure sensor) As shown in Figure 2, the atmospheric pressure sensor 64 is located in the pressure sensor group 62 at the position closest to the processing chamber 20 and has the function of detecting pressure in a region close to atmospheric pressure.

[0034] (First Vacuum Sensor) As shown in Figure 2, the first vacuum sensor 66 is positioned between the atmospheric pressure sensor 64 and the second vacuum sensor 68, which will be described later, and measures pressure from the region close to atmospheric pressure to the high vacuum region (10 －５ Pa or more 10 －１It functions as a wide-range pressure sensor that can detect pressures down to less than 10.5°C. Furthermore, the pipe 62A connecting the first vacuum sensor 66 and the pipe 52A is equipped with a valve 66A that communicates with the atmospheric pressure sensor 64 and opens when the pressure inside the pipe 52A is reduced toward the high vacuum region. Hereafter, the high vacuum region will also be called the high vacuum pressure zone, and the low vacuum region (10°C) will be referred to as the high vacuum pressure zone. －１ Pa or more 10 ２ The range below 10 is sometimes called the low vacuum pressure zone or low pressure zone. Furthermore, the high pressure zone is 10 ２ Pa or more 10 ５ The pressure should be less than the specified value.

[0035] (Second Vacuum Sensor) As shown in Figure 2, the second vacuum sensor 68 is located at the position furthest from the processing chamber 20 in the pressure sensor group 62 and functions as a pressure sensor that detects pressure in the high vacuum region.

[0036] These atmospheric pressure sensor 64, first vacuum sensor 66, and second vacuum sensor 68 are electrically connected to the main control unit 70 and valve controller 53, respectively.

[0037] As shown in Figure 3, the valve controller 53 has an automatic control unit 71 and an opening degree command calculation unit 72. The automatic control unit 71 receives input from the main control unit 70, which is the target pressure PT of the processing chamber 20, and the actual pressure PR measured by the pressure sensor group 62, and outputs a target opening degree to the opening degree command calculation unit 72. The target opening degree corresponds to the conductance of the entire control valve structure in this embodiment and is constantly updated by a method such as feedback control so that the deviation between the target pressure PT and the actual pressure PR is 0. If an upper limit of the pressure change rate is specified, even if a target pressure that changes at a speed exceeding that rate is input, the target pressure is internally modified so that it falls within the rate. The opening degree command calculation unit 72 assigns the opening degree to the on-off valves 56 and 58 according to the input target opening degree and outputs it as an opening degree command to the gate valve actuators 80A and 80B, respectively. The opening degree command can be given, for example, as a relative opening degree when the fully open state of valve bodies 77A and 77B is defined as 100%.

[0038] <Function of Key Components> Here, the functions of the control valve structure 55, the exhaust system 50, and the method for manufacturing the semiconductor device, which are key components of this embodiment, will be explained.

[0039] [Operation of the control valve] In the control valve structure 55 according to this embodiment, the rods 78A and 78B are moved or extended / retracted in the axial direction by the drive of actuators 80A and 80B based on commands from the valve controller 53, and the valve bodies 77A and 77B attached to the rods 78A and 78B are moved linearly in the axial direction of the rods 78A and 78B. This allows the on-off valves 56 and 58 to be opened and closed. Figure 4(A) shows the closed state of the on-off valves 56 and 58. In the closed state, the seal rings 82A and 82B are pressed against the valve seats 76C and 76D of the valve housing 76, thereby sealing the valve openings 76A and 76B. In particular, tapered portions 77T and 76T are provided on the valve body 77A and the valve seat 76C, respectively, and these tapered portions 77T and 76T are configured to be in close contact with each other. Figure 4(D) shows the open state of the on-off valves 56 and 58, specifically the fully open state. In the case of the on-off valve 58, the valve opening 76B becomes fully open when the seal ring 82B separates from the valve seat portion 76D of the valve housing 76. In the case of the on-off valve 56, it becomes fully open when the tip of the tapered portion 77T of the valve body 77A exceeds the height of the valve seat portion 76C of the valve housing 76.

[0040] By driving the actuator 80A with a pressure function according to a command from the main control unit 70, the valve body 77A is linearly moved, so that the valve conductance can be varied, and the pressure in the processing chamber 20 shown in FIGS. 1 to 3 can be adjusted. Specifically, it can be performed by a combination of opening and closing of the on-off valve 58 and adjustment of the opening degree of the on-off valve 56. In FIG. 4(B), the on-off valve 58 is closed, and in FIG. 4(C), the on-off valve 58 is open. The adjustment of the opening degree of the on-off valve 56 is such that, as shown in FIGS. 4(B) and 4(C), a gap (fine space) is generated between the tapered portion 77T of the valve body 77A and the tapered portion 76T of the valve seat portion 76C of the valve housing 76, and the pressure can be adjusted by finely adjusting this gap. FIG. 4(B) shows the pressure adjustment when the target pressure PT of the processing chamber 20 is in the high pressure zone described later, and FIG. 4(C) shows the pressure adjustment when the target pressure PT of the processing chamber 20 is in the low pressure zone described later. Therefore, according to the control valve structure 55, in the region where only the on-off valve 56 operates, excellent responsiveness of the opening and closing operation and fine opening degree control accuracy similar to those of a small-diameter butterfly valve can be obtained. On the other hand, since the control valve structure 55 has a configuration in which a plurality of valves (on-off valves 56 and 58) are combined, a sealing property similar to that of a large-diameter gate valve can be obtained.

[0041] According to the present embodiment, by adopting a combined structure of an on-off valve 56 with an opening degree adjustment function corresponding to an inner diameter of 100A and an on-off valve 58 corresponding to an inner diameter of 150A as an example of the control valve structure 55, large-flow exhaust and high-precision pressure adjustment can be simultaneously realized. Further, a branch system (not shown) corresponding to an inner diameter of 100A becomes unnecessary, and the exhaust system can be constituted only by the pipe 52A with an inner diameter of 200A. Therefore, space saving of the device component layout can be realized. In addition, since there is no branch pipe, the pipe volume is reduced, the replacement efficiency of the gas as the controlled fluid can be improved, and the component cost can be reduced. Furthermore, in the process of pipe heating, the pipe heating range can be reduced, and the particle risk due to uneven heating can be reduced.

[0042] [Operation of the exhaust system] In Figure 3, the exhaust system 50 of this embodiment controls the pressure of the processing chamber 20 by having the valve controller 53 appropriately assign the adjustment of the opening degree of the control valve structure 55 to the on-off valves 56 and 58 based on the target pressure PT and the actual pressure PR from the pressure sensor group 62.

[0043] Figures 8(a) and 8(b) are graphs showing an example of valve opening assignment by the valve opening command calculation unit 72 (see Figure 3). Figure 8(a) shows the assignment to valve 56, and Figure 8(b) shows the assignment to valve 58. The vertical axis represents the valve opening of valves 56 and 58, and the horizontal axis represents the pressure in the processing chamber 20. The pressure in the processing chamber 20 on the horizontal axis represents the range from atmospheric pressure to the low pressure zone (approximately 100 Pa or less). The switching pressure for opening valve 58 is approximately 100 Pa at the boundary between the high and low pressure zones. Furthermore, from atmospheric pressure to the low pressure zone, valve 56 is fully open for exhaust. Figures 8(a) and 8(b) show that by fully opening valve 58 and adjusting the valve opening of valve 56, it is possible to control the pressure in the processing chamber 20 (target pressure PT) in the low pressure zone.

[0044] Opening degree A indicates the degree of opening required to maintain the pressure in the processing chamber 20 at the target pressure PT. Therefore, opening degree A indicates that the opening degree increases appropriately according to the target pressure PT. Note that there are several possible assignments for the on-off valves 56 and 58, which will be explained below using Figures 11 and 12.

[0045] Figures 11(a) and 11(b) are graphs showing examples of the allocation of the opening degree of the on-off valve 56 with an opening degree adjustment function by the opening degree command calculation unit 72. Figures 11(a) and 11(b) instruct the system to adjust the opening degree to perform slow exhaust when the pressure in the processing chamber 20 starts to depressurize from atmospheric pressure. In Figure 11(a), the pressure B when the opening degree of the on-off valve 56 is 100% is lower than atmospheric pressure. Pressure B is set appropriately within the high-pressure range by the opening degree command calculation unit 72. In Figure 11(b), slow exhaust is completed when the opening degree of the on-off valve 56 is A, and exhaust is performed while maintaining the opening degree A. In Figure 11(b), the opening degree A is set to maintain the pressure in the processing chamber 20 at the target pressure PT during the depressurization phase from atmospheric pressure, but it does not need to be the same, and it can be set to any opening degree from 0% to 100%.

[0046] FIG. 12 is a graph showing an example of the assignment of the opening degree of the on-off valve 58 by the opening degree command calculation unit 72. In FIG. 8, the on-off valve 58 is in the open state at the boundary between the high-pressure zone and the low-pressure zone (here, about 100 Pa), but as shown in FIG. 12, the timing of setting the open state can be arbitrarily set. Specifically, it is the pressure B when the slow exhaust ends. Thereby, the pressure in the processing chamber 20 can be rapidly reduced to the low-pressure zone. Further, after the slow exhaust ends, the on-off valve 58 may be opened at the pressure C when a predetermined time has elapsed. Even in this case, the pressure in the processing chamber 20 can be reduced to the low-pressure zone earlier than in the example shown in FIG. 8.

[0047] As described above, the opening degree command calculation unit 72 can handle all processes by appropriately combining the respective assignments of the on-off valves 56 and 58 constituting the control valve structure 55 shown in FIGS. 8, 11, and 12. With such a configuration, large-flow exhaust and high-precision pressure adjustment can be achieved simultaneously. In addition, a conventional sub-exhaust system (for example, a branch system (not shown) corresponding to 100 A) becomes unnecessary, and for example, the exhaust system can be configured only with the pipe 52A of 200 A.

[0048] <Substrate processing step> Next, a substrate processing method having a predetermined processing step, that is, a method for manufacturing a semiconductor device, which is performed using the substrate processing apparatus 100 according to the present embodiment, will be described. Here, the case where the predetermined processing step is a substrate processing step which is one step of the semiconductor device manufacturing process will be taken as an example.

[0049] The method for manufacturing this semiconductor device comprises the steps of: preparing a control valve structure 55 which includes valve openings 76A and 76B that are opened and closed by moving valve bodies 77A and 77B attached to rods 78A and 78B in a straight line in the axial direction of rods 78A and 78B, and configuring the on-off valves 56 and 58 to be drivable independently of each other; transporting the substrate 30 of the semiconductor device into a processing chamber 20 which serves as a reaction chamber of the substrate processing device 100; and either of the following steps: closing the on-off valve 58 and adjusting the flow rate or regulating the pressure using the on-off valve 56 with a pressure adjustment mechanism, or opening the on-off valve 58 and regulating the flow rate or regulating the pressure using the on-off valve 56 with a pressure adjustment mechanism.

[0050] In carrying out the substrate processing process, first a control valve structure 55 is prepared in the substrate processing apparatus 100. Next, the process recipe is loaded into a memory (not shown), and control instructions are appropriately given from the automatic control unit 71 in the main control unit 70 to the opening degree command calculation unit 72, and operation instructions are also given to process system controllers and transport system controllers (not shown). The substrate processing process carried out in this manner comprises at least a loading process, a film formation process, and an unloading process.

[0051] (Transfer Process) The main control unit 70 starts the process of transferring the substrates 30 to the boat 26 using a substrate transfer mechanism (not shown). This transfer process is carried out until all the scheduled substrates 30 have been loaded (wafer charged) into the boat 26.

[0052] (Loading Process) Once a predetermined number of substrates 30 are loaded into the boat 26, the boat 26 is raised by a boat elevator (not shown) and loaded into the processing chamber 20 formed inside the reactor 10 (boat loading). When the boat 26 is fully loaded, the furnace opening cover 28 airtightly closes the lower end of the furnace opening flange 14 of the reactor 10.

[0053] (Processing Steps) Next, the processing chamber 20 is evacuated by a vacuum exhaust device such as a control valve structure 55 and a vacuum pump 60, in accordance with instructions from the main control unit 70 as described above, to reach a predetermined film deposition pressure (processing pressure). The processing chamber 20 is also heated by a heater 18 to reach a predetermined temperature, in accordance with instructions from a temperature control unit (not shown). Subsequently, the boat 26 and substrates 30 are rotated by a rotating mechanism (not shown). Then, while maintained at a predetermined pressure and temperature, a predetermined gas (processing gas) is supplied to the multiple substrates 30 held in the boat 26, and a predetermined process (e.g., film deposition) is performed on the substrates 30. Note that the temperature may be lowered from the processing temperature (predetermined temperature) before the next unloading step.

[0054] Once the film deposition process on the substrate 30 placed on the boat 26 is complete, the rotation of the boat 26 and the substrate 30 by the rotating mechanism is stopped, the processing chamber 20 is purged with nitrogen (nitrogen purging process), and the pressure is returned to atmospheric pressure.

[0055] (Removal process) Then, the furnace opening cover 28 is lowered to open the lower end of the furnace opening flange 14, and the boat 26 holding the processed substrates 30 is removed from the reactor 10 (boat unloading).

[0056] (Recovery Process) The boat 26 holding the processed substrates 30 is then cooled very effectively by clean air blown from the clean unit. When it has cooled to, for example, 150°C or below, the processed substrates 30 are removed from the boat 26 (wafer discharge) and transferred to a pod (not shown), after which new unprocessed substrates 30 are transferred to the boat 26.

[0057] As described above, we have explained an operation in which a control valve structure 55, including a pressure-regulating valve 56 and a gate valve 58, is used in the exhaust pipe 52A to make the exhaust system piping a single pipe 52A. However, the combination of the pressure-regulating valve 56 and the gate valve 58, i.e., the control valve structure 55, can be combined in configurations other than those described above, and these variations will be described below. Note that parts that are the same as the configuration of the control valve structure 55 described above may be omitted.

[0058] (Modification 1) In the example shown in Figure 9, both valve openings 76A and 76B of the on-off valves 56 and 58 are open in the same direction as the fluid flow direction in the piping 52A (direction facing the fluid flow direction). Here, the on-off valve 56 shown in Figure 4 above is rotated 90° counterclockwise, and the on-off valve 58 is rotated 90° clockwise, so that valve opening 76A faces the outlet portion 76EX, and valve opening 76B faces the inlet portion 76EN.

[0059] (Modification 2) In the example shown in Figure 10, the on-off valve 56 has its valve opening 76A opening perpendicular to the fluid flow direction of the piping 52A, and the on-off valve 58 has its valve opening 76B opening in the same direction as the fluid flow direction of the piping 52A (direction facing the fluid flow direction). That is, in this case, the on-off valve 56 shown in Figure 4 above is left in the same position, and the on-off valve 58 is rotated 90° clockwise so that its valve opening 76B faces the inlet portion 76EN.

[0060] According to this embodiment, one or more of the following effects can be obtained.

[0061] (a) By combining multiple on-off valves 56 and 58 that are smaller in diameter than the pipe 52A, it is possible to accommodate a larger diameter pipe 52A and to control and adjust the pressure in the processing chamber 20 effectively. As a result, it becomes possible to exhaust a large flow rate from the processing chamber 20.

[0062] (b) By arranging the inlet portion 76EN and the outlet portion 76EX to face the same direction, an increase in flow resistance can be suppressed.

[0063] (c) By positioning the outlet section 76EX on the extension of the flow direction of the fluid that flows in from the inlet section 76EN, an increase in flow resistance can be suppressed.

[0064] (d) By orienting at least one of the valve openings 76A and 76B of the on-off valves 56 and 58 in a direction that intersects or is perpendicular to the flow direction of the piping 52A, the number of valves can be made more compact.

[0065] (e) The configuration of the on / off valve 56 allows for flow rate adjustment, making it possible to control the pressure in the processing chamber 20 with good controllability.

[0066] (f) By configuring at least one of the valve openings 76A and 76B to be in the same direction as the flow direction of the piping 52A, the increase in flow resistance can be suppressed.

[0067] (g) By controlling the on-off valves 56 and 58 in accordance with the pressure in the processing chamber 20, it becomes possible to adjust the pressure in the processing chamber 20 with good controllability.

[0068] (h) By controlling the valve bodies 77A and 77B in accordance with a preset combination of states of the valve bodies 77A and 77B in response to the pressure in the processing chamber 20, it becomes possible to adjust the pressure in the processing chamber 20 with good controllability.

[0069] (i) Since the valve bodies 77A and 77B are configured to have heaters 90A and 90B inside, it is possible to suppress the adhesion of by-products from the controlled fluid flowing through the valve openings 76A and 76B to the valve bodies 77A and 77B.

[0070] (j) Since the valve bodies 77A and 77B are configured to have thermocouples 92A and 92B inside them, the temperature of the valve bodies 77A and 77B can be detected and heating can be performed appropriately.

[0071] (k) Since the rods 78A and 78B that move the valve bodies 77A and 77B have an extension and retraction function, the valve bodies 77A and 77B can be moved in a space-saving manner.

[0072] (l) By covering the rods 78A and 78B with the expandable members 75A and 75B, the adhesion of particles to the rods 78A and 78B can be suppressed. (Other Embodiments) Although embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the embodiments described above, and can be modified in various ways without departing from the gist of the disclosure.

[0073] In Figure 13, the valve opening 76A is positioned obliquely to the inlet 76EN, and the valve body 77A has an outer diameter that closes the valve opening 76A, forming an on-off valve 56. The valve opening 76A is perpendicular to the flow direction of the piping 52A. The valve body 77A of the on-off valve 56 has an arc-shaped notch 56K formed on its inner circumference, parallel to the valve opening 76A. The valve opening 76A is sealed between the valve opening 76A and the valve seat 76C by a seal ring 82A. The on-off valve 58 has a valve body 77B stacked on the downstream space 76OUT side of the valve body 77A. The valve body 77B has an outer diameter that covers the notch 56K, and the space between the valve body 77A and the valve body 77B is sealed by a seal ring 82B. The cross-sectional area of ​​the valve opening 76A is larger than the cross-sectional area α of the piping 52A. In the configuration shown in Figure 13, the valve opening 76A can be opened by driving the on-off valve 56, and the notch 56K can be opened by closing the on-off valve 56 and opening the on-off valve 58.

[0074] In Figure 14, the valve opening 76A is positioned obliquely to the inlet 76EN, and the on-off valve 56 has a valve body 77A with an outer diameter that closes the valve opening 76A. The valve body 77A of the on-off valve 56 has an opening 56H formed on its inner circumference, which is further inward than the valve opening 76A. The valve opening 76A is sealed between the valve opening 76A and the valve seat 76C by a seal ring 82A. The on-off valve 58 has a valve body 77B stacked on the downstream space 76OUT side of the valve body 77A. The valve body 77B has an outer diameter that covers the opening 56H, and the space between the valve body 77A and the valve body 77B is sealed by a seal ring 82B. The cross-sectional area of ​​the valve opening 76A is larger than the cross-sectional area α of the piping 52A. In the configuration of Figure 13, the valve opening 76A can be opened by driving the on-off valve 56, and the opening 56H can be opened by closing the on-off valve 56 and opening the on-off valve 58.

[0075] Furthermore, the number of valves constituting the control valve structure 55 may be three or more.

[0076] Furthermore, the processing performed by the substrate processing apparatus may include, for example, film deposition, oxide film formation, nitride film formation, and metal-containing film formation. Moreover, the specific content of the substrate processing is not limited, and it can be suitably applied not only to the above-mentioned processing such as film deposition, but also to other substrate processing such as annealing, oxidation, nitriding, diffusion, and lithography.

[0077] Furthermore, this disclosure can be suitably applied to other substrate processing equipment, such as annealing equipment, oxidation equipment, nitriding equipment, exposure equipment, coating equipment, drying equipment, heating equipment, and plasma-based processing equipment. Moreover, this disclosure may apply to a mixture of these equipment.

[0078] Furthermore, although this embodiment describes a semiconductor manufacturing process, this disclosure is not limited thereto. For example, this disclosure can also be applied to substrate processing such as the manufacturing process of liquid crystal devices, solar cells, light-emitting devices, glass substrate processing, ceramic substrate processing, and conductive substrate processing.

[0079] Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations.

[0080] 55 Control valve structure 56 On / off valve (valve) 58 On / off valve (valve)

Claims

1. A control valve structure comprising a plurality of valves, wherein the plurality of valves are provided in an exhaust pipe that discharges the atmosphere of a processing chamber, the flow path cross-sectional area of ​​each of the plurality of valves is smaller than the flow path cross-sectional area of ​​the exhaust pipe, and the sum of the flow path cross-sectional areas of the plurality of valves is larger than the flow path cross-sectional area of ​​the exhaust pipe.

2. The control valve structure according to claim 1, wherein the inlet and outlet portions connected to the exhaust pipe are arranged to face the same direction.

3. The control valve structure according to claim 2, wherein the outlet is located on the extension of the flow direction of the fluid that flows in from the inlet.

4. The control valve structure according to claim 1, wherein at least one of the valve openings of the plurality of valves is oriented in a direction intersecting the flow direction of the exhaust pipe.

5. The control valve structure according to claim 4, wherein at least one of the valve openings of the plurality of valves is oriented in a direction perpendicular to the flow direction of the exhaust pipe.

6. The control valve structure according to claim 1, wherein at least one of the plurality of valves is configured to adjust the flow rate.

7. The control valve structure according to claim 1, wherein at least one of the valve openings of the plurality of valves is configured to have the same flow direction as the exhaust pipe.

8. The control valve structure according to claim 1, further comprising a control unit configured to change the state of each of the valve bodies of the plurality of valves in accordance with the pressure in the processing chamber.

9. The control valve structure according to claim 8, wherein the control unit controls the valve body in accordance with a preset combination of valve body states in response to the pressure in the processing chamber.

10. The control valve structure according to claim 1, wherein the plurality of valves are configured to have a heating mechanism inside each valve body.

11. The control valve structure according to claim 10, further comprising a temperature detection unit for detecting the temperature of each of the valve bodies.

12. The control valve structure according to claim 1, wherein the plurality of valves are configured to have an extension / retraction mechanism for moving each valve body.

13. The control valve structure according to claim 12, wherein the telescopic mechanism is configured to be covered by a telescopic member.

14. The control valve structure according to claim 12, wherein at least one of the plurality of valves has a flow rate adjustment function.

15. The control valve structure according to claim 1, wherein there are three or more valves.

16. A substrate processing apparatus comprising the control valve structure according to any one of claims 1 to 15.

17. A method for manufacturing a semiconductor device, comprising exhausting a processing chamber with an exhaust system including a control valve structure according to any one of claims 1 to 15, and processing a substrate placed in the processing chamber.

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