Flow rate control mechanism, substrate processing apparatus, method of manufacturing semiconductor device, and recording medium

Abstract

To provide a technique capable of suppressing adhesion of foreign matter to a valve element.SOLUTION: A valve body supported to be rotatable about an axis in a direction intersecting a direction in which a gas flows in a processing gas flow path at least a part of which is formed by a pipe, the valve body being heated to a temperature higher than a temperature of the pipe and having a surface at least a part of which has an emissivity equal to or lower than an emissivity of an inner surface of the pipe; SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a flow rate control mechanism, a substrate processing apparatus, a method for manufacturing a semiconductor device, and a program. [Background technology]

[0002] In the manufacturing process of a semiconductor device (substrate processing process), the flow rate of a processing gas in a flow path is sometimes controlled using a mechanism having a valve body that rotates around an axis that intersects with the direction of gas flow in the processing gas flow path (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 156934 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique capable of suppressing adhesion of foreign matter to a valve body. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, a valve body that is supported rotatably about an axis that intersects with the direction of gas flow in a processing gas flow path at least a portion of which is formed by a pipe, that is heated to a temperature higher than that of the pipe, and that has an emissivity of at least a portion of its surface that is equal to or lower than that of the inner surface of the pipe; a drive unit that rotates the valve body to change the opening degree of the flow path; The present invention provides a technique having the following. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to suppress adhesion of foreign matter to the valve body. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic view showing the overall configuration of a substrate processing apparatus according to an embodiment. [Figure 2] Fig. 2(a) is a cross-sectional view of the flow control mechanism in a plane perpendicular to the gas flow direction when the opening of the butterfly valve of the flow control mechanism shown in Fig. 1 is 0%. Fig. 2(b) is a cross-sectional view of the flow control mechanism in the gas flow direction when the opening of the butterfly valve of the flow control mechanism shown in Fig. 1 is 0%. [Figure 3] Fig. 3(a) is a cross-sectional view of the flow control mechanism in a plane perpendicular to the gas flow direction when the butterfly valve of the flow control mechanism shown in Fig. 1 is open to 100%. Fig. 3(b) is a cross-sectional view of the flow control mechanism in the gas flow direction when the butterfly valve of the flow control mechanism shown in Fig. 1 is open to 100%. [Figure 4] Figure 4(a) is a front view of the butterfly valve, and Figure 4(b) is a side view of the butterfly valve. [Figure 5] FIG. 5 is a cross-sectional view in the gas flow direction showing the configuration of a heating mechanism used in the flow rate control mechanism shown in FIG. 2(a). [Figure 6] FIG. 6 is a cross-sectional view perpendicular to the gas flow direction, showing the configuration of a heating mechanism in another embodiment used in the flow rate control mechanism shown in FIG. 2(a). [Figure 7] FIG. 7 is a diagram illustrating heat transfer in the flow rate control mechanism. [Figure 8] Figure 8(a) is an image showing a cross section near the surface of a butterfly valve with a metallic luster film, and Figure 8(b) is an image showing a cross section near the surface of a butterfly valve with a high-transmittance film. [Figure 9] Figure 9(a) shows the simulation results of the relationship between the emissivity of the surface of the butterfly valve, the position in the butterfly valve, and the temperature. Figure 9(b) shows the results of Figure 9(a) in table form. [Figure 10] FIG. 10 is a flowchart showing a substrate processing process applied in the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, one embodiment of the present disclosure will be described mainly with reference to FIGS. 1 to 10. It should be noted that all drawings used in the following description are schematic, and the dimensional relationships, ratios, etc. of elements shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships, ratios, etc. of elements between multiple drawings do not necessarily correspond to the actual ones. Unless otherwise specified in the specification, each element is not limited to one, and multiple elements may be present. In multiple drawings, substantially identical elements are designated by the same reference numerals, and descriptions of elements described in one drawing will be omitted in other drawings.

[0009] (1) Configuration of the substrate processing equipment As shown in FIG. 1, the substrate processing apparatus 100 includes a reactor 10 having a processing chamber 20 for processing wafers 30 as substrates, a spare chamber 22 for storing a boat 26 for holding the wafers 30, a gas inlet line 40 for introducing gas into the processing chamber 20, an exhaust system 50 for exhausting gas from the processing chamber 20, and a main control unit 70 for controlling the operation of the substrate processing apparatus 100.

[0010] [Reactor] A processing chamber 20 including a reaction tube 12 and a throat flange 14 is formed within the reactor 10. The reaction tube 12 is cylindrically shaped with an axis extending in the vertical direction. The throat flange 14 is connected to the lower part of the reaction tube 12 via an airtight member 12A, and is also cylindrically shaped with an axis extending in the vertical direction. An inner tube 16 is supported concentrically within the reaction tube 12 within the reactor 10. A heater 18 is provided around the outer periphery of the reaction tube 12, concentrically with the axis of the reaction tube 12 and spaced apart from the outer surface of the reaction tube 12. The heater 18 generates heat upon receiving a signal from the main controller 70, thereby heating the reaction tube 12. Thus, the reactor 10 includes the reaction tube 12, the throat flange 14, the inner tube 16, the heater 18, and the processing chamber 20. Wafers 30 are placed in the processing chamber 20 and processed with a processing gas.

[0011] [Spare room] The preliminary chamber 22 is formed by a transfer housing 24. The transfer housing 24 is connected to the lower part of the furnace throat flange 14. A boat 26, which carries wafers 30 and transports and inserts the wafers 30 into the processing chamber 20, is stored inside the transfer housing 24. A furnace throat cover 28 is provided to be movable in the vertical direction and airtightly closes the transfer housing 24 when it reaches its upper end. The boat 26 is placed on the furnace throat cover 28 and is introduced into the reaction furnace 10 in accordance with the movement of the furnace throat cover 28. In addition, a second gas inlet line 44, which has a configuration similar to that of the gas inlet line 40 described below, is connected to the lower part of the transfer housing 24. This allows the preliminary chamber 22 to be filled with an atmosphere that makes it difficult for natural oxide films and the like to form on the wafers 30.

[0012] [Gas introduction line] The gas introduction line 40 includes a gas introduction pipe 40A that connects a gas supply source (not shown) to the furnace throat flange 14, and a flow rate controller 42 that is provided between the gas supply source of the gas introduction pipe 40A and the furnace throat flange 14. The flow rate controller 42 has the function of controlling the amount of gas introduced by opening and closing an internal valve (not shown) in response to a signal from the main control unit 70. The number of gas introduction lines 40 is the same as the number of gas supply sources. The second gas introduction line 44 has the same configuration as the gas introduction line 40, except that it connects the gas supply unit to the lower part of the transfer housing 24. The gas used here is an inert gas.

[0013] [Main control unit] The main control unit 70 is a controller (controller) that controls the overall operation of the substrate processing apparatus 100. It includes a CPU 71, a ROM 72, a RAM 73, a storage (STR) 74, and other components, each of which incorporates a computer connected to a bus. Storage devices such as the storage 74 are configured as computer-readable recording media and store a substrate processing program (also referred to as a program product) described below. The main control unit 70 acquires pressure information from the pressure sensor 62 and transmits a target pressure value to the valve controller 53. The main control unit 70 executes a substrate processing program for performing various processes in the substrate processing apparatus 100 based on input information from an input unit (not shown). For example, the main control unit 70 is configured to execute a process recipe, which is one of the substrate processing programs, to cause the substrate processing apparatus 100 to perform a substrate processing process, which is one step in manufacturing a semiconductor device. At this time, the main control unit 70 adjusts the aperture of the butterfly valve 58 of the exhaust system 50 via the valve controller 53 to control the pressure in the processing chamber 20. The valve controller 53 corresponds to, for example, an automatic pressure controller (APC). Furthermore, the main control unit 70 controls external heating units 91 and 92 and internal heating units 93 to 95, which will be described later, based on temperatures measured by thermometers 101 to 105, which will be described later. Note that the program may be provided to the main control unit 70 using a communication means such as the Internet or a dedicated line, without using the storage 74 or the like.

[0014] [Exhaust system] The exhaust system 50 includes an exhaust line 52 including at least pipes 52A and 52B connected to the processing chamber 20 to exhaust gas from the processing chamber 20, a pressure sensor 62 provided in the pipe 52A to detect the pressure in the processing chamber 20, and a flow control mechanism 55 provided between the pipes 52A and 52B. The pipes 52A and 52B connect the processing chamber 20 to a vacuum pump 60 and form a vacuum exhaust flow path. The end of the exhaust line 52 opposite the processing chamber 20 is connected to the suction side of the vacuum pump 60. The vacuum pump 60 has an ultimate vacuum of approximately 10 Pa and is constantly operated to maintain a vacuum downstream of the exhaust line 52. The vacuum pump 60 and the valve controller 53 may be included in the exhaust system 50.

[0015] [Flow control mechanism] 2(a) and 2(b), the flow control mechanism 55 includes a valve box 57, a butterfly valve 58 provided in the valve box 57, and a drive unit 90. The drive unit 90 is electrically connected to the valve controller 53, and operates to control the opening degree of the butterfly valve 58 based on a signal from the valve controller 53.

[0016] Valve box 57 is provided between pipes 52A and 52B, and has a cylindrical through-hole 86 formed therein to allow communication between the two pipes 52A and 52B. Pipes 52A and 52B and valve box 57 form a flow path 89 for a process gas. In other words, valve box 57 forms a part of flow path 89. Here, the process gas refers to a gas (e.g., source gas, reactive gas) that flows from gas inlet line 40 through processing chamber 20 to exhaust line 52 during substrate processing, which will be described later. Note that pipes 52A and 52B may not be separated, and valve box 57 may be provided so that it is covered by the outer surface of the pipe. In this case, butterfly valve 58 is provided inside the pipe.

[0017] The butterfly valve 58 has a valve plate 87 having a shape corresponding to the through hole 86 of the valve box 57, and a shaft 88 for rotating the valve plate 87. The butterfly valve 58 is provided in the through hole 86 so as to be supported rotatably about an axis in a direction (e.g., a vertical direction) intersecting the direction in which gas flows in the flow path 89 (in other words, the direction along the flow path 89, the downstream direction of the flow path 89). Specifically, the valve plate 87 of the butterfly valve 58 is formed, for example, in the shape of a disk, and the shaft 88 is connected to pass through the center of the disk. In other words, the valve box 57 rotatably supports the butterfly valve 58.

[0018] As shown in Figures 4(a) and 4(b), the valve plate 87 has a circular first surface 87a, a second surface 87b on the back side of the first surface 87a, and a third surface (side surface) 87c located between the first surface 87a and the second surface 87b, and the third surface 87c has a smaller area than the first surface 87a and the second surface 87b.

[0019] The shaft portion 88 is composed of an upper shaft 88A that passes through the top of the valve box 57 and connects to the top of the butterfly valve 58, and a lower shaft 88B that is supported in a hole provided in the bottom of the valve box 57 and connects to the bottom of the butterfly valve 58, and is rotatable around the axis of the shaft portion 88.

[0020] As the shaft 88 rotates, the butterfly valve 58 also rotates, opening and closing the butterfly valve 58, allowing the degree of opening to be adjusted. As shown in Figures 2(a) and 2(b), when the first surface 87a and the second surface 87b of the valve plate 87 are perpendicular to the flow path direction, the degree of opening is minimum. As shown in Figures 3(a) and 3(b), when the first surface 87a and the second surface 87b of the valve plate 87 are parallel to the flow path direction, the degree of opening is maximum.

[0021] The drive unit 90 is a drive source that drives the shaft unit 88 to rotate around its axis, and is, for example, a pulse motor or a servo motor, in order to realize a desired opening degree of the butterfly valve 58.

[0022] [Pressure sensor] 1, the pressure sensor 62 is provided in communication with a pipe 62A on the processing chamber 20 side of the installation position of the flow control mechanism 55. The pressure sensor 62 is electrically connected to the main controller 70 and has the function of transmitting pressure information of the processing chamber 20. The pressure sensor 62 is also connected to the pipe 52A by the pipe 62A.

[0023] The valve controller 53 calculates a target aperture based on the target pressure of the processing chamber 20 provided by the main control unit 70 and the actual pressure measured by the pressure sensor 62. The target aperture corresponds to the conductance of the entire flow control mechanism 55 and is constantly updated using a method such as feedback control so that the deviation between the target pressure and the actual pressure becomes zero. If an upper limit on the pressure change rate is specified, even if a target pressure that changes at a rate exceeding the specified rate is input, the target pressure is internally corrected to fall within the rate. The valve controller 53 also outputs an aperture command to the drive unit 90 in accordance with the target aperture. The aperture command may be provided, for example, as a relative aperture when a fully open position of the butterfly valve 58 is 100%. A fully closed position of the butterfly valve 58 is 0%.

[0024] [Heating mechanism] As shown in FIG. 5, a butterfly valve external heating unit 91 is provided to cover the valve box 57 and the actuator 90, and a piping external heating unit 92 is provided to cover the pipes 52A and 52B. The butterfly valve external heating unit 91 and the piping external heating unit 92 are, for example, jacket heaters. The butterfly valve external heating unit 91 heats a part of the flow control mechanism 55. A thermometer 101 is provided on the upper side surface of the actuator 90, and a thermometer 102 is provided on the outer surface of the pipe 52A. The butterfly valve external heating unit 91 heats the valve box 57 and the actuator 90, thereby heating the valve plate 87. Note that the butterfly valve external heating unit 91 may be configured not to heat the actuator 90.

[0025] 6, there are provided an internal heater 93 for the driver that heats the inside of the driver 90, an internal heater 94 for the valve box that heats the inside of the valve box 57, and an internal heater 95 for the valve element that heats the inside of the valve plate 87. In addition, a thermometer 103 is provided on the side of the upper part of the driver 90, a thermometer 104 is provided on the outer surface of the valve box 57, and a thermometer 105 is provided on the surface of the valve plate 87. Note that the internal heater 93 for the driver may be omitted so that the driver 90 is not heated.

[0026] [Effect] The lower the temperature of the pipes 52A, 52B and butterfly valve 58 that constitute the exhaust system 50, the more easily foreign matter originating from the process gas adheres to their surfaces. In addition, because the butterfly valve 58 blocks the flow of the process gas in the flow path, the process gas tends to stagnate and the process gas tends to flow turbulently around the butterfly valve 58. Therefore, foreign matter is more likely to adhere to the butterfly valve 58 than to the pipes 52A, 52B, etc.

[0027] For this reason, it is preferable that the temperature of the butterfly valve 58 is higher than the temperatures of the pipes 52A and 52B. In this embodiment, the butterfly valve 58 is heated by a heating mechanism so that its temperature becomes higher than that of the pipes 52A and 52B.

[0028] The butterfly valve external heating unit 91 heats the valve box 57 to a temperature higher than that of the butterfly valve 58. As a result, as shown by the dashed arrow (b) in Figure 7, the butterfly valve 58 can be heated by thermal radiation and thermal conduction from the valve box 57 to the butterfly valve 58. Therefore, a decrease in the temperature of the butterfly valve 58 can be further suppressed.

[0029] In the heating mechanism shown in Fig. 6, the valve element internal heating unit 95 heats the butterfly valve 58 so that it is hotter than the pipes 52A and 52B. The actuator internal heating unit 93 and the valve box internal heating unit 94 heat the actuator 90 and the valve box 57 so that they are hotter than the butterfly valve 58. Note that the actuator internal heating unit 93 may be omitted, and the valve box 57 may be heated so that it is hotter than the butterfly valve 58, and the actuator 90 may be cooled lower than the butterfly valve 58. Also, either the heating mechanism shown in Fig. 5 or the heating mechanism shown in Fig. 6 may be used, or both the heating mechanism shown in Fig. 5 and the heating mechanism shown in Fig. 6 may be used.

[0030] To make the temperature of the butterfly valve 58 higher than the temperatures of the pipes 52A and 52B, heat radiation occurs from the butterfly valve 58 toward the pipes 52A and 52B, as shown by the dashed arrow (c) in FIG. 7. This causes the temperature of the butterfly valve 58 to drop. Furthermore, the temperature of the butterfly valve 58 may become higher or lower than the temperature of the process gas depending on the substrate processing. Therefore, convective heat conduction occurs between the butterfly valve 58 and the process gas, as shown by the dashed-dotted arrow (d) in FIG. 7. If the temperature of the butterfly valve 58 becomes higher than the temperature of the process gas, the temperature of the butterfly valve 58 drops. For these reasons, it is preferable to reduce the emissivity of the butterfly valve 58 to make it less likely for the thermal energy of the butterfly valve 58 to be released by thermal radiation.

[0031] Here, emissivity is the ratio of the light energy (radiance) emitted by thermal radiation from an object at a certain temperature to the light energy emitted by a black body at the same temperature (blackbody radiation), when the latter is taken as 1. Emissivity is a value (dimensionless quantity) between 0 and 1, and varies depending on the material and the wavelength of the light. If the emissivity is high, the reflectance is low, and conversely, if the emissivity is low, the reflectance is high.

[0032] In this embodiment, for example, the emissivity of at least a portion of the surface of the butterfly valve 58 is set to be equal to or lower than the emissivity of the inner surfaces of the pipes 52A and 52B. More preferably, the emissivity of at least a portion of the surface of the butterfly valve 58 is set to be lower than the emissivity of the inner surfaces of the pipes 52A and 52B. This suppresses heat radiation from the butterfly valve 58 to the pipes 52A and 52B, thereby suppressing a decrease in temperature of the butterfly valve 58.

[0033] Here, because the stem portion 88 has a smaller surface area than the valve plate 87, a temperature drop due to thermal radiation is less likely to occur. Furthermore, unlike the valve plate 87, the stem portion 88 is in direct contact with the valve box 57 and is therefore more likely to be heated by thermal conduction from the valve box 57. For these reasons, the emissivity of the surface of the stem portion 88 contributes less to a temperature drop of the butterfly valve 58 than the emissivity of the surface of the valve plate 87. Therefore, the emissivity of the surface of the stem portion 88 may be equal to or greater than the emissivity of the surface of the valve plate 87, or more preferably, the emissivity of the surface of the stem portion 88 may be greater than the emissivity of the surface of the valve plate 87. Furthermore, the emissivity of the surface of the stem portion 88 may be equal to or greater than the emissivity of the inner surfaces of the pipes 52A and 52B, or more preferably, the emissivity of the surface of the stem portion 88 may be greater than the emissivity of the inner surfaces of the pipes 52A and 52B. In these cases, processing for reducing the emissivity of the surface of the stem portion 88 can be omitted or simplified, thereby reducing the manufacturing cost of the flow control mechanism 55.

[0034] The emissivity of at least a portion of the inner surface of the valve box 57 may be set to be equal to or higher than the emissivity of the surface of the butterfly valve 58. More preferably, the emissivity of at least a portion of the inner surface of the valve box 57 may be set to be higher than the emissivity of the surface of the butterfly valve 58. This can promote heat radiation from the valve box 57 to the butterfly valve 58. Therefore, the temperature drop of the butterfly valve 58 can be further suppressed.

[0035] The emissivity of at least a portion of the inner surface of the valve box 57 may be set to be equal to or higher than the emissivity of the surfaces of the pipes 52A and 52B. More preferably, the emissivity of at least a portion of the inner surface of the valve box 57 may be set to be higher than the emissivity of the surfaces of the pipes 52A and 52B. This can promote heat radiation from the valve box 57 to the butterfly valve 58. Therefore, a decrease in temperature of the butterfly valve 58 can be suppressed.

[0036] The emissivity of at least a portion of the surface of the valve plate 87 may be set to be equal to or lower than the emissivity of the inner surfaces of the pipes 52A and 52B. More preferably, the emissivity of at least a portion of the surface of the valve plate 87 may be set to be lower than the emissivity of the inner surfaces of the pipes 52A and 52B. The valve plate 87 has a larger surface area than the shaft portion 88, and is less likely to be heated by thermal conduction. Therefore, by setting the emissivity of at least a portion of the surface of the valve plate 87 to be equal to or lower than the emissivity of the inner surfaces of the pipes 52A and 52B, it is possible to more easily suppress a decrease in temperature of the butterfly valve 58.

[0037] In order to make the emissivity of at least a part of the surface of the valve plate 87 equal to or lower than the emissivity of the inner surfaces of the pipes 52A and 52B, the following two examples may be used.

[0038] As an example, the emissivity of at least a portion of the first surface 87a and at least a portion of the second surface 87b of the valve plate 87 is set to be equal to or lower than the emissivity of the third surface 87c. More preferably, the emissivity of at least a portion of the first surface 87a and at least a portion of the second surface 87b of the valve plate 87 is set to be lower than the emissivity of the third surface 87c. The first surface 87a and the second surface 87b of the valve plate 87 have a larger surface area than the third surface 87c, making thermal radiation more likely to occur. Therefore, setting the emissivity of at least a portion of the first surface 87a and at least a portion of the second surface 87b to be equal to or lower than the emissivity of the third surface 87c can more easily suppress a temperature drop in the butterfly valve 58. In such a case, the third surface 87c of the butterfly valve 58 may not be processed to reduce its emissivity, or the processing may be simpler than that of the first surface 87a or the second surface 87b. This reduces the manufacturing cost of the butterfly valve 58.

[0039] As another example, the emissivity of the entire first surface 87a and the entire second surface 87b is set to be equal to or lower than the emissivity of the inner surfaces of the pipes 52A and 52B. More preferably, the emissivity of the entire first surface 87a and the entire second surface 87b is set to be lower than the emissivity of the inner surfaces of the pipes 52A and 52B. The first surface 87a and the second surface 87b of the valve plate 87 have a larger surface area than the third surface 87c, and therefore are more susceptible to thermal radiation. Therefore, by setting the emissivity of at least a portion of the first surface 87a and at least a portion of the second surface 87b to be equal to or lower than the emissivity of the inner surfaces of the pipes 52A and 52B, a temperature drop of the butterfly valve 58 can be more easily suppressed. The emissivity of at least a portion of the third surface 87c may also be set to be equal to or lower than the emissivity of the inner surfaces of the pipes 52A and 52B. This makes it easier to suppress a temperature drop of the butterfly valve 58.

[0040] Several examples of reducing the emissivity of a portion of the surface of the butterfly valve 58 are described below.

[0041] As a first example, at least a portion of the surface of the butterfly valve 58 is electropolished. This reduces the emissivity. It also prevents corrosion of the surface of the butterfly valve 58 due to processing gases and cleaning gases. This reduces the frequency of replacing the butterfly valve 58.

[0042] In a second example, as shown in FIG. 8(a), a film 58a having a metallic luster is formed on at least a portion of the surface of a butterfly valve 58. For example, the film 58a having a metallic luster, which contains at least one of metallic elements such as nickel (Ni), chromium (Cr), and iron (Fe), is formed on at least a portion of the surface of the butterfly valve 58. This makes it possible to reduce the emissivity of the surface of the butterfly valve 58. The film 58a having a metallic luster may contain fluorine. Substances containing fluorine have high chemical resistance. This makes it possible to suppress corrosion of the film having a metallic luster and the valve body due to processing gases and cleaning gases.

[0043] As a third example, as shown in FIG. 8( b), a high-transmittance film 58b that transmits electromagnetic waves is formed on at least a portion of the surface of the butterfly valve 58. Forming the high-transmittance film 58b on at least a portion of the butterfly valve 58 can suppress corrosion of the surface of the butterfly valve 58 due to processing gases, cleaning gases, and the like. This reduces the frequency of replacing the butterfly valve 58. Furthermore, the high-transmittance film is less likely to absorb electromagnetic waves radiated from the outside to the butterfly valve 58, and therefore is less likely to increase the emissivity of the butterfly valve 58. The high-transmittance film 58b may contain fluorine. Fluorine-containing substances have high chemical resistance. This can suppress corrosion of the metal-containing film and the butterfly valve 58 due to processing gases and cleaning gases. The high-transmittance film 58b may also contain an amorphous silicon oxide film. The amorphous silicon oxide film not only transmits electromagnetic waves easily but also has high chemical resistance. This can suppress corrosion of the metal-containing film and the valve body due to processing gases and cleaning gases.

[0044] The results of a simulation of the relationship between the emissivity and temperature of the surface of the butterfly valve 58 in the flow control mechanism shown in FIGS. 2(a) and 2(b) will be described with reference to FIG.

[0045] The horizontal axis of FIG. 9(a) represents the position on the first surface 87a or the second surface 87b of the valve plate 87 of the butterfly valve 58. "Top," "bottom," "left," "right," and "center" correspond to positions T, B, L, R, and C on the first surface 87a shown in FIG. 4(a), respectively. The vertical axis of FIG. 9(a) represents the temperature of the butterfly valve 58. FIG. 9(a) shows temperatures (°C) for emissivities of 0.1, 0.15, 0.2, 0.25, 0.3, and 0.4. FIG. 9(b) shows a table showing the temperatures (°C) of the top, bottom, left, right, and center for each of the six emissivities in FIG. 9(a), the average (Ave.) of the temperatures at these five locations, and the difference between the maximum and minimum temperatures (Max-Min) for these five locations.

[0046] The simulation conditions are: Valve box 57 temperature: 230℃ Valve box surface emissivity: 0.25 Butterfly valve 58 opening: 0% Valve box 57 and butterfly valve 58 material: SUS Temperature of pipes 52A and 52B: 180°C Emissivity of the inner surfaces of the pipes 52A and 52B: 0.25 Piping 52A, 52B material: SUS is.

[0047] Compared to when the emissivity of the butterfly valve 58 is higher than the emissivity (0.25) of the inner surfaces of the pipes 52A and 52B, the temperature difference between the lowest temperature point (Center) and other points is smaller when the emissivity is equal to or less than the emissivity (0.25) of the inner surfaces of the pipes 52A and 52B. That is, by making the emissivity of the butterfly valve 58 equal to or less than the emissivity of the inner surfaces of the pipes 52A and 52B, the occurrence of cold spots (points with lower temperatures than other points) within the butterfly valve 58 is suppressed. In this case, the average temperature of the butterfly valve 58 is also higher. That is, by making the emissivity of the butterfly valve 58 equal to or less than the emissivity of the inner surfaces of the pipes 52A and 52B, the amount of energy consumed by the butterfly valve external heating unit 91 and the valve body internal heating unit 95 can be reduced.

[0048] 9(a) and 9(b), the lower the emissivity of the surface of the butterfly valve 58, the higher the temperature of the butterfly valve 58. The temperature of the butterfly valve 58 is lower than the temperature of the valve box 57 and higher than the temperatures of the pipes 52A and 52B. From the perspective of suppressing a drop in temperature of the butterfly valve 58, a lower emissivity is preferable. However, the lower the emissivity, the higher the cost of surface treatment of the butterfly valve 58.

[0049] The emissivity of at least a portion of the surface of the butterfly valve 58 is preferably 0.05 or more and 0.25 or less. If the emissivity of the butterfly valve 58 is greater than 0.25, the temperature of the butterfly valve 58 is more likely to decrease. If it is less than 0.05, the cost of surface treatment of the butterfly valve 58 increases compared to the effect of suppressing the temperature decrease of the butterfly valve 58. Furthermore, as shown in FIGS. 9( a) and 9(b), if the emissivity of the surface of the butterfly valve 58 is 0.25 or less, the change in temperature of the butterfly valve 58 relative to the change in the emissivity of the surface of the butterfly valve 58 is greater than if it is greater than 0.25. Therefore, if the emissivity is 0.05 or more and 0.25 or less, the effect of suppressing the temperature decrease of the butterfly valve 58 can be obtained while preventing an excessive increase in the cost of surface treatment of the butterfly valve 58.

[0050] It is more preferable that the emissivity of at least a portion of the surface of the butterfly valve 58 be 0.08 or more and 0.20 or less. As shown in Figures 9(a) and 9(b), when the emissivity of the surface of the butterfly valve 58 is 0.20 or less, the amount of change in the temperature of the butterfly valve 58 relative to the amount of change in the emissivity of the surface of the butterfly valve 58 is larger than when the emissivity is greater than 0.20. Therefore, when the emissivity is 0.08 or more and 0.20 or less, it is possible to sufficiently obtain the effect of suppressing a temperature drop in the butterfly valve 58 while suppressing an increase in the cost of surface treatment of the butterfly valve 58.

[0051] It is even more preferable that the emissivity of at least a portion of the surface of the butterfly valve 58 be 0.09 or more and 0.15 or less. As shown in Figures 9(a) and 9(b), when the emissivity of the surface of the butterfly valve 58 is 0.15 or less, the amount of change in the temperature of the butterfly valve 58 relative to the amount of change in the emissivity of the surface of the butterfly valve 58 is greater than when the emissivity is greater than 0.15. Therefore, when the emissivity is 0.09 or more and 0.15 or less, the effect of suppressing a temperature drop in the butterfly valve 58 can be further increased while further suppressing an increase in the cost of surface treatment of the butterfly valve 58.

[0052] (2) Substrate processing process 10 , an example of a process for forming a film on a wafer 30 by processing the wafer 30 in the processing chamber 20 with one or more types of processing gases using the substrate processing apparatus 100 as one step in the manufacturing process of a semiconductor device will be described. In the following description, the operation of each component of the substrate processing apparatus 100 is controlled by a main control unit 70.

[0053] In the substrate processing of this embodiment, a cycle of supplying a first process gas as one of the process gases to wafers 30 accommodated in a processing container (processing chamber 20) and supplying a second process gas as one of the process gases to wafers 30 is performed a predetermined number of times (n times, n is an integer of 1 or more) to form a film on wafers 30. Specifically, a cycle of supplying a silicon (Si)-containing gas as the first process gas to wafers 30 and supplying a nitriding gas as the second process gas to wafers 30 is performed a predetermined number of times (n times, n is an integer of 1 or more) to form a silicon nitride film (SiN film) on wafers 30.

[0054] When a film-forming gas is supplied into the processing chamber 20 as a processing gas and a film is formed on the surface of an object in the processing chamber 20, such as the wafer 30, the film as a foreign substance originating from the processing gas may also adhere to the surface of the butterfly valve 58. In this way, even when the butterfly valve 58 is provided in a pipe through which the film-forming gas as the processing gas flows, the technology of the present disclosure can suppress a temperature drop in the butterfly valve 58, thereby suppressing adhesion of foreign substances originating from the processing gas to the butterfly valve 58.

[0055] When a vaporized gas obtained by vaporizing a substance that is in a solid or liquid phase under standard conditions is used as part of the process gas, the solidified or liquefied vaporized gas may adhere to the surface of butterfly valve 58 as foreign matter originating from the process gas. Thus, even when butterfly valve 58 is provided inside a pipe through which vaporized gas flows as the process gas, the technology disclosed herein can be used to suppress a temperature drop in butterfly valve 58, thereby suppressing the adhesion of foreign matter originating from the process gas to butterfly valve 58.

[0056] The term "wafer" used in this specification may refer to the wafer itself or to a laminate of the wafer and a predetermined layer or film formed on its surface. The term "surface of a wafer" used in this specification may refer to the surface of the wafer itself or to the surface of a predetermined layer or the like formed on the wafer. When described in this specification, "forming a predetermined layer on a wafer" may mean forming a predetermined layer directly on the surface of the wafer itself or forming a predetermined layer on a layer or the like formed on the wafer. When used in this specification, the term "substrate" is synonymous with the term "wafer".

[0057] (Wafer charge and boat load) When a plurality of wafers 30 are loaded into the boat 26 (wafer charge), the boat 26 supporting the plurality of wafers 30 is lifted by the boat elevator and carried into the processing chamber 20 (boat load). In this state, the furnace opening cover 28 seals the lower end of the furnace opening flange 14 via an O-ring.

[0058] (Pressure and temperature adjustment) The processing chamber 20, i.e., the space in which the wafers 30 reside, is evacuated (reduced pressure exhausted) by the vacuum pump 60 to a desired pressure (vacuum level). At this time, the pressure inside the reaction tube 12 is measured by the pressure sensor 62, and the flow rate control mechanism 55 is feedback-controlled based on the measured pressure information. That is, the flow rate control mechanism 55 controls the opening of the flow path 89. This adjusts the pressure inside the processing chamber 20 to the desired pressure. The vacuum pump 60 and the flow rate control mechanism 55 are kept in a constantly operating state until the substrate processing is completed. Furthermore, the wafers 30 in the processing chamber 20 are heated by the heater 18 to a desired film formation temperature. At this time, the power supply to the heater 18 is feedback-controlled based on temperature information detected by a temperature sensor (not shown) to achieve a desired temperature distribution inside the processing chamber 20. Heating inside the processing chamber 20 by the heater 18 continues at least until the processing of the wafers 30 is completed.

[0059] (Substrate processing) Subsequently, as substrate processing, the following first process gas supply step, purge gas supply step, second process gas supply step, and purge gas supply step are sequentially performed.

[0060] [First processing gas supply step: S1] In this step, a Si-containing gas and a carrier gas as a first process gas are supplied to the wafers 30 in the processing chamber 20. By supplying the Si-containing gas to the wafers 30, a Si-containing layer is formed as a first layer on the outermost surface of each of the multiple wafers 30.

[0061] [Purge gas supply process: S2] After the first layer is formed, the supply of the Si-containing gas into the inner tube 16 is stopped. At this time, the butterfly valve 58 of the flow control mechanism 55 is left open, and the reaction tube 12 is evacuated by the vacuum pump 60, and any unreacted Si-containing gas remaining in the processing chamber 20 or that has contributed to the formation of the first layer is removed from the processing chamber 20. At this time, the supply of the carrier gas into the processing chamber 20 is maintained. The carrier gas acts as a purge gas, and can enhance the effect of discharging any gas remaining in the processing chamber 20 from the processing chamber 20. When the purging is completed, the supply of the carrier gas into the processing chamber 20 is stopped.

[0062] [Second processing gas supply step: S3] After S2 is completed, nitriding gas and carrier gas are supplied as a second process gas to the wafer 30 in the process chamber 20. The nitriding gas supplied to the wafer 30 reacts with at least a portion of the first layer, i.e., the Si-containing layer, formed on the wafer 30 in S1. As a result, the first layer is nitrided and changed (modified) into a second layer containing Si and N, i.e., a SiN layer.

[0063] [Purge gas supply process: S4] After the second layer (SiN layer) is formed, the supply of nitriding gas into the inner tube 16 is stopped. Then, by the same processing procedure as in S2, the nitriding gas and reaction by-products remaining in the processing chamber 20 are removed from the processing chamber 20.

[0064] [Perform the specified number of times] By performing the above-described steps S1 to S4 asynchronously, i.e., without synchronization, a predetermined number of times (n times, where n is an integer equal to or greater than 1), a SiN film of a predetermined thickness can be formed on wafer 30. The above-described cycle is preferably repeated multiple times. That is, it is preferable to set the thickness of the second layer formed per cycle to be smaller than the desired thickness, and to repeat the above-described cycle multiple times until the thickness of the film formed by stacking the second layer reaches the desired thickness.

[0065] (After purge step: atmospheric pressure return) After the substrate processing is completed, an inert gas is supplied into the reaction tube 12 and exhausted through the exhaust line 52. This purges the processing chamber 20, and any gases or reaction by-products remaining in the processing chamber 20 are removed from the processing chamber 20 (after-purge). Thereafter, the atmosphere in the processing chamber 20 is replaced with an inert gas (inert gas replacement), and the pressure in the processing chamber 20 is returned to normal pressure (return to atmospheric pressure).

[0066] (Boat unloading and wafer discharge) Thereafter, the furnace opening cover 28 is lowered to open the lower end of the furnace opening flange 14, and the processed wafers 30 supported by the boat 26 are unloaded from the reaction tube 12 (boat unloading). After being unloaded from the reaction tube 12, the processed wafers 30 are removed from the boat 26 (wafer discharging).

[0067] According to this embodiment, the butterfly valve 58 is heated to a temperature higher than that of the pipes 52A and 52B, and the emissivity of at least a part of the surface of the butterfly valve 58 is set to be equal to or lower than that of the inner surfaces of the pipes 52A and 52B. This makes it possible to suppress a decrease in the temperature of the heated butterfly valve 58, and therefore makes it possible to suppress adhesion of foreign matter to the butterfly valve 58.

[0068] In the above-described embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied, for example, to a case where a film is formed using a single-wafer substrate processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace.

[0069] When using these substrate processing apparatuses, each process can be performed under the same process procedures and conditions as in the above-described embodiment, and the same effects as in the above-described embodiment can be obtained. [Explanation of symbols]

[0070] 52A, 52B... Piping 55 Flow control mechanism 58. Butterfly valve (valve body) 90 Drive unit

Claims

1. a valve body that is supported rotatably about an axis that intersects with the gas flow direction in a process gas flow path at least a portion of which is formed by a pipe, that is heated to a temperature higher than that of the pipe, and that has an emissivity of at least a portion of its surface that is equal to or lower than that of the inner surface of the pipe; a drive unit that rotates the valve body to change the opening degree of the flow path; having Flow control mechanism.

2. The valve body further includes a valve body that rotatably supports the valve body. The valve body is heated to a temperature higher than that of the valve body. The flow control mechanism of claim 1 .

3. the valve body defining at least a portion of the flow path; The emissivity of at least a part of the inner surface of the valve body is set to be equal to or higher than the emissivity of the surface of the valve body. The flow control mechanism according to claim 2 .

4. the valve body defining at least a portion of the flow path; The emissivity of at least a part of the inner surface of the valve body is set to be equal to or higher than the emissivity of the surface of the piping. The flow control mechanism according to claim 2 .

5. the valve body has a shaft portion rotated by the drive portion and a valve plate provided on the shaft portion, The emissivity of at least a part of the surface of the valve plate is set to be equal to or lower than the emissivity of the inner surface of the pipe. The flow control mechanism of claim 1 .

6. the valve plate has a first surface, a second surface located on a back surface side of the first surface, and a third surface having an area smaller than the first surface and the second surface; The emissivity of at least a portion of the first surface and at least a portion of the second surface is equal to or less than the emissivity of the third surface. The flow control mechanism according to claim 5 .

7. the valve plate has a first surface, a second surface located on a back surface side of the first surface, and a third surface having an area smaller than the first surface and the second surface; The emissivity of the entire first surface and the entire second surface is set to be equal to or less than the emissivity of the inner surface of the pipe. The flow control mechanism according to claim 5 .

8. The emissivity of at least a part of the third surface is set to be equal to or lower than the emissivity of the inner surface of the pipe. The flow control mechanism of claim 7.

9. At least a portion of the surface of the valve body is electropolished. The flow control mechanism of claim 1 .

10. The valve body has a film having a metallic luster formed on at least a part of its surface. The flow control mechanism of claim 1 .

11. the film having metallic luster contains fluorine; The flow control mechanism of claim 10.

12. The valve body has a high transmittance film formed on at least a part of its surface that transmits electromagnetic waves. The flow control mechanism of claim 1 .

13. The flow control mechanism of claim 12 , wherein the high-transmittance film contains fluorine.

14. The flow control mechanism of claim 12 , wherein the high transmittance film comprises an amorphous film of silicon oxide.

15. The emissivity of at least a part of the surface of the valve body is 0.05 or more and 0.25 or less. The flow control mechanism of claim 1 .

16. The emissivity of at least a part of the surface of the valve body is 0.08 or more and 0.20 or less. The flow control mechanism of claim 1 .

17. The emissivity of at least a part of the surface of the valve body is 0.09 or more and 0.15 or less. The flow control mechanism of claim 1 .

18. a processing chamber in which processing of the substrate with a processing gas is performed; a pipe connected to the processing chamber and constituting at least a part of a flow path of the processing gas; a valve element configured to be rotatable about an axis perpendicular to a direction intersecting with a gas flow direction in the flow path, the valve element being heated to a temperature higher than a temperature of the piping, and having an emissivity of at least a part of its surface lower than the emissivity of an inner surface of the piping; a drive unit that rotates the valve body to change the opening degree of the flow path; a flow rate control mechanism having a heating unit that heats at least a part of the flow rate control mechanism; A substrate processing apparatus having:

19. (a) processing a substrate in a processing chamber with a processing gas; (b) controlling the opening of a flow path for the processing gas, the flow path being at least partially constituted by a pipe connected to the processing chamber, using a flow control mechanism; and The flow rate control mechanism includes: a valve body that is supported in the processing gas flow path so as to be rotatable about an axis that intersects with the gas flow direction, that is heated to a temperature higher than that of the pipe, and that has an emissivity of at least a portion of its surface that is equal to or lower than that of the inner surface of the pipe; a drive unit that rotates the valve body to change the opening degree of the flow path; A method for manufacturing a semiconductor device having the above structure.

20. (a) processing a substrate in a processing chamber with a processing gas; (b) controlling, by a flow control mechanism, the opening of a flow path for the processing gas, the flow path being at least partially constituted by a pipe connected to the processing chamber; and The flow rate control mechanism includes: a valve body that is supported in the processing gas flow path so as to be rotatable about an axis that intersects with the gas flow direction, that is heated to a temperature higher than that of the pipe, and that has an emissivity of at least a portion of its surface that is equal to or lower than that of the inner surface of the pipe; a drive unit that rotates the valve body to change the opening degree of the flow path; A program that causes a computer to execute a procedure having the steps.

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