Substrate processing apparatus

Abstract

To provide technology that improves surface uniformity in processing.SOLUTION: A substrate processing apparatus according to one embodiment of the present disclosure comprises: a reaction vessel having a first tube axis extending in the vertical direction; a vacuum pipe provided horizontally spaced apart from the reaction vessel and having a second tube axis parallel to the first tube axis; an exhaust duct having a flow path connecting the interior of the reaction vessel to the interior of the vacuum pipe; and a housing that internally accommodates the reaction vessel, the vacuum pipe, and the exhaust duct.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus. [Background technology]

[0002] Batch-type substrate processing apparatuses that process a plurality of substrates at once are known (see, for example, Patent Documents 1 and 2). In Patent Document 1, gas supplied into an inner tube passes through a gap between the inner tube and the outer tube and is exhausted from an exhaust pipe located below the outer tube. In Patent Document 2, a gas inlet pipe and a gas exhaust pipe are provided opposite each other on the side of a reaction tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-13967 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-172205 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can improve inter-surface processing uniformity. [Means for solving the problem]

[0005] A substrate processing apparatus according to one embodiment of the present disclosure includes a reaction tube having a first tube axis extending in a vertical direction, a vacuum pipe provided horizontally spaced apart from the reaction tube and having a second tube axis parallel to the first tube axis, an exhaust duct having a flow path connecting an inside of the reaction tube with an inside of the vacuum pipe, and a housing that accommodates the reaction tube, the vacuum pipe, and the exhaust duct. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to improve inter-surface processing uniformity. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view (1) showing a substrate processing apparatus according to an embodiment. [Figure 2] FIG. 2 is a perspective view (2) showing the substrate processing apparatus according to the embodiment. [Figure 3] 1 is a vertical cross-sectional view showing a substrate processing apparatus according to an embodiment. [Figure 4] 1 is a horizontal cross-sectional view (1) showing a substrate processing apparatus according to an embodiment. [Figure 5] FIG. 2 is a horizontal cross-sectional view (2) showing the substrate processing apparatus according to the embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of an exhaust duct. [Figure 7] FIG. 1 is a diagram showing a simulation result of gas flow velocity distribution in the vertical direction inside a reaction tube. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding reference numerals are used to designate the same or corresponding members or components, and redundant descriptions will be omitted.

[0009] (Substrate processing equipment) A substrate processing apparatus 1 according to an embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is a perspective view showing the substrate processing apparatus 1 according to an embodiment, as viewed obliquely from above. FIG. 2 is a perspective view showing the substrate processing apparatus 1 according to an embodiment, as viewed obliquely from below. FIG. 3 is a vertical cross-sectional view showing the substrate processing apparatus 1 according to an embodiment. FIG. 4 is a horizontal cross-sectional view showing the substrate processing apparatus 1 according to an embodiment, as viewed along the line IV-IV in FIG. 3. FIG. 5 is a horizontal cross-sectional view showing the substrate processing apparatus 1 according to an embodiment, as viewed along the line VV in FIG. 3.

[0010] The substrate processing apparatus 1 is a batch-type apparatus that performs various processes collectively on a plurality of substrates W. The various processes include, for example, a film formation process for forming a film on the substrate W by atomic layer deposition (ALD) or chemical vapor deposition (CVD). The various processes may also include an etching process for removing a film formed on the substrate W.

[0011] The substrate processing apparatus 1 includes a reaction tube 10, a gas introduction section 20, a vacuum pipe 30, an exhaust duct 40, a housing 50, a heating section 60, a pressure reduction section 70, a pressure increase section 80, and an apparatus housing 90. The housing 50, the heating section 60, the pressure reduction section 70, the pressure increase section 80, and the apparatus housing 90 are not shown in FIGS. 1 and 2. The reaction tube 10, the vacuum pipe 30, and the exhaust duct 40 are joined together by, for example, welding, and are integrally configured. The reaction tube 10, the vacuum pipe 30, and the exhaust duct 40 are made of, for example, quartz.

[0012] The reaction tube 10 has a tube axis 10X extending in the vertical direction. The tube axis 10X is an example of a first tube axis. The reaction tube 10 has a cylindrical shape with a ceiling and an open lower end. An inlet opening 10a and an exhaust opening 10b are provided on the outer wall of the reaction tube 10.

[0013] The inlet openings 10a penetrate the outer wall of the reaction tube 10. The inlet openings 10a are provided at positions in the circumferential direction of the reaction tube 10 where gas inlet ducts 211 to 218, which will be described later, are attached. A plurality of inlet openings 10a are provided at each position in the circumferential direction of the reaction tube 10 along the vertical direction from near the upper end to near the lower end of the reaction tube 10. In this case, it is easy to uniformly supply gas into the reaction tube 10 in a range from the upper end to the lower end.

[0014] The exhaust opening 10b penetrates the outer wall of the reaction tube 10. The exhaust opening 10b is provided at a position different from the inlet opening 10a in the circumferential direction of the reaction tube 10. The exhaust opening 10b is provided at a position in the circumferential direction of the reaction tube 10 where the exhaust duct 40 is attached. The exhaust opening 10b is a rectangular opening extending vertically from near the upper end to near the lower end of the reaction tube 10. In this case, it is easy to uniformly exhaust air from the upper end to the lower end of the reaction tube 10.

[0015] The opening at the bottom of the reaction tube 10 is airtightly closed by a lid (not shown). The lid is made of a metal such as stainless steel. A substrate holder 11 (FIG. 3) is housed inside the reaction tube 10. The substrate holder 11 holds a plurality of substrates W (FIG. 6) arranged in multiple stages in a horizontal position in the vertical direction. The number of substrates W is not limited, but may be, for example, 25 to 200. The substrates W are not shown in FIG. 3. The substrate holder 11 is made of, for example, quartz.

[0016] The gas introduction section 20 has gas introduction ducts 211 to 218, nozzles 221 to 228, gas introduction pipes 231 to 238, and on-off valves 241 to 248. In Fig. 3, gas introduction pipes 231 to 235 and on-off valves 241 to 245 are shown.

[0017] The gas introduction ducts 211-218 are provided along the circumferential direction of the reaction tube 10. The gas introduction ducts 211-218 are provided at intervals from each other in the circumferential direction of the reaction tube 10. In this case, the thermal influence from adjacent gas introduction ducts 211-218 can be reduced. This suppresses a temperature drop in the gas introduction ducts 211-218 and the generation of particles. The gas introduction ducts 211-218 are provided radially at intervals from each other in the circumferential direction of the reaction tube 10. In this case, as shown by the arrows in FIG. 5, gases such as source gas, reactive gas, etching gas, and purge gas can be supplied into the reaction tube 10 from multiple positions (multiple directions) in the circumferential direction of the reaction tube 10. This makes it easy to adjust the in-plane shape of the film formation or etching. For example, by adjusting the gas supply position and the gas supply amount, the residence time and gas concentration distribution of the gas supplied to the surface of the substrate W can be adjusted. Therefore, it is easier to control the in-plane shape of film formation and etching than with a unidirectional gas flow. Gas introduction ducts 211 to 218 are provided in this order, for example, counterclockwise from exhaust opening 10b.

[0018] The gas introduction ducts 211-218 are attached to the outer wall of the reaction tube 10. In this case, the distance from the gas introduction ducts 211-218 to the substrate is shortened. This reduces unnecessary thermal decomposition of gas. Furthermore, when the gas introduction ducts 211-218 are attached to the outer wall of the reaction tube 10, it is not necessary to dispose the nozzles 221-228 inside the reaction tube 10. This reduces the space between the outer peripheral edge of the substrate W and the inner wall of the reaction tube 10, thereby reducing the gas flow into this space. As a result, the efficiency of gas supply between vertically adjacent substrates W is improved. Furthermore, when the gas introduction ducts 211-218 are attached to the outer wall of the reaction tube 10, it is not necessary to protrude the side wall of the reaction tube 10 radially outward to form nozzle chambers for accommodating the nozzles 221-228. The gas introduction ducts 211-218 are, for example, integrally formed with the reaction tube 10. The gas introduction ducts 211 to 218 are made of, for example, quartz.

[0019] The gas introduction ducts 211-218 have a tubular shape with a closed lower end and an open upper end. The upper ends of the gas introduction ducts 211-218 extend above the upper surface of the reaction tube 10 and penetrate the casing 50. In this case, the upper space of the casing 50 can be used as a space for installing the gas introduction pipes 231-238 and the on-off valves 241-248. Therefore, the piping distance from the on-off valves 241-248 to the reaction tube 10 can be shortened. In addition, the shape of the gas introduction pipes 231-238 can be simplified. Gas holes 211a-218a (FIG. 5) are provided in the gas introduction ducts 211-218 at positions facing the reaction tube 10.

[0020] Each of the gas holes 211a-218a has a rectangular shape extending vertically from near the upper end to near the lower end of the reaction tube 10. Each of the gas holes 211a-218a extends, for example, from above the uppermost inlet opening 10a to below the lowermost inlet opening 10a. The gas flowing inside the gas inlet ducts 211-218 is discharged into the reaction tube 10 from the gas holes 211a-218a.

[0021] The gas inlet duct 211 is provided at an angle less than 90° counterclockwise from the exhaust duct 40 in the circumferential direction of the reaction tube 10. The gas inlet duct 212 is provided at an angle position 90° counterclockwise from the exhaust duct 40 in the circumferential direction of the reaction tube 10. The gas inlet ducts 213 and 214 are provided at an angle greater than 90° and less than 180° counterclockwise from the exhaust duct 40. The gas inlet duct 215 is provided at an angle position 180° counterclockwise from the exhaust duct 40 in the circumferential direction of the reaction tube 10. That is, the gas inlet duct 215 is provided at a position opposite to the exhaust duct 40. The gas inlet ducts 216 and 217 are provided at an angle greater than 180° and less than 270° counterclockwise from the exhaust duct 40. The gas introduction duct 218 is provided at an angular position of 270° counterclockwise from the exhaust duct 40. In other words, the gas introduction duct 218 is provided at a position opposite the gas introduction duct 212.

[0022] The nozzles 221-228 are detachably inserted into the gas introduction ducts 211-218. In this case, the shape of the nozzles 221-228 can be changed depending on the type of processing, and the optimal nozzles 221-228 can be used depending on the type of processing. The inner surfaces of the gas introduction ducts 211-218 have a shape that follows the outer surfaces of the nozzles 221-228, for example, and a gap is provided between the inner surfaces of the gas introduction ducts 211-218 and the outer surfaces of the nozzles 221-228. In this case, the volume of the space between the gas introduction ducts 211-218 and the nozzles 221-228 can be reduced. This prevents gas from accumulating in the space, improving the efficiency of gas supply to the substrate W. Furthermore, the surface area in contact with the gas is reduced, which prevents particle generation in the space. This makes cleaning the space easier. In a cross section perpendicular to the longitudinal direction of the nozzles 221 to 228, the inner surfaces of the gas introduction ducts 211 to 218 are, for example, circular, and the outer surfaces of the nozzles 221 to 228 are, for example, circular. In a cross section perpendicular to the longitudinal direction of the nozzles 221 to 228, the inner surfaces of the gas introduction ducts 211 to 218 may be elliptical, and the outer surfaces of the nozzles 221 to 228 may be elliptical.

[0023] The nozzles 221 to 228 are provided with gas discharge holes (not shown). The gas discharge holes are provided, for example, in the portions of the pipe walls of the nozzles 221 to 228 that are inserted into the gas introduction ducts 211 to 218. The upper ends of the nozzles 221 to 228 are connected to gas sources (not shown) via corresponding gas introduction pipes 231 to 238. Gas from the gas sources is introduced into the nozzles 221 to 228 from the upper ends thereof, and is discharged into the reaction tube 10 through the gas discharge holes, gas holes 211a to 218a, and introduction opening 10a. The nozzles 221 to 228 are not shown in FIGS. 2 to 5.

[0024] The nozzles 221-228 do not necessarily have to be provided. In this case, the upper ends of the gas introduction ducts 211-218 are connected to the gas sources via the corresponding gas introduction pipes 231-238. Gas from the gas sources is introduced into the gas introduction ducts 211-218 from the upper ends thereof and discharged into the reaction tube 10 via the gas holes 211a-218a. For example, when a gas that is easily thermally decomposed, such as hexachlorodisilane (HCD) gas or dichlorosilane (DCS) gas, is used, the nozzles 221-228 do not necessarily have to be provided.

[0025] The gas introduction pipes 231-238 are provided in the upper space of the housing 50. One end of the gas introduction pipes 231-238 is connected to the corresponding gas introduction ducts 211-218 or the corresponding nozzles 221-228, and the other end passes through the apparatus housing 90 and extends to the outside of the apparatus housing 90. The gas introduction pipes 231-238 are provided with on-off valves 241-248. The gas introduction pipes 231-238 may be provided with a flow rate controller such as a mass flow controller.

[0026] The on-off valves 241 to 248 are provided in the upper space of the casing 50. The on-off valves 241 to 248 are provided midway along the corresponding gas introduction pipes 231 to 238. The on-off valves 241 to 248 are attached to, for example, the inner wall of the apparatus casing 90. The on-off valves 241 to 248 are valves that switch the flow of gas on and off.

[0027] The vacuum pipe 30 has a tube axis 30X extending in the vertical direction. The tube axis 30X is an example of a second tube axis. The vacuum pipe 30 has a cylindrical shape with a ceiling and an open lower end. The horizontal cross section of the vacuum pipe 30 is circular. However, the horizontal cross section of the vacuum pipe 30 may be rectangular or elliptical. The vacuum pipe 30 is installed horizontally spaced apart from the reaction tube 10. The vacuum pipe 30 is installed adjacent to the reaction tube 10. The vacuum pipe 30 is installed at approximately the same height as the reaction tube 10. An opening 30a (FIG. 5) is provided on the outer wall of the vacuum pipe 30 at the same position as the exhaust duct 40 in the circumferential direction of the vacuum pipe 30. The opening 30a is a rectangular opening extending vertically from near the upper end to near the lower end of the vacuum pipe 30. The vertical length of the opening 30a may be the same as the vertical length of the exhaust opening 10b. The tube axis 30X of the vacuum pipe 30 may be parallel to the tube axis 10X of the reaction tube 10. The lower end of the vacuum pipe 30 is connected to an exhaust device (not shown) such as a vacuum pump via a pipe (not shown).

[0028] The flow path cross-sectional area A2 (FIG. 5) of the vacuum pipe 30 is preferably 0.7 times or more the flow path cross-sectional area A3 (FIG. 6) of the exhaust duct 40. In this case, the exhaust flow velocity in the vertical direction tends to be uniform, and a uniform laminar flow in the vertical direction tends to be formed. Therefore, the inter-surface uniformity of film formation and etching is improved. The flow path cross-sectional area A2 of the vacuum pipe 30 may be the same as the flow path cross-sectional area A3 of the exhaust duct 40. The flow path cross-sectional area A2 of the vacuum pipe 30 may be larger than the flow path cross-sectional area A3 of the exhaust duct 40. The flow path cross-sectional area A2 of the vacuum pipe 30 may be smaller than the flow path cross-sectional area A1 (FIG. 5) of the reaction tube 10. The flow path cross-sectional area A1 of the reaction tube 10 is the cross-sectional area of ​​the reaction tube 10 in a horizontal cross section. The flow path cross-sectional area A2 of the vacuum pipe 30 is the cross-sectional area of ​​the vacuum pipe 30 in a horizontal cross section. The flow path cross-sectional area A3 of the exhaust duct 40 is the sum of the cross-sectional areas of the divided flow paths 411 to 425 in the vertical cross section. The divided flow paths 411 to 425 will be described later.

[0029] In a cross section (FIG. 5) perpendicular to the tube axis 10X and the tube axis 30X, where L1 is the inner diameter of the reaction tube 10, L2 is the inner diameter of the vacuum pipe 30, and L3 is the flow path width of the exhaust duct, it is preferable that the relationship L1>L2>L3 be satisfied. In this case, the exhaust flow velocity in the vertical direction is likely to be uniform, and a uniform laminar flow in the vertical direction is likely to be formed. This improves the inter-surface uniformity of film formation and etching. The inner diameter L1 of the reaction tube 10 is a dimension determined, for example, according to the diameter of the substrate W to be processed, and is set in consideration of the clearance when the substrate holder 11 is loaded into the reaction tube 10, the distance between the gas holes 211a-218a and the substrate W held by the substrate holder 11, and the like. The flow path width L3 of the exhaust duct 40 is set in consideration of, for example, the quality of the processing performed on the substrate W. The processing quality includes, for example, the inter-surface uniformity of the processing and the in-surface uniformity of the processing. The flow path width L3 of the exhaust duct 40 may be equal to or greater than ¼ of the inner diameter L1 of the reaction tube 10. In this case, it is easy to prevent a decrease in the flow rate of the gas flowing inside the reaction tube 10. Therefore, it is easy to improve the in-plane uniformity of the processing.

[0030] The exhaust duct 40 connects the reaction tube 10 and the vacuum pipe 30. The exhaust duct 40 has a flow path 41 that connects the inside of the reaction tube 10 with the inside of the vacuum pipe 30. One end of the exhaust duct 40 is connected to the outer wall of the reaction tube 10 so as to cover the exhaust opening 10b, and the other end is connected to the outer wall of the vacuum pipe 30 so as to cover the opening 30a. In this case, the length X (FIG. 4) occupied by the exhaust duct 40 in the circumferential direction of the reaction tube 10 can be shortened compared to the case where the vacuum pipe 30 is directly connected to the reaction tube 10 without providing the exhaust duct 40. Therefore, the length in the circumferential direction of the reaction tube 10 over which the gas introduction ducts 211-218 can be attached becomes longer. This allows the number of gas introduction ducts 211-218 to be installed on the outer wall of the reaction tube 10 to be increased. The exhaust duct 40 may be divided into multiple parts in the vertical direction. In this case, the gas flow from the inside of the reaction tube 10 toward the vacuum pipe 30 is rectified. Therefore, the uniformity of the gas flow at different positions in the vertical direction inside the reaction tube 10 is improved.

[0031] The housing 50 accommodates the reaction tube 10, the gas inlet 20, the vacuum pipe 30, the exhaust duct 40, and the heating unit 60. Since the housing 50 accommodates the heating unit 60 including a heater, it is also called a heater shell. The housing 50 has a bottom 51, a top 52, and a side 53. The bottom 51 supports the reaction tube 10 and the vacuum pipe 30. The top 52 is provided above the upper surface of the reaction tube 10 and the upper surface of the vacuum pipe 30. The top 52 covers the upper surface of the reaction tube 10 and the upper surface of the vacuum pipe 30. The side 53 is provided around the reaction tube 10, the gas inlet 20, the vacuum pipe 30, and the exhaust duct 40. The side 53 covers the periphery of the reaction tube 10, the gas inlet 20, the vacuum pipe 30, and the exhaust duct 40. The lower end of the side 53 is connected to the bottom 51, and the upper end is connected to the top 52. The bottom portion 51, the top portion 52, and the side portion 53 are, for example, separate bodies, or may be integrally formed.

[0032] The heating unit 60 is provided inside the housing 50. The heating unit 60 includes a first side heater 61, a second side heater 62, a third side heater 63, a first ceiling heater 64, a second ceiling heater 65, and a lower heater 66. The first side heater 61, the second side heater 62, the third side heater 63, the first ceiling heater 64, the second ceiling heater 65, and the lower heater 66 are, for example, carbon wire heaters. In this case, the temperature of the substrate W accommodated inside the reaction tube 10 can be rapidly increased or decreased.

[0033] A plurality of first side heaters 61 are provided around the reaction tube 10. The plurality of first side heaters 61 are radially arranged at intervals in the circumferential direction of the reaction tube 10. Each first side heater 61 is provided at a position different from the exhaust duct 40 in the circumferential direction of the reaction tube 10. Each first side heater 61 may be divided into a plurality of heaters in the vertical direction. In this case, the temperature in the vertical direction can be independently adjusted by independently controlling the divided first side heaters 61. The first side heater 61 heats the substrate W accommodated inside the reaction tube 10 from the outside of the reaction tube 10 by thermal radiation, as indicated by the solid arrows in FIG. 4 .

[0034] The second side heater 62 is provided at a position different from that of the first side heater 61 in the circumferential direction of the reaction tube 10. The second side heater 62 is provided at a position different from that of the plurality of gas inlet ducts 211-218 in the circumferential direction of the reaction tube 10. The second side heater 62 is provided at a position including the same position as that of the exhaust duct 40 in the circumferential direction of the reaction tube 10. Since the exhaust duct 40 is provided around the reaction tube 10 at the same position as the exhaust duct 40 in the circumferential direction of the reaction tube 10, the second side heater 62 cannot be provided there. Therefore, the second side heater 62 is provided around the vacuum pipe 30. That is, the second side heater 62 is provided at a position farther from the center C1 of the reaction tube 10 than the first side heater 61. For example, the second side heater 62 is disposed on an imaginary half line L extending from the center C1 of the reaction tube 10 through the center C3 of the vacuum pipe 30 in a plan view. The second side heater 62 may be divided into multiple parts in the vertical direction. In this case, the temperature in the vertical direction can be independently adjusted by independently controlling the multiple divided second side heaters 62. As shown by the dashed arrows in FIG. 4, the second side heater 62 heats the vacuum pipe 30 and the exhaust duct 40 by thermal radiation and also heats the substrate W accommodated inside the reaction tube 10. As a result, the substrate W accommodated inside the reaction tube 10 is heated from all directions around the reaction tube 10 by the first side heater 61 and the second side heater 62. This improves the temperature uniformity within the substrate surface.

[0035] A plurality of third side heaters 63 are provided around the vacuum pipe 30. The plurality of third side heaters 63 are provided at intervals in the circumferential direction of the vacuum pipe 30. Each third side heater 63 is provided at a different position from the second side heater 62 in the circumferential direction of the vacuum pipe 30. Each third side heater 63 is provided so as not to include on the imaginary half line L in a plan view. Each third side heater 63 may be divided into multiple parts in the vertical direction. In this case, by independently controlling the multiple divided third side heaters 63, the temperature in the vertical direction can be independently adjusted. The third side heater 63 heats the vacuum pipe 30 as indicated by the dashed arrow in FIG. 4.

[0036] The first ceiling heater 64 is provided between the upper surface of the reaction tube 10 and the ceiling part 52 of the housing 50. The first ceiling heater 64 heats the substrate W accommodated inside the reaction tube 10 from above the reaction tube 10 by thermal radiation. The number of first ceiling heaters 64 may be one or two or more.

[0037] The second ceiling heater 65 is provided between the upper surface of the vacuum pipe 30 and the top part 52 of the housing 50. The second ceiling heater 65 heats the vacuum pipe 30 from above the vacuum pipe 30 by thermal radiation. The number of second ceiling heaters 65 may be one, or two or more.

[0038] A plurality of lower heaters 66 are provided around the lower part of the reaction tube 10. The plurality of lower heaters 66 are provided radially at intervals in the circumferential direction of the reaction tube 10. The lower heaters 66 are provided below the substrate holder 11. The lower heaters 66 heat the lower part of the reaction tube 10 by thermal radiation and suppress heat radiation from the opening at the lower end of the reaction tube 10.

[0039] The pressure reducing unit 70 reduces the pressure inside the housing 50. The pressure reducing unit 70 includes a pipe 71, a safety valve 72, an on-off valve 73, and a vacuum pump 74.

[0040] The pipe 71 is connected to a port 53a provided on the side portion 53 of the housing 50. The pipe 71 passes through the side portion 53 and the device housing 90 and extends to the outside of the device housing 90. The pipe 71 is provided with a safety valve 72, an on-off valve 73, and a vacuum pump 74, in this order from the housing 50 side. The safety valve 72, the on-off valve 73, and the vacuum pump 74 are provided, for example, outside the device housing 90. The safety valve 72, the on-off valve 73, and the vacuum pump 74 may also be provided outside the housing 50 and inside the device housing 90.

[0041] When the pressure inside the housing 50 exceeds a set pressure, the safety valve 72 changes from a closed state to an open state, thereby maintaining the pressure inside the housing 50 at or below the set pressure.

[0042] The on-off valve 73 is a valve that switches the flow of gas on and off.

[0043] The vacuum pump 74 reduces the pressure inside the housing 50 through the piping 71 .

[0044] When the on-off valve 73 is opened, the vacuum pump 74 depressurizes the interior of the housing 50. When the interior of the housing 50 is depressurized, heat transfer due to convection is suppressed. This suppresses heat transfer to the outside of the housing 50, allowing the space above the housing 50 to be used as a space for installing the on-off valves 241-248. Furthermore, since a heat insulating material is not required, the distance between the reaction tube 10 and the housing 50 can be reduced. This shortens the distance from the on-off valves 241-248 to the substrate, improving gas controllability. Furthermore, when the side heaters (the first side heater 61, the second side heater 62, and the third side heater 63) are divided into multiple heaters in the vertical direction, there is no influence of convection inside the housing 50, and the heaters are less likely to be affected by other heaters in the vertical direction. This improves temperature controllability between the surfaces (vertical direction). This makes it easy to selectively heat only the lower part of the reaction tube 10, selectively heat only the center of the reaction tube 10, or selectively heat only the upper part of the reaction tube 10.

[0045] The pressure increasing unit 80 returns the reduced pressure inside the housing 50 to atmospheric pressure. The pressure increasing unit 80 includes a pipe 81, a gas source 82, a flow rate controller 83, and an on-off valve 84.

[0046] The pipe 81 is connected to a port 53b provided on the side part 53 of the housing 50. The pipe 81 extends through the side part 53 and the device housing 90 to the outside of the device housing 90. A gas source 82, a flow rate controller 83, and an on-off valve 84 are provided on the pipe 81 in this order from the upstream side to the downstream side in the gas flow direction. The gas source 82, the flow rate controller 83, and the on-off valve 84 are provided, for example, outside the device housing 90. The gas source 82, the flow rate controller 83, and the on-off valve 84 may be provided outside the housing 50 and inside the device housing 90.

[0047] The gas source 82 is, for example, a source of inert gas. The inert gas is, for example, nitrogen gas. The inert gas may also be argon gas.

[0048] The flow rate controller 83 controls the flow rate of the gas flowing through the pipe 81. The flow rate controller 83 is, for example, a mass flow controller.

[0049] The on-off valve 84 is a valve that switches the flow of gas on and off.

[0050] When the on-off valve 84 is opened, the flow rate of the gas from the gas source 82 is controlled by the flow rate controller 83, and the gas with the controlled flow rate is supplied to the inside of the housing 50. As a result, the pressure inside the housing 50, which has been reduced, returns to atmospheric pressure.

[0051] The device housing 90 surrounds the housing 50. The device housing 90 covers the entire housing 50. The device housing 90 supports the bottom 51 of the housing 50.

[0052] As described above, the substrate processing apparatus 1 according to this embodiment includes a reaction tube 10, a vacuum pipe 30, and an exhaust duct 40. The reaction tube 10 has a tube axis 10X extending in the vertical direction. The vacuum pipe 30 is installed horizontally spaced apart from the reaction tube 10 and has a tube axis 30X parallel to the tube axis 10X. The exhaust duct 40 has a flow path 41 connecting the inside of the reaction tube 10 with the inside of the vacuum pipe 30. In this case, gas inside the reaction tube 10 flows horizontally or approximately horizontally through the flow path 41 of the exhaust duct 40 and is then exhausted through the vacuum pipe 30. This makes it easy to uniformize the exhaust flow velocity in the vertical direction and to form a uniform laminar flow in the vertical direction. As a result, the inter-surface uniformity of film formation and etching is improved.

[0053] (exhaust duct) An example of exhaust duct 40 will be described with reference to Fig. 6. Fig. 6 is a diagram showing an example of exhaust duct 40. The left diagram in Fig. 6 shows a cross section taken along line VI-VI in Fig. 4, and the right diagram in Fig. 6 shows substrate holder 11.

[0054] The exhaust duct 40 has a flow path 41 including a plurality of divided flow paths 411 to 425. The divided flow paths 411 to 425 are arranged at intervals along the vertical direction. In this case, the gas flow from the inside of the reaction tube 10 toward the vacuum pipe 30 is rectified. Therefore, the uniformity of the gas flow at different positions in the vertical direction inside the reaction tube 10 is improved.

[0055] The divided flow path 411 is provided in a height region above the top plate 11a of the substrate holder 11. The divided flow path 411 mainly exhausts gas flowing along the upper surface of the top plate 11a. The divided flow path 411 is an example of a first divided flow path. The divided flow paths 412 to 425 are provided in a height region (hereinafter referred to as the "substrate holding region") below the top plate 11a of the substrate holder 11 and above the bottom plate 11b of the substrate holder 11. The divided flow paths 412 to 425 mainly exhaust gas flowing along the surface of the substrate W held by the substrate holder 11. The divided flow paths 412 to 425 are an example of a second divided flow path.

[0056] The divided flow paths 413 to 423 have, for example, the same flow path cross-sectional area, which makes it easier to improve the uniformity of the exhaust amount in the vertical direction in the substrate holding area.

[0057] The cross-sectional area of ​​the divided flow path 411 is smaller than that of each of the divided flow paths 413 to 423, for example. In this case, the amount of gas flowing along the upper surface of the top plate 11a can be reduced, and the amount of gas flowing into the substrate holding region can be increased. Therefore, the gas introduced into the reaction tube 10 from the gas inlet 20 can be used efficiently. The cross-sectional area of ​​the divided flow path 412 may be larger than that of each of the divided flow paths 413 to 423. The cross-sectional areas of the divided flow paths 424 and 425 may be smaller than that of each of the divided flow paths 413 to 423.

[0058] Each of the multiple substrates W held by the substrate holder 11 is preferably positioned at the same height as one of the multiple divided channels 412 to 425. In other words, it is preferable that the substrates W are not positioned at a height where the multiple divided channels 412 to 425 are not provided. In this case, the multiple divided channels 412 to 425 can efficiently exhaust gas flowing along the surface of each substrate W. The example in Figure 6 shows a case where substrates W1, W2, and W3 are positioned at the same height as the divided channel 412, and substrates W4 and W5 are positioned at the same height as the divided channel 413.

[0059] 6, the exhaust duct 40 has 15 divided flow paths 411-425, but the number of divided flow paths 411-425 is not limited to 15. The exhaust duct 40 may have a single flow path instead of the divided flow paths 411-425.

[0060] (Simulation results) In the substrate processing apparatus 1 shown in FIGS. 1 to 6 , gas was supplied into the reaction tube 10 from the gas inlet 20 and exhausted from the vacuum pipe 30. The gas flow velocities at multiple positions along the vertical direction in the reaction tube 10 were calculated by simulation. This simulation was performed using three-dimensional thermal fluid analysis software. The ratio of the flow path cross-sectional area A2 of the vacuum pipe 30 to the flow path cross-sectional area A3 of the exhaust duct 40 was changed, and the other conditions were kept constant. In this simulation, the ratio of the flow path cross-sectional area A2 of the vacuum pipe 30 to the flow path cross-sectional area A3 of the exhaust duct 40 was changed, thereby changing the ratio.

[0061] 7 is a diagram showing the simulation results of the gas flow velocity distribution in the vertical direction in the reaction tube 10. In FIG. 7, the horizontal axis represents the gas flow velocity [m / sec], and the vertical axis represents the vertical position in the reaction tube 10. In FIG. 7, a thick dashed line, a thick broken line, a thick solid line, a thin dashed line, a thin broken line, and a thin solid line represent the results when the ratio (A2 / A3) of the flow path cross-sectional area A2 of the vacuum pipe 30 to the flow path cross-sectional area A3 of the exhaust duct 40 is set to 0.2, 0.27, 0.34, 0.7, 0.9, and 1.4, respectively. In FIG. 7, the thick dashed line represents the condition satisfying the relationship L1 > L2 = L3, and the thick broken line, thick solid line, thin dashed line, thin broken line, and thin solid line represent the condition satisfying the relationship L1 > L2 > L3.

[0062] As shown in Fig. 7, when the relationship of L1>L2>L3 is satisfied, the difference in gas flow velocity between the upper and lower parts in the vertical direction in the reaction tube 10 is smaller than when the relationship of L1>L2=L3 is satisfied. From the results in Fig. 7, it can be said that when the relationship of L1>L2>L3 is satisfied, the inter-surface uniformity of the gas flow velocity is improved.

[0063] 7, when the ratio of the flow path cross-sectional area A2 of the vacuum pipe 30 to the flow path cross-sectional area A3 of the exhaust duct 40 is 0.7 or more, the difference in gas flow velocity between the upper and lower parts in the vertical direction in the reaction tube 10 is small. On the other hand, when the ratio of the flow path cross-sectional area A2 of the vacuum pipe 30 to the flow path cross-sectional area A3 of the exhaust duct 40 is less than 0.7, the flow velocity in the lower part in the vertical direction in the reaction tube 10 tends to be larger than the flow velocity in the upper part (downward tendency). From the results in FIG. 7, it can be said that the inter-surface uniformity of the gas flow velocity is improved by setting the ratio of the flow path cross-sectional area A2 of the vacuum pipe 30 to the flow path cross-sectional area A3 of the exhaust duct 40 to be 0.7 or more (the flow path cross-sectional area A2 of the vacuum pipe 30 is 0.7 times or more the flow path cross-sectional area A3 of the exhaust duct 40).

[0064] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0065] 1. Substrate processing equipment 10 Reaction tube 10X tube shaft 30 Vacuum piping 30X tube shaft 40 Exhaust duct 41 Flow path 50 cabinets

Claims

1. a reaction tube having a first tube axis extending in a vertical direction; a vacuum pipe provided horizontally apart from the reaction tube and having a second tube axis parallel to the first tube axis; an exhaust duct having a flow path that connects the inside of the reaction tube with the inside of the vacuum piping; a housing that accommodates the reaction tube, the vacuum pipe, and the exhaust duct therein; A substrate processing apparatus comprising:

2. The vacuum pipe has a cylindrical shape with a ceiling and an open lower end, The lower end of the vacuum pipe is connected to an exhaust device. The substrate processing apparatus according to claim 1 .

3. The flow path cross-sectional area of ​​the vacuum pipe is 0.7 times or more the flow path cross-sectional area of ​​the exhaust duct. The substrate processing apparatus according to claim 1 or 2.

4. each of the reaction tube and the vacuum pipe has a cylindrical shape; when viewed in a cross section perpendicular to the first tube axis and the second tube axis, a relationship of L1 > L2 > L3 is satisfied, where L1 is an inner diameter of the reaction tube, L2 is an inner diameter of the vacuum pipe, and L3 is a flow path width of the exhaust duct. The substrate processing apparatus according to claim 1 or 2.

5. The flow path includes a plurality of divided flow paths spaced apart along a vertical direction. The substrate processing apparatus according to claim 1 .

6. a substrate holder accommodated inside the reaction tube; the substrate holder has a top plate and a bottom plate that are arranged parallel to each other, the substrate holder is configured to hold a plurality of substrates arranged in multiple stages in a vertical direction in a horizontal position between the top plate and the bottom plate, The plurality of divided flow paths are a first divided channel provided in a height region above the top plate of the substrate holder; a second divided flow channel provided in a height region below the top plate and above the bottom plate of the substrate holder; and a flow path cross-sectional area of ​​the first divided flow path is smaller than a flow path cross-sectional area of ​​the second divided flow path; The substrate processing apparatus according to claim 5 .

7. each of the plurality of substrates held by the substrate holder is positioned at the same height as one of the plurality of divided flow paths; The substrate processing apparatus according to claim 6 .

Images