Substrate processing apparatus, processing tube, substrate processing method, semiconductor device manufacturing method, and program

Abstract

The present invention provides a substrate processing apparatus, a processing method and program thereof, and a method for manufacturing a semiconductor device, which improve the uniformity of the flow of raw material gas on the substrate surface. [Solution] The substrate processing apparatus comprises an outer tube 14 having an inner tube 12 that is covered at the top and houses a substrate 200 inside, a supply buffer 222 provided on the side wall of the inner tube and projecting outward from the side wall, gas nozzles 340a, 340b, 341a, 341b that constitute a first injection device provided inside the supply buffer and extending along the direction of the axis of the inner tube, and a main exhaust slit 236 and a plurality of sub-exhaust slits 238 formed on the side wall of the inner tube for exhausting raw material gas. The sub-exhaust slits 238 open on both sides of a virtual plane A that is set to pass through the circumferential center of the inner tube and the axis of the inner tube at the boundary between the supply buffer and the inner tube in a plan view.

Description

Technical Field

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

Background Art

[0002] Conventionally, as an example of a substrate processing apparatus, a semiconductor manufacturing apparatus for manufacturing a semiconductor device is known. As an example of a semiconductor manufacturing apparatus, Japanese Unexamined Patent Application Publication No. 2019-203182, Japanese Unexamined Patent Application Publication No. 2022-52622, and Korean Patent Publication No. 101464644 disclose a vertical semiconductor manufacturing apparatus that processes a plurality of substrates held in multiple stages in the vertical direction. In the vertical semiconductor manufacturing apparatus, a film formation process for forming a predetermined film on the surface of the substrate can be performed as substrate processing.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-203182 Patent Document 2: Japanese Unexamined Patent Application Publication No. 2022-52622 Patent Document 3: Korean Patent Publication No. 101464644

Summary of the Invention

Problems to be Solved by the Invention

[0004] During the film formation process, when the raw material gas is injected onto the substrate in the processing chamber, uneven flow of the raw material gas on the substrate surface may cause a bias in the concentration of the raw material gas or intermediate. When there is a bias in the concentration of these gases on the substrate surface, the in-plane uniformity of the gas adsorbed on the substrate surface may decrease, or the step coverage (i.e., step coverage) may decrease.

[0005] The present disclosure provides a technique capable of improving the uniformity of the flow of the raw material gas on the substrate surface.

Means for Solving the Problems

[0006] According to one aspect of the present disclosure, (a) a processing tube having a cylindrical portion with an upper part covered and accommodating a substrate inside, (b) A supply buffer provided on the side wall of the cylindrical portion and protruding outward from the side wall, (c) A first injection device provided inside the supply buffer and extending along the direction of the axis of the cylindrical portion, (d) A configuration is provided comprising a plurality of exhaust sections formed on the side wall of the cylindrical section for exhausting raw material gas, each having a pair of exhaust sections that open on both sides of a virtual plane set to pass through the circumferential center of the cylindrical section and the axis of the cylindrical section at the boundary between the supply buffer and the cylindrical section in a plan view. [Effects of the Invention]

[0007] According to this disclosure, the uniformity of the flow of the raw material gas on the substrate surface can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a front view illustrating a substrate processing apparatus according to an embodiment of this disclosure, with a portion of it cut off in a vertical plane along the depth direction. [Figure 2] Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1, illustrating the substrate processing apparatus according to this embodiment, cut horizontally. [Figure 3] Figure 3 is a cross-sectional view taken along line 3-3 in Figure 2, illustrating the processing container of the substrate processing apparatus according to this embodiment, cut across a vertical plane along the width direction. [Figure 4] Figure 4 is a side view illustrating the main exhaust slit and sub-exhaust slit formed in the inner tube of the processing vessel of the substrate processing apparatus according to this embodiment, as seen from the outer tube side. [Figure 5] Figure 5 is a cross-sectional view illustrating the first injection device that injects the raw material gas in the substrate processing apparatus according to this embodiment, cut horizontally. [Figure 6] Figure 6 is a block diagram illustrating the control system of the control unit of the substrate processing apparatus according to this embodiment. [Figure 7] Figure 7 is a flowchart illustrating the substrate processing steps according to this embodiment. [Figure 8]Figure 8 is a diagram illustrating the distribution of raw material gas concentration inside the cylindrical portion using a simulation model, when the distance between the centers of the two first injection devices of the substrate processing apparatus according to this embodiment is 22 mm. [Figure 9] Figure 9 is a graph illustrating the simulation results that analyze the relationship between the uniformity of the raw material gas concentration and the distance between the centers of the two first injection devices. [Figure 10A] Figure 10A is a diagram illustrating the flow of raw material gas and the distribution of partial pressure inside the cylindrical portion in the substrate processing apparatus according to this embodiment, when the ejection holes of the first injection device are in a single row and a pair of sub-exhaust slits are not provided. [Figure 10B] Figure 10B is a diagram illustrating the flow of raw material gas and the distribution of partial pressure inside the cylindrical portion in the substrate processing apparatus according to this embodiment, where the ejection holes of the first injection device are in three rows and a pair of sub-exhaust slits are not provided. [Figure 10C] Figure 10C is a diagram illustrating the flow of raw material gas and the distribution of partial pressure inside the cylindrical portion in a substrate processing apparatus according to the seventh modified example of this embodiment, where the ejection holes of the first injection device are in three rows and a pair of sub-exhaust slits are provided. [Figure 11] Figure 11 is a diagram illustrating the state of return flow generation inside the cylindrical portion of the substrate processing apparatus according to this embodiment, with conditions separated according to the shape of the first injection device and the flow rate of the raw material gas. [Figure 12A] Figure 12A is a diagram illustrating a substrate processing apparatus according to a first modification, which is equipped with six first injection devices. [Figure 12B] Figure 12B illustrates a substrate processing apparatus according to a second modified example, in which multiple first injection devices are arranged away from the substrate. [Figure 12C] Figure 12C illustrates a third modified substrate processing apparatus in which a side wall having a slit is provided between the first injection device and the substrate, and the injection holes of the multiple first injection devices open toward the side wall opposite the substrate. [Figure 12D]FIG. 12D is a diagram for explaining a substrate processing apparatus according to a fourth modification example, in which a side wall having a slit is provided between the first injection device and the substrate, and injection holes of a plurality of the first injection devices open toward the side wall having the slit. [Figure 12E] FIG. 12E is a diagram for explaining a substrate processing apparatus according to a fifth modification example, in which a plurality of the first injection devices are arranged away from the substrate, a side wall having a slit is provided between the first injection device and the substrate, and injection holes of a plurality of the first injection devices open toward the side wall having the slit. [Figure 13] FIG. 13 is a perspective view for explaining a substrate processing apparatus according to a sixth modification example in which fins are provided in each of a main exhaust slit and a sub-exhaust slit.

Embodiments of the Invention

[0009] Hereinafter, one aspect of the present disclosure will be mainly described with reference to FIGS. 1 to 13. In the following description, the drawings used are all schematic, and the dimensional relationships and ratios of the respective elements shown in the drawings do not necessarily match the actual ones. Also, the dimensional relationships and ratios of the respective elements do not necessarily match even between a plurality of drawings.

[0010] Also, unless otherwise specified in the specification, each element is not limited to one, and a plurality of elements may exist. Also, in the drawings, substantially the same elements are denoted by the same reference numerals, and duplicate descriptions in the specification are omitted.

[0011] <Overall Configuration of Substrate Processing Apparatus> First, the overall configuration of the substrate processing apparatus 10 according to the present embodiment will be described with reference to FIGS. 1 to 6. Note that the vertical direction H of the apparatus indicates the vertical direction, the width direction W of the apparatus indicates the horizontal direction, and the depth direction D of the apparatus indicates the horizontal direction.

[0012] As shown in Figure 1, the substrate processing apparatus 10 comprises a control unit 280 that controls various parts and a processing furnace 202. The processing furnace 202 has a heater 207, which is a heating means. The heater 207 is cylindrical and is mounted in the vertical direction of the apparatus by being supported by a heater base (not shown). The heater 207 also functions as an activation mechanism that activates the processing gas with heat. Details of the control unit 280 will be described later.

[0013] Inside the heater 207, a reaction tube 203 is arranged upright in a concentric circle with the heater 207, forming a reaction vessel. The reaction tube 203 corresponds to the processing vessel of this disclosure. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC). The substrate processing apparatus 10 is a so-called hot-wall type.

[0014] As shown in Figure 2, the reaction tube 203 has a cylindrical inner tube 12 and a cylindrical outer tube 14 that surrounds the inner tube 12. That is, the outer tube 14 together with the inner tube 12 constitutes the reaction tube 203. By surrounding the inner tube 12, the outer tube 14 forms a gap between itself and the cylindrical part, which serves as an exhaust space S. The inner tube 12 is arranged concentrically with the outer tube 14. The inner tube 12 is an example of a pipe member.

[0015] The inner tube 12 has a covered upper section and side walls that serve as cylindrical sections for housing multiple substrates inside. Specifically, as shown in Figure 1, the inner tube 12 is formed in a closed-end shape with an open lower end and a flat wall at the upper end. Similarly, the outer tube 14 is also formed in a closed-end shape with an open lower end and a flat wall at the upper end.

[0016] Furthermore, as shown in Figure 2, a supply buffer 222, which serves as a nozzle chamber, is formed in the exhaust space S between the inner pipe 12 and the outer pipe 14. In other words, the supply buffer 222 is a supply space where nozzles for supplying the processed gas are located. Details of the supply buffer 222 will be described later.

[0017] Inside the inner tube 12, as shown in Figure 1, a processing chamber 201 is formed for processing the wafers 200 as substrates. This processing chamber 201 is also capable of housing a boat 217, which is an example of a substrate holder capable of holding wafers 200 in a horizontal position with multiple layers aligned vertically, and the inner tube 12 surrounds the housed wafers 200. Multiple wafers 200 are arranged inside the cylindrical portion of the inner tube 12, along the direction of the axis of the cylindrical portion. Further details about the inner tube 12 will be described later.

[0018] The lower end of the reaction tube 203 is supported by a cylindrical manifold 226. The manifold 226 is made of a metal such as nickel alloy or stainless steel, or a heat-resistant material such as SiO2 or SiC. A flange is formed at the upper end of the manifold 226, and the lower end of the outer tube 14 is placed on this flange. An airtight member 220, such as an O-ring, is placed between this flange and the lower end of the outer tube 14, making the inside of the reaction tube 203 airtight.

[0019] A seal cap 219 is airtightly attached to the opening at the lower end of the manifold 226 via an airtight member 220 such as an O-ring, thereby airtightly sealing the opening at the lower end of the reaction tube 203, i.e., the opening of the manifold 226. The seal cap 219 is made of a metal such as nickel alloy or stainless steel and is formed in a disc shape. The seal cap 219 may also be configured to cover its outside with a heat-resistant material such as SiO2 or SiC.

[0020] A boat support base 218 is provided on the seal cap 219 to support the boat 217. The boat support base 218 is made of a heat-resistant material such as SiO2 or SiC and functions as an insulating part.

[0021] The boat 217 is erected on a boat support base 218. The boat 217 is made of a heat-resistant material such as SiO2 or SiC. As shown in Figure 2, the boat 217 has a bottom plate (not shown) fixed to the boat support base 218 and a top plate positioned above it, with a number of support columns 217a installed between the bottom plate and the top plate.

[0022] Boat 217 holds multiple wafers 200 to be processed in the processing chamber 201 within the inner tube 12. As shown in Figure 2, the multiple wafers 200 are supported by the pillars 217a of boat 217, maintaining a horizontal orientation with a certain distance between them and with their centers aligned. The loading direction of the multiple wafers 200 is the axial direction of the reaction tube 203. In other words, the center of the substrate is aligned with the central axis of boat 217, and the central axis of boat 217 coincides with the central axis of reaction tube 203.

[0023] A rotating mechanism 267 for rotating the boat is provided on the underside of the seal cap 219. The rotating shaft 265 of the rotating mechanism 267 passes through the seal cap 219 and is connected to the boat support base 218, and the rotating mechanism 267 rotates the boat 217 via the boat support base 218, thereby rotating the wafer 200.

[0024] The seal cap 219 is raised and lowered vertically by an elevator 115, which is a lifting mechanism located outside the reaction tube 203, allowing the boat 217 to be moved in and out of the processing chamber 201.

[0025] Multiple nozzle support sections are installed in the manifold 226 so as to penetrate the manifold 226, supporting the gas nozzle 342a, return nozzle 340, return nozzle 341, and gas nozzle 342c that supply gas to the processing chamber 201. In this embodiment, four nozzle support sections are installed. In Figure 1, the return nozzle 341 and nozzle support section 350c are shown as examples. The nozzle support sections are made of materials such as nickel alloy or stainless steel.

[0026] Gas supply pipes 310a to 310d, which supply gas to the processing chamber 201, are connected to one end of the nozzle support section. Gas nozzle 342a, return nozzle 340, return nozzle 341, and gas nozzle 342c are connected to the other end of the nozzle support section. Gas nozzles 342a and 342c are made of a heat-resistant material such as SiO2 or SiC. Details of gas nozzles 342a and 342c will be described later.

[0027] (Gas supply pipe) Gas supply pipe 310a communicates with the corresponding gas nozzle 342a via a nozzle support part (not shown). Gas supply pipe 310d communicates with the corresponding gas nozzle 342c via a nozzle support part (not shown). Gas supply pipe 310b communicates with the return nozzle 340 via a nozzle support part (not shown). Gas supply pipe 310c communicates with the return nozzle 341 via a nozzle support part 350c (not shown).

[0028] In the gas supply pipe 310a, the following components are provided in order from upstream in the direction of gas flow: a gas supply source 360a for supplying assist gas as a process gas, a mass flow controller (MFC) 320a, which is an example of a flow control device, and a valve 330a, which is an on / off valve. In the gas supply pipe 310b, the following components are provided in order from upstream: a gas supply source 360b for supplying raw material gas as a process gas, an MFC 320b, a tank 322b, and a valve 330b.

[0029] The gas supply pipe 310c is equipped with, in order from upstream, a gas supply source 360c, an MFC 320c, a tank 322c, and a valve 330c, which supply the raw material gas as the process gas. The gas supply pipe 310d is equipped with, in order from upstream, a gas supply source 360d, an MFC 320d, and a valve 330d, which supply the reaction gas as the process gas.

[0030] The reaction gas is supplied from the gas supply pipe 310d. The raw material gas is supplied from the gas supply pipes 310b and 310c. Although not shown in the figures, each gas nozzle in this embodiment is also provided with a gas supply pipe, along with the MFC and valve, to supply nitrogen (N2) gas or the like for purging or as an assist gas.

[0031] Multiple exhaust slits, including a main exhaust slit 236 and sub-exhaust slits 238, are formed in the side wall of the inner pipe 12. The multiple exhaust slits exhaust the gas inside the inner pipe 12 to the exhaust space S. In this embodiment, the main exhaust slit 236 corresponds to the exhaust section and the main exhaust section in this disclosure. In this embodiment, the number of multiple exhaust slits is three, consisting of one main exhaust slit 236 and two sub-exhaust slits 238. In this disclosure, the number of multiple exhaust slits may be at least two or more.

[0032] The lower exhaust port 237 is an auxiliary opening in the inner pipe below the main exhaust slit 236, and discharges gas near the boat support base 218. Note that the lower exhaust port 237 is not essential.

[0033] An exhaust port 230 is formed in the outer tube 14 of the reaction tube 203. The exhaust port 230 is formed below the lower end of the main exhaust slit 236 and connects the exhaust space S with the outside of the reaction tube 203. As shown in Figure 2, the exhaust port 230 is located on the opposite side of the supply buffer 222, and in a plan view, the supply buffer 222, the exhaust port 230, and the main exhaust slit 236 (described later) are arranged to lie on a straight line passing through the center of the substrate.

[0034] The exhaust section may be, for example, an exhaust port having an opening inside the processing chamber 201 that communicates with the exhaust space S, indirectly discharging the gas inside the processing chamber 201 to the outside via the exhaust space S, or it may be an opening that is directly connected to an exhaust duct, which will be described later. The latter form will be described later as the seventh modification. The exhaust duct 231 is a conduit that extends outward from the exhaust port 230 and guides the exhaust from the reaction tube 203 to the vacuum pump 246, which is a vacuum evacuation device.

[0035] The exhaust duct 231 is equipped with a pressure sensor 245 for detecting the pressure inside the processing chamber 201, and an APC (Auto Pressure Controller) valve 244 as a pressure regulator. Downstream of the vacuum pump 246, it is connected to an exhaust gas treatment device (not shown). This configuration allows for vacuum evacuation of the processing chamber 201 to achieve a predetermined pressure (vacuum level) by controlling the output of the vacuum pump 246 and the opening of the APC valve 244.

[0036] Furthermore, a temperature sensor (not shown) is installed inside or on the outer wall of the reaction tube 203 as a temperature detector. Based on the temperature information detected by the temperature sensor, the power supplied to the heater 207 is adjusted so that the temperature inside the processing chamber 201 reaches a desired temperature distribution.

[0037] In this specification, "processing temperature" refers to the temperature of the wafer 200 or the temperature inside the processing chamber 201, and "processing pressure" refers to the pressure inside the processing chamber 201. Furthermore, "processing time" refers to the duration for which the processing is continued. These same terms apply in the following description.

[0038] In the processing furnace 202, a boat 217, which holds multiple wafers 200 to be processed in batches, is brought into the processing chamber 201 by a boat support 218. The wafers 200 brought into the processing chamber 201 are then heated to a predetermined temperature by a heater 207. A device having such a processing furnace is called a vertical batch processing device.

[0039] <Main part configuration> Next, the supply buffer 222, the return nozzles 340 and 341 as first injection devices, and the exhaust slits including the main exhaust slit 236 and the sub-exhaust slit 238 in the substrate processing apparatus 10 according to this embodiment will be described in detail. Note that the first injection device is not limited to a tubular member such as a nozzle, as long as it is capable of injecting the raw material gas into the processing chamber 201.

[0040] (Supply buffer) As shown in Figure 2, the supply buffer 222 is provided on the side wall of the cylindrical portion of the inner pipe 12 and is a region that protrudes outward from the side wall. The supply buffer 222 is formed in the exhaust space S between the outer circumferential surface 12c of the inner pipe 12 and the inner circumferential surface 14a of the outer pipe 14. The supply buffer 222 is divided into three parts along the circumferential direction of the cylindrical portion by the third partition 18c and the fourth partition 18d.

[0041] The supply buffer 222 is formed between the first partition 18a and the second partition 18b, and between the arc-shaped top plate 20 connecting the tip of the first partition 18a and the tip of the second partition 18b and the inner tube 12. Both the first partition 18a and the second partition 18b extend from the outer circumferential surface 12c of the inner tube 12 toward the outer tube 14. Both the first partition 18a and the second partition 18b are continuous with the inner tube 12.

[0042] Inside the supply buffer 222, a third partition 18c and a fourth partition 18d are formed, extending from the outer circumferential surface 12c of the inner tube 12 toward the top plate 20. Both the third partition 18c and the fourth partition 18d extend toward the top plate 20 parallel to the first partition 18a and the second partition 18b. The third partition 18c and the fourth partition 18d are arranged in this order, from the first partition 18a side toward the second partition 18b side.

[0043] The top plate 20 is separated from the outer tube 14. The end of the third partition 18c opposite the wafer 200 and the end of the fourth partition 18d opposite the wafer 200 reach the top plate 20. The first partition 18a, the second partition 18b, the third partition 18c, the fourth partition 18d and the top plate 20 are examples of partitioning members.

[0044] The first partition 18a and the second partition 18b form the central portion 222b of the divided supply buffer 222. Return nozzles 340 and 341 for supplying raw material gas are provided in the central portion 222b.

[0045] At the boundary between the central portion 222b of the supply buffer 222 and the cylindrical portion, a sector is formed by a virtual arc connecting both ends of the cylindrical portion in the circumferential direction and the center C1 of the wafer 200. In this embodiment, the central angle θ of the sector is less than 30 degrees. If the central angle θ is 30 degrees or more, the circumferential width of the cylindrical portion of the supply buffer 222 will increase, requiring more gas nozzles to be installed in the supply buffer 222, which would lead to increased manufacturing costs and equipment downtime, even if inexpensive tubular nozzles are used.

[0046] Furthermore, the central angle θ of the sector is more preferably between 15 degrees and 45 degrees. If the central angle θ of the sector is less than 15 degrees, it becomes difficult to uniformly expose the entire surface of the wafer to the raw material gas. Also, if the central angle θ of the sector exceeds 45 degrees, the advantages of this example, in which multiple nozzles are arranged, are lost for the reasons mentioned above. In this disclosure, the central angle of the sector can be set arbitrarily.

[0047] As shown in Figure 2, on the inner circumferential surface 12a of the inner tube 12 on the supply slits 235a and 235c side, a supply slit 235b is formed in the central portion 222b of the supply buffer 222. As shown in Figure 3, the supply slit 235b opens over the entire vertical direction H and the entire width direction W of the device in the central portion 222b. Therefore, the entire vertical direction H and the entire width direction W of the return nozzles 340 and 341 face the wafer 200 inside the cylindrical portion.

[0048] (1st injection device) Multiple gas nozzles, namely return nozzles 340 and 341, are provided inside the supply buffer 222 and extend along the axial direction of the cylindrical section. Specifically, four nozzles, including two gas nozzles 340a and 340b and two gas nozzles 341a and 341b, are arranged along the circumferential direction of the cylindrical section and configured to supply the same raw material gas. The four gas nozzles 340a, 340b, 341a, and 341b in this embodiment correspond to the multiple gas nozzles of the present disclosure.

[0049] (Return nozzle) In this embodiment, four gas nozzles 340a, 340b, 341a, and 341b are formed by two return nozzles 340 and 341. That is, gas nozzles 340a and 340b adjacent to each other on the lower side in the width direction W in Figure 2 are formed by one return nozzle 340, while gas nozzles 341a and 341b adjacent to each other on the upper side opposite to gas nozzles 340a and 340b in the width direction W are formed by the other return nozzle 341. In this disclosure, two nozzles may be formed by only one return nozzle.

[0050] Furthermore, in this disclosure, the number of return nozzles 340, 341 may be one or any number of two or more. Also, in this disclosure, the multiple nozzles do not necessarily have to be return nozzles; for example, they may be an array of multiple independent nozzles (nozzle array).

[0051] As shown in Figure 3, the return nozzle 340 has a forward pipe corresponding to gas nozzle 340a and a return pipe corresponding to gas nozzle 340b, and the raw material gas flows through each by connecting the upper end of the forward pipe and the upper end of the return pipe. The return nozzle 341 is configured symmetrically with respect to the return nozzle 340. The return pipes of the return nozzles 340 and 341 are adjacent to each other, and the forward pipes are spaced apart. In this embodiment, the inner diameter of the forward pipe and the inner diameter of the return pipe are the same. In this disclosure, the inner diameter of the forward pipe and the inner diameter of the return pipe may be different.

[0052] (Injection hole) The forward and return pipes of the return nozzles 340 and 341 each have three or more rows of injection holes 234 extending along the longitudinal direction of the return nozzle. The injection holes 234 provide a cylindrical flow path that connects the inside and outside of the return nozzle. Such injection holes usually form a subsonic jet, but the velocity boundary layer formed can act like a Laval nozzle to achieve a supersonic flow. The same source gas is injected from the injection holes 234. The source gas is injected radially in a plan view.

[0053] In this disclosure, it is not mandatory for the gas nozzles 340a, 340b, 341a, and 341b to have three or more rows of injection holes arranged along the vertical direction; they may have three or more injection holes arranged along the circumferential direction of the cylindrical portion in a plane parallel to the surface of the substrate. Furthermore, in this disclosure, the number of injection holes can be arbitrarily set to one, two, or four or more.

[0054] Of the four gas nozzles 340a, 340b, 341a, and 341b arranged in a row in the central portion 222b of the supply buffer 222, the gas nozzles 340a and 341a on both sides in the width direction W inject the raw material gas toward the outermost part of the wafer 200. In addition, of the three injection holes 234 of the bottommost gas nozzle 340a in Figure 2, which is furthest opposite to gas nozzle 341a in the width direction W, the injection hole 234 furthest opposite to gas nozzle 341a in the width direction W of the topmost gas nozzle 341a in Figure 2, which is furthest opposite to gas nozzle 340a in the width direction W, the injection hole 234 furthest opposite to gas nozzle 340a in the width direction W in the wafer 200 also inject the raw material gas toward the outermost part of the wafer 200.

[0055] In Figure 2, the injection direction of each injection hole 234 that injects the raw material gas toward the outermost part of the wafer 200 in a plan view is illustrated by dotted arrows. A space is formed between the wafer 200 and each injection hole 234 that injects the raw material gas toward the outermost part of the wafer 200, allowing the raw material gas to travel in a straight line along the injection direction. That is, no other structures such as partitions are provided in the injection direction between the injection hole 234 and the wafer 200. This disclosure does not exclude the placement of other structures between at least one injection hole 234 that injects the raw material gas toward the outermost part of the wafer and the wafer.

[0056] As shown in Figure 5, in this embodiment, the diameter R1 of the injection hole 234 that injects the raw material gas outward in a plan view from the center C1 of the wafer 200 (i.e., both ends of the width direction W of the apparatus in Figure 5) is larger than the diameter R2 of the other injection holes 234. In this disclosure, the diameter of the injection hole 234 that injects the raw material gas outward from the center C1 of the wafer 200 may be less than or equal to the diameter of the other injection holes 234.

[0057] As shown in Figure 5, in this embodiment, the first injection direction F1 of the injection holes 234 of the forward tube of one return nozzle that is closest to the return tube, and the second injection direction F2 of the injection holes 234 of the return tube that is closest to the forward tube, intersect in the central portion 222b of the supply buffer 222, which is away from the wafer 200.

[0058] For example, in Figure 5, the gas nozzle 340a of the return nozzle 340 to the left of the virtual plane A is the forward pipe, while the gas nozzle 340b to the right is the return pipe. Of the three injection holes 234 of the gas nozzle 340a of the forward pipe, the injection direction F1 of the rightmost injection hole 234 is closest to the adjacent gas nozzle 340b of the return pipe. Also, of the three injection holes 234 of the gas nozzle 340b of the return pipe, the injection direction F2 of the leftmost injection hole 234 is closest to the adjacent gas nozzle 340a of the forward pipe.

[0059] The injection direction F1 of the rightmost injection hole 234 of the gas nozzle 340a of the forward pipe and the injection direction F2 of the leftmost injection hole 234 of the gas nozzle 340b of the return pipe intersect at intersection FX. In Figure 5, intersection FX is illustrated inside the central portion 222b of the supply buffer 222. Similarly, in Figure 5, the intersection FX of the first injection direction F1 and the second injection direction F2 of the two gas nozzles 341a and 341b of the return nozzle 341 to the right of the virtual plane A is illustrated inside the central portion 222b of the supply buffer 222.

[0060] Furthermore, in this embodiment, the inner diameter of the forward pipe and the inner diameter of the return pipe have the same radius r. The first injection direction F1 and the second injection direction F2 intersect outside the wafer 200, i.e., at a position away from the wafer 200, within a distance of 3r from the center C2 of the forward pipe and within a distance of 3r from the center C2 of the return pipe, in a plan view. Similarly, an intersection FY of the respective injection directions can be defined between the gas nozzle 340b of the adjacent return nozzle 340 and the gas nozzle 341b of the return nozzle 341. Intersection FY, like intersection FX, is located away from the wafer 200, within a distance of 3r from the center C2 of the forward pipe and within a distance of 3r from the center C2 of the return pipe. Furthermore, matching the distance between the center C2 and intersection FX with the distance between the center C2 and intersection FY may allow for more uniform gas mixing.

[0061] Furthermore, in this disclosure, the position of the intersection of the first injection direction and the second injection direction is not limited to the position of the intersection in this embodiment. Also, the state in which the first injection direction F1 and the second injection direction F2 intersect within the supply buffer 222 away from the wafer 200 may be realized independently. Also, when the inner diameter of the forward pipe and the inner diameter of the return pipe have the same radius r, the state in which the first injection direction F1 and the second injection direction F2 intersect at a position away from the wafer 200, within a distance of 3r from the center C2 of the forward pipe and within a distance of 3r from the center C2 of the return pipe in a plan view, may be realized independently.

[0062] <Exhaust vents> As shown in Figure 2, a plurality of exhaust slits, including a main exhaust slit 236 and a secondary exhaust slit 238, are formed in the side wall of the cylindrical portion and exhaust the raw material gas from the inside of the cylindrical portion. In this disclosure, the main exhaust slit 236 is not essential.

[0063] (Main exhaust slit) The main exhaust slit 236 is formed in the side wall of the cylindrical portion opposite the supply buffer 222 with respect to the center C1 of the wafer 200. The main exhaust slit 236 opens on the side of each wafer 200 and discharges raw material gas and the like that has flowed over the wafer 200. The main exhaust slit 236 can be formed as a single opening extending between the side of the uppermost wafer 200 and the side of the lowermost wafer 200, or as a plurality of holes distributed between them.

[0064] (Secondary exhaust slit) The two sub-exhaust slits 238 open on either side of a virtual plane A set on the inside of the cylindrical portion. As shown in Figure 2, the virtual plane A is set to pass through the circumferential center of the cylindrical portion and the axis of the cylindrical portion at the boundary between the supply buffer 222 and the cylindrical portion in a plan view. The axis of the cylindrical portion coincides with the center of the wafer 200.

[0065] The two sub-exhaust slits 238, as a pair of exhaust slits, sandwich the main exhaust slit 236 within the same height range as the main exhaust slit 236. In a plan view, a first virtual line L1 is set connecting the center of each sub-exhaust slit 238 to the center C1 of the wafer 200. In this embodiment, the angle between the first virtual line L1 and the virtual plane A is obtuse. In this disclosure, the angle between the first virtual line L1 and the virtual plane A is not limited to an obtuse angle.

[0066] As shown in Figure 2, the width of each of the two sub-exhaust slits 238 in the circumferential direction of the cylindrical portion is smaller than the width of the main exhaust slit 236 at the same height. In this disclosure, the width of the sub-exhaust slits 238 may be greater than or equal to the width of the main exhaust slit 236.

[0067] As shown in Figure 2, the return nozzles 340, 341 and the two sub-exhaust slits 238 are configured symmetrically with respect to the virtual plane A. In this disclosure, it is not essential that the return nozzles 340, 341 and the pair of exhaust slits are configured symmetrically with respect to the virtual plane A.

[0068] As shown in Figure 4, in this embodiment, the opening width W1 along the circumferential direction of the cylindrical portion of the main exhaust slit 236 narrows along the axis direction of the cylindrical portion from the side opposite the exhaust port 230 (i.e., the upper side in Figure 4) towards the exhaust port 230 (i.e., the lower side in Figure 4). Similarly, the opening width along the circumferential direction of the cylindrical portion of each of the pair of sub-exhaust slits 238 narrows along the axis direction of the cylindrical portion from the side opposite the sub-exhaust port (i.e., the upper side in Figure 4) towards the sub-exhaust port (i.e., the lower side in Figure 4). The sub-exhaust ports are not shown.

[0069] In this disclosure, the opening width along the circumferential direction of the cylindrical portions of the main exhaust slit 236 and the pair of sub-exhaust slits 238 can be arbitrarily set. Note that, for clarity, the counter buffer is omitted from Figure 4. The counter buffer will be explained later.

[0070] (tank) As shown in Figure 1, the substrate processing apparatus 10 according to this embodiment further comprises tanks 322b and 322c connected to the return nozzles 340 and 341. Tanks 322b and 322c can store the raw material gas separately so that it is not mixed with the carrier gas. Tanks 322b and 322c supply the stored raw material gas to the return nozzles 340 and 341 in a pulsed manner almost simultaneously through on-off valves.

[0071] In other words, in this embodiment, a high-concentration flash supply of raw material gas can be performed. In flash supply, the raw material gas accumulated in tanks 322b and 322c is supplied at a high flow rate from tanks 322b and 322c towards the reaction tube 203. The raw material gas supplied at a high flow rate is also called "flash flow". During the film deposition process, the flash flow raw material gas flows at a relatively high speed on the surface of the wafer 200 inside the cylindrical portion of the inner tube 12.

[0072] Flash feeding exposes the entire surface of the wafer 200 to a high-speed flow of source gas during the film deposition process. A high-speed gas flow is one of the most effective means of promoting gas replacement within microstructures such as trenches and holes formed on the surface of the wafer 200, and is particularly useful in processing patterned wafers with high aspect ratios.

[0073] Furthermore, this disclosure is not limited to the flash supply of raw material gases, but may also be applied to high-flow supply of, for example, ammonia (NH3) as a purge gas using a general MFC. For this reason, tanks 322b and 322c for flash supply are not essential in this disclosure.

[0074] In this embodiment, the total instantaneous maximum flow rate of the raw material gas injected in a pulsed manner from each of the return nozzles 340 and 341 is between 1 slm and 300 slm. If the total instantaneous maximum flow rate of the raw material gas is less than 1 slm, the flow velocity is insufficient, causing the raw material gas to deteriorate while flowing over the wafer 200, or resulting in insufficient gas replacement within the microstructure, thus reducing the quality and uniformity of the film. Conversely, if the total instantaneous maximum flow rate of the raw material gas exceeds 300 slm, the effect of promoting replacement saturates, while the flow rate of the raw material gas becomes too high, resulting in increased raw material gas costs.

[0075] Furthermore, it is even more preferable if the total instantaneous maximum flow rate of the raw material gas is 12 slm or more and 50 slm or less. If the total instantaneous maximum flow rate of the raw material gas is less than 12 slm, the flow velocity on the wafer 200 may not be sufficiently high (e.g., 10 m / s or more), resulting in insufficient step coverage of the formed film. Also, if the total instantaneous maximum flow rate of the raw material gas exceeds 50 slm, the configuration of the supply system for storing the raw material gas in the tank at high pressure without decomposition becomes more complex, increasing the cost of the equipment. In this disclosure, the total instantaneous maximum flow rate of the pulsed raw material gas is not limited to this and can be changed as appropriate.

[0076] (Second injection device) As shown in Figure 2, the substrate processing apparatus 10 according to this embodiment further comprises gas nozzles 342a and 342c as second injection devices for supplying assist gas. The gas nozzles 342a and 342c are provided on each of the portions 222a and 222c on both sides of the supply buffer 222. In this disclosure, the second injection device is not essential. The second injection device is not limited to tubular members such as nozzles, as long as it is capable of injecting the raw material gas.

[0077] As shown in Figure 2, a partition wall is provided between the portions 222a and 222c on both sides in the width direction W of the supply buffer 222 and the cylindrical portion. Also, as shown in Figure 3, supply slits 235a and 235c are formed in the partition wall. The gas nozzles 342a and 342c have a plurality of injection holes 344 along the vertical direction.

[0078] (Third injection device) As shown in Figure 2, the substrate processing apparatus 10 according to this embodiment further includes a counter nozzle 343 as a third injection device for supplying assist gas. One or more counter nozzles 343 may be provided as counter nozzles at positions where, in a plan view, the angle between the second virtual line L2 connecting the injection direction of the counter nozzle 343 and the center C1 of the wafer 200 and the virtual plane A is obtuse.

[0079] The counter nozzle 343 is housed inside the counter buffer 222d. The counter buffer 222d, like the supply buffer 222, is a region provided on the side wall of the cylindrical portion of the inner tube 12 and protruding outward from the side wall. The counter buffer 222d may be provided between the main exhaust slit 236 and the two sub-exhaust slits 238 in the circumferential direction of the cylindrical portion, or between the supply buffer 222 and the two sub-exhaust slits 238. In this disclosure, the counter nozzle 343 is not essential. A temperature sensor may be placed in the counter buffer 222d. The third injection device is not limited to a tubular member such as a nozzle, as long as it is capable of injecting the processing gas.

[0080] (Control Unit) Next, the control unit 280 will be described with reference to Figure 6. Figure 6 is a block diagram showing the substrate processing apparatus 10, and the control unit 280 (i.e., the controller) of the substrate processing apparatus 10 is configured as a computer. This computer is equipped with a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, storage device 121c, and I / O port 121d.

[0081] The RAM 121b, storage device 121c, and I / O port 121d are configured to exchange data with the CPU 121a via the internal bus 121e. An input / output device 122, configured as, for example, a touch panel, is connected to the control unit 280.

[0082] The storage device 121c is composed of, for example, flash memory, an HDD (Hard Disk Drive), etc. The storage device 121c contains, in a readable format, control programs that control the operation of the circuit board processing device, and process recipes that describe the procedures and conditions for circuit board processing, as described later.

[0083] The process recipe is a combination of steps in the substrate processing process described later that can be executed by the control unit 280 to obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, control program, etc., will be collectively referred to simply as the program.

[0084] In this specification, the term "program" may include only a process recipe, only a control program, or both. RAM121b is configured as a memory area (i.e., a work area) where programs and data read by CPU121a are temporarily held.

[0085] I / O port 121d is connected to the MFCs 320a to 320d, valves 330a to 330d, pressure sensor 245, APC valve 244, vacuum pump 246, heater 207, temperature sensor, rotary mechanism 267, elevator 115, etc.

[0086] The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a process recipe from the storage device 121c in response to input of operation commands from the input / output device 122, etc.

[0087] The CPU 121a is configured to control the flow rate adjustment operations of various gases by the MFCs 320a to 320d, the opening and closing operations of valves 330a to 330d, and the opening and closing operations of the APC valve 244 in accordance with the contents of the read process recipe. The CPU 121a is also configured to control the pressure adjustment operations of the APC valve 244 based on the pressure sensor 245, the starting and stopping of the vacuum pump 246, and the temperature adjustment operations of the heater 207 based on the temperature sensor. Furthermore, the CPU 121a is configured to control the rotation and rotation speed adjustment operations of the boat 217 by the rotating mechanism 267, and the raising and lowering operations of the boat 217 by the elevator 115.

[0088] The control unit 280 is not limited to being configured as a dedicated computer; it may also be configured as a general-purpose computer. For example, the control unit 280 of this embodiment can be configured by preparing an external storage device 123 containing the above-mentioned program and installing the program on a general-purpose computer using this external storage device 123. Examples of external storage devices include magnetic disks such as hard disks, optical disks such as CDs, magneto-optical disks such as MOs, and semiconductor memory such as USB memory.

[0089] <Substrate Processing Method> Next, a substrate processing method using the substrate processing apparatus 10 according to this embodiment will be described with reference to Figure 7. In this embodiment, as an example of a semiconductor device manufacturing process, a cycle process in which a film deposition process is performed by alternately supplying a raw material gas and a reaction gas to the processing chamber will be described.

[0090] In the cyclic process, a Si source gas is used as an example of a source, and an N-containing gas is used as a reactant, thereby forming a Si nitride film (Si3N4 film, hereinafter also called SiN film) on the wafer 200.

[0091] The SiN film is formed by performing the film formation process 1 in step S3, film formation process 2 in step S4, film formation process 3 in step S5, and film formation process 4 in step S6 in step 7, in a non-simultaneous cycle, one or more predetermined times.

[0092] Film formation process 1 is a process of supplying a raw material gas to the wafer 200 in the inner tube 12. Film formation process 2 is an exhaust process to remove the remaining raw material gas from the inner tube 12. Film formation process 3 is a process of supplying a reaction gas containing nitrogen to the wafer 200 in the inner tube 12. Film formation process 4 is an exhaust process to remove the remaining reaction gas from the inner tube 12.

[0093] First, in step S1 in Figure 7, the wafer 200 is loaded into the boat 217. By moving the boat 217 into the inner tube 12, the substrate is housed inside the cylindrical portion of the inner tube 12. Next, in step S2 in Figure 7, after moving the boat 217 into the inner tube 12, the pressure and temperature inside the inner tube 12 are adjusted. Then, the four steps of the film deposition process 1 to 4 are executed sequentially. Each step will be described in detail below.

[0094] (Film forming process 1) In the film deposition process 1, in step S3 in Figure 7, a first injection device is used to inject a raw material gas toward the wafer 200, while the injected raw material gas is exhausted to the outside of the cylinder using the main exhaust slit 236 and two sub-exhaust slits 238. Specifically, one or more flash supplies are performed in which the raw material gas and carrier gas are released instantaneously, i.e., for a relatively short time, from gas nozzles 340a, 340b, 341a, and 341b. At this time, assist gas may be injected from gas nozzles 342a, 342c or counter nozzle 343. If multiple flash supplies are performed intermittently, the flow rate of the assist gas may change in response.

[0095] As the raw material gas, for example, a Si and halogen-containing gas can be used. As the Si and halogen-containing gas, for example, inorganic chlorosilane gases such as tetrachlorosilane (SiCl4, abbreviated as STC) gas, hexachlorodisilane (Si2Cl6, abbreviated as HCDS) gas, and octachlorotrisilane (Si3Cl8, abbreviated as OCTS) gas can be used. One or more of these can be used as the Si and halogen-containing gas.

[0096] In this disclosure, "high flow rate" means a mass flow rate [kg / s] of 8 × 10⁻⁶ -4 This means a state of being greater than or equal to kg / s. 8 × 10 -4 A mass flow rate [kg / s] of kg / s or more corresponds, for example, to a volumetric flow rate [slm] of HCDS gas of approximately 4 slm or more. -4A mass flow rate [kg / s] of kg / s or more corresponds to a volumetric flow rate [slm] of N2 gas of approximately 38 slm or more. In this specification, 1 [slm] = 1 [L / m]. At high flow rates, various difficulties in gas supply tend to occur, such as the formation of vortices and backflow within the processing chamber 201.

[0097] The volumetric flow rate [slm] is calculated by "mass flow rate / density of the gas species". Therefore, the volumetric flow rate can be used as a flow rate applicable to this disclosure regardless of the gas species. Typical high-flow volumetric flow rates for gases used in applicable membrane species are, for example, approximately 5.5 slm or more for titanium tetrachloride (TiCl4), approximately 30 slm or more for oxygen (O2), approximately 15 slm or more for trimethylaluminum (TMA), and approximately 65 slm or more for NH3.

[0098] The intermittent operation of flash supply causes the raw material gas to adsorb onto the surface of the wafer 200. Adsorption forms a Si-containing film on the underlayer of the wafer 200. The substrate processing method according to this embodiment can be constructed by steps S1 and S3 described above.

[0099] (Film formation process 2) In the film deposition process 2, in step S4 in Figure 7, first, the supply of the raw material gas and carrier gas is stopped. Next, by controlling the exhaust pump such as the vacuum pump 246 and the APC valve 244, the raw material gas is evacuated under vacuum so that the pressure inside the reaction tube 203 reaches a predetermined pressure (i.e., a vacuum). The vacuum evacuation causes any raw material gas remaining in the inner tube 12 to be exhausted from the inner tube 12 to the outside. In addition, in the film deposition process 2, supplying an inert gas, such as N2 gas, as a purge gas into the inner tube 12 further enhances the effect of exhausting the remaining raw material gas.

[0100] (Film forming process 3) In the film formation process 3, in step S5 in Figure 7, a reaction gas is supplied into the inner tube 12 using a second injection device. As the reaction gas, for example, an N-containing gas, a Si-free gas, an oxidizing gas, or a reducing gas such as hydrogen (H2) can be used. In step S5, for example, NH3 gas is supplied into the inner tube 12 as the reaction gas while being exhausted from multiple exhaust slits. When an N-containing gas is supplied, the Si-containing film on the wafer 200 reacts with the N-containing gas. As a result of the reaction, a SiN film is formed on the wafer 200. Alternatively, if a mixed gas of O2 and H2 is used as the reaction gas, SiO2 is formed.

[0101] (Film forming process 4) In the film formation process 4, after the film is formed in step S6 in Figure 7, the reaction gas is evacuated by vacuum by controlling the exhaust pump such as the vacuum pump 246 and the APC valve 244, etc., so that the pressure inside the reaction tube 203 reaches a predetermined pressure (vacuum level). Through vacuum evacuation, the N2-containing gas that remains in the inner tube 12 after contributing to film formation is exhausted from the inner tube 12 to the outside. In addition, in the film formation process 4, if an inert gas, such as the N2 gas used as a carrier gas, is supplied into the inner tube 12 as a purge gas, the effect of exhausting the reaction gas containing residual N2 from the inner tube 12 is further enhanced.

[0102] The above-described film deposition steps 1 to 4 constitute one cycle, and in step S7 in Figure 7, a SiN film of a predetermined thickness can be formed on the wafer 200 by performing the cycle of film deposition steps 1 to 4 a predetermined number of times. In this embodiment, film deposition steps 1 to 4 are repeated multiple times. In this disclosure, film deposition steps 1 to 4 may be performed one at a time without being repeated.

[0103] In film deposition using a cyclic process like the one described here, one gas may dominate the film quality, particularly its uniformity, among multiple processing gases. For example, if uniform adsorption of the chlorosilane-based source gas to adsorption sites within the microstructure is crucial for good step coverage, then only the source gas may be supplied planarly by the first injection device. As a result, both the flow rate and partial pressure of the source gas or intermediate can be maintained within a predetermined range on the wafer surface. On the other hand, the wafer's exposure to the reaction gas does not require the same level of uniformity as the source gas.

[0104] After the above-described film formation process is completed, in step S8 in Figure 7, the pressure inside the inner tube 12 is returned to normal pressure (i.e., atmospheric pressure). Specifically, for example, an inert gas such as N2 gas is supplied into the inner tube 12 and exhausted. This purges the inside of the inner tube 12 with the inert gas, removing any remaining gases from inside the inner tube 12. Subsequently, the atmosphere inside the inner tube 12 is replaced with the inert gas, and the pressure inside the inner tube 12 is returned to normal pressure.

[0105] Then, in step S9 in Figure 7, when the wafer 200 is removed from the inner tube 12, the substrate processing according to this embodiment is completed. The above series of steps constitutes a method for manufacturing a semiconductor device using the wafer 200 according to this embodiment.

[0106] In this specification, the term "wafer" may refer to the wafer itself or to a laminate of a wafer and a predetermined layer or film formed on its surface. In this specification, the term "surface of the wafer" may refer to the surface of the wafer itself or to the surface of a predetermined layer formed on the wafer. In this specification, when it is stated that "a predetermined layer is formed on the wafer," it may mean that the predetermined layer is formed directly on the surface of the wafer itself or that the predetermined layer is formed on a layer already formed on the wafer. In this specification, the term "substrate" has the same meaning as when it is used with the term "wafer."

[0107] (Analysis example) Next, the first to third analysis examples for confirming the features of the substrate processing apparatus according to this embodiment will be described with reference to Figures 8 to 12.

[0108] (1st analysis example) First, we will explain the first analysis example, which analyzes the distance between the centers of two straight-tube nozzles. Figure 8 illustrates the distribution of raw material gas concentration inside the cylindrical section when the distance d between the centers of two gas nozzles 345, corresponding to gas nozzles 340b and 341b of the substrate processing apparatus according to this embodiment, is 22 mm. In the first analysis example, the substrate processing apparatus is not provided with a secondary exhaust slit, and only a main exhaust slit is provided.

[0109] As shown in Figure 8, even without a secondary exhaust slit, the presence of two gas nozzles 345 suppresses overall unevenness in the distribution of raw material gas concentration on the substrate compared to the case with only one gas nozzle 345. Figure 8 illustrates a state in which areas with relatively high raw material gas concentrations are located on the outer edges of both sides of the substrate, on the side of the main exhaust slit in the depth direction D of the apparatus.

[0110] Furthermore, Figure 9 illustrates the analysis results regarding the relationship between the uniformity of the raw material gas concentration and the distance d between the centers of the two gas nozzles. Each gas nozzle had three injection holes. As shown in Figure 9, the uniformity of the raw material gas concentration on the substrate is expressed as the standard deviation [±%] of the average concentration [%]. The average concentration [%] is the concentration of the raw material gas per unit area across the entire substrate surface.

[0111] Furthermore, Figure 9 plots a value of 25% as the uniformity of the raw gas concentration when the distance d between the centers of the two gas nozzles is 0 mm. When the distance d between the centers is 0 mm, it means that there is only one gas nozzle.

[0112] As shown in Figure 9, it was found that when the distance d between the centers of the two gas nozzles is between 20 mm and 100 mm, the standard deviation can be suppressed to approximately 14% or less, thereby improving the uniformity of the raw material gas concentration. When the distance d between the centers exceeds 100 mm, the dimensions of the supply buffer become larger, which raises concerns about the bulkiness of the inner tube.

[0113] Furthermore, it was found that when the distance d between the centers of the two gas nozzles is between 40 mm and 100 mm, the standard deviation can be suppressed to approximately 7% or less, thereby further improving the uniformity of the raw material gas concentration. Moreover, it was found that when the distance d between the centers of the two gas nozzles is between 60 mm and 80 mm, the standard deviation can be suppressed to approximately 3% or less, thereby further improving the uniformity of the raw material gas concentration.

[0114] (Second analysis example) Next, we will explain a second analysis example that analyzes the flow of the raw material gas inside the cylindrical section of the inner tube and the distribution of the partial pressure [Pa] of the intermediate. In the second analysis example, an inorganic chlorosilane gas was used as the raw material gas, and the intermediate was SiCl2 produced by the decomposition of the raw material gas. The raw material gas was supplied to the wafer at a high flow rate through four gas nozzles. Note that in Figures 10A to 10C, since the flow of the raw material gas is symmetrical with respect to the virtual plane A, only the state on the left side is illustrated, and the state on the right side is omitted.

[0115] Figure 10A illustrates the flow and partial pressure distribution of the raw material gas in an analytical model in the substrate processing apparatus according to this embodiment, in which the injection holes of the gas nozzles 340a and 340b are each in a single row, and there is only one main exhaust slit 236. In other words, a pair of secondary exhaust slits 238 are not provided.

[0116] In the analysis model of Figure 10A, as shown in the upper panel, a return flow, i.e., a vortex, was formed when the raw material gas was supplied, returning from gas nozzles 340a and 340b to the vicinity of gas nozzle 342a. Furthermore, as shown in the lower panel of Figure 10A, on the wafer, areas with high intermediate partial pressures of approximately 10 Pa were formed along the entire depth direction D at positions corresponding to both sides of the virtual surface A, and a concentration gradient was distributed across the entire wafer. The high intermediate partial pressure suggests a relatively low flow velocity.

[0117] Furthermore, Figure 10B illustrates the flow and partial pressure distribution of the raw material gas in an analytical model in which the injection holes of the gas nozzles 340a and 340b in the substrate processing apparatus according to this embodiment are each in three rows, and there is only one main exhaust slit 236. Other analytical conditions are the same as those in Figure 10A.

[0118] In the analysis model of Figure 10B, as shown in the upper panel, no return flow was formed. Furthermore, as shown in the lower panel of Figure 10B, the partial pressure concentration of the intermediate was distributed relatively constant except for the sides in the width direction W, which is an improvement compared to the case of Figure 10A. Specifically, at positions corresponding to both sides of the wafer, in the parts on the gas nozzle 340a and 340b sides in the depth direction D, the partial pressure concentration of the raw material gas was suppressed to 10 Pa or less.

[0119] Furthermore, Figure 10C illustrates the flow and partial pressure distribution of the raw material gas in an analytical model in which the injection holes of the gas nozzles 340a and 340b in the substrate processing apparatus according to this embodiment are each arranged in three rows, and one main exhaust slit 236 and two secondary exhaust slits 238 are provided. Other analytical conditions are the same as those in Figure 10A.

[0120] In the analysis model shown in Figure 10C, where two sub-exhaust slits 238 are added, no return flow was formed, as shown in the upper panel. It was also found that the two sub-exhaust slits 238 created a flow of source gas that flowed near the outer edge of the wafer's side. Furthermore, as shown in the lower panel of Figure 10C, the deviation in the partial pressure of the intermediate was clearly reduced compared to the cases in Figures 10A and 10B.

[0121] (Third analysis example) Next, we will explain a third analysis example that analyzes the return flow inside the cylindrical section of the inner tube. As shown in Figure 11, in the third analysis example, the presence or absence of return flow was evaluated in each pattern in which the shape of the injection holes was different when the raw material gas was injected from two gas nozzles 340a and 340b. The analysis conditions for the simulation in the third analysis example, such as pressure, temperature, and gas type, were set to mimic those used in actual film deposition processes.

[0122] As shown in Figure 11, the presence or absence of backflow was evaluated in three stages: "◎", "△", and "×". "◎" means that there was no backflow at all, or very little backflow. "△" means that a weak backflow was observed. "×" means that a strong backflow was present.

[0123] In the third analysis example, five patterns were set according to the different shapes of the gas nozzles 340a and 340b. In the first pattern, each of the two gas nozzles 340a and 340b had one injection hole, and the diameter of the injection hole was 4.6 mm.

[0124] In the second pattern, the number of injection holes in each of the two gas nozzles 340a and 340b was two, along the circumferential direction of the gas nozzles 340a and 340b. In the second pattern, in a plan view, each injection hole was positioned such that the angle between the injection direction of each injection hole and the direction from the center of the gas nozzles 340a and 340b toward the center of the wafer was 30 degrees. The diameter of the injection holes was 1.9 mm.

[0125] In the third pattern, each of the two gas nozzles 340a and 340b had three injection holes along the circumferential direction of the gas nozzle. In the third pattern, the injection holes were arranged such that the angle between adjacent injection holes was 30 degrees in a plan view. Also, in a plan view, the injection direction of the central injection hole among the three injection holes was aligned from the center of gas nozzles 340a and 340b toward the center of the wafer. The diameter of the injection holes was 1.9 mm.

[0126] In the fourth pattern, each of the two gas nozzles 340a and 340b had four injection holes along the circumferential direction of the gas nozzle. In the fourth pattern, the injection holes were arranged such that, in a plan view, the angle between adjacent injection holes was 30 degrees. Also, in a plan view, the injection direction of the two central injection holes out of the four injection holes was arranged such that the angle between the direction from the center of gas nozzles 340a and 340b toward the center of the wafer was 30 degrees. The diameter of the injection holes was 1.9 mm.

[0127] In the fifth pattern, the number of injection holes in each of the two gas nozzles 340a and 340b was four, along the circumferential direction of gas nozzle 340b. In the fifth pattern, each injection hole was positioned such that, in a plan view, the angle between adjacent injection holes was 20 degrees. Also, in a plan view, each injection hole was positioned such that, in a plan view, the angle between the injection direction of the two central injection holes and the direction from the center of gas nozzles 340a and 340b toward the center of the wafer was 20 degrees.

[0128] In other words, in the fourth pattern, the injection range centered on the direction from the center of the gas nozzles 340a and 340b toward the center of the wafer was set wider than the injection range in the fifth pattern. The diameter of the injection hole was 1.9 mm.

[0129] Furthermore, the inner diameter and thickness of the cylinders of the gas nozzles 340a and 340b were set to be the same throughout patterns 1 through 5. In pattern 1, a partition wall was provided between the central portion 222b of the supply buffer 222 where the gas nozzles 340a and 340b are located and the cylindrical portion of the inner tube 12, and a slit opening opposite the injection hole was provided, as shown in the supply slit 235a in Figure 3. On the other hand, in patterns 2 through 5, as shown in this embodiment in Figure 3, no partition wall was provided between the central portion 222b of the supply buffer 222 where the gas nozzles 340a and 340b are located and the cylindrical portion of the inner tube 12.

[0130] In the third analysis example, the flow rate per gas nozzle was varied to five different values: 1 slm, 5 slm, 12 slm, 20 slm, and 50 slm. As shown in Figure 11, in the first pattern, a return flow was continuously present regardless of whether the flow rate per gas nozzle was 5 slm, 12 slm, 20 slm, or 50 slm. In the second pattern, it was found that the smaller the flow rate per gas nozzle, the more the return flow was suppressed.

[0131] Furthermore, in the third, fourth, and fifth patterns, it was found that no backflow occurred except in the fourth pattern when the flow rate per gas nozzle was 50 slm. In the fourth pattern, when the flow rate per gas nozzle was 50 slm, the injection range centered on the direction from the center of gas nozzles 340a and 340b toward the center of the wafer was wider than the injection range in the fifth pattern. As a result, the flow of raw material gas from the injection holes collided with the side walls of the supply buffer adjacent to the injection holes. Therefore, a backflow was continuously present.

[0132] Furthermore, in the fourth pattern, even when the flow rate per gas nozzle was 50 slm, another analysis example was conducted in which no other structures, such as the side walls of the supply buffer, were placed near the gas nozzles 340a and 340b. As a result, it was found that obstruction of the raw gas flow by other structures was avoided.

[0133] <Variation> Next, the substrate processing apparatus according to the first to sixth modified examples will be described with reference to Figures 12 to 13. In the first to sixth modified examples, the internal structure of the supply buffer 222 differs from that of this embodiment.

[0134] (First variation) As shown in Figure 12A, in this disclosure, the number of gas nozzles 340a, 340b, 341a, and 341b constituting the first injection device can be changed as appropriate to one or more. Figure 12A illustrates a substrate processing apparatus according to the first modified example, which is provided with six gas nozzles corresponding to the gas nozzles 340a, etc., constituting the first injection device. The same effects as in this embodiment can be obtained in the first modified example as well.

[0135] (Second variation) As shown in Figure 12B, in the second modified example, a plurality of gas nozzles, such as the gas nozzle 340a, are arranged away from the wafer 200. Specifically, the supply buffer 222 is configured such that a certain distance M is formed between the center of each gas nozzle and the wafer 200. In this embodiment, the certain distance M is preferably, for example, more than twice the Kolmogorov length and less than or equal to 10 times the Kolmogorov length.

[0136] If the constant distance M is less than twice the Kolmogorov length of the gas flow from the gas nozzle, the source gas will hit the wafer 200 without sufficient homogenization of the flow. If the constant distance M exceeds 10 times the Kolmogorov length, there is a concern that the substrate processing apparatus will become too large. In this embodiment, the constant distance can be set arbitrarily.

[0137] The same effects as in this embodiment can be obtained in the second modified example. Furthermore, in the second modified example, by positioning the multiple gas nozzles away from the wafer 200, mixing of the raw material gases is promoted before the raw material gases injected from the multiple gas nozzles reach the wafer 200. As a result, the mixed raw material gases can be delivered onto the surface of the wafer 200.

[0138] (Third variation) As shown in Figure 12C, in the third modified example, the injection holes of the multiple gas nozzles 345, corresponding to the gas nozzle 340a, etc., open toward the side wall opposite to the wafer 200 (i.e., the upper side in Figure 12C). The same effects as in this embodiment can be obtained in the third modified example as well. Furthermore, in the third modified example, because the injection holes of the multiple gas nozzles 345 open toward the side wall opposite to the wafer 200, the injected raw material gas collides with the side wall opposite to the wafer 200. The raw material gas that collides with the side wall opposite to the wafer 200 heads toward the ventilation slit 380a of the partition wall 380 provided between the gas nozzle 345 and the wafer 200. The raw material gas reaches the wafer 200 through the ventilation slit 380a.

[0139] The ventilation slit 380a in the third modified example is an example of a ventilation opening having an opening. In this disclosure, the shape of the opening of the ventilation opening formed in the partition wall is not limited to a slit shape, but can be arbitrarily changed to, for example, a hole shape. In this disclosure, the ventilation opening is an example of a ventilation section formed between the gas nozzle 345 and the wafer 200 to pass the raw material gas to the wafer 200 side. Furthermore, in this disclosure, the ventilation section is not limited to a ventilation opening in the partition wall. For example, a ventilation device having an overall tubular shape with a gas flow path formed inside may be provided as a ventilation section.

[0140] Therefore, in the third modified example, the mixing of the raw material gases is promoted between the time the raw material gas is injected from the gas nozzle 345 and the time it reaches the wafer 200. As a result, the mixed raw material gas can be delivered onto the surface of the wafer 200.

[0141] (Fourth variation) As shown in Figure 12D, in the fourth modification, the injection holes of multiple gas nozzles, such as the gas nozzle 340a, open toward the side wall provided between the gas nozzle and the wafer 200. The same effects as in this embodiment can be obtained in the fourth modification. Furthermore, in the fourth modification, the injection holes of multiple gas nozzles open toward the partition wall 380 provided between the gas nozzle and the wafer 200, causing the injected raw material gas to collide with the partition wall 380.

[0142] The raw material gas that collides with the partition wall 380 passes through the ventilation slit 380a of the partition wall 380 and reaches the wafer 200. Therefore, mixing of the raw material gases is promoted between the time the raw material gas is injected from the gas nozzle 340b and the time it reaches the wafer 200. As a result, the mixed raw material gas can be delivered onto the surface of the wafer 200.

[0143] (Fifth variation) Furthermore, in this disclosure, the configurations of each of the first to fourth modified examples described above may be partially combined. Figure 12E illustrates, for example, a fifth modified example in which the configurations of the second modified example and the fourth modified example are combined. That is, in the supply buffer 222 according to the fifth modified example, similar to the second modified example, a plurality of gas nozzles are arranged away from the wafer 200 such that a certain distance M is formed between the center of the gas nozzle and the wafer 200.

[0144] Furthermore, in the fifth modification, similar to the fourth modification, a partition wall 380 having a ventilation slit 380a is provided between the gas nozzle and the wafer 200, and the injection holes of multiple gas nozzles corresponding to gas nozzles 340a, etc., open toward the partition wall 380 having the ventilation slit 380a. Therefore, in the fifth modification, in addition to the same effects as in this embodiment, both the effects of the second modification and the effects of the fifth modification can be obtained.

[0145] (Sixth variation) As shown in Figure 13, in the substrate processing apparatus according to the sixth modified example, both the shape of the main exhaust slit 236 and the shape of the pair of sub-exhaust slits 238 are rectangular. In the sixth modified example, a fin 250 is provided as an exhaust flow rate adjustment section, projecting from the side wall toward the outer tube 14 to a part of the side wall forming the main exhaust slit 236 and the pair of sub-exhaust slits 238 in the cylindrical portion.

[0146] The protruding length of the fins 250 provided on the side wall of the main exhaust slit 236 decreases along the axis direction of the cylindrical section, from the upper side in Figure 13, which is opposite the main exhaust port, to the lower side in Figure 13, where the main exhaust port is located. The main exhaust port is not shown. The protruding length of the fins 250 provided on the side wall of the secondary exhaust slit 238 decreases along the axis direction of the cylindrical section, from the upper side in Figure 13, which is opposite the secondary exhaust port, to the lower side in Figure 13, where the secondary exhaust port is located. The secondary exhaust port is not shown.

[0147] The same effects as in this embodiment can be obtained in the sixth modified example. Furthermore, in the sixth modified example, the fins 250 can equalize the flow rate of the exhausted raw material gas between the substrates stacked in multiple stages along the axis of the cylindrical section, that is, equalize the conductance in the vertical direction. Details of the effects of the sixth modified example will be described later.

[0148] Although Figure 13 illustrates a case where the fins 250 are formed in a stepped shape by a plate-shaped member having five plate-shaped portions with increasing protrusion lengths from top to bottom, the shape of the exhaust flow rate adjustment section is not limited to a stepped shape in this disclosure. For example, in this disclosure, the exhaust flow rate adjustment section may be composed of a plate-shaped member having plate-shaped portions whose protrusion length gradually decreases towards the main exhaust port. Furthermore, the exhaust flow rate adjustment section is not limited to a plate-shaped member and may be composed of a block-shaped member, an annular member, or the like.

[0149] (Seventh variation) Furthermore, as shown in Figure 10C, the substrate processing apparatus according to the seventh modified example includes a main exhaust buffer 232a formed to airtightly cover the main exhaust slit 236 from the outside of the inner tube 12, and two sub-exhaust buffers 232b formed separately from the main exhaust buffer to similarly cover each of the two sub-exhaust slits 238 from the outside of the inner tube 12. The main exhaust buffer 232a and the sub-exhaust buffers 232b are each connected to an exhaust duct 231.

[0150] The main exhaust buffer 232a and the secondary exhaust buffer 232b, like the supply buffer 222, are formed on the outside of the inner tube, extending axially along the distribution of the corresponding main exhaust slits 236 and secondary exhaust slits 238, respectively. The main exhaust buffer 232a alleviates the internal pressure gradient and works in cooperation with the main exhaust slits 236 to provide uniform exhaust to the wafer 200. The secondary exhaust buffer 232b does the same.

[0151] The main exhaust buffer 232a corresponds to the main exhaust system that sends the raw material gas to the outside in this disclosure. The two secondary exhaust buffers 232b correspond to the two secondary exhaust systems that send the raw material gas to the outside in this disclosure. In this disclosure, the main exhaust system is not limited to the main exhaust buffer, but can be any main exhaust space that can alleviate the internal pressure gradient. Similarly, in this disclosure, the secondary exhaust system is not limited to the secondary exhaust buffer, but can be any secondary exhaust space that can alleviate the internal pressure gradient.

[0152] The same effects as in this embodiment can be obtained in the seventh modification. In the seventh modification, the main exhaust buffer 232a and the like are further provided, eliminating the need for the outer pipe 14, and making it possible to use a single-pipe processing container. In this context, the term processing pipe refers to the inner pipe 12 and the outer pipe 14, respectively, and may particularly include a single pipe that has the same shape and pressure resistance as the inner pipe 12 and is used on its own.

[0153] (Effects and Benefits) According to this embodiment, one or more of the following effects can be obtained.

[0154] The substrate processing apparatus 10 according to this embodiment includes a reaction tube 203 having an inner tube 12 and an outer tube 14, a supply buffer 222 provided in the cylindrical portion of the inner tube 12, four gas nozzles 340a, 340b, 341a, and 341b provided in the supply buffer 222, and two sub-exhaust slits 238 provided in the cylindrical portion.

[0155] The two sub-exhaust slits 238 are formed in the side walls of the cylindrical portion and open on both sides of a virtual plane A, which is set to pass through the circumferential center of the cylindrical portion and the axis of the cylindrical portion at the boundary between the supply buffer 222 and the cylindrical portion in a plan view. In other words, the two sub-exhaust slits 238 face both sides of the wafer 200, with the virtual plane A in between.

[0156] Therefore, the raw material gas injected from the four gas nozzles 340a, 340b, 341a, and 341b is promoted to flow not only towards the center of the wafer 200 in a plan view, but also towards both sides of the wafer 200. As a result, the uniformity of the flow of the raw material gas on the surface of the wafer 200 can be improved during the film deposition process.

[0157] Furthermore, in this embodiment, to improve the uniformity of the raw material gas flow, it is only necessary to form two sub-exhaust slits 238 on the cylindrical portion that sandwich the virtual surface A from both sides, thus eliminating the need for any additional components. As a result, the substrate processing apparatus 10 can be constructed relatively inexpensively and compactly.

[0158] In this embodiment, a single main exhaust slit 236 is provided in the side wall of the cylindrical portion opposite to the supply buffer 222 relative to the center C1 of the wafer 200. Two sub-exhaust slits 238 are positioned at the same height as the main exhaust slit 236 but at a distance from it, flanking the main exhaust slit 236. In plan view, the angle between each first virtual line L1 connecting the center of the sub-exhaust slit 238 and the center C1 of the wafer 200 and the virtual plane A is obtuse. Furthermore, the width of each of the two sub-exhaust slits 238 in the circumferential direction of the cylindrical portion is smaller than the width of the main exhaust slit 236.

[0159] Because the main exhaust slit 236 and the two sub-exhaust slits 238 further disperse the raw material gas, the region around the wafer 200 where the flow of the raw material gas decreases is reduced. This further improves the uniformity of the flow of the raw material gas on the surface of the wafer 200.

[0160] Furthermore, in this embodiment, four gas nozzles 340a, 340b, 341a, and 341b are arranged along the circumferential direction of the cylindrical portion and configured to supply the same raw material gas. Each of the four gas nozzles 340a, 340b, 341a, and 341b has a forward pipe and a return pipe through which the raw material gas flows, and is a return nozzle having an injection hole 234 that injects the same raw material gas by connecting the upper end of the forward pipe and the upper end of the return pipe.

[0161] In this embodiment, the raw material gas is further dispersed by the four gas nozzles 340a, 340b, 341a, and 341b. Furthermore, the four gas nozzles 340a, 340b, 341a, and 341b can be easily configured using two return nozzles.

[0162] Furthermore, in this embodiment, the four gas nozzles 340a, 340b, 341a, and 341b arranged along the circumferential direction of the cylindrical portion increase the flow rate of gas injected to the periphery of the wafer 200 compared to the flow rate of gas injected to the center C1 of the wafer 200. As a result, the region around the wafer 200 where the raw material gas flow is slow is reduced. Therefore, the uniformity of the raw material gas flow on the surface of the wafer 200 can be further improved.

[0163] Furthermore, in this embodiment, the four gas nozzles 340a, 340b, 341a, and 341b each have three or more injection holes 234 arranged along the circumferential direction of the cylindrical portion in a plane parallel to the surface of the wafer 200.

[0164] Since the raw material gas is ejected radially through three or more injection holes 234, the region around the wafer 200 where the flow of the raw material gas decreases is reduced. This further improves the uniformity of the flow of the raw material gas on the surface of the wafer 200.

[0165] Furthermore, in this embodiment, the four gas nozzles 340a, 340b, 341a, and 341b and the two sub-exhaust slits 238 are configured symmetrically with respect to the virtual plane A. This further improves the uniformity of the raw material gas flow on the surface of the wafer 200.

[0166] In this embodiment, multiple wafers 200 are arranged inside the cylindrical portion along the axis of the cylindrical portion. In addition, four gas nozzles 340a, 340b, 341a, and 341b are arranged along the circumferential direction of the cylindrical portion and configured to supply the same raw material gas. Each of the four gas nozzles 340a, 340b, 341a, and 341b has a forward pipe and a return pipe through which the raw material gas flows, and the upper ends of the forward pipe and the upper ends of the return pipe are connected, forming four gas nozzles 340a, 340b, 341a, and 341b that inject the same raw material gas.

[0167] Furthermore, the two return nozzles 340 and 341 are arranged so that their return pipes are adjacent to each other, while their forward pipes are spaced apart. In addition, each of the forward and return pipes of the two return nozzles 340 and 341 has three or more rows of injection holes 234 that extend along the longitudinal direction of the return nozzle. The injection holes 234 inject the raw material gas radially in a plan view.

[0168] By positioning the forward pipe, which has a relatively high internal pressure, outside the center C1 of the wafer 200, a larger supply of gas can be provided to the outer periphery of the wafer 200, where flow rate and gas concentration tend to be insufficient during radial injection. This suppresses the generation of return flow of the raw material gas.

[0169] Furthermore, in this embodiment, tanks 322b and 322c are provided, which are connected to the four gas nozzles 340a, 340b, 341a, and 341b. These tanks store the raw material gas independently without mixing it with the carrier gas and supply the stored raw material gas to the four gas nozzles 340a, 340b, 341a, and 341b almost simultaneously in a pulsed manner. The sum of the instantaneous maximum flow rates of the raw material gas injected in a pulsed manner from each of the four gas nozzles 340a, 340b, 341a, and 341b is 5 slm or more.

[0170] In this case, when flash supply is performed, if the total instantaneous maximum flow rate of the raw material gas is small, the film-forming gas may receive sufficient heat and the gas may deteriorate. On the other hand, when the gas is supplied at a large flow rate, it becomes possible to supply fresh gas to the wafer 200 without receiving much heat. For this reason, this embodiment, in which flash supply of raw material gas of 5 slm or more is performed, is advantageous in that it can further improve the quality of the formed film.

[0171] Furthermore, in this embodiment, among the three or more injection holes 234, the diameter R1 of the injection hole 234 that injects the raw material gas from the center C1 of the wafer 200 toward the outermost part may be larger than the diameter R2 of the other injection holes 234. As a result, the flow rate of the exhausted raw material gas is more evenly distributed, improving the inter-plane uniformity of the film between the surfaces of multiple wafers 200.

[0172] Furthermore, in this embodiment, a space is formed between the wafer 200 and one of the three or more injection holes 234 that injects the raw material gas toward the outermost part of the wafer 200 in a plan view, allowing the raw material gas to travel in a straight line along the injection direction. In other words, no other structures are provided as obstacles that would obstruct the flow of the raw material gas before it reaches the wafer 200. As the flow rate of the exhausted raw material gas is more evenly distributed, the inter-plane uniformity of the film between the surfaces of the multiple wafers 200 is improved.

[0173] Furthermore, in this embodiment, the reaction tube 203 further includes an outer tube 14 that surrounds the cylindrical portion, thereby forming an exhaust space S between itself and the cylindrical portion. The outer tube 14 has an exhaust port 230 and a pair of sub-exhaust ports (not shown) that connect the exhaust space S to the outside of the reaction tube 203. As a result, the raw material gas passes through the exhaust space and is exhausted to the outside from the exhaust port 230 and the pair of sub-exhaust ports, reducing the area around the wafer 200 where the flow of the raw material gas decreases. Therefore, the uniformity of the flow of the raw material gas on the surface of the wafer 200 can be further improved.

[0174] Furthermore, in this embodiment, the opening width of one main exhaust slit 236 along the circumferential direction of the cylindrical portion narrows along the axial direction of the cylindrical portion, from the opposite side of the exhaust port 230 toward the exhaust port 230. Similarly, the opening width of each of the two sub-exhaust slits 238 along the circumferential direction of the cylindrical portion narrows along the axial direction of the cylindrical portion, from the opposite side of each of the pair of sub-exhaust ports toward the pair of sub-exhaust ports. As a result, the flow rate of the exhausted raw material gas is more evenly distributed between the wafers 200 stacked in multiple stages along the axial direction, thereby improving the inter-plane uniformity of the film between the surfaces of the multiple wafers 200.

[0175] In the sixth modified example, fins 250 are provided on a portion of the side wall forming one main exhaust slit 236 and two sub-exhaust slits 238 in the cylindrical section. The fins 250 protrude from the side wall toward the outer pipe 14, and their protruding length decreases along the axis of the cylindrical section, from the opposite side of the main exhaust port and the pair of sub-exhaust ports toward the main exhaust port and the pair of sub-exhaust ports. That is, in a plan view, the distance between the inner pipe and the outer pipe in the exhaust space decreases as one moves toward the main exhaust port and the pair of sub-exhaust ports along the vertical direction H.

[0176] Here, consider the case where, for example, no fins 250 are provided, and the distance between the inner and outer tubes in the exhaust space is approximately constant in a plan view as you move towards the main exhaust port and the pair of sub-exhaust ports. When the distance between the inner and outer tubes is approximately constant, the flow rate of the raw material gas exhausted from the part of one main exhaust slit 236 closer to the main exhaust port is greater than the flow rate of the raw material gas exhausted from the part further away from the main exhaust port.

[0177] Similarly, in the two sub-exhaust slits 238, the flow rate of the raw material gas exhausted from the portion closer to the sub-exhaust port is greater than the flow rate of the raw material gas exhausted from the portion further away from the sub-exhaust port. In other words, the difference in exhaust volume between the top and bottom of the one main exhaust slit 236 and the two sub-exhaust slits 238 becomes large. As a result, the unevenness in the flow rate of the exhausted raw material gas becomes large among the wafers 200 stacked in multiple stages along the axial direction.

[0178] On the other hand, in the sixth modified example, the fins 250 suppress the flow rate of the raw material gas exhausted from the bottom side near the main exhaust port and the sub-exhaust port so that the difference between this flow rate and the flow rate of the raw material gas exhausted from the top side is reduced. As a result, the flow rate of the exhausted raw material gas is equalized between the wafers 200 stacked in multiple stages along the axial direction. Consequently, the inter-plane uniformity of the film between the surfaces of the multiple wafers 200 is improved. Furthermore, there is no need to process the side walls of the cylindrical section so that the opening width of the slit narrows along the axial direction from the opposite side of the exhaust port toward the exhaust port.

[0179] Furthermore, in the seventh modified example, a main exhaust buffer 232a and two secondary exhaust buffers 232b are provided, each sending the raw material gas to the outside. This promotes the exhaust of the raw material gas to the outside.

[0180] Furthermore, in this embodiment, the first injection direction F1, which is closest to the return pipe among the injection directions of the injection holes 234 of the return nozzle's forward pipe, and the second injection direction F2, which is closest to the forward pipe among the injection directions of the injection holes 234 of the return pipe, intersect outside the wafer 200 or within the supply buffer 222.

[0181] Therefore, the raw material gas injected along one injection direction and the raw material gas injected along the second injection direction F2 collide at a position away from the wafer 200. As a result, the raw material gas, whose concentration has been equalized by the collision, can be supplied to the wafer 200. If the intersection FX is outside the supply buffer 222 and close to the wafer 200, the collision position between the raw material gases is too close to the wafer 200, making it difficult to supply the raw material gas with equalized concentration to the entire surface of the wafer 200. Also, if the intersection FX is located outside the range of within 3r from the center C2 of the forward pipe and within 3r from the center C2 of the return pipe, the distance between the collision position between the raw material gases and the wafer 200 becomes short. As a result, it is difficult to supply the raw material gas with equalized concentration to the entire surface of the wafer 200.

[0182] Furthermore, in this embodiment, the supply buffer 222 is divided into three sections along the circumferential direction of the cylindrical portion by a third partition 18c and a fourth partition 18d. The central section 222b of the divided supply buffer 222 is provided with four gas nozzles 340a, 340b, 341a, and 341b, which are return nozzles 340 and 341, and the sections on both sides of the central section are provided with gas nozzles 342a and 342c, which supply assist gas and reaction gas. The assist gas from the gas nozzles 342a, etc., makes it easy to adjust the in-plane or inter-plane uniformity of the raw material gas concentration.

[0183] Furthermore, in this embodiment, the counter nozzle 343 that supplies the assist gas is positioned such that, in a plan view, the angle between the second virtual line L2 connecting the injection direction of the third injection device and the center C1 of the wafer 200 and the virtual plane A is obtuse. The assist gas from the counter nozzle 343 as the third injection device is mixed with the raw material gas, making it easier to further adjust the uniformity of the raw material gas concentration.

[0184] If all four gas nozzles 340a, 340b, 341a, and 341b, which serve as the first injection device, are not used, then 5 slm to 10 slm of assist gas is required per nozzle, such as gas nozzle 342a. On the other hand, if all four first injection devices are used, the amount of N2 used as assist gas per nozzle, such as gas nozzle 342a and counter nozzle 343, can be reduced to about 1 slm. Furthermore, the amount of pure N2 (i.e., high-purity N2) used in the entire substrate processing can be reduced by 10% to 20%.

[0185] In this specification, numerical ranges such as "3slm~4slm" mean that the lower and upper limits are included within that range. For example, "3slm~4slm" means "3slm or more and 4slm or less." The same applies to other numerical ranges.

[0186] Furthermore, in this embodiment, the central angle θ of the sector formed by the virtual arc connecting both ends of the cylindrical portion of the supply buffer 222 in the circumferential direction and the center C1 of the wafer 200 is less than 30 degrees. If the central angle θ is 30 degrees or more, the circumferential width of the cylindrical portion of the supply buffer 222 becomes wider, and as a result, the overall dimensions of the supply buffer 222 become larger. In other words, in this embodiment, the circumferential width of the cylindrical portion of the supply buffer 222 can be made narrower than when the central angle θ is 30 degrees or more. Therefore, the overall dimensions of the supply buffer 222 can be reduced.

[0187] Furthermore, the substrate processing method using the substrate processing apparatus 10 according to this embodiment can improve the uniformity of the flow of the raw material gas on the surface of the wafer 200.

[0188] Furthermore, in the semiconductor device manufacturing method including the substrate processing method according to this embodiment, the uniformity of the flow of the raw material gas on the surface of the wafer 200 can be improved, so that a semiconductor device can be manufactured with improved in-plane uniformity and step coverage of the raw material gas adsorbed on the surface of the wafer 200.

[0189] In particular, in the manufacturing of semiconductor devices, relatively deep pinholes may form on the surface of the wafer 200, such as in 3D NAND flash memory. As the depth of the pinholes increases, the surface area of ​​the wafer 200 increases, and consequently, the amount of raw material gas required for the film deposition process also increases. Therefore, this embodiment, which improves the uniformity of the raw material gas flow, can be advantageously applied to the film deposition process in the manufacturing process of semiconductor devices in which relatively deep holes are formed on the surface.

[0190] <Other aspects of this disclosure> Although this disclosure has been described in accordance with the embodiments disclosed above, the descriptions and drawings that constitute part of this disclosure should not be understood as limiting this disclosure. This disclosure is not limited to the embodiments described above and can be modified in various ways without departing from its essence.

[0191] For example, the above-described embodiment described an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at once. The present disclosure is not limited to the above-described embodiment and can also be suitably applied to cases where a film is formed using a single-wafer substrate processing apparatus that processes one or several substrates at once.

[0192] Furthermore, the above-described embodiments described an example of forming a film using a substrate processing apparatus having a hot-wall type processing furnace. However, this disclosure is not limited to the above-described embodiments and can also be suitably applied when forming a film using a substrate processing apparatus having a cold-wall type processing furnace.

[0193] Even when using these substrate processing devices, each process can be carried out using the same processing procedures and conditions as described above, and the same effects as described above can be obtained.

[0194] Furthermore, the present disclosure may be constructed by partially combining the configurations included in the multiple embodiments, modifications, and aspects disclosed above. In the present disclosure constructed by such combination, the processing procedures and processing conditions to be performed can be configured, for example, in the same way as the processing procedures and processing conditions described in the embodiments of this present example.

[0195] This disclosure includes various embodiments not described above, and the technical scope of this disclosure is defined solely by the inventive features of the claims that are reasonable in light of the above description.

[0196] The disclosure of Japanese Patent Application No. 2022-017389, filed on 7 February 2022, is incorporated herein by reference in its entirety. Furthermore, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated as being incorporated by reference. [Explanation of symbols]

[0197] 10 Substrate Processing Equipment 200 wafers (substrates) 203 Reaction tube (processing tube) 222 supply buffer 236 Main exhaust slit (exhaust section) 238 Secondary exhaust slit (exhaust section) 340a Gas nozzle (first injection device) 340b Gas nozzle (first injection device) 341a Gas nozzle (first injection device) 341b Gas nozzle (first injection device) A Virtual Surface

Claims

1. A processing tube that houses the substrate on the inside, A first injection unit is provided inside the processing tube and configured to supply gas to the substrate, A first exhaust section is formed on the side wall of the processing tube opposite to the first injection section, with the substrate in between, A second exhaust section is positioned in the circumferential direction of the processing pipe, away from the first exhaust section, A region formed on the side wall of the processing pipe between the first exhaust section and the second exhaust section, which protrudes outward, A substrate processing apparatus comprising:

2. The first exhaust section and the second exhaust section are slit-shaped openings, The second exhaust section is positioned at the same height as the first exhaust section. In a plan view, the angle between the first virtual line connecting the center of the second exhaust section and the center of the substrate, and the virtual plane set to pass through the axis of the first injection section and the processing tube, is an obtuse angle. The width of each of the second exhaust sections in the circumferential direction of the side wall of the processing pipe is smaller than the width of the first exhaust section. The substrate processing apparatus according to claim 1.

3. The first injection unit has a plurality of nozzles arranged along the circumferential direction of the side wall of the processing pipe and configured to supply the same raw material gas, Each of the plurality of nozzles has a forward pipe and a return pipe through which the raw material gas flows, the upper end of the forward pipe and the upper end of the return pipe are in communication, and the forward pipe and the return pipe are return nozzles having injection holes for injecting the same raw material gas. The substrate processing apparatus according to claim 1.

4. Each of the forward and return pipes of the return nozzle has a plurality of injection holes in a plane parallel to the surface of the substrate. The substrate processing apparatus according to claim 3.

5. The first injection unit has four nozzles arranged along the circumferential direction of the side wall of the processing tube, and each of the four nozzles has three or more injection holes that radially inject the same gas into a plane parallel to the substrate. The substrate processing apparatus according to claim 1.

6. The first injection section is formed symmetrically with respect to the virtual plane, and two second exhaust sections are provided symmetrically with respect to the virtual plane. The substrate processing apparatus according to claim 2.

7. A processing tube that houses the substrate on the inside, A first injection unit is provided inside the processing tube and configured to supply gas to the substrate, A first exhaust section is formed on the side wall of the processing tube opposite to the first injection section, with the substrate in between, The processing tube comprises a second exhaust section located away from the first exhaust section in the circumferential direction of the processing tube, Multiple substrates are arranged inside the processing tube along the direction of the processing tube's axis. Multiple of the first injection units are arranged along the circumferential direction of the processing pipe and are configured to be able to supply the same raw material gas. Each of the plurality of first injection units has a forward pipe and a return pipe through which the raw material gas flows, the upper end of the forward pipe and the upper end of the return pipe are in communication, and the forward pipe and the return pipe have four first injection units formed by two return nozzles having injection holes for injecting the same raw material gas. The two return nozzles are arranged such that their respective return pipes are adjacent to each other, and their respective forward pipes are spaced apart. Each of the two return nozzles, the forward pipe and the return pipe, has three or more rows of injection holes extending along the longitudinal direction of the return nozzle. The injection holes, in a plan view, eject the raw material gas radially. Circuit board processing equipment.

8. Multiple of the first injection units are arranged along the circumferential direction of the side wall of the processing pipe and are configured to be able to supply the same raw material gas. The tank is further connected to a plurality of the first injection units, stores the raw material gas on its own without being mixed with the carrier gas, and supplies the stored raw material gas to the plurality of first injection units in a pulsed manner almost simultaneously. The sum of the instantaneous maximum flow rates of the raw material gas injected in a pulsed manner from each of the multiple first injection units is 5 slm or more or 8 × 10⁻¹⁰ －４ It is 1 kg / s or more. The substrate processing apparatus according to claim 1 or 7.

9. Of the three or more injection holes, the diameter of one injection hole that injects the raw material gas from the center of the substrate outward is larger than the diameters of the other injection holes. The substrate processing apparatus according to claim 5.

10. Between one of the three or more injection holes that injects the raw material gas toward the outermost part of the substrate in a plan view, and the substrate, a space is formed in which the raw material gas can travel in a straight line along the injection direction, without any structure being provided. The substrate processing apparatus according to claim 5.

11. The processing tube further comprises an inner tube that constitutes the side wall of the processing tube, and an outer tube that surrounds the inner tube, thereby forming an exhaust space between the inner tube and the outer tube, and having an exhaust port that connects the exhaust space to the outside of the processing tube. The first exhaust section and the second exhaust section are openings that directly connect the inside of the inner tube to the exhaust space. The substrate processing apparatus according to claim 1.

12. The processing tube further comprises an exhaust port that communicates with the outside of the processing tube, The opening widths of the first exhaust section and the second exhaust section, along their respective circumferential directions, narrow as they move from the opposite side of the exhaust port toward the exhaust port along the axial direction of the processing pipe. The substrate processing apparatus according to claim 1.

13. In the inner tube, an exhaust flow rate adjustment section is provided on a part of the side wall forming the first exhaust section and the second exhaust section, the side wall protruding toward the outer tube, the length of which the protrusion increases along the axis direction of the side wall of the processing tube from the opposite side of the exhaust port toward the exhaust port, The substrate processing apparatus according to claim 11, further comprising the above.

14. The exhaust port is positioned on a virtual plane that is set to pass through the axis of the first injection unit and the processing pipe. A substrate processing apparatus according to any one of claims 11 to 13.

15. The first injection unit has three or more injection holes arranged along the circumferential direction of the processing tube in a plane parallel to the surface of the substrate, and injects the same gas, and the maximum angle formed by the injection directions of the three or more injection holes is between 60 and 90 degrees. The substrate processing apparatus according to claim 3.

16. The processing tube is further provided with a supply buffer that is located on the side wall and protrudes outward from the side wall, and the supply buffer is divided into three parts along the circumferential direction of the processing tube by a partition wall. A return nozzle is provided as the first injection unit in the central portion of the divided portion of the supply buffer, A second injection unit is provided on both sides of the central portion to supply an assist gas or a reaction gas, The substrate processing apparatus according to claim 1, further comprising the following:

17. A third injection unit for supplying assist gas, wherein, in a plan view, the third injection unit is provided as a counter nozzle at a position where the angle between a second imaginary line connecting the injection direction of the third injection unit and the center of the substrate and an imaginary plane set to pass through the first injection unit and the axis of the processing tube is obtuse. The substrate processing apparatus according to claim 7, further comprising the above.

18. The processing tube is further provided with a supply buffer that is located on the side wall and protrudes outward from the side wall, The first injection unit has three or more injection holes arranged parallel to the surface of the substrate and injecting the same gas, and is located inside the supply buffer, supplying the raw material gas at a rate of 5 slm or more or 8 × 10 －４ It is configured to allow pulsed injection at a maximum instantaneous flow rate of kg / s or more. The central angle of the sector formed by the virtual arc connecting both ends of the supply buffer in the circumferential direction and the center of the substrate is less than 30 degrees. The substrate processing apparatus according to claim 1 or 7.

19. A cylindrical section that houses the circuit board on the inside, Inside the cylindrical portion, a supply buffer is provided which a first injection unit for supplying gas to the substrate is located, A first exhaust section is formed on the side wall of the cylindrical section opposite to the first injection section, with the substrate in between, A second exhaust section is positioned away from the first exhaust section in the circumferential direction of the cylindrical section, A region formed on the side wall of the cylindrical portion between the first exhaust portion and the second exhaust portion, which protrudes outward, A processing tube equipped with a processing tube.

20. (A) The substrate is housed inside the processing tube, (B) Using the first injection unit provided inside the processing tube, gas is injected onto the substrate. (C) A substrate processing method comprising exhausting the injected gas to the outside of the processing tube using a first exhaust section formed on the side wall of the processing tube opposite to the first injection section with respect to the substrate, and a second exhaust section positioned away from the first exhaust section in the circumferential direction of the processing tube via a region formed to protrude outward from the side wall of the processing tube.

21. (α) A step of housing the substrate inside the processing tube, (β) A step of injecting gas onto the substrate using a first injection unit provided inside the processing tube, A method for manufacturing a semiconductor device, comprising the steps of (γ) exhausting the injected gas to the outside of the processing tube using a first exhaust section formed on the side wall of the processing tube opposite to the first injection section with respect to the substrate, and a second exhaust section positioned away from the first exhaust section in the circumferential direction of the processing tube via a region formed to protrude outward from the side wall of the processing tube.

22. (a) Procedure for housing the substrate inside the processing tube, (b) A procedure for injecting gas onto the substrate using a first injection unit provided inside the processing tube, (c) A procedure for exhausting the injected gas to the outside of the processing tube using a first exhaust section formed on the side wall of the processing tube opposite to the first injection section with respect to the substrate, and a second exhaust section positioned away from the first exhaust section in the circumferential direction of the processing tube via a region formed to protrude outward from the side wall of the processing tube, A program that causes a circuit board processing unit to execute commands via a computer.

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