Substrate processing device, semiconductor device manufacturing method, substrate processing method, and recording medium

Abstract

The present invention provides a substrate processing device, a method for manufacturing a semiconductor device, a substrate processing method, and a recording medium. The substrate processing device of the present invention comprises: a wafer cassette that arranges and holds a plurality of substrates in a predetermined arrangement direction; an inner tube that surrounds the wafer cassette and has exhaust holes formed in a direction perpendicular to the arrangement direction of the substrates for exhausting the gas; a mixing unit that premixes a plurality of gases for substrate processing that react with each other at a temperature within the inner tube to generate a mixed gas; and a nozzle that is separated from the inner wall of the inner tube and discharges the mixed gas supplied by the mixing unit into the inner tube through a plurality of discharge holes formed along the arrangement direction of the substrates; the discharge holes are oriented toward the inner wall of the inner tube rather than toward the wafer cassette.

Description

Technical Field

[0001] The present invention relates to a substrate processing device, a method for manufacturing a semiconductor device, a substrate processing method, and a recording medium. Background Art

[0002] In the past, the following process was known: a plurality of substrates (wafers) arranged in a predetermined arrangement direction are surrounded by an inner tube, and a gas for substrate processing is supplied into the inner tube to form a film of desired quality on the plurality of substrates. As a substrate processing device, patent documents 1 and 2 disclose a vertical processing device, in which a plurality of substrates are arranged in the vertical direction inside an inner tube (cylindrical heating element or reaction tube), and a nozzle extending in the vertical direction is provided near the substrate. In order to supply gas to the substrate, the nozzle of patent documents 1 and 2 forms a plurality of discharge holes (gas supply holes) with openings in the vertical direction inside the inner tube.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 06-349761

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2014-175494 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] When multiple ejection holes are formed in parallel within a single nozzle, the internal pressure of the nozzle decreases from upstream to downstream. Therefore, the pressure difference between the inside and outside of the nozzle decreases as the ejection holes are located further downstream compared to those located upstream. Consequently, the difference in gas supply volume increases between upstream and downstream substrates.

[0009] One possible method to reduce the variation in the amount of supplied gas is to increase the internal pressure of the nozzle to reduce the effect of the pressure difference between the nozzle and the outside on the downstream outlet. However, as the internal pressure increases, the gas is more likely to thermally decompose within the nozzle.

[0010] Furthermore, when a mixed gas containing multiple gases is supplied from the same nozzle, increasing the internal pressure of the nozzle can easily cause abnormal reactions between the multiple gases within the nozzle, resulting in increased particle generation within the inner tube. Furthermore, these abnormal reactions can generate new film precursors that are not necessary for the film formation process, leading to uneven film thickness within the substrate and between substrates.

[0011] In response to this, Patent Document 1 discloses a technique for reducing the variation in the amount of supplied gas by decreasing the interval (pitch) between adjacent ejection holes from upstream to downstream, thereby ejecting a constant flow rate of reaction gas per unit length of the nozzle.

[0012] However, Patent Document 1 only supplies a single reactive gas through a single nozzle, and does not consider the possibility of supplying a mixed gas comprising multiple gases through the same nozzle. Consequently, the problem of particle generation, uneven film thickness within a substrate, and uneven film thickness between substrates caused by abnormal reactions between multiple gases cannot be adequately addressed.

[0013] Furthermore, even if the nozzle internal pressure is reduced to a certain extent by reducing the spacing between adjacent ejection holes, as in Patent Document 1, the multiple gases cannot be fully dispersed and mixed, resulting in the concern that the required concentration of mixed gas cannot be uniformly supplied to each substrate. Therefore, even simply applying the technology of Patent Document 1 is difficult to reduce the nozzle internal pressure when transporting and supplying a mixed gas containing multiple gases.

[0014] Furthermore, Patent Document 2 discloses a configuration in which, to prevent particles and metallic contaminants blown up by the process gas from adhering to the substrate surface, the discharge direction of the discharge port is directed toward a position where no substrate is present, so that the discharged process gas flows around the substrate. In Patent Document 2, the gas supplied by a single nozzle is a single process gas. Therefore, as in Patent Document 1, this configuration fails to adequately address the problems of particle generation, uneven film thickness within the substrate surface, and uneven film thickness between substrates caused by abnormal reactions between multiple gases.

[0015] Furthermore, in Patent Document 2, the nozzle is positioned so that it contacts the inner wall of the inner tube. Therefore, in configurations where the discharge hole is directed toward a position where the substrate is not present, the discharge hole may come into contact with the inner wall of the inner tube. This narrows the gas passage between the discharge hole and the inner wall, resulting in increased internal pressure within the nozzle during gas discharge, which can lead to thermal decomposition of the gas within the nozzle and abnormal reactions among various gases.

[0016] The present invention is proposed in view of the above situation, and its purpose is to provide a technology that, when using the same nozzle to supply a mixed gas of multiple gases as a processing gas to multiple substrates in an inner tube, can reduce the internal pressure of the nozzle and prevent the generation of particles, thereby improving the uniformity of the film thickness within the surface of the substrate and the uniformity of the film thickness between each substrate.

[0017] Solutions to Problems

[0018] According to one embodiment of the present invention, a substrate processing device is provided, comprising: a wafer box for arranging and holding a plurality of substrates in a predetermined arrangement direction, an inner tube arranged around the wafer box and having exhaust holes for exhausting gas in a direction perpendicular to the arrangement direction of the substrates, a mixing section for pre-mixing a plurality of gases for substrate processing that react with each other at a temperature in the inner tube to generate a mixed gas, and a nozzle arranged separately from an inner wall of the inner tube and ejecting the mixed gas supplied from the mixing section into the inner tube from a plurality of ejection holes formed along the arrangement direction of the substrates; the ejection direction of the ejection holes is not toward the wafer box but toward the inner wall of the inner tube.

[0019] Effects of the Invention

[0020] According to the present invention, when using the same nozzle to supply a mixed gas of multiple gases as a processing gas to multiple substrates in an inner tube, it is possible to reduce the internal pressure of the nozzle and prevent the generation of particles, thereby improving the uniformity of the film thickness within the surface of the substrate and the uniformity of the film thickness between each substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of a vertical processing furnace of a substrate processing apparatus according to an embodiment of the present invention, and shows a portion of the processing furnace in a vertical cross-sectional view.

[0022] Figure 2 This is a schematic diagram of a vertical processing furnace of a substrate processing device according to this embodiment. Figure 1 The cross section along line 2-2 shows a portion of the processing furnace.

[0023] Figure 3 This is a schematic configuration diagram of a controller of the substrate processing apparatus according to the present embodiment, and shows a control system of the controller in the form of a block diagram.

[0024] Figure 4 This is a flowchart illustrating a method for manufacturing a semiconductor device according to this embodiment.

[0025] Figure 5 This graph illustrates the relationship between the distance from the most upstream discharge hole of the nozzle and the nozzle internal pressure obtained at the position of each discharge hole.

[0026] Figure 6 This is a graph illustrating the relationship between the separation distance from the most upstream discharge hole of the nozzle and the gas flow rate ratio from each discharge hole.

[0027] Figure 7 So with Figure 1 A cross section at the same position as line 2-2 shows a processing furnace portion of a vertical processing furnace of a substrate processing apparatus according to a first modified example.

[0028] Figure 8 So with Figure 1 A cross section at the same position as line 2-2 shows a processing furnace portion of a vertical processing furnace of a substrate processing apparatus according to a second modified example.

[0029] Figure 9 So with Figure 1 A cross section at the same position as line 2-2 shows a processing furnace portion of a vertical processing furnace of a substrate processing apparatus according to a third modified example.

[0030] Figure 10 This is a schematic structural diagram of a buffer portion of a substrate processing apparatus according to a fourth modified example when viewed from the center of the wafer toward the outside.

[0031] Figure 11 yes Figure 10 Cross-section diagram along line 11-11.

[0032] Explanation of symbols

[0033] 200: Wafer (substrate), 204: Inner tube, 204a: Buffer part, 204c: Exhaust hole, 207: Heater, 217: Wafer box, 232a, 232b, 232c: Gas supply pipe (first supply pipe), 232g, 232h, 232d: Gas supply pipe (second supply pipe), 233a, 233b, 233c: Confluence part, 235a, 235b, 235c: Gas supply pipe (third supply pipe), 237: Interface, 239: Interface heater, 249a, 249b, 249c: Nozzle, 249a1, 249a2, 249a3: Nozzle, 250a, 250b, 250c: Ejection hole, 250a1, 250a2, 250a3: Ejection hole, θ: Angle. DETAILED DESCRIPTION

[0034] The following describes embodiments of the present invention. In the following figures, identical or similar parts are designated by identical or similar reference numerals. The figures are schematic diagrams, and the relationship between thickness and planar dimensions, the ratio of thickness of various devices and components, and other aspects may differ from those in reality.

[0035] Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, the drawings may include portions with different dimensional relationships and ratios. Furthermore, in some cases, the upward direction in the drawings will be referred to as "upper" or "upper portion," and the downward direction will be referred to as "lower" or "lower portion." Furthermore, the pressures described in this embodiment refer to "atmospheric pressure" unless otherwise specified.

[0036] <Structure of substrate processing apparatus>

[0037] Reference Figures 1 to 3The substrate processing apparatus according to this embodiment will now be described. The processing furnace 202 of the substrate processing apparatus includes a heater 207 serving as a heating mechanism (temperature adjustment unit). Heater 207 is cylindrical and supported vertically by a retaining plate. Heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas using heat.

[0038] A reaction tube 210 is disposed inside the heater 207 concentrically with the heater 207 .

[0039] Reaction tube 210 has a double-tube structure consisting of an inner tube 204, which constitutes an inner reaction tube, and an outer tube 203, which serves as an outer reaction tube and concentrically surrounds inner tube 204. Inner tube 204 and outer tube 203 are each made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC), and are cylindrical in shape with a closed upper end and an open lower end.

[0040] The inner tube 204 is provided so as to surround the wafer cassette 217. The sidewall of the inner tube 204 extends vertically in the up-down direction. In this embodiment, a top portion is provided on the upper portion of the inner tube 204, which has an end surface that closes the upper end.

[0041] A processing chamber 201 for processing wafers 200, which serve as substrates, is formed in the hollow portion of the inner tube 204. The processing chamber 201 is configured to accommodate the wafers 200 arranged in a direction perpendicular to the surface of the wafers 200 from one end (lower side) to the other end (upper side) within the processing chamber 201. The area within the processing chamber 201 where multiple wafers 200 are arranged is also referred to as a substrate arrangement area (wafer arrangement area). In addition, the arrangement direction of the wafers 200 within the processing chamber 201 is also referred to as a substrate arrangement direction (wafer arrangement direction).

[0042] The inner tube 204 and the outer tube 203 are each supported from below by a manifold 209. The manifold 209 is made of a metal material such as stainless steel (SUS) and is formed into a cylindrical shape with both the upper and lower ends open. An annular flange portion 209a made of a metal material such as SUS is provided at the upper end of the inner wall of the manifold 209 and extends radially inwardly of the manifold 209. The lower end of the inner tube 204 abuts the upper surface of the flange portion 209a. The lower end of the outer tube 203 abuts the upper end of the manifold 209. An O-ring 220a is provided as a sealing member between the outer tube 203 and the manifold 209. The lower end opening of the manifold 209 constitutes the furnace opening of the processing furnace 202 and is airtightly sealed by a disc-shaped sealing cap 219 serving as a cover when the wafer cassette 217 is lifted by the wafer cassette elevator 115 described later. An O-ring 220 b serving as a sealing member is provided between the header 209 and the sealing cap 219 .

[0043] The top of the inner tube 204 is formed into a flat shape, while the top of the outer tube 203 is formed into a dome shape. When the top of the inner tube 204 is formed into a dome shape, the gas supplied into the processing chamber 201 does not flow between the multiple wafers 200, but rather easily flows into the internal space of the dome portion of the top of the inner tube 204. By making the top of the inner tube 204 flat, the gas supplied into the processing chamber 201 can flow efficiently between the multiple wafers 200. By reducing the gap (space) between the top of the inner tube 204 and the top plate of the wafer cassette 217 described later, for example, by making it approximately the same size as the arrangement interval (pitch) of the wafers 200, the gas can flow efficiently between the wafers 200.

[0044] like Figure 2 As shown, a buffer portion 204a is formed on the sidewall of inner tube 204 to accommodate nozzles 249a, 249b, and 249c. Buffer portion 204a protrudes from the sidewall of inner tube 204 radially outward, forming a groove extending vertically. The inner walls of buffer portion 204a each constitute a portion of the inner wall of processing chamber 201. Nozzles 249b and 249c housed within buffer portion 204a are arranged on either side of nozzle 249a, sandwiching nozzle 249a. Specifically, they are arranged along the inner wall of buffer portion 204a (the outer periphery of wafer 200) to sandwich nozzle 249a from both sides.

[0045] The nozzles 249a, 249b, 249c are arranged from the bottom of the buffer portion 204a upward, that is, vertically upward along the wafer arrangement direction. That is, in the area horizontally surrounding the wafer arrangement area on the side of the wafer arrangement area, the nozzles 249a, 249b, 249c are respectively arranged along the wafer arrangement area. Figure 2 As shown, the nozzles 249a, 249b, and 249c are provided with ejection holes 250a, 250b, and 250c as first to third gas supply holes, respectively. The nozzles 249a, 249b, and 249c are made of a heat-resistant material such as quartz or SiC.

[0046] It is possible to consider arranging the above wafers along Figure 1 The vertical direction of the wafer arrangement region is divided into a plurality of partitions. In this embodiment, the partition on one end side (here, the upper side) in the wafer arrangement direction of the wafer arrangement region is also referred to as the first partition (top partition). In addition, the partition on the central part of the wafer arrangement region in the wafer arrangement direction is also referred to as the second partition (middle partition). In addition, the partition on the other end side (here, the lower side) in the wafer arrangement direction of the wafer arrangement region is also referred to as the third partition (bottom partition).

[0047] The nozzles 249a, 249b, 249c are provided with a plurality of discharge holes 250a, 250b, 250c extending from the top to the bottom of the nozzles 249a, 249b, 249c so as to cover the entire wafer arrangement region in the wafer arrangement direction. The nozzles 249a, 249b, 249c are configured to supply gas to all of the first to third sections.

[0048] like Figure 2 As shown, the nozzles 249a, 249b, 249c are connected to the gas supply pipes 232a, 232b, 232c, respectively.

[0049] Gas supply pipes 232a, 232b, and 232c are provided with mass flow controllers (MFCs) 241a, 241b, and 241c, respectively, serving as flow controllers (flow control units), and valves 243a, 243b, and 243c, respectively, serving as on / off valves, in order from the upstream side of the gas flow. Downstream of valve 243a, gas supply pipe 232a is connected to gas supply pipe 232g. Gas supply pipe 232g is also provided with MFCs 241g and valves 243g, respectively, in order from the upstream side of the gas flow.

[0050] Downstream of valve 243b, gas supply pipe 232b is connected to gas supply pipe 232h. MFC 241h and valve 243h are provided in gas supply pipe 232h, sequentially from the upstream side of the gas flow. Downstream of valve 243c, gas supply pipe 232c is connected to gas supply pipe 232d. MFC 241d and valve 243d are provided in gas supply pipe 232d, sequentially from the upstream side of the gas flow.

[0051] Gas supply pipes 232a, 232b, and 232c correspond to the "first supply pipe" of the present invention. The first supply pipe is connected to a supply source (not shown) of a first gas, one of the multiple gases of the present invention. Gas supply pipes 232g, 232h, and 232d correspond to the "second supply pipe" of the present invention. The second supply pipe is connected to a supply source (not shown) of a second gas, another of the multiple gases of the present invention.

[0052] The various gases used for substrate processing react with each other at the temperature within inner tube 204. The confluences 233a, 233b, and 233c, where the first and second supply tubes merge, function as the mixing section of the present invention. These confluences 233a, 233b, and 233c premix the gases before introducing them into inner tube 204 to create a mixed gas.

[0053] Gas supply pipes 235a, 235b, 235c serving as third supply pipes are provided between the merging portions 233a, 233b, 233c and the nozzles 249a, 249b, 249c. The third supply pipes connect the merging portions 233a, 233b, 233c to the nozzles 249a, 249b, 249c for fluid communication.

[0054] The mixed gas flows through the third supply pipe and is delivered to nozzles 249a, 249b, and 249c. The first supply pipe, the second supply pipe, the mixing unit, and the third supply pipe constitute the gas supply system of the substrate processing apparatus. Furthermore, heating tape, an example of a pipe heater, is wrapped around the first, second, and third supply pipes. The heating tape heats the gas flowing through the first, second, and third supply pipes.

[0055] In this embodiment, the flow path area of the third supply pipe is greater than or equal to the sum of the flow path areas of the first and second supply pipes. For example, when the nominal diameters (in inches) of the first and second supply pipes are 1 / 4, the nominal diameter of the third supply pipe can be 1 / 2. It should be noted that, in the present invention, the flow path area of the third supply pipe may not be greater than or equal to the sum of the flow path areas of the first and second supply pipes. In addition, the length of the third supply pipe is set to a sufficient length to ensure that the first gas and the second gas are evenly mixed when the mixed gas ejected from the nozzles 249a, 249b, and 249c hits the inner wall and is supplied to the substrate.

[0056] At the ends of the gas supply pipes 235a, 235b, 235c on the opposite side to the merging parts 233a, 233b, 233c, an interface 237 for introducing the merged first gas and second gas into the processing furnace 202 is provided outside the processing furnace 202 (see Figure 1 In addition, an interface heater 239 for heating the interface 237 is provided on the interface 237 and is provided on the outside of the interface 237 .

[0057] The first gas, for example, is a raw material gas containing silicon (Si), which is a main element constituting a film to be formed. Such a raw material gas is supplied into the processing chamber 201 via the MFC 241 a , the valve 243 a , and the nozzle 249 a .

[0058] The so-called raw material gas refers to a raw material in a gaseous state, for example, a gas obtained by vaporizing a raw material in a liquid state at room temperature and pressure, or a raw material in a gaseous state at room temperature and pressure. As a silane-based gas, for example, a gas containing Si and a halogen, i.e., a halosilane gas, can be used. The so-called halosilane-based gas refers to a silane-based gas having a halogen group. Halogen groups include halogen elements such as chlorine (Cl), fluorine (F), bromine (Br), and iodine (I). Halosilane-based gases act as a Si source.

[0059] As the raw material gas, for example, monochlorosilane (SiH3Cl, abbreviated as: MCS) gas, dichlorosilane (SiH2Cl2, abbreviated as: DCS) gas, trichlorosilane (SiHCl3, abbreviated as: TCS) gas, tetrachlorosilane (SiCl4, abbreviated as: STC) gas, hexachlorodisilane gas (Si2Cl6, abbreviated as: HCDS) gas, octachlorotrisilane (Si3Cl8, abbreviated as: OCTS) gas and other chlorosilane gases can be used. As the raw material gas, one or more of these can be used. As the raw material gas, in addition to chlorosilane gas, for example, fluorosilane gases such as tetrafluorosilane (SiF4) gas and difluorosilane (SiH2F2) gas, bromosilane gases such as tetrabromosilane (SiBr4) gas and dibromosilane (SiH2Br2) gas, iodosilane gases such as tetraiodosilane (SiI4) gas and diiodosilane (SiH2I2) gas can also be used. As the raw material gas, one or more of these can be used. As a raw material gas, in addition to this, for example, a gas containing Si and an amino group, i.e., aminosilane gas, can also be used. The so-called amino group refers to a monovalent functional group after removing hydrogen (H) from ammonia, primary ammonia or secondary ammonia, which can be expressed as -NH2, -NHR, -NR2. It should be noted that R represents an alkyl group, and the two Rs in -NR2 can be the same or different. As a raw material gas, in addition to this, for example, a gas containing Si and an alkyl group, i.e., alkylsilane gas, can also be used.

[0060] The second gas, as a reactant (reaction gas), includes, for example, a nitrogen (N)-containing gas and an oxygen (O)-containing gas. Such reaction gas is supplied to the processing chamber 201 via MFC241b, valve 243b, and nozzle 249b. The N-containing gas acts as a nitriding agent (nitriding gas), that is, an N source. A gas containing nitrogen (N) and hydrogen (H) can be used as a nitriding gas (nitriding agent). A gas containing N and H is both an N-containing gas and an H-containing gas. The gas containing N and H preferably has an NH bond. As a reaction gas, for example, ammonia (NH3) gas, diimide (N2H2) gas, hydrazine (N2H4) gas, N3H8 gas and other nitriding hydrogen-based gases can be used. As a reaction gas, one or more of these can be used. A gas containing nitrogen (N) and hydrogen (H) can be used as a nitriding gas (nitriding agent). As a reaction gas, in addition to these, for example, a gas containing nitrogen (N), carbon (C) and hydrogen (H) can also be used. As the gas containing N, C, and H, for example, an amine gas or an organic hydrazine gas can be used. The gas containing N, C, and H is an N-containing gas, a C-containing gas, an H-containing gas, and a N- and C-containing gas.

[0061] As the reaction gas, for example, ethylamine gases such as monoethylamine (C2H5NH2, abbreviated as MEA) gas, diethylamine ((C2H5)2NH, abbreviated as DEA) gas, and triethylamine ((C2H5)3N, abbreviated as TEA) gas, methylamine gases such as monomethylamine (CH3NH2, abbreviated as MMA) gas, dimethylamine ((CH3)2NH, abbreviated as DMA) gas, and trimethylamine ((CH3)3N, abbreviated as TMA) gas, and organic hydrazine gases such as monomethylhydrazine ((CH3)HN2H2, abbreviated as MMH) gas, dimethylhydrazine ((CH3)2N2H2, abbreviated as DMH) gas, and trimethylhydrazine ((CH3)2N2(CH3)H, abbreviated as TMH) gas can be used. As the reaction gas, one or more of these can be used.

[0062] The O-containing gas acts as an oxidant (oxidizing gas), that is, an O source. Oxygen (O)-containing gases such as oxygen (O2) gas, ozone (O3) gas, plasma-excited O2 gas (O2*), O2 gas + hydrogen (H2) gas, water vapor (H2O gas), hydrogen peroxide (H2O2) gas, nitrous oxide (N2O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO2) gas, carbon monoxide (CO) gas, and carbon dioxide (CO2) gas can be used.

[0063] Furthermore, an inert gas or a carrier gas is supplied from gas supply pipes 232a, 232h, and 232d into the processing chamber 201 via MFCs 241a, 241h, and 241d, valves 243a, 243h, and 243d, gas supply pipes 233a, 233b, and 233c, and nozzles 249a, 249b, and 249c, respectively. The inert gas supplied into the processing chamber 201 from the nozzles 249a, 249b, and 249c primarily functions as a dilution gas, a purge gas, or a carrier gas. For example, nitrogen (N2) gas or an inert gas can be used as the inert gas. Hydrogen (H2) gas can be used as the carrier gas.

[0064] The first gas (raw material) supply system primarily consists of gas supply pipe 232a, MFC 241a, and valve 243a. The second gas (reactant) supply system primarily consists of gas supply pipe 232g, MFC 241g, and valve 243g. The inert gas supply system primarily consists of gas supply pipes 232g, 232h, and 232d, MFCs 241g, 241h, and 241d, and valves 243g, 243h, and 243d. It should be noted that gas supply pipes 232b, 232c, MFCs 241b, 241c, and valves 243b, 243c may be omitted or utilized as a dopant or purge gas supply system.

[0065] The raw material supply system is configured to supply a raw material at a controlled flow rate from nozzle 249a to a plurality of zones, namely, all of the first to third zones. The oxidant supply system is configured to supply an oxidant at a controlled flow rate from nozzle 249b to a plurality of zones, namely, all of the first to third zones. The nitriding agent supply system is configured to supply a nitriding agent at a controlled flow rate from nozzle 249c to a plurality of zones, namely, all of the first to third zones. The inert gas supply system is configured to supply an inert gas at a controlled flow rate from each of nozzles 249a, 249b, and 249c to each of the plurality of zones, namely, the first to third zones.

[0066] An exhaust hole (exhaust slit) 204c, for example, a slit-shaped through-hole, is provided in the vertical direction on the side surface (side wall) of the inner tube 204. The exhaust hole 204c is, for example, rectangular in shape when viewed from the front, and is provided from the lower portion to the upper portion of the side wall of the inner tube 204. The annular space between the inner tube 204 and the outer tube 203 in the processing chamber 201, i.e., the exhaust space 205, is connected via the exhaust hole 204c. The exhaust hole 204c is arranged at the connection buffer portion 204a when viewed from the plan view. Figure 2 The buffer portion 204a and the exhaust hole 204c are located on a straight line extending from the left-right center of the inner tube 204 to the center of the inner tube 204. Specifically, the buffer portion 204a and the exhaust hole 204c face each other, sandwiching the center C2 of the wafers 200 housed in the processing chamber 201. Furthermore, the discharge hole 250a of the nozzle 249a and the exhaust hole 204c are located on a straight line passing through the center C2. The exhaust hole 204c exhausts air in a direction perpendicular to the direction in which the substrates are arranged.

[0067] like Figure 1 As shown, the lower portion of outer tube 203 is connected to exhaust pipe 231, which exhausts the atmosphere within processing chamber 201, via exhaust space 205. Exhaust pipe 231 is connected to vacuum pump 246, which serves as a vacuum exhaust device, via pressure sensor 245, a pressure detector (pressure detection unit) that detects the pressure within exhaust space 205 (i.e., within processing chamber 201), and APC (Auto Pressure Controller) valve 244, a pressure regulator (pressure adjustment unit). APC valve 244 is configured to enable and disable vacuum exhaust within processing chamber 201 by opening and closing the valve while vacuum pump 246 is operating. Furthermore, the pressure within processing chamber 201 can be adjusted by adjusting the valve opening based on pressure information detected by pressure sensor 245 while vacuum pump 246 is operating. The exhaust system primarily comprises exhaust pipe 231, APC valve 244, and pressure sensor 245. It is also conceivable to incorporate exhaust port 204c, exhaust space 205, and vacuum pump 246 into the exhaust system.

[0068] The lower end opening of the manifold 209 is hermetically sealed by the sealing cap 219 via an O-ring 220b. Below the sealing cap 219, a rotating mechanism 267 is provided for rotating the wafer box 217. The rotating shaft 255 of the rotating mechanism 267 passes through the sealing cap 219 and is connected to the wafer box 217. The rotating mechanism 267 is configured to rotate the wafer 200 by rotating the wafer box 217. The sealing cap 219 is configured to be raised and lowered in the vertical direction by a wafer box elevator 115 as a lifting mechanism vertically provided outside the reaction tube 210. The wafer box elevator 115 is configured as a conveying device (conveying mechanism) that moves the wafer 200 supported by the wafer box 217 into and out of the processing chamber 201 by raising and lowering the sealing cap 219.

[0069] The wafer cassette 217, serving as a substrate support, is configured to support multiple wafers 200 (e.g., 25 to 200) in a horizontal position, aligned with their centers C2, in a vertically aligned, multi-stage arrangement. The wafer cassette 217 is constructed from a heat-resistant material such as quartz or SiC. A heat shield 218, constructed from a heat-resistant material such as quartz or SiC, is supported in multiple stages at the bottom of the wafer cassette 217.

[0070] A temperature sensor 263, serving as a temperature detector, is provided between outer tube 203 and inner tube 204. By adjusting the power supply to heater 207 based on the temperature information detected by temperature sensor 263, the temperature within processing chamber 201 can be adjusted to a desired temperature distribution. Temperature sensor 263 is provided along the inner wall of outer tube 203.

[0071] (Inner tube)

[0072] Here, the inner tube 204, nozzles 249a, 249b, 249c, and discharge holes 250a, 250b, 250c according to the embodiment will be described in detail. The inner tube 204 according to this embodiment has an inner diameter that is smaller than twice the distance between the center C1 of the nozzles 249a, 249b, 249c and the center C2 of the wafer. Specifically, assuming that the arc of the inner diameter of the main body of the inner tube 204, which surrounds the substrate, is located at the opening of the buffer portion 204a in a plan view, the center C1 of the nozzles 249a, 249b, 249c is located outside the arc of the inner diameter and opens on the side opposite the substrate. In other words, the buffer portion 204a is formed to protrude outward from the arc of the inner diameter of the inner tube 204 so that the nozzles 249a, 249b, 249c, located inside the buffer portion 204a, do not interfere with the inner wall of the inner tube 204 at the inner diameter position.

[0073] (nozzle)

[0074] The nozzles 249a, 249b, and 249c of this embodiment are cylindrical in shape. However, the shape of the nozzles in the present invention is not limited thereto and may be modified to an elliptical cylindrical shape, etc. The nozzles 249a, 249b, and 249c are separated from the inner wall of the inner tube 204. The mixed gas from the converging portions 233a, 233b, and 233c is supplied through the nozzles 249a, 249b, and 249c.

[0075] (Discharge hole)

[0076] In this embodiment, multiple discharge holes 250a, 250b, and 250c are formed in the nozzles 249a, 249b, and 249c, along the substrate arrangement direction. When viewed from the front, the discharge holes 250a, 250b, and 250c are formed into a perfect circle, but other shapes such as ellipses are also possible. The mixed gas is discharged into the inner tube 204 through the discharge holes 250a, 250b, and 250c.

[0077] In this embodiment, the spacing between the ejection holes 250a, 250b, and 250c gradually narrows from the upstream side of the gas flow within the nozzle toward the downstream side, ensuring that the gas flow rate per unit length of the nozzles 249a, 249b, and 249c is consistent. Therefore, within the substrate arrangement area within the inner tube 204, at least the first and second sub-zones receive the same amount of mixed gas per unit volume of each substrate. Specifically, in the present invention, for example, rather than having each ejection hole 250a, 250b, and 250c correspond to a single substrate, the spacing between the multiple ejection holes 250a, 250b, and 250c differs from the spacing between the substrates. It should be noted that "unit volume of a substrate" in this specification is defined as the volume of a space at a certain height above the surface of the substrate undergoing film formation. In the third sub-zone, exhaust becomes stronger as it approaches the exhaust pipe 231. Therefore, to maintain the partial pressure of the mixed gas equal to that of the other sub-zones, it is sometimes desirable to increase the supply amount as the position decreases.

[0078] like Figure 2 As shown, the ejection direction of the ejection holes 250a, 250b, and 250c is not the substrate side mounted on the wafer cassette 217 ( Figure 2 the lower side of the inner tube 204, but toward the buffer portion 204a of the inner tube 204 Figure 2 In other words, it extends radially outward from the center C1 of the discharge holes 250a, 250b, and 250c. The discharge direction is toward the opposite side of the substrate, so that it does not overlap with the substrate in a plan view.

[0079] Although not shown in the figure, the ejection direction of the ejection holes 250a, 250b, and 250c in the side view is perpendicular to the arrangement direction of the substrates (the vertical direction) (horizontal direction). It should be noted that in the present invention, the ejection direction in the side view is not limited to the horizontal direction, and can also be an oblique upward direction or an oblique downward direction.

[0080] In this embodiment, the mixed gas discharged from the discharge holes 250a, 250b, and 250c reaches and collides with the inner wall of the buffer portion 204a of the inner tube 204 before the substrate (see Figures 7 to 9 ). After collision, the dispersion and mixing of various gases contained in the mixed gas are promoted.

[0081] In addition, in the present embodiment, the angle θ between the ejection direction of the ejection holes 250a, 250b, 250c and the imaginary line from the center C1 of the nozzles 249a, 249b, 249c to the center C2 of the wafer is set to 90 degrees < θ < 270 degrees (see Figures 7 to 9 The angle θ can be measured in either clockwise or counterclockwise rotation direction.

[0082] In this embodiment, the centers C1 of the nozzles 249a, 249b, and 249c are located outside the assumed inner diameter of the main body of the inner tube 204, and the angle θ is set to 90 degrees < θ < 270 degrees. This setting of angle θ ensures that the mixed gas ejected from the discharge holes 250a, 250b, and 250c into the buffer portion 204a is directed only toward the inner wall of the buffer portion 204a, not toward the inner wall of the main body. This ensures that the effect of promoting the dispersion and mixing of the first and second gases due to the collision of the mixed gas with the inner wall is more reliably achieved. On the other hand, when the angle θ is less than 90 degrees or greater than 270 degrees, the dispersion and mixing effect achieved by the collision of the mixed gas with the inner wall of the buffer portion 204a is less than when the angle θ is 90 degrees < θ < 270 degrees.

[0083] It should be noted that the gap between the inner wall of the buffer portion 204a of the inner tube 204 and the nozzles 249a, 249b, and 249c is preferably approximately 1 mm. If the gap is less than approximately 1 mm, it is difficult to reduce the internal pressure of the nozzle. It should be noted that as long as the gap is at least 1 mm, the discharge direction of the discharge holes 250a, 250b, and 250c can be set arbitrarily as long as the angle θ is within the range of 90 degrees < θ < 270 degrees. In addition, as long as the angle θ is within the range of 90 degrees < θ < 270 degrees, for example, the mixed gas can collide with an adjacent nozzle, promoting dispersion and mixing.

[0084] like Figure 3As shown, the controller 121, which serves as a control unit (control unit), is configured as a computer having a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, a storage device 121c, and an I / O interface 121d. The RAM 121b, storage device 121c, and I / O interface 121d are configured to exchange data with the CPU 121a via an internal bus 121e. The controller 121 is connected to an input / output device 122, such as a touch panel.

[0085] The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), etc. A control program for controlling the actions of the substrate processing device is stored in the storage device 121c, and a process recipe of the process, conditions, etc. of the substrate processing described later is recorded and can be read out. The process recipe is a combination of the various processes in the substrate processing described later so that it is executed by the controller 121 and a predetermined result is obtained, and functions as a program. Hereinafter, process recipes, control programs, etc. are simply collectively referred to as programs. In addition, process recipes are also simply referred to as recipes. When the term "program" is used in this specification, it includes the case of only a single recipe, the case of only a single control program, and the case of both. RAM121b is configured as a storage area (working area) for temporarily storing programs, data, etc. read by CPU121a.

[0086] The I / O interface 121d is connected to the above-mentioned MFC241a, 241b, 241c, 241g, 241h, 241d, valves 243a, 243b, 243c, 243g, 243h, 243d, pressure sensor 245, APC valve 244, vacuum pump 246, heater 207, heating belt and interface heater 239, temperature sensor 263, rotating mechanism 267, wafer box elevator 115, etc.

[0087] The CPU 121a is configured to read and execute a control program from the storage device 121c and, in addition, read a recipe from the storage device 121c in response to input of an operation command from the input / output device 122. The CPU 121a is further configured to control, in accordance with the contents of the read recipe, flow rate adjustment of various gases by the MFCs 241a, 241b, 241c, 241g, 241h, and 241d, opening and closing of valves 243a, 243b, 243c, 243g, 243h, and 243d, opening and closing of the APC valve 244 and pressure adjustment by the APC valve 244 using the pressure sensor 245, starting and stopping of the vacuum pump 246, temperature adjustment of the heater 207, the heating belt, and the interface heater 239 using the temperature sensor 263, rotation and rotation speed adjustment of the wafer cassette 217 by the rotation mechanism 267, and raising and lowering of the wafer cassette 217 by the wafer cassette elevator 115.

[0088] The controller 121 can be constructed by installing the above-mentioned program stored in the external storage device 123 into the computer. The external storage device 123 includes, for example, magnetic disks such as HDD, optical disks such as CD, optical magnetic disks such as MO, semiconductor memories such as USB memories, etc. The storage device 121c and the external storage device 123 are configured as recording media that can be read by a computer. Hereinafter, these will be simply collectively referred to as recording media. When the term "recording medium" is used in this specification, it includes the case where there is only a separate storage device 121c, the case where there is only a separate external storage device 123, or the case where both are included. It should be noted that providing a program to a computer does not require the use of an external storage device 123, and can be carried out using communication methods such as the Internet and dedicated lines.

[0089] <Substrate processing method>

[0090] Next, as a step in the manufacturing process of a semiconductor device (equipment), an example process of forming a film on a substrate (hereinafter also referred to as film formation process) using the aforementioned substrate processing apparatus will be described. The example of forming a film on wafer 200 by alternately supplying a first process gas (source gas) and a second process gas (reactant gas) to the substrate will be described.

[0091] Below, refer to Figure 4 The following description will be made by taking the formation of a silicon-rich silicon nitride film (hereinafter also referred to as a SiN film) on a wafer 200 as an example. It should be noted that in the following description, the controller 121 controls the operations of the various components constituting the substrate processing apparatus.

[0092] In the film formation process in this embodiment, the wafer 200 in the processing chamber 201 is exposed to a mixed gas of a source gas and a reaction gas, and a SiN film is formed on the wafer 200 by a CVD method.

[0093] In this specification, the term "wafer" means "the wafer itself (bare wafer)" and "a laminate (complex) of a wafer and predetermined layers, films, etc. formed on its surface." Similarly, the term "wafer surface" can mean "the surface of the wafer itself" or "the surface of predetermined layers, films, etc. formed on the wafer, that is, the outermost surface of the wafer as a laminate." The term "substrate" has the same interpretation as "wafer."

[0094] (S901: Wafer loading and wafer cassette loading)

[0095] Initially, the standby state of the device is released, and multiple wafers 200 are loaded into the wafer box 217 (wafer loading), and the wafer box 217 is moved into the processing chamber 201 by the wafer box elevator 115 (wafer box loading). In the wafer box 217, the wafers 200 are arranged in the up and down directions. At this time, the controller 121 controls to set the MFC241a to a predetermined small flow rate (for example, less than 50sccm) and open the valve 243a. A small amount of N2 gas (axial purge gas) flows out from the rotating mechanism 267. After the moving in is completed, the sealing cap 219 becomes a state in which the lower end of the manifold 209 is airtightly closed (sealed) via the O-ring 220b. It should be noted that it is also possible to open valves 243a and 243g from the standby state before wafer loading (i.e., normal times) to start supplying purge gas. The shaft purge gas can prevent particles drawn in from the outside during wafer loading from adhering to the heat insulation portion, and the purge gas can prevent gases such as air from flowing back into the nozzle.

[0096] (S902: Pressure Adjustment)

[0097] The vacuum pump 246 performs vacuum exhaust (decompression exhaust) so that the space in the processing chamber 201 where the wafer 200 exists reaches a predetermined pressure (vacuum degree). At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. The vacuum pump 246 maintains a continuous working state at least until the processing of the wafer 200 is completed. In addition, a small amount of N2 gas (exhaust gas) is released by controlling the MFC232g, valve 243g and APC valve 244 through the controller 121. The released exhaust gas and shaft purge gas are exhausted. It should be noted that the exhaust gas is continuously released at least during the period when the processing gas that generates solid by-products flows through the processing chamber 201, and can also be released continuously.

[0098] (S903: Temperature Adjustment)

[0099] Furthermore, heater 207 heats the interior of processing chamber 201 to a predetermined temperature for wafers 200 therein. Feedback control is performed on the power supply to heater 207 based on temperature information detected by temperature sensor 263 to achieve a flat temperature distribution within processing chamber 201. Heating of processing chamber 201 by heater 207 continues at least until processing of wafers 200 is completed.

[0100] (S904: Supplying Processing Gas)

[0101] After the temperature in the processing chamber 201 stabilizes at a predetermined processing temperature (first temperature), the raw material gas and the reaction gas are supplied and the gases are exhausted. It should be noted that during this period, the wafer cassette 217 is rotated by the rotation mechanism 267 via the rotation shaft 255, thereby rotating the wafer 200.

[0102] (Supply of raw material gas and reaction gas)

[0103] The valve 243a is opened to allow the raw material gas, which is the first gas of the present invention, to flow into the gas supply pipe 233a. The flow rate of the raw material gas is adjusted by the MFC 241a.

[0104] Furthermore, valve 243g is opened to allow the reactant gas, serving as the second gas of the present invention, to flow into gas supply pipe 233a. The flow rate of the reactant gas is regulated by MFC 241g. The raw material gas and the reactant gas merge and mix at confluence 233a, generating a mixed gas containing the raw material gas and the reactant gas. Hereinafter, this mixed gas of the raw material gas and the reactant gas will be referred to simply as "raw material gas." While flowing through the third supply pipe, which is heated by the heating belt, the mixed gas is thoroughly and evenly mixed, and its temperature rises.

[0105] The raw material gas, which is a mixed gas, flows into the nozzle 249a and is supplied to the inner tube 204 through the discharge hole 250a. The raw material gas is further heated in the nozzle 249a, and the raw material gas reacts with a portion of the reaction gas to generate molecules with the same composition as the film formed on the substrate, film precursors with different compositions, and polymers thereof. These reaction products can be supplied to the inner tube 204 along with the flow of unreacted gas. It is desirable that the reaction in the nozzle be suppressed to be limited to a local area. Here, the raw material gas is discharged from multiple discharge holes 250a toward the inner wall of the buffer portion 204a of the inner tube 204, colliding with the inner wall, rather than being discharged toward the wafer box 217. The collision promotes the dispersion and mixing of the raw material gas in all directions of the vertical and horizontal directions within the buffer portion 204a. Then, the raw material gas forms a cross flow across the wafer 200, flows toward the wafer box 217 in the processing chamber 201, and is supplied to the substrate arrangement area. Figure 2 In FIG, the cross flow is exemplified by the downward white arrows on the wafer 200. The supplied source gas contributes to the film formation process on the substrate and is then exhausted by the exhaust pipe 231 through the exhaust holes 204c and the exhaust space 205.

[0106] At this time, controller 121 performs constant pressure control using the first pressure as the target pressure. During the initial stages of raw gas supply, since the chamber pressure is significantly lower than the target pressure, APC valve 244 can be completely closed. However, as long as the auxiliary exhaust valve (not shown) outside the constant pressure control remains open, nearly all of the exhaust gas and shaft purge gas can be discharged to vacuum pump 246 through this valve. Alternatively, APC valve 244 can be maintained at a low flow rate rather than completely closed.

[0107] (Processing gas exhaust process)

[0108] After forming a film of the desired thickness, valves 243a and 243g are closed, the supply of raw material and reaction gases is stopped, and APC valve 244 is fully opened. This evacuates the interior of process chamber 201, discharging any remaining unreacted gases or byproducts that contributed to the formation of the first layer. At this point, valves 243b and 243c can be opened to purge the remaining gases with an inert gas supplied to process chamber 201. The flow rate of the inert gas is adjusted by MFCs 241h and 241d. The flow rate of the purge gas from nozzles 249b and 249c is set so that the partial pressure of the low-vapor-pressure gas in the exhaust path is lower than the saturated vapor pressure, or so that the flow rate within inner tube 204 is sufficient to overcome the diffusion rate. Typically, this flow rate is significantly greater than the flow rate of the purge gas from nozzle 249 or rotating shaft 255.

[0109] (S905: Cooling)

[0110] In this step, as needed, the temperature adjustment in step S903, which is continued during the film formation process, is stopped or set to a lower temperature, thereby gradually lowering the temperature within the processing chamber 201. It should be noted that, before the temperature reduction step S905, the temperature within the processing chamber 201 may be maintained at a second temperature, which is higher than the processing temperature (first temperature) in S904, for a predetermined period of time to perform annealing.

[0111] (S906: Emission(ベント))

[0112] An inert gas is introduced from, for example, an interruption filter (not shown) or nozzle 249b provided in the substrate processing apparatus until atmospheric pressure is reached in the processing chamber 201. When the nozzle 249b is used, the controller 121 controls, for example, MFC 241h to be set to a predetermined high flow rate (e.g., greater than 2 slm) and valve 243h to be opened. When atmospheric pressure is reached, control is performed to set MFC 241h to a predetermined low flow rate (e.g., less than 50 sccm) or to close valve 243h. It should be noted that steps S905 and S906 can be performed in parallel, or the order of their start can be reversed.

[0113] (S907: Wafer cassette unloading and wafer release)

[0114] The cassette elevator 115 slowly lowers the sealing cap 219, opening the lower end of the manifold 209. The processed wafers 200, supported by the cassettes 217, are then unloaded from the lower end of the manifold 209 to the exterior of the inner tube 204 (cassette unloading). The processed wafers 200 are then removed from the cassettes 217 by a transfer mechanism (not shown) (wafer release).

[0115] The above series of steps constitutes a method for manufacturing a semiconductor device using the substrate processing apparatus according to this embodiment. It should be noted that, in this embodiment, SiN film formation using nitrogen-containing gas as a reaction gas is exemplified, but the present invention is not limited thereto, and film formation using oxygen-containing gas as a reaction gas may also be performed.

[0116] (Relationship between nozzle internal pressure and discharge hole diameter)

[0117] In the semiconductor device manufacturing method according to this embodiment, during the source gas supply and reaction gas supply steps, the discharge holes 250a, 250b, and 250c are oriented toward the inner wall. The mixed gas collides with the inner wall and then flows toward the substrate. As a result, a uniformly mixed gas ratio can be supplied to each wafer 200 within the inner tube 204 without the use of a special gas mixer. Specifically, in this embodiment, in addition to increasing the diameter of the discharge holes 250a, 250b, and 250c, the internal pressure of the nozzles 249a, 249b, and 249c is reduced by adjusting the discharge direction of the discharge holes 250a and 250c.

[0118] Here, for the relationship between the discharge hole diameter and the nozzle internal pressure, refer to Figure 5 and Figure 6 For example, when a plurality of discharge holes that are circular when viewed from the front are formed in parallel in one nozzle, Figure 5 As shown in , the internal pressure of the nozzle decreases from the upstream side to the downstream side. Figure 5In the upper portion of FIG, a series of nozzle internal pressure values at each of the ejection holes located from upstream to downstream in a reference nozzle having multiple ejection holes arranged vertically is illustrated by line X. The gas flow within the reference nozzle flows from bottom to top. Furthermore, the ejection holes of the reference nozzle are arranged at regular intervals and all have the same diameter.

[0119] In addition, Figure 5 In the lower part of the figure, a series of nozzle internal pressure values at the positions of the discharge holes from the upstream side to the downstream side of the comparison nozzle having multiple discharge holes arranged in parallel in the vertical direction are shown as line Y. The hole spacing and shape of the comparison nozzle are the same as those of the reference nozzle, but the hole diameter of the comparison nozzle is enlarged to 2.5 times that of the reference nozzle. Figure 5 As shown, at all the ejection holes located from the upstream side to the downstream side, the internal pressure of the comparative nozzle is lower than that of the ejection holes corresponding to the reference nozzle, and the positional variation of the ejection holes is also greater.

[0120] In addition, regarding the gas flow rate ratio of each of the multiple discharge holes Figure 6 In FIG, line X represents the gas flow rate ratio of the reference nozzle, and line Y represents the gas flow rate ratio of the comparison nozzle. Figure 6 The gas flow rate ratio value of the center line X and the gas flow rate ratio value of the line Y are normalized by the total discharge flow rate. If the hole diameter is fixed, the internal pressure is proportional to the discharge flow rate, so the shape of the line X and line Y is Figure 6 and Figure 5 The difference between the upstream side and the downstream side in the comparison nozzle is larger than the difference between the upstream side and the downstream side in the reference nozzle. Figure 5 and Figure 6 It is found that when gas is supplied to the substrate using a nozzle with a simply enlarged aperture, the internal pressure of the nozzle can be reduced, but the variation in the amount of gas supplied between the upstream and downstream substrates increases.

[0121] As a method of reducing the deviation in the amount of supplied gas, it is considered to increase the internal pressure of the nozzle in contrast to reduce the influence of the pressure difference between the inside and outside of the nozzle on the discharge hole located on the downstream side. However, as the internal pressure increases, the gas is easily thermally decomposed in the nozzle. In addition, when a mixed gas containing multiple gases is supplied together using the same nozzle, if the internal pressure of the nozzle is increased, abnormal reactions caused by the multiple gases are likely to occur in the nozzle, resulting in a problem of increased particle generation in the inner tube. In addition, due to the abnormal reaction of the multiple gases, new film precursors that are not required in the original film forming process are generated, thereby inducing uneven film thickness within the surface of the substrate and uneven film thickness between each substrate. On the other hand, the nozzle 249a, etc. of this embodiment can make the supply amount per unit volume uniform by setting the spacing of the discharge holes 250a, etc. to be proportional to the internal pressure or the flow rate ratio from each discharge amount.

[0122] (Effect)

[0123] In this embodiment, the discharge direction of the discharge holes 250a, 250b, and 250c is not toward the wafer cassette 217 holding the substrate, but toward the inner wall of the inner tube 204. Therefore, the mixed gas discharged from the discharge holes 250a, 250b, and 250c collides with the inner wall of the inner tube 204 before the substrate, and this collision promotes the dispersion and mixing of the various gases contained in the mixed gas.

[0124] Therefore, even without increasing the internal pressure of the nozzles 249a, 249b, and 249c, the uniformly mixed mixed gas can be uniformly supplied to each wafer 200. This prevents the generation of particles caused by increasing the internal pressure of the nozzles 249a, 249b, and 249c. Furthermore, the mixed gas that collides with the inner wall disperses, forming a cross flow along the wafer surface toward the wafer cassette 217, thereby enabling efficient supply to the center of the wafer.

[0125] That is, even if the mixed gas does not reach the required mixing degree of the multiple gases for substrate processing when the mixed gas is discharged into the inner tube 204, the mixed gas can be improved by the collision of the multiple gases with the inner wall. Therefore, compared to a case where the mixed gas is delivered to the substrate without colliding with the inner wall of the inner tube 204, the reaction within the nozzles 249a, 249b, and 249c can be suppressed, and the mixed gas can reach the required mixing degree before reaching the substrate.

[0126] In this embodiment, the nozzles 249a, 249b, 249c are separated from the inner wall of the inner tube 204, and the discharge holes 250a, 250b, 250c do not contact the inner wall. Therefore, the passage of the mixed gas is narrowed, and the internal pressure of the nozzles 249a, 249b, 249c can be prevented from increasing.

[0127] Therefore, according to the substrate processing apparatus of this embodiment, when a mixed gas containing multiple gases is supplied as a processing gas to multiple substrates within the inner tube 204 using the same nozzles 249a, 249b, and 249c, the internal pressure of the nozzles 249a, 249b, and 249c can be reduced, thereby preventing the generation of particles and improving the uniformity of the film thickness within the substrate surface and between the substrates. Furthermore, according to the method for manufacturing a semiconductor device using the substrate processing apparatus of this embodiment, it is possible to manufacture a semiconductor device that prevents the adhesion of particles and improves the uniformity of the film thickness within the substrate surface and between the substrates.

[0128] Furthermore, in this embodiment, the discharge direction of the discharge holes 250a, 250b, and 250c is perpendicular to the arrangement direction of the substrates (horizontally). Therefore, the mixed gas is more likely to collide perpendicularly with the inner wall of the vertically extending inner tube 204. As a result, the mixed gas after the collision is more likely to form a turbulent flow within the inner tube 204, further promoting dispersion and mixing.

[0129] Furthermore, in this embodiment, the spacing between the discharge holes 250a, 250b, and 250c is set to gradually narrow from the upstream side to the downstream side of the gas flow, so that the gas flow rate per unit length of the nozzles 249a, 249b, and 249c is uniform. This makes it easier to uniformly distribute the amount of mixed gas per unit volume supplied to multiple substrates.

[0130] In the present invention, the pattern for adjusting the intervals of the discharge holes is not limited to the pattern of gradually narrowing the intervals from the upstream side toward the downstream side of the gas flow, and other interval adjustment patterns may be employed.

[0131] For example, a group including an arbitrary number of discharge holes may be set, and fixed intervals may be formed between the discharge holes included in the set discharge hole group. At the same time, the intervals between the discharge hole groups may gradually narrow from the upstream side to the downstream side of the gas flow.

[0132] Furthermore, for example, the spacing between the multiple substrates can be set to a fixed value, and the maximum spacing between the multiple ejection holes can be set to be larger than the fixed spacing between the substrates. That is, the substrate arrangement pattern and the ejection hole configuration pattern are not limited to a configuration where each substrate corresponds to a single ejection hole. In other words, in the present invention, any pattern for adjusting the ejection hole spacing can be adopted as long as the amount of mixed gas supplied per unit volume to the multiple substrates is consistent.

[0133] It should be noted that, in the present invention, as another method for supplying the same amount of mixed gas per unit volume to each substrate in the substrate arrangement region within the inner tube, an adjustment method of gradually reducing the aperture diameter from the upstream side to the downstream side of the gas flow within the nozzle can be employed, either alone or in combination. Specifically, in the present invention, at least one of the aperture diameter setting and the spacing setting of the multiple ejection holes can be employed.

[0134] However, the nozzle machining accuracy when adjusting the ejection hole spacing is often higher than when adjusting the hole diameter. Therefore, when using only the ejection hole spacing adjustment method, the amount of mixed gas supplied per unit volume to each substrate is more easily consistent than when using only the hole diameter adjustment method.

[0135] Furthermore, in this embodiment, the collision of the mixed gases within the buffer portion 204a facilitates the generation of gas flows in opposite directions. This further promotes the dispersion and mixing of the mixed gases within the buffer portion 204a, forming a wider flow (cross flow) toward the wafer cassette 217, thereby forming a substrate with uniform film thickness and quality.

[0136] Furthermore, in this embodiment, the gas supply system includes confluences 233a, 233b, and 233c, where the first and second supply pipes merge, and third supply pipes that connect the confluences 233a, 233b, and 233c to the nozzles 249a, 249b, and 249c. This allows for stable generation of a mixed gas, a mixture of the first and second gases.

[0137] Furthermore, in this embodiment, an interface heater 239, which is provided at the end of the third supply pipe to heat the interface 237, allows the mixed gas flowing through the third supply pipe to be more efficiently heated and supplied to the substrate. It should be noted that in the present invention, the heater for heating the mixed gas is not limited to the interface heater 239 or a heating belt. Any heating device that heats at least a portion of the third supply pipe through which the mixed gas flows to a temperature above a predetermined temperature suitable for substrate processing can be provided, and its location and shape can be modified as appropriate.

[0138] Furthermore, in this embodiment, because the flow path area of the third supply pipe is equal to or greater than the combined flow path area of the first and second supply pipes, the internal pressure within the third supply pipe upstream of the nozzles 249a, 249b, and 249c does not become higher than that of the first and second supply pipes. This prevents the internal pressure of the nozzles 249a, 249b, and 249c from increasing after the mixed gas is delivered to the nozzles 249a, 249b, and 249c via the third supply pipe.

[0139] Furthermore, in this embodiment, since the inner tube 204 has a top portion and the top portion has an end surface that closes one end in the arrangement direction of the substrates, the sealing property within the inner tube 204 can be improved, thereby improving the supply efficiency of the mixed gas.

[0140] In addition, in this embodiment, by setting the angle θ between the ejection direction of the ejection holes 250a, 250b, 250c and the imaginary line from the center C1 of the nozzle 249a, 249b, 249c to the center C2 of the wafer to 90<θ<270, the mixed gas can collide with the inner wall, further improving the effect of promoting the dispersion and mixing of multiple gases.

[0141] Next, other configuration examples of the inner tube and the nozzle of the substrate processing apparatus according to the present invention will be described using first to fourth modified examples.

[0142] <First Modification>

[0143] like Figure 7 As shown, the present invention is also applicable even if a buffer portion is not provided on the inner wall of the inner tube 204. Furthermore, the number of nozzles 249a may be one. In the first modified example, similar to the present embodiment, the discharge direction of the discharge hole 250a of the nozzle 249a is not toward the wafer cassette holding the wafers 200, but toward the inner wall of the inner tube 204. Therefore, the mixed gas discharged from the discharge hole 250a collides with the inner wall of the inner tube 204 before the wafers 200. This collision promotes the dispersion and mixing of the various gases contained in the mixed gas.

[0144] <Second Modification>

[0145] also, Figure 2 The shape of the buffer portion 204a shown in the example is a rectangular protrusion in a plan view, but in the present invention, the shape of the buffer portion can be appropriately changed. For example, Figure 8 As shown, the shape of the buffer portion 204a can be a semicircular protrusion in a plan view. It should be noted that in the present invention, the shape of the buffer portion can also be not a semicircular protrusion, but a protrusion composed of two or more arcs in a plan view, or a combination of straight lines and arcs.

[0146] <Third Modification>

[0147] also, Figure 9 The shape of the buffer portion 204a of the third modified example is different from Figure 2 The buffer portion 204a shown in FIG is similarly a rectangular protrusion in a plan view. However, the number of nozzles 249a arranged in the buffer portion 204a is the same as that in FIG. Figure 2 The nozzles 249a, 249b, and 249c illustrated in FIG. 2 are different in that there is only one nozzle instead of three nozzles.

[0148] <Fourth Modification>

[0149] In this embodiment, the substrate arrangement region is divided into three sections along the arrangement direction (vertical direction) of the wafers 200. Furthermore, the discharge holes 250a, 250b, 250c of the respective nozzles 249a, 249b, 249c are provided throughout the nozzles 249a, 249b, 249c to discharge gas toward all three sections.

[0150] However, in the fourth modification, the substrate arrangement region is divided into three partitions along the arrangement direction (up and down direction) of the wafer 200. Figure 10 As shown, three nozzles 249a1, 249a2, and 249a3 are respectively provided to correspond to the three partitions. It should be noted that the number of partitions can be 2 or more than 4. Figure 11 As shown, the ejection directions of the ejection holes 250a1, 250a2, 250a3 of the respective nozzles 249a1, 249a2, 249a3 are configured to be directed not toward the wafer cassette on which the substrate is mounted but toward the inner wall of the inner tube 204 and not to collide with other nozzles.

[0151] lie in Figure 10 The nozzle 249a3 on the right side of the image and corresponding to the bottom partition in the substrate arrangement area is a reflux nozzle. It should be noted that, in the present invention, the nozzle corresponding to the bottom partition in the substrate arrangement area is not limited to the reflux nozzle. In addition, Figure 10 The nozzle 249a1 on the middle left and the nozzle 249a2 in the center are provided corresponding to the partitions other than the lowermost partition in the substrate arrangement area.

[0152] Figure 10 The plurality of discharge holes 250a3 of the return nozzle (nozzle 249a3) on the right side are provided on the rod-shaped portion on the right side of the nozzle 249a3 of the return nozzle. Figure 10 The plurality of ejection holes 250a1 of the nozzle 249a1 on the left side are provided in a portion above the central nozzle 249a2. Figure 10 The multiple discharge holes 250a2 of the nozzle 249a2 in the center are provided in a part above the return nozzle (nozzle 249a3) on the right side. Figure 10 The gases ejected from the three nozzles 249a1, 249a2, and 249a3 will not collide with other adjacent nozzles.

[0153] In addition, if Figure 10 and Figure 11As shown, the discharge hole 250a1 of the left nozzle 249a1 and the discharge hole 250a2 of the center nozzle 249a2 open toward the inner wall on the right side of the inner tube 204 through the space above the return nozzle (nozzle 249a3).

[0154] In the fourth modified example, the angle θ between the ejection direction of each ejection hole 250a1, 250a2, and 250a3 and the imaginary line extending from the center C1 of the nozzles 249a1, 249a2, and 249a3 to the center C2 of the wafer 200 is also set to 90 degrees < θ < 270 degrees. Setting the angle θ to 90 degrees < θ < 270 degrees enhances the dispersion and mixing effect achieved by the collision of the mixed gas with the inner wall of the buffer portion 204a. It should be noted that the angle θ can be appropriately varied within the range of 90 degrees < θ < 270 degrees, as long as the mixed gas process after ejection is ensured for a long time.

[0155] Furthermore, in the fourth modification, since the nozzles 249a1, 249a2, and 249a3 are provided to face the three sections, respectively, the flow rate of the supply gas can be adjusted for each section.

[0156] Furthermore, in the fourth modified example, the mixed gas discharged into the buffer section 204a collides with the inner wall of the buffer section 204a rather than with other nozzles. This allows for a longer path for the mixed gas from the nozzles 249a1, 249a2, and 249a3 to the substrate within the buffer section 204a. In other words, the space within the buffer section 204a for the three nozzles 249a1, 249a2, and 249a3 can be effectively utilized. Furthermore, by dispersing and mixing the mixed gas within the buffer section 204a, heating and mixing processes using multiple gases can be performed regardless of the position of the substrate slot.

[0157] Furthermore, in the fourth variant, the return nozzle allows for a longer travel distance for the mixed gas before discharge to reach the substrate, making it easier to improve the mixing of the various gases before discharge. Furthermore, since the discharge hole is directed away from the center of the substrate, the travel distance for the mixed gas after discharge to reach the substrate is longer. Consequently, even after discharge, the mixing of the various gases is easier to improve.

[0158] In the fourth modification, the mixed gas discharged from the nozzles corresponding to the sub-areas other than the lowermost sub-area flows over the reflow nozzle, thereby making the path to the substrate longer and easily improving the mixing degree of the multiple gases.

[0159] Furthermore, in the fourth modification, the nozzles 249a1, 249a2, and 249a3, each provided for a plurality of zones, can also be provided separately within the gas supply system described in this embodiment. For example, nozzles 249a1, 249a2, and 249a3 can be provided as replacement nozzles 249b, 249a, and 249c. Supply pipes 232b and 232c, like supply pipe 232a, are connected to the source gas, while supply pipes 232h and 232d, like supply pipe 232b, are connected to the reaction gas. In other words, by providing one or more nozzles and gas supply systems for each zone, a mixed gas can be supplied to each zone. By adjusting the flow rate of the supplied gas, film uniformity between zones can be improved.

[0160] In the fourth modification, similarly to the present embodiment, the length of the third supply pipe is set to a length sufficient to uniformly mix the first gas and the second gas when the mixed gas ejected from the corresponding nozzle hits the inner wall and is supplied to the substrate.

[0161] <Other implementation methods>

[0162] While the present invention has been described using the embodiments disclosed above, the discussion and drawings, which constitute part of this disclosure, should be understood as not limiting the present invention. For example, this embodiment illustrates a case where the mixed gas is pre-mixed outside inner tube 204, but the present invention is not limited to this embodiment; mixing within the inner tube is also possible. Furthermore, while substrate processing using a substrate processing apparatus has been described using CVD film formation as an example, the present invention is not limited to this embodiment. In other words, a mixing unit for pre-mixing multiple gases is not essential.

[0163] Furthermore, the components of the substrate processing apparatus shown in the drawings may be partially combined to constitute the present invention. The present invention includes various embodiments not described above.

Claims

1. A substrate processing device comprising: A wafer cassette that arranges and holds a plurality of substrates in a predetermined arrangement direction. The inner tube is provided around the wafer box and has exhaust holes formed in a direction perpendicular to the arrangement direction of the substrates for exhausting the air. a plurality of mixing sections that pre-mix a plurality of gases for substrate processing that react with each other at a temperature within the inner tube and generate solid by-products to generate a mixed gas, and a plurality of nozzles, which are separated from the inner wall of the inner tube and discharge the mixed gas supplied by the plurality of mixing parts into the inner tube through a plurality of discharge holes formed along the arrangement direction of the substrates; The plurality of nozzles are arranged to correspond to a plurality of partitions that divide the substrate arrangement area in the inner tube along the arrangement direction of the substrates. All the ejection directions of the plurality of ejection holes are not toward the wafer box but toward the inner wall of the inner tube, and do not conflict with other nozzles. Multiple substrates are arranged in the vertical direction. The ejection holes of the nozzles provided corresponding to the subareas other than the lowermost subarea in the substrate arrangement region open toward the inner wall of the inner tube through the space above the nozzles provided corresponding to the lowermost subarea.

2. The substrate processing apparatus according to claim 1, wherein: The spacing between the plurality of ejection holes is different from the arrangement spacing of the substrate. The ejection direction of the ejection hole is perpendicular to the arrangement direction of the substrates.

3. The substrate processing apparatus according to claim 1, wherein: A buffer portion protruding outward is formed on the inner wall of the inner tube. The nozzle is arranged in the buffer portion, The discharge direction of the discharge hole is toward the inner wall of the buffer portion, The mixed gas is discharged from the discharge hole into the buffer portion.

4. The substrate processing apparatus according to claim 1, wherein: The intervals between the plurality of discharge holes gradually narrow from the upstream side toward the downstream side of the gas flow in the nozzle.

5. The substrate processing apparatus according to claim 1, wherein: The hole diameters or intervals of the plurality of discharge holes are set so that the same amount of mixed gas is supplied per unit volume to each substrate in the substrate arrangement region within the inner tube.

6. The substrate processing apparatus according to claim 4, wherein: The arrangement intervals of multiple substrates are fixed. The maximum interval between the plurality of ejection holes is greater than the fixed arrangement interval of the substrate.

7. The substrate processing apparatus according to claim 5, wherein: The diameter of the discharge hole gradually increases from the upstream side to the downstream side of the gas flow in the nozzle.

8. The substrate processing apparatus according to claim 1, wherein: The nozzle corresponding to the lowest partition in the substrate arrangement area is a reflux nozzle. The discharge direction of the discharge hole of the reflow nozzle is opposite to the center of the wafer.

9. The substrate processing apparatus according to claim 1, wherein: There is further provided a gas supply system, the gas supply system comprising: a first supply pipe connected to a supply source of a first gas, which is one of the plurality of gases; a second supply pipe connected to a supply source of a second gas which is another one of the plurality of gases; a merging portion serving as a mixing portion for merging the first supply pipe and the second supply pipe, and The third supply pipe connects the confluence portion and the nozzle to fluid communication.

10. The substrate processing apparatus according to claim 9, wherein: A heater is provided for heating at least a portion of the third supply pipe to a temperature higher than a predetermined temperature.

11. The substrate processing apparatus according to claim 10, wherein: The heater further includes an interface heater and a heating interface. The interface is provided at the end of the third supply pipe opposite to the merging portion and introduces the merged first gas and second gas into the processing furnace.

12. The substrate processing apparatus according to claim 9, wherein: The flow path area of the third supply pipe is equal to or greater than the total flow path area of the first supply pipe and the second supply pipe.

13. The substrate processing apparatus according to claim 9, wherein: Set up gas supply systems corresponding to each partition respectively. The third supply pipe has a sufficient length to uniformly mix the first gas and the second gas when supplied from the corresponding nozzles.

14. The substrate processing apparatus according to claim 1, wherein: In a planar view, an angle θ between the ejection direction of the ejection hole and a straight line from the nozzle center to the wafer center is 90 degrees < θ < 270 degrees.

15. A method for manufacturing a semiconductor device, using the substrate processing apparatus according to claim 1, comprising the following steps: a step of arranging a plurality of substrates in a predetermined arrangement direction in the wafer cassette; a step of generating a mixed gas in the plurality of mixing sections, and The mixed gas is supplied to the inner tube, and the mixed gas is discharged from the plurality of discharge holes not to the wafer box but to the inner wall of the inner tube without colliding with other nozzles to disperse and mix the mixed gas, so that the dispersed and mixed mixed gas flows to the wafer box to perform film forming on the substrate. The substrate processing device is equipped with multiple nozzles corresponding to multiple partitions that divide the substrate arrangement area in the inner tube along the arrangement direction of the substrates. The multiple substrates are arranged in the up and down directions. The discharge holes of the nozzles arranged corresponding to the partitions other than the lowest partition in the substrate arrangement area pass through the space above the nozzles arranged corresponding to the lowest partition and open toward the inner wall of the inner tube.

16. A substrate processing method using the substrate processing apparatus according to claim 1, comprising the following steps: a step of arranging a plurality of substrates in a predetermined arrangement direction in the wafer cassette; a step of generating a mixed gas in the plurality of mixing sections, and The mixed gas is supplied to the inner tube, and the mixed gas is discharged from the plurality of discharge holes not to the wafer box but to the inner wall of the inner tube without colliding with other nozzles to disperse and mix the mixed gas, so that the dispersed and mixed mixed gas flows to the wafer box to perform film forming on the substrate. The substrate processing device is equipped with multiple nozzles corresponding to multiple partitions that divide the substrate arrangement area in the inner tube along the arrangement direction of the substrates. The multiple substrates are arranged in the up and down directions. The discharge holes of the nozzles arranged corresponding to the partitions other than the lowest partition in the substrate arrangement area pass through the space above the nozzles arranged corresponding to the lowest partition and open toward the inner wall of the inner tube.

17. A recording medium storing a program for causing a computer of the substrate processing apparatus according to claim 1 to execute the following process: Using the substrate processing apparatus, The process of arranging a plurality of substrates in a predetermined arrangement direction in the wafer box, a process of generating mixed gas in the plurality of mixing sections, and The mixed gas is supplied to the inner tube, and the mixed gas is discharged from the plurality of discharge holes not to the wafer box but to the inner wall of the inner tube without colliding with other nozzles to disperse and mix the mixed gas, so that the dispersed and mixed mixed gas flows to the wafer box to perform film forming on the substrate. The substrate processing device is equipped with multiple nozzles corresponding to multiple partitions that divide the substrate arrangement area in the inner tube along the arrangement direction of the substrates. The multiple substrates are arranged in the up and down directions. The discharge holes of the nozzles arranged corresponding to the partitions other than the lowest partition in the substrate arrangement area pass through the space above the nozzles arranged corresponding to the lowest partition and open toward the inner wall of the inner tube.

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