Gas supply system, substrate processing apparatus, semiconductor device manufacturing method, and recording medium

Abstract

The present application relates to a gas supply system, a substrate processing apparatus, a method of manufacturing a semiconductor device, and a recording medium. Provided is a technology capable of appropriately controlling the flow rate of a gas even with a simple structure. The gas supply system has: a container that generates a gas; a first pipe that is connected between the container and a reaction chamber, and has a straight pipe portion; a first pressure measuring portion that is provided at a first position of the straight pipe portion, and measures the pressure of the gas; a second pressure measuring portion that is provided at a second position of the straight pipe portion on a downstream side of the flow of the gas from the first position, and measures the pressure of the gas; and a control portion that is capable of calculating the pressure loss of the straight pipe portion based on a measured signal from the first pressure measuring portion and a measured signal from the second pressure measuring portion, calculating the flow rate of the gas flowing through the straight pipe portion based on the calculated pressure loss, and controlling the flow rate of the gas based on the calculation result.

Description

Technical Field

[0001] This disclosure relates to a gas supply system, a substrate processing apparatus, a method for manufacturing a semiconductor device, and a recording medium. Background Technology

[0002] Conventionally, in the manufacture of semiconductor devices, substrate processing is known, such as a film-forming process to form a desired oxide film on the surface of a substrate. There is a substrate processing apparatus that includes a gas supply system that supplies film-forming gas to a reaction chamber (processing chamber) containing the substrate, and processes the substrate using the supplied gas (e.g., Patent Document 1).

[0003] Typically, mass flow controllers (MFCs) are used to control the flow rate of gas supplied to the reaction chamber. In this case, an MFC for flow control is installed in the gas supply pipe connecting the container for storing raw materials and the reaction chamber (for example, Patent Document 1). However, in the manufacture of semiconductor devices, there is a need for a new technology that can stably flow large volumes of gas regardless of the presence or absence of an MFC.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-045880 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] This disclosure was made in view of the above circumstances, and provides a technique that enables a large flow rate of gas to flow stably.

[0009] Methods for solving problems

[0010] According to a technical solution of this disclosure, a technology is provided, comprising: a container that generates gas; a first pipe connected between the container and a reaction chamber, having a straight pipe section; a first pressure measuring unit disposed at a first position of the straight pipe section for measuring the pressure of the gas; a second pressure measuring unit disposed at a second position of the straight pipe section downstream of the first position in the flow of the gas for measuring the pressure of the gas; and a control unit configured to calculate the flow rate of the gas flowing in the straight pipe section based on the pressure loss of the straight pipe section calculated from the measurement signals from the first pressure measuring unit and the measurement signals from the second pressure measuring unit, and to control the flow rate of the gas based on the calculation result.

[0011] Invention Effects

[0012] Based on the above structure, a technology can be provided that enables a stable flow of large volumes of gas. Attached Figure Description

[0013] Figure 1 This is a schematic longitudinal cross-sectional view of a vertical processing furnace of a substrate processing apparatus according to one embodiment of the present disclosure.

[0014] Figure 2 yes Figure 1 A rough cross-sectional view of line AA in the diagram.

[0015] Figure 3 This is a schematic structural diagram of the controller of the substrate processing apparatus in one embodiment of the present disclosure, and is a diagram of the control system of the controller shown in block diagram.

[0016] Figure 4 This is a flowchart illustrating a substrate processing step in one embodiment of the present disclosure.

[0017] Figure 5 (A) is a cross-sectional view of the substrate before the formation of the Mo-containing film on the substrate. Figure 5 (B) is a cross-section of the substrate after a Mo-containing film has been formed on it.

[0018] Figure 6 This is a flowchart illustrating the gas flow rate calculation process in one embodiment of the present disclosure.

[0019] Figure 7 It is a cross-sectional view of the straight pipe section illustrating gas flow.

[0020] Figure 8 (A) is a graph illustrating the change in the flow rate over time of the first raw material gas, the first inert gas, and the second inert gas, as an example in substrate processing. Figure 8 (B) is a graph illustrating an example of the change in the flow rates of the first feed gas, the first inert gas, and the second inert gas over time, controlled based on the calculated flow rate of the first feed gas.

[0021] Figure 9 (A) is a diagram illustrating the method for calculating pressure loss in this embodiment, where pressure is measured at two points in the straight pipe section. Figure 9 (B) is a diagram illustrating the calculation method of pressure loss in the first modified example where pressure is measured at 5 points in the straight pipe section.

[0022] Figure 10 Figure (A) is a diagram illustrating the calculation of pressure loss using a first pressure measuring unit and a differential pressure gauge in the gas supply system of the second modified example. Figure 10 (B) is a diagram illustrating the calculation of pressure loss using the second pressure measuring unit and differential pressure gauge.

[0023] Figure 11 This is a diagram illustrating the structure of the gas supply system in the third variation.

[0024] Explanation of reference numerals in the attached figures

[0025] 10 Substrate Processing Device

[0026] 12 Gas Supply System

[0027] 14 containers

[0028] 16. First Pressure Measurement Unit (Pressure Sensor)

[0029] 18. Second pressure measuring unit (pressure sensor)

[0030] 121 Controller (Control Unit)

[0031] 200 wafers (substrate)

[0032] 201 Processing Room (Reaction Chamber)

[0033] 310 Gas Supply Pipe (First Pipeline)

[0034] 515 Second Pipe

[0035] SR Straight Pipe Section. Detailed Implementation

[0036] The following is for reference Figures 1 to 11 This explanation is provided below. Furthermore, the accompanying drawings used in the following explanation are schematic diagrams, and the dimensional relationships and ratios of the elements shown in the drawings may not necessarily correspond to reality. Additionally, the dimensional relationships and ratios of elements may not be consistent between different accompanying drawings.

[0037] (1) Structure of the substrate processing device

[0038] First, the structure of the substrate processing apparatus 10 using the gas supply system 12 (also referred to as the raw material gas supply system 12) of this embodiment will be described. Furthermore, below, an outline of the structure of the substrate processing apparatus 10 will be described first, and the structure of the gas supply system 12 in the structure of the substrate processing apparatus 10 will be described separately in "(2) Structure of the gas supply system" later.

[0039] The substrate processing apparatus 10 includes a processing furnace 202 equipped with a heater 207, which serves as a heating unit (heating mechanism, heating system). The heater 207 is cylindrical and is vertically mounted by means of a heater base (not shown) that serves as a holding plate.

[0040] An outer tube 203, concentrically arranged with the heater 207, forms a reaction vessel (processing vessel) inside the heater 207. The outer tube 203 is made of a heat-resistant material such as quartz (SiO2) or silicon carbide (SiC), and is formed into a cylindrical shape that is closed at the top and open at the bottom. Below the outer tube 203, a manifold (inlet flange) 209 is arranged concentrically with the outer tube 203. The manifold 209 is made of a metal such as stainless steel (SUS), and is formed into a cylindrical shape that is open at both the top and bottom. An O-ring 220a, serving as a sealing component, is provided between the upper end of the manifold 209 and the outer tube 203. By supporting the manifold 209 on the heater base, the outer tube 203 is installed vertically.

[0041] An inner tube 204, constituting a reaction vessel, is disposed inside the outer tube 203. The inner tube 204 is made of heat-resistant materials such as quartz (SiO2) or silicon carbide (SiC), and is formed into a cylindrical shape that is closed at the top and open at the bottom. The processing vessel (reaction vessel) is mainly composed of the outer tube 203, the inner tube 204, and the manifold 209. A processing chamber 201 is formed in the hollow part of the processing vessel (inside the inner tube 204).

[0042] The processing chamber 201 is configured to house the wafer 200, which serves as a substrate, in a state in which multiple layers are arranged in a horizontal orientation in the vertical direction via the crystal boat 217 described later.

[0043] Inside the processing chamber 201, nozzles 410 and 420 are provided so as to penetrate the side wall of the manifold 209 and the inner pipe 204. The nozzles 410 and 420 are connected to the gas supply pipes 310 and 320, respectively. However, the processing furnace 202 of this embodiment is not limited to the above-described manner.

[0044] Mass flow controllers (MFCs) 312 and 322, serving as flow controllers (flow control units), are sequentially installed on gas supply pipes 310 and 320, respectively, starting from the upstream side. Additionally, valves 314 and 324, serving as on / off valves, are installed on gas supply pipes 310 and 320, respectively. Gas supply pipes 510 and 520, supplying inert gas, are connected downstream of valves 314 and 324 on gas supply pipes 310 and 320, respectively. On gas supply pipes 510 and 520, MFCs 512 and 522, serving as flow controllers (flow control units), and valves 514 and 524, serving as on / off valves, are sequentially installed on the upstream side.

[0045] Nozzles 410 and 420 are connected to the front ends of gas supply pipes 310 and 320, respectively. Nozzles 410 and 420 are configured as L-shaped nozzles, with their horizontal portions arranged to penetrate the side wall of manifold 209 and inner tube 204. The vertical portions of nozzles 410 and 420 are disposed inside a preparation chamber 201a, which is formed in a channel shape (groove shape) that protrudes radially outward from the inner tube 204 and extends vertically. They are disposed upward (above the arrangement direction of wafer 200) along the inner wall of the inner tube 204 within the preparation chamber 201a.

[0046] Nozzles 410 and 420 are configured to extend from the lower region of the processing chamber 201 to the upper region of the processing chamber 201, and multiple gas supply holes 410a and 420a are respectively provided at positions opposite to the wafer 200. Processing gas is supplied to the wafer 200 from the gas supply holes 410a and 420a of the nozzles 410 and 420. Multiple gas supply holes 410a and 420a are provided from the lower to the upper part of the inner tube 204, each having the same opening area and the same opening spacing. However, the gas supply holes 410a and 420a are not limited to the above configuration. For example, the opening area can gradually increase from the lower to the upper part of the inner tube 204. This allows for a more uniform flow rate of gas supplied from the gas supply holes 410a and 420a.

[0047] The gas supply holes 410a and 420a of the nozzles 410 and 420 are provided at a height from the lower part to the upper part of the wafer 217 (described later). Therefore, the processing gas supplied to the processing chamber 201 from the gas supply holes 410a and 420a of the nozzles 410 and 420 is supplied to the entire area of ​​the wafer 200 housed from the lower part to the upper part of the wafer 217. The nozzles 410 and 420 can be configured to extend from the lower region to the upper region of the processing chamber 201, but are preferably configured to extend to near the top of the wafer 217.

[0048] Inert gas is supplied into the processing chamber 201 from the gas supply pipe 310 via MFC 312, valve 314, and nozzle 410. In addition, the raw material gas for processing is supplied into the processing chamber 201 from the container 14 via valve 316 and gas supply pipe 310.

[0049] Reducing gas, used as processing gas, is supplied from gas supply pipe 320 into processing chamber 201 via MFC 322, valve 324, and nozzle 420.

[0050] Nitrogen (N2) gas is supplied as an inert gas to the processing chamber 201 through gas supply pipes 510 and 520 via MFCs 512 and 522, valves 514 and 524, and nozzles 410 and 420, respectively. The following description uses N2 gas as an inert gas, but other than N2 gas, rare gases such as argon (Ar), helium (He), neon (Ne), and xenon (Xe) can also be used as inert gases.

[0051] The processing gas supply system mainly consists of gas supply pipes 310 and 320, MFCs 312 and 322, valves 314 and 324, and nozzles 410 and 420. However, nozzles 410 and 420 can also be considered as the processing gas supply system alone. The processing gas supply system can also be simply referred to as the gas supply system. When Mo-containing gas flows through gas supply pipe 310, the Mo-containing gas supply system mainly consists of gas supply pipe 310, MFC 312, and valve 314. However, nozzle 410 can also be included in the Mo-containing gas supply system. Similarly, when reducing gas flows through gas supply pipe 320, the reducing gas supply system mainly consists of gas supply pipe 320, MFC 322, and valve 324. However, nozzle 420 can also be included in the reducing gas supply system. Furthermore, the inert gas supply system mainly consists of gas supply pipes 510 and 520, MFCs 512 and 522, and valves 514 and 524.

[0052] In this embodiment, the gas supply method involves supplying gas via nozzles 410 and 420 disposed within a preparatory chamber 201a, which is an annular longitudinal space defined by the inner wall of the inner tube 204 and the ends of multiple wafers 200. Furthermore, gas is ejected into the inner tube 204 from multiple gas supply holes 410a and 420a located on the nozzles 410 and 420 opposite to the wafers 200. More specifically, processing gas is ejected through the gas supply holes 410a of the nozzles 410 and 420a of the nozzles 420 in a direction parallel to the surface of the wafers 200.

[0053] The exhaust port (exhaust outlet) 204a is a through-hole formed on the side wall of the inner tube 204 and opposite to the nozzles 410 and 420. For example, it is a narrow, slit-like through-hole elongated in the vertical direction. Gas supplied from the gas supply holes 410a and 420a of the nozzles 410 and 420 into the processing chamber 201 and flowing on the surface of the wafer 200 flows through the exhaust port 204a into the exhaust path 206, which is formed by the gap between the inner tube 204 and the outer tube 203. The gas flowing into the exhaust path 206 then flows into the exhaust pipe 231 and is discharged outside the processing furnace 202.

[0054] The vent 204a is positioned opposite to the plurality of wafers 200. Gas supplied from the gas supply holes 410a and 420a to the vicinity of the wafers 200 in the processing chamber 201 flows horizontally and then flows into the exhaust path 206 through the vent 204a. The vent 204a is not limited to being configured as a slit-shaped through hole, but may also be composed of multiple holes.

[0055] An exhaust pipe 231 for venting the atmosphere inside the processing chamber 201 is provided on the manifold 209. From upstream, a pressure sensor 245 (a pressure detector, or pressure sensing unit) is connected sequentially to the exhaust pipe 231, along with an APC (Auto Pressure Controller) valve 243 and a vacuum pump 246 (a vacuum venting device). The APC valve 243 opens and closes when the vacuum pump 246 is operating, thereby enabling vacuum venting and stopping of vacuum venting within the processing chamber 201. Furthermore, adjusting the valve opening while the vacuum pump 246 is operating allows for adjustment of the pressure inside the processing chamber 201. The exhaust system mainly consists of an exhaust port 204a, an exhaust path 206, an exhaust pipe 231, an APC valve 243, and a pressure sensor 245. It is also possible to include the vacuum pump 246 within the exhaust system.

[0056] A sealing cover 219, serving as a furnace opening cover, is provided below the manifold 209 to airtightly seal the lower opening of the manifold 209. The sealing cover 219 is configured to abut against the lower end of the manifold 209 from the lower vertical direction. The sealing cover 219 is made of a metal such as SUS and is formed in a disc shape. An O-ring 220b, serving as a sealing member, is provided on the upper surface of the sealing cover 219 and abuts against the lower end of the manifold 209. On the side of the sealing cover 219 opposite to the processing chamber 201, a rotation mechanism 267 is provided to rotate a wafer boat 217 that houses the wafer 200. The rotation shaft 255 of the rotation mechanism 267 passes through the sealing cover 219 and is connected to the wafer boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the wafer boat 217. The sealing cover 219 is configured to be raised and lowered in the vertical direction via a crystal boat lift 115, which is vertically mounted outside the outer tube 203 and serves as a lifting mechanism. The crystal boat lift 115 is configured to move the crystal boat 217 in and out of the processing chamber 201 by raising and lowering the sealing cover 219. The crystal boat lift 115 is configured as a conveying device (conveyor system) for conveying the crystal boat 217 and the wafer 200 housed in the crystal boat 217 in and out of the processing chamber 201.

[0057] The crystal boat 217, serving as a substrate support, is configured such that multiple wafers 200, for example 25 to 200, are arranged horizontally and aligned with each other at intervals in the vertical direction. The crystal boat 217 is made of heat-resistant materials such as quartz or SiC. At the lower part of the crystal boat 217, a heat insulation plate 218, made of heat-resistant materials such as quartz or SiC, is supported horizontally in multiple layers (not shown). With this structure, heat from the heater 207 is difficult to transfer to the sealing cover 219 side. However, this embodiment is not limited to the above-described manner. For example, instead of providing the heat insulation plate 218 at the lower part of the crystal boat 217, a heat insulation cylinder may be provided, which is a cylindrical component made of heat-resistant materials such as quartz or SiC.

[0058] like Figure 2 As shown, a temperature sensor 263, serving as a temperature detector, is installed inside the inner tube 204. The electrical current supplied to the heater 207 is adjusted based on the temperature information detected by the temperature sensor 263, thereby achieving the desired temperature distribution within the processing chamber 201. The temperature sensor 263, like the nozzles 410 and 420, is configured in an L-shape and is installed along the inner wall of the inner tube 204.

[0059] like Figure 3 As shown, the controller 121, serving as the control unit (control unit), is configured as a computer equipped with a CPU (Central Processing Unit) 121a, RAM (Random Access Memory) 121b, storage device 121c, and I / O port 121d. The RAM 121b, storage device 121c, and I / O port 121d are configured to exchange data with the CPU 121a via an internal bus. The controller 121 is connected, for example, to an input / output device 122 configured as a touch panel or similar device.

[0060] The storage device 121c is configured such as flash memory or HDD (Hard Disk Drive). The storage device 121c stores, in a readable manner, a control program that controls the operation of the substrate processing device, and a process flow that describes the steps and conditions of the semiconductor device manufacturing method (described later). The process flow is a combination of methods that enable the controller 121 to execute each step in the semiconductor device manufacturing method (described later) to obtain a predetermined result, and functions as a program. Hereinafter, the process flow, control program, etc., will be collectively referred to as a program. When the term "program" is used in this specification, sometimes only the process flow is included, sometimes only the control program is included, or sometimes a combination of the process flow and the control program is included. RAM 121b is configured as a storage area (working area) for temporarily storing programs, data, etc., read from the CPU 121a.

[0061] I / O port 121d connects to MFC312, 322, 516, 526, 512, 522, valves 314, 316, 324, 514, 518, 524, 528, pressure sensors 16, 18, 245, etc. Additionally, I / O port 121d connects to APC valve 243, vacuum pump 246, heaters 207, 307, temperature sensor 263, rotating mechanism 267, crystal boat lift 115, etc.

[0062] CPU 121a is configured to read and execute control programs from storage device 121c, and to read process data from storage device 121c based on input commands from input / output device 122. CPU 121a is configured to control the flow rate adjustment of various gases by MFCs 312, 322, 512, and 522, and the opening and closing of valves 314, 324, 514, and 524, according to the read process data. Furthermore, CPU 121a is configured to control the opening and closing of APC valve 243, the pressure adjustment of pressure sensor 245 based on APC valve 243, the temperature adjustment of heater 207 based on temperature sensor 263, and the starting and stopping of vacuum pump 246. Additionally, CPU 121a is configured to control the rotation and speed adjustment of crystal boat 217 based on rotating mechanism 267, the lifting and lowering of crystal boat 217 based on crystal boat elevator 115, and the storage of wafers 200 into crystal boat 217.

[0063] The controller 121 is configured to install the aforementioned program stored in an external storage device (e.g., magnetic tape, floppy disk, hard disk, CD, DVD, MO, USB memory, memory card, etc.) 123 onto a computer. The storage device 121c and the external storage device 123 constitute a computer-readable recording medium. Hereinafter, they will be collectively referred to as the recording medium. In this specification, the recording medium may sometimes contain only the storage device 121c, sometimes only the external storage device 123, or sometimes both. Providing the program to the computer may also be done without using the external storage device 123, but rather using communication means such as the Internet or a dedicated line.

[0064] (2) Structure of the gas supply system

[0065] Next, the gas supply system (raw material gas supply system) of this embodiment will be described in detail. For example... Figure 1 As shown, the gas supply system 12 includes a container 14, a gas supply pipe 310 as a first pipe, a second pipe 515, a third pipe 525, a first pressure measuring unit 16, a second pressure measuring unit 18, and a controller 121 as a control unit.

[0066] (raw material)

[0067] In this embodiment, the raw material is a material having a vapor pressure characteristic of reaching a saturated vapor pressure of 0.01 to 100 kPa at 50°C to 200°C. More preferably, it is a material having a low vapor pressure characteristic of reaching a saturated vapor pressure of 0.01 to 5 kPa at 50°C to 200°C. Furthermore, materials having such low vapor pressure characteristics are referred to as low vapor pressure materials (low vapor pressure raw materials). In addition, in this disclosure, the raw material present in container 14 can be any of a solid, liquid, or gas. Furthermore, it can also be a material that is solid at room temperature and pressure and has a low vapor pressure.

[0068] Raw materials can be, for example, materials containing metallic elements and halogens. Metallic elements are selected from Al, Mo, W, Hf, Zr, etc. Halogens are selected from F, Cl, Br, I, etc. Raw materials that are solids at room temperature and pressure include, for example, AlCl3, Al2Cl6, MoCl5, WCl6, HfCl4, ZrCl4, MoO2Cl2, MoOCl4. Raw materials that are liquids at room temperature and pressure include, for example, metallic elements such as Ru and La.

[0069] (container)

[0070] Raw materials are stored inside container 14. Container 14 causes the raw materials to vaporize or sublimate to generate raw material gas. Furthermore, in this specification, for ease of explanation, the case of raw materials changing into gas is not distinguished as "vaporization or sublimation," and is simply referred to as "vaporization" unless otherwise specified.

[0071] A heater 307 is installed in container 14 to regulate the temperature of container 14, thereby controlling the amount of raw material vaporization. The temperature of container 14 can be changed each time the substrate is processed. In addition, a valve 316 is provided between container 14 and the confluence of gas supply pipe 310 and gas supply pipe 510.

[0072] (First piping)

[0073] The gas supply pipe 310, corresponding to the first piping of this disclosure, is connected between the container 14 and the processing chamber 201, and has a straight pipe section SR. In this embodiment, the straight pipe section SR is a straight cylindrical shape. However, in this disclosure, the straight pipe section SR is not limited to a straight cylindrical shape; for example, it can also be a right-angled cylinder with a triangular or quadrilateral base. The method for calculating pressure loss will be explained later.

[0074] The straight pipe section SR has a first position B1 and a second position B2 at both ends along the axial direction of the pipe. The second position B2 is located at a constant interval from the first position B1 on the downstream side of the feed gas flow. The interval can be appropriately set, for example, 500 mm in this embodiment. A first pressure measuring unit 16 is provided at the first position B1 of the straight pipe section SR. In addition, a second pressure measuring unit 18 is provided at the second position B2 of the straight pipe section SR. Although not shown in the figure, a piping heater and heat insulation material are wound around the straight pipe section SR. Through the heat insulation material, the temperature of the feed gas is kept constant relative to the gas flow direction in the straight pipe section SR.

[0075] In this embodiment, the pressure loss between the first position B1 and the second position B2 in the straight pipe section SR is configured as a predetermined pressure loss so that the flow rate of the raw material gas flowing inside the straight pipe section SR can be calculated. In this embodiment, "configured as a predetermined pressure loss" specifically refers to the pressure loss caused by friction generated between the raw material gas and the inner wall surface.

[0076] Therefore, in this embodiment, no throttling orifice, valve, or other components are provided in the part where pressure loss is measured. Furthermore, no bends or throttling sections are formed. That is, inside the straight pipe section SR, since there is no change in the inner diameter of the flow path or any bends in the flow path, the pressure loss other than friction with the inner wall surface is "0".

[0077] (Second piping)

[0078] The second piping 515 is a branch pipe from the gas supply pipe 510 and is connected to the container 14, supplying the container 14 with a first inert gas. The second piping 515 is equipped with a first inert gas supply section 516 and a valve 518. The first inert gas is, for example, Ar or N2, which promotes the vaporization of the raw material. By adjusting the supply of the first inert gas, the amount of vaporization of the raw material can be controlled.

[0079] (First Inert Gas Supply Department)

[0080] The first inert gas supply unit 516 may be composed of a flow control unit or a flow measurement unit, so as to be able to measure the flow rate of the first inert gas flowing in the second piping 515. The flow control unit is, for example, an MFC (mass flow controller), and the flow measurement unit is, for example, an MFM (mass flow meter). In addition, as the first inert gas supply unit, not only MFC or MFM can be considered, but also a part or all of an inert gas supply system can be considered.

[0081] The first inert gas supply unit 516 supplies a first inert gas to the container 14 via the second pipe 515. During the supply of the first inert gas to the container 14, the temperature of the container 14 remains constant. Through the supply of the first inert gas, the vaporized raw material, which serves as the first feed gas, mixes with the first inert gas within the container 14. The mixed gas is generated as the second feed gas and is transported downstream from the container 14. Furthermore, in this disclosure, the second pipe 515, the first inert gas supply unit 516, and the valve 518 are not essential.

[0082] (Third piping)

[0083] The third piping 525 is a branch pipe from the gas supply pipe 520 and is connected to the gas supply pipe 310 to supply the second inert gas to the gas supply pipe 310. The third piping 525 is provided with a second inert gas supply section 526 and a valve 528 for supplying the second inert gas.

[0084] (Second Inert Gas Supply Department)

[0085] The second inert gas supply unit 526 can be configured as a flow control unit or a flow measurement unit to measure the flow rate of the second inert gas flowing in the third piping 525. The flow control unit is, for example, an MFC, and the flow measurement unit is, for example, an MFM. The second inert gas is, for example, Ar or N2, used to dilute the feed gas. Furthermore, the second inert gas supply unit can be not only an MFC or an MFM, but also a part or all of an inert gas supply system.

[0086] The second inert gas is further mixed into the mixed gas, i.e., the second raw material gas, delivered from container 14 by the supply of the second inert gas. Then, the mixed gas containing the vaporized raw material, the first inert gas, and the second inert gas is delivered as the third raw material gas to the straight pipe section SR of the gas supply pipe 310. Furthermore, in this disclosure, the third piping 525, the second inert gas supply section 526, and the valve 528 are not essential.

[0087] (Pressure Measurement Department)

[0088] A first pressure measuring unit 16 and a second pressure measuring unit 18 are connected in series along the gas supply pipe 310. The first pressure measuring unit 16 measures the pressure of the raw material gas at a first position B1. The second pressure measuring unit 18 measures the pressure of the raw material gas at a second position B2. The first pressure measuring unit 16 and the second pressure measuring unit 18 are, for example, pressure sensors. The measurement signals from the first pressure measuring unit 16 and the second pressure measuring unit 18 are input to the controller 121. Furthermore, in this disclosure, the measurement signal is not limited to the numerical value of the pressure itself (pressure value). As a measurement signal, for example, it can also be a digital signal that includes a combination of values, symbols, etc., set by the pressure measuring unit corresponding to the numerical value of the pressure itself. In this disclosure, any measurement signal can be used as long as the pressure loss can be calculated.

[0089] In this embodiment, both the first pressure measuring unit 16 and the second pressure measuring unit 18 are composed of absolute pressure gauges. That is, the measuring signal in this embodiment is the value of absolute pressure. When using an absolute pressure gauge, for example, a pump can be used to create a vacuum, and the state of 0 (zero) Pa can be stored as a temporary zero point of the pressure gauge, where there are no fluid molecules. Furthermore, in this disclosure, the pressure gauge is not limited to an absolute pressure gauge; for example, any other pressure gauge, such as a pressure gauge that measures gauge pressure based on atmospheric pressure, can be used.

[0090] (Control Department)

[0091] The controller 121, which corresponds to the control unit of this disclosure, calculates the pressure loss between the first position B1 and the second position B2 based on the measurement signals from the first pressure measuring unit 16 and the second pressure measuring unit 18. The controller 121 is configured to calculate the flow rate of the feed gas (third feed gas) based on the calculated pressure loss.

[0092] (3) Substrate processing process

[0093] Next, as a substrate processing step, the manufacturing process of the semiconductor device using the substrate processing apparatus 10 of this embodiment will be described. Furthermore, below, an overview of the semiconductor device manufacturing process will first be described, and the part of the semiconductor device manufacturing process related to the raw material gas supply method using the raw material gas supply system 12 will be described separately in "(4) Raw material gas supply method" later.

[0094] As a step in the manufacturing process of semiconductor devices, using Figure 4 , Figure 5 (A) and Figure 5(B) describes an example of a process for forming a molybdenum (Mo)-containing film on wafer 200, for example, as the gate electrode of a controller for a 3D NAND flash memory. Here, as Figure 5 As shown in (A), a wafer 200 with a metal-containing film containing aluminum (Al), a non-transition metal element, i.e., an aluminum oxide (AlO) film as a metal oxide film, is used. Then, through a substrate processing step described later, as... Figure 5 As shown in (B), a Mo-containing film is formed on a wafer 200 on which an AlO film is formed. The process of forming the Mo-containing film is performed using the processing furnace 202 of the substrate processing apparatus 10 described above. In the following description, the operation of each part constituting the substrate processing apparatus 10 is controlled by the controller 121.

[0095] In this specification, the term "wafer" sometimes refers to "the wafer itself" and sometimes to "a laminate of a wafer and a predetermined layer, film, etc., formed on its surface." Similarly, the term "surface of a wafer" sometimes refers to "the surface of the wafer itself" and sometimes to "the surface of a predetermined layer, film, etc., formed on the wafer." The use of the term "substrate" in this specification is similar to the use of the term "wafer."

[0096] (Wafer loading)

[0097] When multiple wafers 200 are loaded (wafer loading) into the crystal boat 217, such as Figure 1 As shown, a crystal boat 217 supporting multiple wafers 200 is lifted by a crystal boat elevator 115, moved (crystal boat loading) into the processing chamber 201, and stored in a processing container. In this state, the sealing cap 219 closes the lower opening of the outer tube 203 via an O-ring 220.

[0098] (Pressure and temperature adjustments)

[0099] Vacuum pump 246 is used to exhaust vacuum, so that the processing chamber 201, i.e., the space where wafer 200 is located, reaches the desired pressure (vacuum level). At this time, the pressure in the processing chamber 201 is measured by pressure sensor 245, and based on the measured pressure information, APC valve 243 is controlled by feedback (pressure adjustment). Vacuum pump 246 remains operational at least until the processing of wafer 200 is completed.

[0100] Additionally, heating is performed by heater 207 to bring the processing chamber 201 to a desired temperature. At this time, feedback control (temperature adjustment) is applied to the power supply to heater 207 based on temperature information detected by temperature sensor 263 to achieve a desired temperature distribution within the processing chamber 201. Hereinafter, the temperature of heater 207 is set to a temperature such that the temperature of wafer 200 is, for example, in the range of 300°C or higher and 600°C or lower. Furthermore, heating of the processing chamber 201 by heater 207 continues at least until the processing of wafer 200 is completed.

[0101] [Step S10] (Supply metal-containing gas)

[0102] Valve 314 is opened to allow inert gas to flow in container 314. Meanwhile, valve 316 is opened to allow the metal-containing gas, serving as the raw material gas, to flow from container 14 into gas supply pipe 310. The flow rate of the metal-containing gas is adjusted according to the inert gas flow rate adjusted by MFC 312, and it is supplied from the gas supply port 410a of nozzle 410 into processing chamber 201, and discharged from exhaust pipe 231. At this time, metal-containing gas is supplied to wafer 200. Simultaneously, valve 514 is opened to allow inert gas to flow in gas supply pipe 510. The inert gas flowing in gas supply pipe 510 is flow-adjusted by MFC 512, and supplied to processing chamber 201 along with the metal-containing gas, and discharged from exhaust pipe 231. At this time, to prevent metal-containing gas from entering nozzle 420, valve 524 is opened to allow inert gas to flow in gas supply pipe 520. Inert gas is supplied into the processing chamber 201 through the gas supply pipe 320 and the nozzle 420, and discharged from the exhaust pipe 231.

[0103] At this time, the APC valve 243 is adjusted to set the pressure in the processing chamber 201 to, for example, a pressure within the range of 1 to 3990 Pa, such as 1000 Pa. The supply flow rate of the inert gas controlled by the MFC 312 is set to, for example, a flow rate within the range of 0.1 to 1.0 slm, preferably 0.1 to 0.5 slm. The supply flow rates of the inert gas controlled by the MFCs 512 and 522 are set to, for example, a flow rate within the range of 0.1 to 20 slm. Furthermore, the expression of a numerical range such as "1 to 3990 Pa" in this disclosure means that the lower and upper limits are included in the range; therefore, for example, "1 to 3990 Pa" means "above 1 Pa and below 3990 Pa". The same applies to other numerical ranges.

[0104] At this time, the gases flowing within the processing chamber 201 are only metal-containing gases and inert gases. Here, a molybdenum (Mo)-containing gas can be used as the metal-containing gas. For example, MoCl5, MoO2Cl2, and MoOCl4 gases can be used as the Mo-containing gas. By supplying the metal-containing gas, a metal-containing layer is formed on the wafer 200 (which serves as the substrate film on the surface of the AlO film). Here, when either MoO2Cl2 or MoOCl4 is used as the metal-containing gas, the metal-containing layer is a Mo-containing layer. The Mo-containing layer can be a Mo layer containing Cl and O, or an adsorption layer of MoO2Cl2 (MoOCl4), or both. Furthermore, the Mo-containing layer is a film with Mo as the main component, and it can also contain elements such as Cl, O, and H in addition to Mo.

[0105] [Step S11 (First purging process)]

[0106] (Removal of residual gases)

[0107] After a predetermined time elapsed since the start of supplying the metal-containing gas, for example, 0.01 to 10 seconds, valve 316 (valve 314) of the gas supply pipe 310 is closed to stop the supply of the metal-containing gas. That is, the time for supplying the metal-containing gas to the wafer 200 is, for example, within the range of 0.01 to 10 seconds. At this time, the APC valve 243 of the exhaust pipe 231 is kept open, and the vacuum pump 246 is used to perform vacuum venting in the processing chamber 201 to remove any unreacted or metal-containing gases remaining in the processing chamber 201 that may contribute to the formation of the metal-containing layer. In other words, the processing chamber 201 is purged. At this time, valves 514 and 524 remain open to maintain the supply of inert gas to the processing chamber 201. The inert gas acts as a purging gas, which can improve the effect of removing any unreacted or metal-containing gases remaining in the processing chamber 201 that may contribute to the formation of the metal-containing layer.

[0108] [Step S12]

[0109] (Supply reducing gas)

[0110] After removing residual gas from processing chamber 201, valve 324 is opened to allow reducing gas to flow in gas supply pipe 320. The reducing gas flow rate is adjusted by MFC 322, supplied to processing chamber 201 from gas supply port 420a of nozzle 420, and discharged from exhaust pipe 231. At this time, reducing gas is supplied to wafer 200. Simultaneously, valve 524 is opened to allow inert gas to flow in gas supply pipe 520. The inert gas flowing in gas supply pipe 520 is flow rate adjusted by MFC 522. The inert gas, along with the reducing gas, is supplied to processing chamber 201 and discharged from exhaust pipe 231. At this time, to prevent reducing gas from entering nozzle 410, valve 514 is opened to allow inert gas to flow in gas supply pipe 510. The inert gas is supplied to processing chamber 201 via gas supply pipe 310 and nozzle 410 and discharged from exhaust pipe 231.

[0111] At this time, adjust APC valve 243 to set the pressure in processing chamber 201 to, for example, a pressure in the range of 1 to 3990 Pa, such as 2000 Pa. Set the supply flow rate of reducing gas controlled by MFC 322 to, for example, a flow rate in the range of 1 to 50 slm, preferably 15 to 30 slm. Set the supply flow rate of inert gas controlled by MFC 512 and 522 to, for example, a flow rate in the range of 0.1 to 30 slm. Set the time for supplying reducing gas to wafer 200 to, for example, a time in the range of 0.01 to 120 seconds.

[0112] At this time, the gases flowing inside the processing chamber 201 are only reducing gases and inert gases. For example, hydrogen (H2), deuterium (D2), or gases containing activated hydrogen can be used as reducing gases. When using H2 as the reducing gas, the H2 gas undergoes a displacement reaction with at least a portion of the Mo-containing layer formed on the wafer 200 in step S10. That is, O and chlorine (Cl) in the Mo-containing layer react with H2, detach from the Mo layer, and are discharged from the processing chamber 201 as reaction byproducts such as water vapor (H2O), hydrogen chloride (HCl), and chlorine (Cl2). Then, a metal layer (Mo layer) containing Mo but substantially free of Cl and O is formed on the wafer 200.

[0113] [Step S13 (Second purging process)]

[0114] (Removal of residual gases)

[0115] After the metal layer is formed, valve 324 is closed to stop the supply of reducing gas.

[0116] Then, through the same processing steps as step S11 (first purging step) described above, unreacted gases or reducing gases and reaction byproducts remaining in the processing chamber 201 that contribute to the formation of the metal layer are removed from the processing chamber 201. That is, the processing chamber 201 is purged.

[0117] (Number of scheduled implementations)

[0118] By performing the above steps S10 to S13 at least once (a predetermined number of times (n times)), a metal-containing film of a predetermined thickness (e.g., 0.5 to 20.0 nm) is formed on the wafer 200. It is preferable to repeat the above cycle multiple times. Alternatively, steps S10 to S13 may each be performed at least once.

[0119] (Post-purging and atmospheric pressure recovery)

[0120] Inert gas is supplied into the processing chamber 201 through gas supply pipes 510 and 520, and discharged through exhaust pipe 231. The inert gas acts as a purging gas, thereby removing residual gases and reaction byproducts from the processing chamber 201 (post-purging). Afterwards, the atmosphere in the processing chamber 201 is replaced with inert gas (inert gas replacement), and the pressure inside the processing chamber 201 is restored to atmospheric pressure (atmospheric pressure restoration).

[0121] (Wafer removal)

[0122] Next, the sealing cover 219 is lowered using the crystal boat lift 115, opening the lower end of the outer tube 203. Then, the processed wafer 200, supported by the crystal boat 217, is moved from the lower end of the outer tube 203 to the outside of the outer tube 203 (crystal boat unloading). Afterward, the processed wafer 200 is removed from the crystal boat 217 (wafer removal).

[0123] (4) Raw material gas supply method

[0124] Next, refer to Figures 6-8 The specific description describes the raw material gas supply method using the raw material gas supply system 12 of this embodiment. The raw material gas supply method is as follows: Figure 4 The process of supplying a metal-containing gas as a raw material gas to the processing chamber 201, which serves as the reaction chamber, in step S10 is carried out.

[0125] First, such as Figure 6As shown in step S20, the raw material is vaporized in container 14 to generate a first raw material gas. Next, as shown in step S21, a first inert gas is supplied to container 14 to promote the vaporization of the raw material. That is, a second raw material gas is generated by mixing the first raw material gas and the first inert gas. Then, the second raw material gas is allowed to flow downstream of container 14.

[0126] Next, as shown in step S22, a second inert gas is supplied to the gas supply pipe 310 to dilute the second raw material gas. In this embodiment, the first and second inert gases are gases of the same type, such as N2 gas. That is, a third raw material gas is generated by mixing the second raw material gas and the second inert gas. The generated third raw material gas flows into the straight pipe section SR.

[0127] Next, as shown in step S23, the pressure of the third raw material gas at the first position B1 of the straight pipe section SR is measured, and as shown in step S24, the pressure of the third raw material gas at the second position B2 of the straight pipe section SR is measured. The measured pressure values ​​at the first position B1 and the second position B2 are input to the controller 121.

[0128] Next, as shown in step S25, the pressure loss Δp between the first position B1 and the second position B2 is calculated based on the pressure at the first position B1 and the pressure at the second position B2.

[0129] <Flow rate calculation and processing of raw material gases>

[0130] Next, as shown in step S26, the flow rate of the third feed gas flowing in the straight pipe section SR is calculated based on the calculated pressure loss Δp. Additionally, the flow rate and concentration of the first feed gas are calculated.

[0131] Specifically, firstly, such as Figure 7 As shown, the flow rate Q of the fluid flowing in the straight pipe section SR is... mix The pressure difference Δp between the pressure p1 at the first position B1 and the pressure p2 at the second position B2, i.e., the pressure loss, holds according to the following equation (1). Equation (1) is based on the Hagen-Poiseuille equation.

[0132] [Formula 1]

[0133]

[0134] Where d is the inner diameter of the straight pipe section SR. L is the interval between the first position B1 and the second position B2. π is pi. d, L, and π are all known constants.

[0135] μ mixIt is the viscosity coefficient of a third raw material gas comprising a first raw material gas as a film-forming raw material (precursor), a first inert gas as a carrier gas for promoting vaporization, and a second inert gas as a dilution gas. mix It is an unknown that varies depending on the concentration of each gas contained within. Additionally, Q... mix This is the volumetric flow rate of the third feed gas. Alternatively, a correction factor can be appropriately added to Equation 1 for calculation. Adding a correction factor improves the accuracy of the calculation.

[0136] In this embodiment, the first inert gas and the second inert gas are the same gas. Furthermore, the flow rates of the first and second inert gases are controlled by an MFC, thus allowing the determination of their respective flow rate values. Therefore, the concentration of the first raw material gas, which is the vaporized raw material, can be calculated for a third raw material gas that is a mixture of the first raw material gas, the first inert gas, and the second inert gas.

[0137] Next, the molar concentration of the first raw material gas is set as x1, and the molar concentration of the gas corresponding to the sum of the first and second inert gases is set as x2 (x2 = 1 - x1). Furthermore, the viscosity coefficients of each gas when existing as monomers are set as μ1 and μ2. At this point, the viscosity coefficient μ of the third raw material gas, formed by the mixture of the first raw material gas, the first inert gas, and the second inert gas, is... mix It is represented by the following equations (2) and (3).

[0138] [Formula 2]

[0139]

[0140] [Formula 3]

[0141]

[0142] Here, M1 and M2 are the molecular weights (molar masses) of the first raw material gas and the gas corresponding to the sum of the first and second inert gases, respectively. Additionally, (T) s P s The state with K = (273.15 K, 101325 Pa) is called the standard state. Furthermore, let Q′ be the volumetric flow rate of the third feed gas, the first feed gas, and the gas corresponding to the sum of the first and second inert gases under the standard state. mix If Q′1 and Q′2 are given, then the following relationships (4) and (5) hold true.

[0143] [Formula 4]

[0144] Q′ mix =Q′1+Q′2…(4)

[0145] [Formula 5]

[0146] Q′1=x1Q′ mix Q′2=x2Q′ mix …(5)

[0147] Furthermore, in equations (4) and (5), the variables with a superscript ′ (apostrophe) refer to flow rates in units of [SLM] or [SCCM]. The following equation (6) holds true between the flow rate Q at any temperature T and pressure p and the flow rate Q′ under standard conditions.

[0148] [Formula 6]

[0149]

[0150] Here, temperature T and pressure p are equal to the temperature and average pressure of the straight pipe section SR, respectively, and are all measurable values. In equations (1) to (6) above, the independent unknown is the flow rate Q. mix And x2. The solution to the unknown can be obtained by performing iterative calculations based on the bisection method.

[0151] The flow rate and concentration of the first raw material gas are calculated through the above calculations. In addition, at least one of the following properties of the first raw material gas and the gas corresponding to the sum of the first inert gas and the second inert gas is equivalent to the "properties of the gas" of this disclosure: molar concentration, viscosity coefficient, molecular weight, and vapor pressure.

[0152] <Control actions based on calculation results>

[0153] The controller 121 is configured to control the first inert gas supply unit 516 based on the calculated flow rate of the first raw material gas, and to adjust the flow rate of the first inert gas supplied to the container 14 by controlling the first inert gas supply unit 516.

[0154] In addition, the controller 121 is configured to control the second inert gas supply unit 526 based on the calculated flow rate of the first raw material gas, and to adjust the flow rate of the second inert gas supplied to the gas supply pipe 310 by controlling the second inert gas supply unit 526.

[0155] exist Figure 8In (A), the changes in the flow rates over time of the precursor gas (first raw material gas), the carrier gas (first inert gas), and the dilution gas (second inert gas) set in the substrate processing are illustrated. The flow rate of the first raw material gas in container 14 remains constant over time. Furthermore, the flow rate of the gas corresponding to the sum of the first and second inert gases also remains constant over time. Additionally, the flow rate of the first inert gas gradually increases over time, while the flow rate of the second inert gas gradually decreases over time.

[0156] On the other hand, Figure 8 In (B), the changes in the flow rates of the first raw material gas, the first inert gas, and the second inert gas over time are illustrated, based on the calculated flow rate of the first raw material gas.

[0157] like Figure 8 As shown in (B), in this embodiment, when the controller 121 detects a decrease in the flow rate of the first raw material gas through calculation, it increases the flow rate of the first inert gas to keep the total flow rate of the third raw material gas supplied to the processing chamber 201 constant. Furthermore, when the controller 121 increases the flow rate of the first inert gas, it decreases the flow rate of the second inert gas to keep the concentration of the first raw material gas in the third raw material gas supplied to the processing chamber 201 constant.

[0158] Furthermore, when the controller 121 detects an increase in the flow rate of the first raw material gas through calculation, it reduces the flow rate of the first inert gas to keep the total flow rate of the third raw material gas supplied to the processing chamber 201 constant. Additionally, when the controller 121 reduces the flow rate of the first inert gas, it increases the flow rate of the second inert gas to keep the concentration of the first raw material gas in the third raw material gas constant. That is, in this embodiment, any one of the flow rates of the first, second, and third raw material gases is controlled based on the calculation results. Furthermore, the concentration of the first raw material gas in either the second or third raw material gas is also controlled.

[0159] (5) Effects of this implementation method

[0160] In this embodiment, the gas supply pipe 310 has a straight pipe section SR, and the pressure loss between the first position B1 on the upstream side and the second position B2 on the downstream side of the straight pipe section SR is configured as a predetermined pressure loss so that the flow rate of the raw material gas flowing inside can be calculated.

[0161] Furthermore, the flow rate of the feed gas can be calculated, for example, using the ratio of volumetric flow rate to pressure loss as specified by the Hagen-Poiseuille formula. Moreover, by comparing the calculated feed gas flow rate with the feed gas flow rate set for substrate processing, subsequent feed gas supply processes can be adjusted to achieve the set flow rate.

[0162] In this embodiment, the portion of the gas supply pipe 310 where the pressure loss is measured—that is, the portion between the first position B1 and the second position B2—is a simple straight pipe section SR. Therefore, the pressure loss measured between the first position B1 and the second position B2 is solely the pressure loss caused by friction between the raw gas and the inner wall surface as it passes through the gas supply pipe 310. Thus, in this embodiment, the structure of the raw gas supply system 12 can be simplified, resulting in improved accuracy of pressure measurement for controlling the flow rate of the raw gas. Therefore, according to this embodiment, even with a simple structure, the flow rate of the raw gas can be appropriately controlled.

[0163] Furthermore, MFCs are typically used for flow control of raw material gases. However, when using MFCs for flow control, the pressure loss of the fluid in the MFC increases, so it is necessary to increase the pressure in the piping upstream of the MFC for proper control. On the other hand, currently, the types of raw materials used in the raw material gas supply system 12 of the substrate processing apparatus are diverse. For example, materials that vaporize at relatively low vapor pressure, such as HfCl4 and ZrCl4 (low vapor pressure raw materials), are sometimes used as raw materials.

[0164] When the feed gas is a low vapor pressure feed gas and the MFC is located downstream of the feed gas flow, there is a concern that the partial pressure of the feed gas in the low vapor pressure feed gas in the piping upstream of the MFC may exceed the saturated vapor pressure. In this case, there is a problem that the required flow rate cannot be achieved. In addition, the low vapor pressure feed gas exceeding the saturated vapor pressure may sometimes solidify or liquefy.

[0165] As an example of a flow control method that can minimize pressure loss, the use of infrared (IR) sensors can be considered. However, IR sensors present the problem of increased cost. Furthermore, they require regular maintenance, thus increasing the maintenance burden.

[0166] In this embodiment, a low vapor pressure feedstock in a solid state is vaporized to generate a feedstock gas. In this embodiment, even though the feedstock gas is generated by vaporizing a low vapor pressure feedstock, an MFC is not required, and the flow rate of the feedstock gas can be appropriately controlled. Therefore, situations where the required flow rate cannot be achieved, as is the case when using an MFC, can be suppressed. That is, compared to an MFC, a larger flow rate of gas can be stably maintained. Furthermore, in this embodiment, the flow rate of the feedstock gas can be appropriately controlled with a simple structure, thus eliminating the need for complex structures like IR sensors. Therefore, this embodiment is particularly effective when generating a feedstock gas using a low vapor pressure feedstock.

[0167] Furthermore, in this embodiment, since the flow rate of the first raw material gas, which is the raw material after vaporization, is calculated, feedback control in the raw material gas supply process can be appropriately performed.

[0168] In addition, in this embodiment, the concentration is calculated in addition to the flow rate of the first raw material gas, so feedback control in the raw material gas supply process can be performed more appropriately.

[0169] Furthermore, in this embodiment, both the first pressure measuring unit 16 and the second pressure measuring unit 18 are composed of absolute pressure gauges. Here, for example, in calculating the flow rate of a feed gas with low vapor pressure, when performing a conversion from volumetric flow rate to mass flow rate, the average value of the absolute pressure is sometimes calculated during the conversion. Therefore, measuring the pressure based on an absolute pressure gauge is advantageous in terms of improving the accuracy of the feed gas flow rate calculation.

[0170] Furthermore, in this embodiment, when the controller 121 detects changes in the flow rate of the first raw material gas through calculation, it adjusts the flow rate of the first inert gas accordingly to keep the total flow rate of the third raw material gas supplied to the processing chamber 201 constant. Therefore, the supply amount of the third raw material gas per unit time can be kept constant, thus preventing a shortage of the third raw material gas required for substrate processing.

[0171] Furthermore, in this embodiment, the controller 121 increases or decreases the flow rate of the second inert gas while increasing or decreasing the flow rate of the first inert gas, thereby keeping the concentration of the first raw material gas in the third raw material gas constant. Therefore, it is possible to fix the deviation in film formation quality during substrate processing.

[0172] Furthermore, the substrate processing apparatus 10 equipped with the raw material gas supply system 12 of this embodiment can be easily configured, and the quality of the substrate can be improved by using a third raw material gas with appropriately controlled flow rate.

[0173] Similarly, according to the semiconductor device manufacturing method using the substrate processing apparatus 10 equipped with the raw material gas supply system 12 of this embodiment, it is possible to manufacture a semiconductor device with improved quality using raw material gas with appropriately controlled flow rate.

[0174] Alternatively, in the raw material gas supply system 12 of this embodiment, a program can be created that causes the controller 121 to execute a series of processes for performing the raw material gas supply method via a computer. The created program can be stored in a computer-readable recording medium.

[0175] (6) Other implementation methods

[0176] The embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the embodiments described above, and various modifications can be made without departing from its spirit.

[0177] For example, the above embodiments were described using a case containing Mo gas, but this disclosure is not limited thereto.

[0178] Furthermore, in the above embodiments, the case of using H2 gas as a reducing gas was described as an example, but this disclosure is not limited to this.

[0179] Furthermore, in the above embodiments, an example of film deposition using a substrate processing apparatus that is a batch-type vertical device for processing multiple substrates at a time has been described, but this disclosure is not limited thereto. This disclosure can also be appropriately applied to cases where film deposition is performed using a monolithic substrate processing apparatus that processes one or more substrates at a time.

[0180] (First variation)

[0181] For example, in this disclosure, one or more third pressure measuring units may also be provided between the first position B1 and the second position B2. That is, the number of pressure gauges provided in the pressure measuring units can be three or more. Figure 9 In (A), a two-point measurement using two pressure gauges is illustrated. In the two-point measurement case, the pressure gauge error increases, resulting in concerns that it may be difficult to accurately estimate the flow rate calculation formula Δp / L. On the other hand, in Figure 9 In (B), a measurement method is illustrated in a first modified example in which three pressure gauges serving as the third pressure measuring unit 19 are provided between the first position B1 and the second position B2.

[0182] In the first variation, by measuring the pressure at three or more points and using the least-squares approximation of the measured pressures, the pressure loss (pressure gradient) between the first position B1 and the second position B2 can be calculated with further improved accuracy. That is, the error of the pressure gauge can be reduced. Therefore, the accuracy of flow rate calculation can be improved. In particular, the first variation is useful when the pressure difference is small relative to the full scale of the pressure gauge, and when the accuracy of flow rate calculation cannot ignore the errors of individual pressure gauges.

[0183] As in the first variation, when measuring the pressure at three or more points, the controller 121 uses the first pressure measuring unit 16, the second pressure measuring unit 18, and the third pressure measuring unit to calculate the flow rate of the raw material gas.

[0184] When a first pressure measuring unit 16, a second pressure measuring unit 18, and one or more third pressure measuring units are provided, the process of calculating the flow rate of the raw material gas can select to use two pressure measuring units or all pressure measuring units. Specifically, the controller 121 has both a calculation program for using two pressure measuring units and a calculation program for using all pressure measuring units, and the calculation program used in the process is configured to be changeable according to the number of pressure measuring units selected.

[0185] Furthermore, when using two pressure measuring units, the controller 121 can select any two of the first pressure measuring unit 16, the second pressure measuring unit 18, and the third pressure measuring unit, and perform processing to calculate the flow rate of the raw material gas using the selected two pressure measuring units. Alternatively, when using all pressure measuring units, the controller 121 performs processing to calculate the flow rate of the raw material gas using all of the pressure measuring units of the first pressure measuring unit 16, the second pressure measuring unit 18, and the third pressure measuring unit.

[0186] (Second variation)

[0187] In addition, such as Figure 10 As shown, in this disclosure, the pressure gauge of one of the upstream first pressure measuring unit 16 and the downstream second pressure measuring unit 18 can also be replaced with a differential pressure gauge 17 to measure the pressure at the first position B1 and the second position B2 respectively. Figure 10 In (A), an example is shown where a differential pressure gauge 17 is installed in place of a pressure gauge at the second position B2. Additionally, in... Figure 10 In (B), a case is illustrated where a differential pressure gauge 17 is configured instead of a pressure gauge in the first position B1.

[0188] Specifically, the differential pressure gauge 17 can be a type of differential pressure gauge that utilizes a diaphragm for measurement. By using the differential pressure gauge 17, compared to using two pressure gauges, it is less likely to produce measurement errors caused by zero-point deviation of the pressure gauges, thus improving the accuracy of flow measurement.

[0189] (Third variation)

[0190] In addition, such as Figure 11 As shown, in this disclosure, a temperature control unit HX for controlling the temperature of the first inert gas may also be provided upstream of the container 14. The temperature control unit HX is connected to the controller 121. The temperature control unit HX may include, for example, a pipe heater capable of temperature adjustment, a temperature sensor, etc.

[0191] In the third variation, the temperature of the first inert gas can be changed during film formation via feedback control from the controller 121 through the temperature control unit HX. By changing the temperature of the first inert gas, the temperature inside the container 14 where the raw material vaporizes changes, and the saturated vapor pressure of the raw material changes accordingly. Therefore, the maximum amount of raw material vaporization can be controlled.

[0192] For example, if the temperature control unit HX is operated to increase the temperature of the first inert gas, the temperature inside the container 14 rises, and therefore the saturated vapor pressure increases. As a result, the amount of material that can vaporize inside the container 14 increases, thereby increasing the flow rate of material supplied to the processing chamber 201. Furthermore, after supplying the first inert gas to the container 14, the saturated vapor pressure of the material can be rapidly changed by altering the temperature of the container 14.

Claims

1. A gas supply system, characterized in that, The gas supply system has the following features: A container that generates gas from a feedstock with low vapor pressure characteristics; The first piping, which connects the container and the reaction chamber, has a straight section; A first pressure measuring unit is disposed at a first position of the straight pipe section to measure the pressure of the gas. The second pressure measuring unit is located at a second position on the downstream side of the gas flow of the straight pipe section, which is closer to the first position, to measure the pressure of the gas. A second piping is connected to the container and supplies the first inert gas to the container; A first inert gas supply unit is provided in the second piping and is capable of measuring the flow rate of the first inert gas flowing in the second piping. as well as The control unit is configured to calculate the flow rate of the gas flowing in the straight pipe section based on the pressure loss of the straight pipe section calculated from the measurement signals from the first pressure measuring unit and the second pressure measuring unit, and to control the flow rate of the gas based on the calculation result. Furthermore, it calculates the flow rate of the raw material within the gas generated in the container based on the flow rate of the gas flowing in the straight pipe section and the flow rate of the first inert gas. The raw material is a material with vapor pressure characteristics that reach a saturated vapor pressure of 0.01 to 5 kPa at 50°C to 200°C. The control unit is configured to calculate the concentration of the raw material in the gas flowing in the straight pipe section based on the calculated flow rate of the gas flowing in the straight pipe section, the flow rate of the first inert gas, the characteristics of the gas, and the characteristics of the first inert gas.

2. The gas supply system according to claim 1, characterized in that, The gas supply system also has: A third piping, connected to the first piping, supplies a second inert gas to the first piping; and A second inert gas supply unit, which is installed in the third piping, is capable of measuring the flow rate of the second inert gas flowing in the third piping. The control unit is configured to calculate the flow rate of the raw material in the vaporized gas in the container based on the calculated flow rate of the gas flowing in the straight pipe, the flow rate of the first inert gas, and the flow rate of the second inert gas.

3. The gas supply system according to claim 2, characterized in that, The control unit is configured to calculate the concentration of the raw material in the gas flowing in the straight pipe section based on the calculated flow rate of the gas flowing in the straight pipe section, the flow rate of the first inert gas, the flow rate of the second inert gas, the characteristics of the gas, the characteristics of the first inert gas, and the characteristics of the second inert gas.

4. The gas supply system according to claim 1, characterized in that, The control unit is configured to calculate the flow rate of the raw material in the gas flowing in the straight pipe section based on the difference between the pressure value measured by the first pressure measuring unit and the pressure value measured by the second pressure measuring unit.

5. The gas supply system according to claim 1, characterized in that, The gas supply system also has one or more third pressure measuring units disposed between the first position and the second position. The control unit is configured to use the first pressure measuring unit, the second pressure measuring unit, and the third pressure measuring unit to calculate the flow rate of the raw material in the gas flowing in the straight pipe section.

6. The gas supply system according to claim 5, characterized in that, The control unit is configured to modify the following processes: The process of calculating the gas flow rate using two of the following pressure measuring units: the first pressure measuring unit, the second pressure measuring unit, and the third pressure measuring unit; and The process of calculating the flow rate of raw material in the gas flowing in the straight pipe section is performed using the first pressure measuring unit, the second pressure measuring unit, and one or more of the third pressure measuring units.

7. The gas supply system according to claim 1, characterized in that, The control unit is configured to control the first inert gas supply unit based on the calculated flow rate of the gas flowing in the straight pipe section, thereby adjusting the flow rate of the first inert gas supplied to the container.

8. The gas supply system according to claim 1, characterized in that, The control unit is configured to control the first inert gas supply unit in the following manner: when a decrease in the flow rate of the gas flowing in the straight pipe is detected by the calculation, the flow rate of the first inert gas is increased; when an increase in the flow rate of the gas flowing in the straight pipe is detected, the flow rate of the first inert gas is decreased.

9. The gas supply system according to claim 1, characterized in that, The control unit is configured to control the second inert gas supply unit based on the calculated flow rate of the gas flowing in the straight pipe section, thereby adjusting the flow rate of the second inert gas supplied to the first piping.

10. The gas supply system according to claim 9, characterized in that, The control unit is configured to control the second inert gas supply unit in such a way that when the flow rate of the first inert gas is increased, the flow rate of the second inert gas is decreased, and when the flow rate of the first inert gas is decreased, the flow rate of the second inert gas is increased.

11. The gas supply system according to claim 1, characterized in that, Both the first pressure measuring unit and the second pressure measuring unit are composed of absolute pressure gauges.

12. A substrate processing apparatus, characterized in that, The substrate processing apparatus includes: The reaction chamber is used to process the substrate; A container that generates gas from a feedstock with low vapor pressure characteristics; The first piping, which connects the container and the reaction chamber, has a straight section; A first pressure measuring unit is disposed at a first position of the straight pipe section to measure the pressure of the gas. The second pressure measuring unit is located at a second position on the downstream side of the gas flow of the straight pipe section, which is closer to the first position, to measure the pressure of the gas. The second piping has one end connected to the container and the other end connected to a gas supply pipe located downstream of the first piping, supplying the container with the first inert gas. A first inert gas supply unit is provided in the second piping and is capable of measuring the flow rate of the first inert gas flowing in the second piping. as well as The control unit is configured to calculate the flow rate of the gas flowing in the straight pipe section based on the pressure loss of the straight pipe section calculated from the measurement signals from the first pressure measuring unit and the second pressure measuring unit, and to control the flow rate of the gas based on the calculation result. Furthermore, it calculates the flow rate of the raw material within the gas generated in the container based on the flow rate of the gas flowing in the straight pipe section and the flow rate of the first inert gas. The raw material is a material with vapor pressure characteristics that reach a saturated vapor pressure of 0.01 to 5 kPa at 50°C to 200°C. The control unit is configured to calculate the concentration of the raw material in the gas flowing in the straight pipe section based on the calculated flow rate of the gas flowing in the straight pipe section, the flow rate of the first inert gas, the characteristics of the gas, and the characteristics of the first inert gas.

13. A method for manufacturing a semiconductor device, characterized in that, The manufacturing method uses the substrate processing apparatus of claim 12 and includes the following steps: Gas is generated in the container; The pressure of the gas at the first position of the straight pipe is measured by the first pressure measuring unit; The pressure of the gas at the second position of the straight pipe is measured by the second pressure measuring unit; Based on the pressure loss of the straight pipe section calculated according to the measurement signals from the first pressure measuring unit and the second pressure measuring unit, the flow rate of the gas flowing in the straight pipe section is calculated, and the flow rate of the gas is controlled based on the calculation result. Furthermore, based on the flow rate of the gas flowing in the straight pipe section and the flow rate of the first inert gas, the flow rate of the raw material in the gas generated in the container is calculated. as well as The gas, with its flow rate controlled, is supplied to the substrate within the reaction chamber. The raw material is a material with vapor pressure characteristics that reaches a saturated vapor pressure of 0.01 to 5 kPa at 50°C to 200°C.

14. A computer-readable recording medium, characterized by comprising: The recording medium recorded the program. In the gas supply system of claim 1, the program causes the gas supply system to perform the following steps via a computer: In the container, gas is generated from a raw material having low vapor pressure characteristics and a vapor pressure characteristic of a material having a saturated vapor pressure of 0.01 to 5 kPa at 50°C to 200°C. The pressure of the gas at the first position of the straight pipe is measured by the first pressure measuring unit; The pressure of the gas at the second position of the straight pipe is measured by the second pressure measuring unit; as well as calculating the pressure loss of the straight pipe section based on the measurement signal from the first pressure measurement section and the measurement signal from the second pressure measurement section, calculating the flow rate of the gas flowing in the straight pipe section based on the calculated pressure loss, and controlling the flow rate of the gas based on the calculation result, and calculating the flow rate of the raw material in the gas generated in the vessel based on the flow rate of the gas flowing in the straight pipe section and the flow rate of the first inert gas; and calculating the concentration of the raw material in the gas flowing in the straight pipe section based on the calculated flow rate of the gas flowing in the straight pipe section, the flow rate of the first inert gas, the characteristics of the gas, and the characteristics of the first inert gas.

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