Gas supply method, method for manufacturing semiconductor device, gas supply system, substrate processing apparatus, and program product

Abstract

This invention relates to a gas supply method, a semiconductor device manufacturing method, a gas supply system, a substrate processing apparatus, and a process product. The objective is to provide a technique for stably supplying a gas obtained by turning a material into a gaseous state to a processing chamber. The solution comprises: a step (a) of venting a processing gas containing the gas used to turn the material into a gaseous state from a container holding the material, without passing through a processing chamber; and a step (b) of switching from step (a) at a point when the gas flow rate reaches saturation, supplying the processing gas to the processing chamber.

Description

Technical Field

[0001] This invention relates to a gas supply method, a method for manufacturing semiconductor devices, a gas supply system, a substrate processing apparatus, and process products. Background Technology

[0002] As an example of a substrate processing apparatus, semiconductor manufacturing apparatuses for manufacturing semiconductor devices are known. For example, substrate processing involves supplying a processing gas to process the substrate. Due to recent advancements in device miniaturization, various processing gases, such as those obtained by vaporizing liquids or sublimating solids, are sometimes used as the processing gas, and a stable supply of the processing gas is required. For example, in Patent Document 1, multiple containers are appropriately used to supply a flow-controlled processing gas to the processing chamber.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2025-000487 Summary of the Invention

[0004] The problem that the invention aims to solve This invention provides a technique for stably supplying a gas obtained by turning a material into a gaseous state to a processing chamber.

[0005] Methods for solving problems According to one aspect of the present invention, a technology is provided, comprising: Step (a) involves venting the processing gas, which contains the gas used to gasify the material, from a container holding the material without passing through a processing chamber; and In step (b), the process switches from step (a) at the point when the gas flow rate becomes saturated, and supplies the processing gas to the processing chamber.

[0006] Invention Effects According to the present invention, a gas obtained by turning the material into a gaseous state can be stably supplied to the processing chamber. Attached Figure Description

[0007] Figure 1 This is a longitudinal cross-sectional view showing the schematic configuration of the processing furnace of a substrate processing apparatus according to an embodiment of the present invention.

[0008] Figure 2 yes Figure 1 A rough cross-sectional view of line AA in the diagram.

[0009] Figure 3 A schematic diagram of the peripheral structure of the processing furnace of a substrate processing apparatus according to an embodiment of the present invention is shown.

[0010] Figure 4 This is a schematic diagram illustrating the gas supply system of a substrate processing apparatus according to an embodiment of the present invention.

[0011] Figure 5 This is a schematic configuration diagram of the controller of a substrate processing apparatus according to an embodiment of the present invention, and is a block diagram showing the control system of the controller.

[0012] Figure 6 This is a graph showing the relationship between the flow rate and time of each gas in the gas supply system of a substrate processing apparatus according to an embodiment of the present invention.

[0013] Figure 7A This is a graph showing the relationship between the flow rate and time of the raw material gas in the gas supply system of a substrate processing apparatus according to an embodiment of the present invention.

[0014] Figure 7B This is a graph showing the relationship between the flow rate and time of the raw material gas in the gas supply system of a substrate processing apparatus according to an embodiment of the present invention.

[0015] Figure 8A This is a schematic diagram showing the exhaust state of the processing gas in the gas supply system of a substrate processing apparatus according to an embodiment of the present invention.

[0016] Figure 8B This is a schematic diagram showing the supply state of the processing gas in the gas supply system of a substrate processing apparatus according to an embodiment of the present invention.

[0017] Figure 9 This is a graph showing the relationship between the flow rate and time of each gas in the modified gas supply system.

[0018] Explanation of reference numerals in the attached figures 50 Raw materials (an example of materials) 60 Raw material container (an example of a container) Detailed Implementation

[0019] [The Invention] The following is mainly based on Figures 1 to 8B The invention will now be described. It should be noted that the accompanying drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings may not necessarily correspond to reality. Furthermore, the dimensional relationships and ratios of the elements in the various drawings may not be consistent with each other.

[0020] Figure 1 The schematic configuration of the processing furnace 202 of the substrate processing apparatus 10 according to an embodiment of the present invention is shown in longitudinal cross-section.

[0021] like Figure 1 As shown, the processing furnace 202 has a heater 207 as a heating unit (heating mechanism). The heater 207 is cylindrical and is supported by a heater base (not shown).

[0022] Inside the heater 207, a reaction tube 203 constituting a reaction vessel (processing vessel) is arranged concentrically with the heater 207. The reaction 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. The processing chamber 201 is configured to accommodate a wafer 200, which serves as a substrate, arranged in multiple layers in a horizontal orientation in the vertical direction via a crystal boat 217, described later.

[0023] In the processing chamber 201, nozzles 410, 420, and 430 are arranged to penetrate the side wall of the manifold 209. Gas supply pipes 310, 320, and 330, serving as gas supply lines, are respectively connected to the nozzles 410, 420, and 430. Thus, with three nozzles 410, 420, and 430 and three gas supply pipes 310, 320, and 330 arranged on the reaction pipe 203, a configuration is established to supply various gases (processing gases) to the processing chamber 201.

[0024] It should be noted that the processing furnace 202 of this embodiment is not limited to the above-described manner. For example, a metal manifold supporting the reaction tube 203 may be provided below the reaction tube 203, and each nozzle may be provided in a manner that penetrates the side wall of the manifold. In this case, an exhaust pipe 231, which will be described later, may also be provided further in the manifold. In this case, the exhaust pipe 231 may be provided in the lower part of the reaction tube 203 instead of in the manifold. In this way, the furnace opening of the processing furnace 202 may be made of metal, and nozzles and the like may be installed in the metal furnace opening.

[0025] Processing gas is supplied to the processing chamber 201 from the first gas supply pipe 310, the second gas supply pipe 320, and the third gas supply pipe 330 via nozzles 410, 420, and 430, respectively.

[0026] Here, as the processing gas, an O-containing gas (reactant) containing oxygen (O) or a N-containing gas (reactant) containing nitrogen (N) can be used. For example, a N-containing gas that does not contain any metal elements can be used as the N-containing gas.

[0027] Furthermore, as the processing gas, a raw material gas can be used that vaporizes a raw material (liquid raw material) in a liquid state at room temperature and pressure to become a gas, or a raw material gas that sublimates a raw material (solid raw material) in a solid state at room temperature and pressure to become a gas (hereinafter also referred to as "precursor gas"). It should be noted that the raw material and raw material gas in this embodiment are examples of the material of the present invention and the gas obtained by making the material into a gas.

[0028] like Figure 2 As shown, nozzles 410, 420, and 430 are connected to the front ends of gas supply pipes 310, 320, and 330. The horizontal portions of nozzles 410, 420, and 430 are arranged to penetrate the sidewall of manifold 209. The vertical portions of nozzles 410, 420, and 430 are arranged to stand upright along the inner wall of reaction tube 203 (above the loading direction of wafer 200) in an annular space formed between the inner wall of reaction tube 203 and wafer 200.

[0029] Gas supply holes 410a, 420a, and 430a are provided on the sides of nozzles 410, 420, and 430 for supplying (ejecting) gas. Gas supply holes 410a, 420a, and 430a open toward the center of reaction tube 203. Multiple gas supply holes 410a, 420a, and 430a are provided from the bottom to the top of reaction tube 203.

[0030] In this embodiment, gas is transported via nozzles 410, 420, and 430 disposed within the space formed by the inner wall of the reaction tube 203 and the ends of multiple wafers 200. Furthermore, gas is ejected into the reaction tube 203 from gas supply holes 410a, 420a, and 430a, which are respectively opened in the nozzles 410, 420, and 430. Moreover, the main flow of gas within the reaction tube 203 is in a horizontal direction, parallel to the surface of the wafers 200. The residual gas after reaction, flowing over the surface of the wafers 200, flows toward the exhaust port, i.e., the exhaust pipe 231 described later.

[0031] An exhaust pipe 231 is provided on the reaction tube 203 to exhaust the atmosphere of the processing chamber 201. A vacuum pump 246, serving as a vacuum exhaust device, is connected to the exhaust pipe 231 via a pressure sensor 245 (pressure detector, pressure sensing unit) and an APC (Auto Pressure Controller) valve 243 (pressure regulator, pressure regulating unit). The APC valve 243 is configured to perform vacuum exhaust and stop vacuum exhaust within the processing chamber 201 by opening and closing the valve while the vacuum pump 246 is operating. Furthermore, it can regulate the pressure of the processing chamber 201 by adjusting the valve opening based on the pressure information detected by the pressure sensor 245 while the vacuum pump 246 is operating. The exhaust system mainly consists of the exhaust pipe 231, the APC valve 243, and the pressure sensor 245. It should be noted that the vacuum pump 246 can also be considered as being included in the exhaust system.

[0032] A furnace opening cover 219 is provided below the reaction tube 203 to airtightly seal the lower opening of the reaction tube 203. The furnace opening cover 219 is configured to abut against the lower end of the reaction tube 203 from the lower vertical direction. The furnace opening cover 219 is made of metal such as SUS and is formed in a disc shape. An O-ring 220, which abuts against the lower end of the reaction tube 203, is provided on the upper surface of the furnace opening cover 219 as a sealing component.

[0033] On the side of the furnace cover 219 opposite to the processing chamber 201, a rotation mechanism 267 is provided to rotate the crystal boat 217 (described later). The rotation shaft 255 of the rotation mechanism 267 passes through the furnace cover 219 and is connected to the crystal boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the crystal boat 217. The furnace cover 219 is raised and lowered vertically by a crystal boat lift 115, which is a lifting mechanism, vertically installed outside the reaction tube 203. 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 furnace cover 219.

[0034] The crystal boat 217, serving as a substrate support, is configured to support multiple wafers 200, for example, 25 to 200 wafers, arranged horizontally and aligned at their centers in a vertical direction, in multiple layers, i.e., arranged at intervals. 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 in multiple layers in a horizontal orientation. With this configuration, heat from the heater 207 is less likely to be transferred to the furnace opening cover 219 side. However, this embodiment is not limited to the above method. For example, the heat insulation plate 218 may not be provided at the lower part of the crystal boat 217, and a heat insulation cylinder made of a cylindrical component made of heat-resistant materials such as quartz or SiC may be provided instead.

[0035] A temperature sensor 263, which serves as a temperature detector, is installed inside the reaction tube 203 (see [reference]). Figure 2 Based on the temperature information detected by the temperature sensor 263, the power supply to the heater 207 is adjusted, thereby making the temperature inside the processing chamber 201 the desired temperature distribution. The temperature sensor 263 may also be configured in an L-shape, similar to the nozzles 410, 420, and 430, and disposed along the inner wall of the reaction tube 203.

[0036] Next, the peripheral structure of the processing furnace 202 of the substrate processing apparatus 10 will be described. A first gas supply pipe 310, a second gas supply pipe 320, and a third gas supply pipe 330 are provided in the processing chamber 201.

[0037] The first gas supply pipe 310 branches into first branch pipes 82a and 82b upstream. On the first branch pipe 82a, an oxidizing gas supply source 86, supplying oxygen as the first raw material, is connected via valve v3 and an MFC (Mass Flow Controller) 84a. On the first branch pipe 82b, a first inert gas supply source 88, supplying inert gases such as nitrogen (N2) as the first inert gas, is connected via valve v4 and MFC 84b. When referring only to piping branching from the first gas supply pipe 310, the term "first branch pipe" is used; when referring to the MFC installed on the first branch pipe 82, the term "MFC" is used. Hereinafter, the same rules will be used to designate numbers.

[0038] In this manner, the first gas supply pipe 310 introduces the first raw material gas, which serves as the first reaction gas, or a mixture of the first raw material gas and inactive gases such as N2, into the processing chamber 201. For example, the first raw material gas supply system is mainly composed of the first gas supply pipe 310, the first branch pipe 82a, the valve v3, the MFC 84a, and the oxidizing gas supply source 86.

[0039] The second gas supply pipe 320 branches into second branch pipes 72a and 72b upstream. On the second branch pipe 72a, a nitriding gas supply source 76, supplying a nitriding gas, which is used as the second raw material gas, is connected via valve v1 and MFC 74a. On the second branch pipe 72b, a second inactive gas supply source 78, supplying an inactive gas such as N2 as the second inactive gas, is connected via valve v2 and MFC 74b. Hereinafter, when referring only to the piping branching from the second gas supply pipe 320, it will be called the second branch pipe 72; when referring to the MFC installed on the second branch pipe 72, it will be called MFC 74.

[0040] In this way, the second gas supply pipe 320 introduces the second raw material gas, which serves as the second reaction gas, or the second raw material gas and inactive gases such as N2, into the processing chamber 201. The nitriding gas supply system is mainly composed of the second gas supply pipe 320, the second branch pipe 72a, the valve v1, the MFC 74a, and the nitriding gas supply source 76.

[0041] It can also be configured to use inert gases supplied from the first inert gas supply source 88 and the second inert gas supply source 78. Furthermore, these gases sometimes function as purge gases, dilution gases, or carrier gases in the substrate processing steps described later. It should be noted that exhaust pipes for discharging gases to the outside can also be provided in the first gas supply pipe 310, the second gas supply pipe 320, and the third gas supply pipe 330. The exhaust pipe provided on the third gas supply pipe 330 will be described later.

[0042] A control unit 121 (not shown) is electrically connected to components such as valves v1 to v4, MFC74, MFC84, APC valve 243, and exhaust device 246. The control unit 121 controls these components at desired times to ensure that the flow rate of the supplied gas and the pressure in the processing chamber 201 reach predetermined values. Here, MFC74 and MFC84 are collectively referred to as MFC74a, 74b, MFC84a, and 84b, respectively.

[0043] <Gas Supply System> The substrate processing apparatus 10 has Figure 4 The gas supply system 100 shown. The gas supply system 100 includes a gas supply system 100a, an exhaust system 100b, and a controller 121 described later.

[0044] (Gas supply system) The gas supply system 100a is a system that supplies the processing chamber 201 with a processing gas containing a gas obtained by turning the material into a gaseous state. Specifically, the gas supply system 100a supplies the processing chamber 201 with a processing gas containing a gas obtained by sublimating the solid raw material 50 (hereinafter, sometimes referred to as the precursor gas) via a third gas supply pipe 330.

[0045] It should be noted that in the gas supply system 100a of this embodiment, a carrier gas flow method is adopted. The carrier gas flow method is as follows: while heating the raw material container 60, which is a container holding the solid raw material 50, a carrier gas with regulated flow rate is supplied to the raw material container 60, thereby causing the solid raw material 50 to undergo a phase change from solid to generate a precursor gas.

[0046] The gas supply system 100a has a raw material gas supply pipeline and a dilution gas supply pipeline.

[0047] The raw material gas supply pipeline mainly includes: a third gas supply pipe 330; an on / off valve 97; a supply valve 110; a concentration meter 98; a secondary valve v7; a raw material container 60; an inlet pipe 350a as an inlet; a primary valve v6; an inlet valve v5; an MFC 96; and a carrier gas source 101. It should be noted that the raw material gas supply pipeline may also include a nozzle 430 connected to the third gas supply pipe 330.

[0048] The third gas supply pipe 330 is a piping that connects the nozzle 430 and the raw material container 60. Additionally, the third gas supply pipe 330 is also referred to as the secondary side piping of the raw material container 60. Processing gas is supplied to the processing chamber 201 via the third gas supply pipe 330 and the nozzle 430.

[0049] The on / off valve 97 is located closest to the processing chamber 201 in the third gas supply pipe 330. Specifically, the on / off valve 97 is located near the connection between the third gas supply pipe 330 and the nozzle 430. This on / off valve 97 is also called the final valve.

[0050] The supply valve 110 is located upstream of the on / off valve 97 in the third gas supply pipe 330.

[0051] A concentration meter 98 is installed upstream of the supply valve 110 in the third gas supply pipe 330 to measure the concentration of the processed gas flowing in the piping. Here, the concentration of the processed gas refers to the proportion of precursor gas contained in the processed gas (the mixed gas described later) supplied to the processing chamber 201. Specifically, the concentration meter 98 consists of a pressure sensor 109 for measuring the total pressure of the gas, a temperature sensor 111 for measuring the temperature of the gas, and an optical system 112 for measuring the absorbance of the gas, configured to calculate the concentration of the raw material gas based on their measured values.

[0052] The following explains the concentration calculation in the concentration meter 98.

[0053] Here, as the relationship between absorbance and concentration, the following equation (Equation 1) of Lambert-Beer is known.

[0054] [Mathematical Expression 1] If PV=nR0T, C M =n / V, when transformed, becomes the following formula (Equation 2). In this way, concentration conversion can be performed through the transformation of these three mathematical formulas. The concentration is calculated using the following formula (Equation 2) in the concentration meter 98.

[0055] [Mathematical Expression 2] Here, C represents the concentration, and α represents the absorbance coefficient (m). 2 L is the optical path length (m), T is the absolute temperature (K), and P is the optical path length (m). t R0 is the total pressure (Pa) and the general gas constant = 8.314 (J / mol·K).

[0056] The concentration meter 98 is located downstream of the connection between the inlet pipe 350b and the third gas supply pipe 330, as described later. The secondary valve v7 is located upstream of the concentration meter 98 in the third gas supply pipe 330. Specifically, the secondary valve v7 is located between the concentration meter 98 and the raw material container 60 in the third gas supply pipe 330, and is close to the raw material container 60. More specifically, the secondary valve v7 is located near the connection between the third gas supply pipe 330 and the raw material container 60.

[0057] The raw material container 60 contains materials (raw materials). These materials are, for example, solid raw materials with low vapor pressure characteristics. It should be noted that "vapor pressure" here refers to the pressure of a substance in a solid-gas equilibrium state. Furthermore, "low vapor pressure material" refers to a material whose pressure in a solid-gas equilibrium state is lower than that of other materials. Therefore, changing the state of a low vapor pressure material from solid to gas requires higher temperatures and higher vacuum compared to other materials.

[0058] The inlet pipe 350a is a piping that connects the raw material container 60 to the carrier gas source 101. Additionally, the inlet pipe 350a is also referred to as the primary side piping of the raw material container 60. Carrier gas from the carrier gas source 101 is introduced (supplied) into the raw material container 60 via this inlet pipe 350a.

[0059] The primary valve v6 is located in the inlet pipe 350a at the position closest to the raw material container 60. Specifically, the primary valve v6 is located near the connection between the inlet pipe 350a and the raw material container 60.

[0060] The inlet valve v5 is positioned upstream of the primary valve v6 in the inlet pipe 350a.

[0061] The MFC96 is positioned upstream of the inlet valve v5 in the inlet pipe 350a. The MFC96 regulates the flow rate of the carrier gas flowing within the inlet pipe 350a.

[0062] Carrier gas source 101 supplies carrier gas to inlet pipe 350a and inlet pipe 350b, which will be described later. As carrier gas, a non-reactive gas that does not react with solid raw materials is preferred.

[0063] Additionally, a bypass pipe 360 ​​is provided that connects the inlet pipe 350a to the third gas supply pipe 330 without passing through the raw material container 60. Specifically, the bypass pipe 360 ​​connects the portion between the inlet valve v5 and the primary valve v6 in the inlet pipe 350a to the portion between the concentration meter 98 and the secondary valve v7 in the third gas supply pipe 330. A bypass valve v8 is provided in this bypass pipe 360. Thus, the third gas supply pipe 330 can be purged using carrier gas without passing through the raw material container 60. It should be noted that the gas supply system 100a also includes the aforementioned bypass pipe 360 ​​and bypass valve v8.

[0064] The raw material container 60 is surrounded by an auxiliary heater 70. The auxiliary heater 70 is configured to heat the solid raw material 50 inside the raw material container 60 to a temperature above which the solid raw material 50 is transformed into a gaseous state.

[0065] The temperatures of the third gas supply pipe 330, on / off valve 97, supply valve 110, concentration meter 98, secondary valve v7, inlet pipe 350a, primary valve v6, inlet valve v5, MFC 96, bypass pipe 360, bypass valve v8, exhaust valve 342, and exhaust pipe 340 are controlled by the piping heater 71 to achieve a temperature higher than that at which the solid raw material 50 is transformed into a gaseous state. Regarding the temperature control of the piping heater 71, it is preferable to control it to a temperature higher than the heating temperature at which the raw material container 60 is heated by the auxiliary heater 70. It should be noted that the exhaust valve 342 and exhaust pipe 340 can also be temperature-controlled by a separate piping heater relative to the piping heater 71.

[0066] The dilution gas supply line mainly includes an inlet pipe 350b as the dilution section, a valve 370, and an MFC99.

[0067] The inlet pipe 350b is a branch pipe branching from the inlet pipe 350a and connected to the third gas supply pipe 330. Specifically, the inlet pipe 350b branches off from the portion between the carrier gas source 101 and the MFC 96 in the inlet pipe 350a and connects to the portion between the bypass pipe 360 ​​and the concentration meter 98 in the third gas supply pipe 330. Through this inlet pipe 350b, the carrier gas from the carrier gas source 101 is introduced (supplied) to the third gas supply pipe 330 without passing through the raw material container 60. It should be noted that the carrier gas flowing in the inlet pipe 350b is a gas diluted with the processing gas containing the precursor gas obtained by sublimating the solid raw material 50, and is therefore referred to herein as a dilution gas. It should also be noted that the processing gas supplied to the processing chamber 201 is a mixture of the precursor gas obtained by sublimating the solid raw material 50, the carrier gas, and the dilution gas. That is, in this embodiment, the processing gas containing the precursor gas obtained by sublimating the solid raw material 50 is diluted by the dilution gas to become a mixture of precursor gas, carrier gas and dilution gas, which is then supplied to the processing chamber 201.

[0068] Valve 370 is disposed in inlet pipe 350b near third gas supply pipe 330. Specifically, valve 370 is disposed in inlet pipe 350b near the connection between inlet pipe 350b and third gas supply pipe 330.

[0069] MFC99 ​​is positioned upstream of valve 370 in inlet pipe 350b. Specifically, MFC99 ​​is located near the connection between inlet pipe 350a and inlet pipe 350b. MFC99 ​​regulates the flow rate of the dilution gas flowing within inlet pipe 350a.

[0070] The temperatures of the inlet pipe 350b, valve 370, and MFC99 ​​are controlled by the piping heater 73 to a temperature above which the solid raw material 50 is transformed into a gaseous state. Regarding the temperature control of the piping heater 73, it is preferable to control it to a temperature higher than the heating temperature at which the raw material container 60 is heated by the auxiliary heater 70. It should be noted that in this embodiment, the heating temperatures of the piping heater 71 and the piping heater 73 are controlled to the same temperature, but they can also be different temperatures.

[0071] The exhaust system 100b exhausts the processing gas, which contains the gas obtained by making the material into a gaseous state, without passing through the processing chamber 201. Specifically, the exhaust system 100b exhausts the processing gas (mixed gas) containing the precursor gas obtained by sublimating the solid raw material 50, upstream of the on / off valve 97. The exhaust system 100b includes an exhaust pipe 340 and an exhaust valve 342.

[0072] The exhaust pipe 340 is a piping used to exhaust the processed gas in the third gas supply pipe 330. The exhaust pipe 340 branches off from the portion between the on / off valve 97 and the supply valve 110 in the third gas supply pipe 330. It should be noted that the end of the exhaust pipe 340 may or may not be connected to a vacuum pump. Even without connecting a vacuum pump to the end of the exhaust pipe 340 to generate negative pressure within the pipe, the processed gas in the third gas supply pipe 330 can still be exhausted because the carrier gas is compressed from the carrier gas source 101.

[0073] An exhaust valve 342 is provided in the exhaust pipe 340. The exhaust valve 342 is located in the exhaust pipe 340 near the portion of the exhaust pipe 340 from which the third gas supply pipe 330 branches off.

[0074] A controller 121 (not shown) is electrically connected to components such as valves v5-v8, MFC96, 99, valve 370, exhaust valve 342, concentration meter 98, auxiliary heater 70, and piping heaters 71, 73. The controller 121 controls these components at desired times to ensure that the flow rate, pressure, etc., of the supplied gases reach specified values.

[0075] (Operation of the gas supply system) The situation of supplying a processing gas containing a precursor gas to the processing chamber 201 is shown in the figure. Figure 8B At this time, bypass valve v8 and exhaust valve 342 are closed, while inlet valve v5, primary valve v6, secondary valve v7, supply valve 110, and on / off valve 97 are open. Additionally, valve 370 is open. The controller 121 is configured to monitor the concentration (flow rate) of the gas (precursor gas) obtained by heating and sublimating the solid raw material 50 in the raw material container 60 using the auxiliary heater 70, along with the mixture of carrier gas and dilution gas, while supplying this mixed gas to the processing chamber 201. Furthermore, the supply of precursor gas is stopped by closing secondary valve v7. Additionally, the supply of dilution gas can also be stopped by closing valve 370 at this time.

[0076] (Operation of the exhaust system) The case where the process gas containing the precursor gas is vented without passing through the processing chamber 201 is shown. Figure 8AAt this time, bypass valve V8 and on / off valve 97 are closed, while inlet valve V5, primary valve V6, secondary valve V7, supply valve 110, and exhaust valve 342 are open. Controller 121 monitors the concentration (flow rate) of the gas (precursor gas) obtained by heating and sublimating the solid raw material 50 in the raw material container 60 using auxiliary heater 70, along with the mixture of carrier gas and dilution gas. Simultaneously, at the point when the precursor gas flow rate reaches saturation, controller 121 opens on / off valve 97 and closes exhaust valve 342. Thus, controller 121 switches the operation of the exhaust system to that of the gas supply system. It should be noted that "saturation" here means that not only is the precursor gas constant, but the flow rates of the carrier gas and dilution gas are also constant.

[0077] like Figure 5 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. An input / output device 122, such as a touch panel, is connected to the controller 121.

[0078] 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 apparatus, and a process flow that describes the substrate processing steps and conditions, as described later. The process flow is a combination of steps in the substrate processing process described later, executed by the controller 121, to obtain a predetermined result, and functions as a program. Hereinafter, the process flow, control program, etc., are collectively referred to as a program. In this specification, when the term "program" is used, there may be cases where only the process flow is included, cases where only the control program is included, or cases where both are included. RAM 121b is configured as a memory area (working area) that temporarily holds the program, data, etc., read by the CPU 121a.

[0079] I / O port 121d is connected to the aforementioned MFC96, 99, concentration meter 98, valves v1 to v8, 110, APC valve 243, pressure sensor 245, vacuum pump 246, heater 207, auxiliary heater 70, and piping heaters 71 and 73, rotating mechanism 267, and crystal boat lift 115.

[0080] 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, according to the read process data: flow rate regulation of various gases based on each MFC; opening and closing of valves; opening and closing of APC valve 243 and pressure regulation based on pressure sensor 245 using APC valve 243; temperature regulation of heater 207 based on temperature sensor 263; starting and stopping of vacuum pump 246; rotation and speed regulation of crystal boat 217 based on rotation mechanism 267; lifting and lowering of crystal boat 217 based on crystal boat lift 115, etc. Furthermore, in this embodiment, CPU 121a performs operation control of each component of gas supply system 100a and each component of exhaust system 100b, etc.

[0081] The controller 121 is not limited to being configured as a dedicated computer, but can also be configured as a general-purpose computer. For example, an external storage device (e.g., magnetic tape, floppy disk, hard disk, etc., optical disc, CD, DVD, etc., optical disk, USB memory, memory card, etc.) 123 storing the above-described program can be prepared, and an installation program can be installed on a general-purpose computer using the external storage device 123, thereby configuring the controller 121 of this embodiment. However, the method of providing the program to the computer is not limited to providing it via the external storage device 123. For example, the program can also be provided without using the external storage device 123 using communication means such as the Internet or dedicated lines. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, they will also be collectively referred to as recording media. In this specification, when the term "recording media" is used, there may be a case where only the storage device 121c is included, a case where only the external storage device 123 is included, or a case where both are included.

[0082] <Substrate Treatment Methods> Next, an example of processing wafer 200 will be described. As an example of a semiconductor device manufacturing process, an example of forming a film on wafer 200 will be described. First, wafer 200 is loaded into a wafer boat 217 and moved into processing chamber 201. At this time, after the wafer boat 217 is moved into processing chamber 201, the pressure and temperature of processing chamber 201 are adjusted. Then, the four steps of film formation process 1 to 4 are performed sequentially.

[0083] In the process of this embodiment, the following steps are performed non-simultaneously a predetermined number of times (more than once) to form a film on the wafer 200: a step of supplying a processing gas containing a precursor gas to the wafer 200 in the processing chamber 201 (film formation step 1); a purging step of removing residual gas from the processing chamber 201 (film formation step 2); a step of supplying a nitrogen-containing gas to the wafer 200 in the processing chamber 201 (film formation step 3); and a purging step of removing nitrogen-containing gas (residual gas) from the processing chamber 201 (film formation step 4).

[0084] The following details each step.

[0085] (Film forming process 1) Film forming process 1 includes the following steps (a) and (b).

[0086] In step (a), firstly, the process gas containing the precursor gas is vented without passing through the processing chamber 201. Specifically, the on / off valve 97 and the bypass valve v8 are set to the closed state, and the vent valve 342, the supply valve 110, the secondary valve v7, the primary valve v6, and the inlet valve v5 are set to the open state. In addition, valve 370 is set to the open state. Then, the auxiliary heater 70 and the piping heaters 71 and 73 are heated, and a carrier gas with flow control by MFC 96 is supplied to the raw material container 60. The process gas containing the precursor gas and the carrier gas generated from the solid raw material 50 in the raw material container 60 is supplied to the third gas supply pipe 330. In addition, a dilution gas with flow control by MFC 99 is supplied to the third gas supply pipe 330, so that the dilution gas is mixed with the process gas containing the precursor gas and the carrier gas. The concentration of the mixed process gas is measured by the concentration meter 98. While monitoring the concentration (flow rate) of the processed gas measured by the concentration meter 98, the processed gas is discharged through the exhaust pipe 340 until the flow rate of the precursor gas reaches saturation.

[0087] Then, at the point when the concentration (flow rate) of the processed gas, as measured by the concentration meter 98, reaches saturation, the process is switched from process (a) to process (b).

[0088] In step (b), the on / off valve 97 is in the open state, and the exhaust valve 342 is in the closed state. As a result, a processing gas mixed with dilution gas is supplied to the processing chamber 201 via the third gas supply pipe 330.

[0089] (Film forming process 2) Film deposition step 2 includes step (c) of stopping the supply of processing gas to processing chamber 201. Specifically, in step (c), at least the on / off valve 97 is closed to stop the supply of processing gas containing precursor gas to processing chamber 201. Specifically, secondary valve v7 and valve 370 are changed to the closed state. Alternatively, the supply valve 110 can also be changed to the closed state. It should be noted that the auxiliary heater 70, piping heaters 71, 73, MFC 96, 99 are kept in an ON state until the substrate processing step is completed. In addition, in film deposition step 2, the valve 243 of exhaust pipe 231 is kept open, and the processing furnace 202 is vented to below 20 Pa using vacuum pump 246 to remove residual mixed gas from processing chamber 201. Furthermore, if an inactive gas, such as N2 gas used as a carrier gas, is supplied to processing furnace 202 at this time, the effect of removing residual raw material gas will be further improved.

[0090] (Film forming process 3) In film formation step 3, oxygen-containing gas, which serves as the reaction gas, flows in. Specifically, valve v3, provided on branch pipe 82a of the first gas supply pipe 310, is opened, and valve v4, provided on branch pipe 82b, is closed. Oxygen-containing gas, whose flow rate is regulated by MFC 84a, is supplied from the first gas supply port 410a of the first nozzle 410 to the processing chamber 201 from the first gas supply pipe 310, while exhaust is simultaneously discharged from the exhaust pipe 231. Through the supply of oxygen-containing gas, the film on the wafer 200 reacts with the oxygen-containing gas to form an oxide film on the wafer 200.

[0091] It should be noted that when nitrogen-containing gas flows as the reaction gas, valve v1 provided on branch pipe 72a of the second gas supply pipe 320 is opened, and valve v2 provided on branch pipe 72b is closed. Nitrogen-containing gas, whose flow rate is regulated by MFC 74a, is supplied from the second gas supply port 420a of the second nozzle 420 to the processing chamber 201 from the second gas supply pipe 320, while exhaust is simultaneously discharged from the exhaust pipe 231. Through the supply of nitrogen-containing gas, the film on the wafer 200 reacts with the nitrogen-containing gas to form a nitride film on the wafer 200. Similarly, when forming an oxynitride film, in this process, as described above, oxygen-containing gas flows in from the first gas supply port 410a of the first nozzle 410, and nitride-containing gas flows in from the second gas supply port 420a of the second nozzle 420. For example, oxygen-containing gas and nitrogen-containing gas can be supplied simultaneously, or they can be supplied separately.

[0092] (Film forming process 4) In film formation step 4, after the oxide film is formed, valve v3 is closed at least, and vacuum pump 246, which serves as an exhaust device, is used to evacuate the processing chamber 201 to remove residual oxygen-containing gas that contributed to film formation. Furthermore, if an inactive gas, such as N2 gas used as a carrier gas, is supplied to the processing chamber 201 at this time, the effect of removing residual oxygen-containing gas from the processing chamber 201 will be further improved.

[0093] Furthermore, by treating the film formation processes 1 to 4 as one cycle and performing the film formation processes 1 to 4 a predetermined number of times, an oxide film of a predetermined thickness can be formed on the wafer 200. In this embodiment, the film formation processes 1 to 4 are repeated multiple times.

[0094] Here, the flow rate of the precursor gas switching from process (a) to process (b) is predetermined to make the flow rate of the processing gas flowing in process (b) of the first cycle equal to the flow rate of the processing gas in process (b) after the second cycle. It should be noted that the present invention is not limited to this configuration; the flow rate of the precursor gas switching from process (a) to process (b) can be smaller or larger than the saturation flow rate of process (b) of the first cycle. Furthermore, the switching from process (a) to process (b) is performed only in the first cycle. That is, after the second cycle, process (b) of film formation process 1 and film formation processes 2 to 4 are repeatedly performed.

[0095] It should be noted that the flow rate of the precursor gas after the second cycle is preferably set to be the same as the flow rate of the precursor gas at the end of step (a) of the first cycle.

[0096] Furthermore, before the film formation process 1 is executed, the concentration SV of the precursor gas used for substrate processing is set in the controller 121. The concentration SV can be input externally by the user or stored in the storage unit. If the concentration SV is set, the associated output quantity MV is set, the MFC96 controls the flow rate of the carrier gas, and the MFC99 ​​controls the flow rate of the dilution gas. Additionally, the concentration PV of the processing gas measured by the concentration meter 98 is output to the controller 121, and the output quantity MV' is set. Finally, the gas flow rate is controlled so that the set concentration SV becomes the gas concentration PV. At this time, as... Figure 6 As shown, the carrier gas, dilution gas, and gas concentrations are all close to constant (stabilized state).

[0097] like Figure 6 As shown, the flow rates of each gas are unstable in the first cycle. Therefore, in this embodiment, the processed gas is discarded in the exhaust pipe 340 in step (a). Therefore, there is a tendency for the time of the first cycle to become longer than that of subsequent cycles. It should be noted that in... Figure 6 In the diagram, solid lines represent precursor gases, dashed lines represent carrier gases, and dashed lines represent dilution gases. Additionally, Figure 6 The target value of the precursor gas in the middle is ±X%, where X is a value preset based on empirical values. Figure 7A This represents an example of the precursor gas converging to the target value. Figure 7B An example is shown where the flow rate of the processing gas supplied to the processing chamber 201 is the same in the first and second cycles.

[0098] In addition, Figure 6 In the diagram, the time it takes for the precursor gas to reach saturation is indicated by a double-dotted line. This is preferably related to the supply time of the processing gas after the second cycle. Figure 6 The middle is 60 seconds), which correspondingly makes the supply time of the first cycle consistent (area A = area B). Furthermore, the double-dotted line in the first cycle corresponds to the time of film formation step 1 in the process. On the other hand, by changing (adjusting) the time of film formation step 1 in the first cycle of the process each time, it is possible to make it approximately... Figure 7B The area shown is equal to the area B.

[0099] In addition, Figure 6 and Figure 7A The diagram illustrates steps (a), (b), and (c). When the flow rate of the upstream gas reaches saturation, the process switches from step (a) to step (b). After the switch, steps (b) and (c) are repeated.

[0100] After the above-described film formation process is completed, the pressure in the processing chamber 201 is restored to atmospheric pressure. Specifically, for example, an inactive gas such as N2 is supplied to the processing chamber 201 and exhaust is performed. As a result, the processing chamber 201 is purged by the inactive gas, and any gases remaining in the processing chamber 201 are removed (inactive gas purging). Afterwards, the atmosphere in the processing chamber 201 is replaced with an inactive gas (inactive gas replacement), and the pressure in the processing chamber 201 is restored to atmospheric pressure. Then, if the wafer 200 is removed from the processing chamber 201, the substrate processing of this embodiment is completed.

[0101] According to this method, one or more of the following effects can be obtained.

[0102] In this embodiment, firstly, the processing gas containing the precursor gas is exhausted from the raw material container 60 without passing through the processing chamber 201. Then, the processing gas containing the precursor gas is supplied to the processing chamber 201 at the point when the flow rate of the precursor gas reaches saturation. Therefore, a constant gas flow rate (or gas concentration) of precursor gas can be stably supplied to the processing chamber 201 without performing MFC-based flow control. Since the exhaust volume of the precursor gas can be controlled at an optimal level, the unnecessary consumption of expensive solid raw materials can be suppressed.

[0103] Furthermore, in this embodiment, when a preset threshold (e.g., gas flow rate) is reached, the processing gas containing the precursor gas can be switched from exhaust to supply to the processing chamber 201. Therefore, a continuous and stable supply of precursor gas to the processing chamber 201 can be achieved without performing MFC-based flow control. By setting the threshold in this way, a constant flow rate of precursor gas can be stably supplied to the processing chamber 201 in each cycle.

[0104] In addition, in this embodiment, by means of the piping heaters 71 and 73, the re-solidification of the precursor gas (or re-liquefaction if it is a liquid raw material) can be suppressed in the raw material container 60 and in the third gas supply pipe 330 from the raw material container 60 to the processing chamber 201.

[0105] Furthermore, in this embodiment, even for materials with extremely low vapor pressure that cannot be controlled by MFC, the flow rate (concentration adjustment) of the precursor gas to the processing chamber 201 can be adjusted due to the carrier gas supply method.

[0106] Furthermore, in this embodiment, the concentration of the precursor gas contained in the processing gas can be adjusted while suppressing the re-solidification (or re-liquefaction if it is a liquid raw material). Therefore, a continuous and stable supply of precursor gas to the processing chamber 201 can be achieved without performing MFC-based flow control.

[0107] Furthermore, in this embodiment, by utilizing the flow control of the carrier gas and the dilution gas, a constant concentration of precursor gas contained in the mixed gas used as the processing gas can be stably supplied to the processing chamber 201.

[0108] In addition, in this embodiment, in the case of unstable flow rate (e.g., vibration state) at the beginning of the supply of precursor gas, exhaust can be discharged from the third gas supply pipe 330 to the exhaust pipe 340, which can help to stably supply a constant concentration of precursor gas to the processing chamber 201.

[0109] In this embodiment, various solid raw materials containing metallic elements are supplied to the processing chamber 201 from the third gas supply pipe 330. For example, raw materials that contain metallic elements but do not contain carbon (C), i.e., inorganic metal-based raw materials (inorganic metal compounds), and are also halogen-based raw materials (also called halide raw materials) can be used. It should be noted that in this embodiment, the third gas supply pipe 330 is included in a gas supply system 100 configured to supply the processing chamber 201 with precursor gases obtained by forming various raw materials containing metallic elements into a gaseous state. Specifically, as the solid raw material 50, for example, a molybdenum (Mo)-containing material can be used. For example, MoCl5 gas, MoO2Cl2 gas, and MoOCl4 gas can be used.

[0110] As the carrier gas and dilution gas used in the above embodiments, N2 gas can be used, but it is not limited to this; Ar gas, He gas, Ne gas, Xe gas, etc., can also be used. Alternatively, a separate supply source for the dilution gas can be provided relative to the carrier gas supply source. In this case, the dilution gas and the carrier gas can be different gases.

[0111] In the aforementioned embodiments, such as Figure 6 As shown, the first cycle includes steps (a) and (b), but the invention is not limited to this configuration. Alternatively, it can be as follows... Figure 9 As shown, process (a) up to the double-dotted line (representing saturation) in Figure 7 is considered the first cycle, and the next process (B) is considered the second cycle. Processes (B) and (C) are repeated after the second cycle. It should be noted that alternatively, all the processed gas generated in the first cycle shown in Figure 7 can be exhausted, and then processes (b) and (c) can be repeated starting from the second cycle.

[0112] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit. For example, in the embodiments described above, the processing performed as a substrate processing apparatus is exemplified by film formation processing in semiconductor devices, but the present invention is not limited to this. That is, in addition to film formation processing, it can also be processing to form an oxide film, a nitride film, or a film containing a metal.

[0113] Furthermore, the specific content of substrate treatment is not limited. It is not limited to film formation treatment, but can also be appropriately applied to other substrate treatments such as annealing, oxidation, nitriding, diffusion, and photolithography.

[0114] Furthermore, the present invention can also be suitably applied to other substrate processing apparatuses, such as annealing apparatuses, oxidation apparatuses, nitriding apparatuses, exposure apparatuses, coating apparatuses, drying apparatuses, heating apparatuses, plasma-based processing apparatuses, and other substrate processing apparatuses. Additionally, in the present invention, these apparatuses can also be combined.

[0115] Furthermore, while semiconductor manufacturing processes have been described in this embodiment, the present invention is not limited thereto. For example, the present invention can also be applied to substrate processing such as manufacturing processes for liquid crystal devices, solar cells, light-emitting devices, glass substrates, ceramic substrates, and conductive substrates.

[0116] Furthermore, it is possible to replace a portion of the configuration of a certain embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of a certain embodiment. In addition, for a portion of the configuration of each embodiment, it is also possible to add, delete, or replace other configurations.

Claims

1. A gas supply method, having the following characteristics: Step (a) involves venting the processing gas, which contains the gas used to gasify the material, from a container holding the material without passing through a processing chamber; and In step (b), the process switches from step (a) at the point when the gas flow rate becomes saturated, and supplies the processing gas to the processing chamber.

2. The gas supply method according to claim 1, wherein, The flow rate of the processing gas switching from step (a) to step (b) is preset in such a way that the flow rate of the processing gas flowing in step (b) in the first cycle is the same as the flow rate of the processing gas in step (b) after the second cycle.

3. The gas supply method according to claim 1 or 2, wherein, The flow rate of the gas switched from process (a) to process (b) is less than the flow rate at saturation in process (b) during the first cycle.

4. The gas supply method according to claim 1 or 2, wherein, The flow rate of the gas switched from process (a) to process (b) is greater than the flow rate at saturation in process (b) during the first cycle.

5. The gas supply method according to any one of claims 1 to 4, wherein, The switch from process (a) to process (b) is performed only in the first cycle.

6. The gas supply method according to claim 5, wherein, It also includes a step (c) of stopping the supply of the processing gas to the processing chamber. After the second cycle, steps (b) and (c) are performed repeatedly.

7. The gas supply method according to claim 6, wherein, The gas flow rate after the second cycle is the same as the gas flow rate at the end of step (a) in the first cycle.

8. The gas supply method according to any one of claims 1 to 7, wherein, In steps (a) and (b), the container and the piping from the container to the processing chamber are heated to above the sublimation temperature or evaporation temperature of the material.

9. The gas supply method according to any one of claims 1 to 8, wherein, The material is a solid raw material with low vapor pressure.

10. The gas supply method according to any one of claims 1 to 9, wherein, An inlet for introducing carrier gas into the container is connected to the piping on the primary side of the container. In steps (a) and (b), a carrier gas supply method is applied to pressurize the processing gas by supplying the carrier gas from the inlet into the container.

11. The gas supply method according to any one of claims 1 to 10, wherein, A dilution section for supplying dilution gas is connected to the secondary side piping of the container. In steps (a) and (b), the dilution gas is mixed with the processing gas via the dilution section.

12. The gas supply method according to claim 11, wherein, The diluent gas is mixed at a temperature higher than that of the processing gas.

13. The gas supply method according to any one of claims 1 to 12, wherein, A concentration meter is installed on the secondary side piping of the container. In steps (a) and (b), the concentration of the gas contained in the processed gas is determined by the concentration meter.

14. The gas supply method according to claim 13, wherein, A dilution section for supplying dilution gas is connected to the secondary side piping of the container. The concentration meter is installed on a pipe downstream of the connection to the dilution section.

15. The gas supply method according to claim 14, wherein, The processing gas is a mixture of a carrier gas and the diluent gas. The concentration of the treated gas, as measured by the concentration meter, is the proportion of the gas contained in the mixed gas.

16. The gas supply method according to any one of claims 1 to 15, wherein, Downstream of the piping from the container to the processing chamber, an exhaust pipe branching off from the piping is provided. In step (a), the gas is discharged from the piping to the exhaust pipe via the exhaust pipe.

17. A method for manufacturing a semiconductor device, comprising: supplying a processing gas to the processing chamber using the gas supply method according to any one of claims 1 to 16, and processing a substrate disposed in the processing chamber.

18. A gas supply system comprising a control unit configured to perform the following processes: (a) exhausting a processing gas containing a gas used to make the material gaseous from a container containing material without passing through a processing chamber; and (b) supplying the processing gas to the processing chamber. The control unit is configured to switch the process (a) to the process (b) at the point when the flow rate of the gas reaches saturation.

19. A substrate processing apparatus comprising a control unit configured to supply the processing gas using the gas supply system of claim 18 and to process a substrate disposed in the processing chamber.

20. A process product that causes a substrate processing apparatus to perform the following steps: Step (a) is to exhaust the processing gas containing the gas that caused the material to become gaseous from the container containing the material without passing through the processing chamber. Step (b), supplying the processing gas to the processing chamber; and The switching step involves switching from step (a) to step (b) at the point when the gas flow rate reaches saturation.

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