Cleaning method, method for manufacturing semiconductor device, substrate processing apparatus, and recording medium

Abstract

The cleaning method is a method of cleaning a processing chamber in which a substrate is subjected to film formation processing, and includes: a heating step of heating the inside of the processing chamber in such a manner that the inside of the processing chamber to which a cleaning gas is supplied is divided into three or more regions in a gas flow direction, so that a temperature difference between a region on an upstream side in the gas flow direction in the processing chamber and a region adjacent to the region is made larger than a temperature difference between a region on a downstream side in the gas flow direction in the processing chamber and a region adjacent to the region; and a supply step of supplying the cleaning gas to the inside of the processing chamber after the heating step.

Description

Technical Field

[0001] This disclosure relates to cleaning methods, methods for manufacturing semiconductor devices, substrate processing apparatus, and recording media. Background Technology

[0002] As a step in the manufacturing process of semiconductor devices (appliances), a film formation process is sometimes performed where a raw material gas and a reactant gas are supplied to a substrate in a processing chamber to form a film on the substrate. During the film formation process, deposits containing film-forming materials may adhere to the inner surface of the processing chamber. Therefore, a method for cleaning the processing chamber by supplying a cleaning gas to the processing chamber of the substrate after the film formation process is known (see, for example, Japanese Patent Application Laid-Open No. 2007-13205 and Japanese Patent Application Laid-Open No. 2012-216696). Summary of the Invention

[0003] However, during the film formation process after cleaning, there is a situation where the treatment of each substrate becomes uneven.

[0004] The purpose of this disclosure is to provide a technique for making the treatment of each substrate nearly uniform in a post-cleaning substrate processing step.

[0005] Methods for solving problems

[0006] According to one aspect of this disclosure, a cleaning method is provided, which is a method for cleaning a processing chamber for film deposition on a substrate, comprising:

[0007] The heating process heats the aforementioned processing chamber in such a manner that the processing chamber to which the clean gas is supplied is divided into three or more zones in the airflow direction, such that the temperature difference between the zone upstream of the aforementioned processing chamber in the airflow direction and its adjacent zone becomes greater than the temperature difference between the zone downstream of the aforementioned processing chamber and its adjacent zone; and

[0008] The supply process involves supplying the aforementioned clean gas into the aforementioned processing chamber after the aforementioned heating process.

[0009] Invention Effects

[0010] According to this disclosure, it is possible to make the treatment of each substrate nearly uniform in the post-cleaning substrate processing step. Attached Figure Description

[0011] [ Figure 1 [This is a schematic configuration diagram of a substrate processing apparatus according to one embodiment of this disclosure.]

[0012] [ Figure 2 To show Figure 1The diagram shows the flow of clean gas in the processing furnace.

[0013] [ Figure 3 To show in Figure 1 The diagram shows the state of clean gas being supplied from the second nozzle into the processing chamber in the processing furnace.

[0014] [ Figure 4 This diagram illustrates the configuration of the control unit of a substrate processing apparatus according to one embodiment of this disclosure.

[0015] [ Figure 5 [This is a flowchart of a substrate processing procedure according to one embodiment of the present disclosure.]

[0016] [ Figure 6 [This is a graph showing the relationship between the cumulative film thickness and the film thickness variation rate in the processing chamber of the substrate processing apparatus in the comparative example.]

[0017] [ Figure 7 [This is a graph showing the relationship between the cumulative film thickness and the film thickness variation rate within the processing chamber of the substrate processing apparatus in the embodiment.]

[0018] [ Figure 8 [This is a longitudinal cross-sectional view of a processing furnace included in a substrate processing apparatus according to another embodiment of this disclosure.] Detailed Implementation

[0019] Hereinafter, one embodiment of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the drawings used in the following description are schematic, and the dimensional relationships and ratios of the elements shown in the drawings may not be consistent with the actual figures. Furthermore, the dimensional relationships and ratios of the elements may not be consistent among the various drawings.

[0020] <Substrate processing device>

[0021] Figure 1 The diagram illustrates the substrate processing apparatus 10 according to this embodiment. This substrate processing apparatus 10 is used for the manufacture of semiconductor devices. Specifically, the substrate processing apparatus 10 of this embodiment is configured as a batch vertical heat treatment apparatus.

[0022] like Figure 1 As shown, the substrate processing apparatus 10 of this embodiment includes a processing furnace 20. The processing furnace 20 includes a processing chamber 30, a processing gas supply system 40, a cleaning gas supply system 50, a heater 60 as a heating unit, and a controller 70 as a control unit.

[0023] (Processing Room)

[0024] like Figure 1As shown, the processing furnace 20 includes a reaction tube 32 that serves as a processing container. This reaction tube 32 is arranged axially (i.e., along the tube axis) within the processing furnace 20 in the vertical direction. Furthermore, the reaction tube 32 has an inner tube 34 and an outer tube 36.

[0025] The inner tube 34 is formed in a cylindrical shape (in this embodiment, it is cylindrical). The internal space of the inner tube 34 constitutes a processing chamber 30. The processing chamber 30 processes the wafer 200, which serves as a substrate. The processing chamber 30 is configured to accommodate a crystal boat 148, which serves as an example of a substrate holder. Using the crystal boat 148, described later, the wafer 200 can be held in a state where it is arranged in multiple layers in a horizontal orientation along the vertical direction.

[0026] In addition, the inner tube 34 is made of a heat-resistant material. Examples of materials that constitute the inner tube 34 include quartz (SiO2) and silicon carbide (SiC).

[0027] The outer tube 36 is formed as a closed-end cylindrical shape (in this embodiment, it is cylindrical). The outer tube 36 is arranged to surround the inner tube 34 radially outside the inner tube 34. Furthermore, the outer tube 36 and the inner tube 34 are arranged concentrically. Thus, as... Figure 1 As shown, a gap is formed between the inner tube 34 and the outer tube 36.

[0028] Furthermore, the outer tube 36 is formed of a heat-resistant material. Examples of materials constituting the outer tube 36 include quartz (SiO2) and silicon carbide (SiC). It should be noted that in this embodiment, the inner tube 34 and the outer tube 36 are formed of the same heat-resistant material, but this disclosure is not limited to this configuration.

[0029] Below the outer tube 36, a manifold 38 is provided concentrically with the outer tube 36. This manifold 38 is formed into a cylindrical shape with openings at both the upper and lower ends. Furthermore, the manifold 38 engages with the inner tube 34 and the outer tube 36, supporting them. For example, materials constituting the manifold 38 can be metallic materials such as nickel alloys or stainless steel, or heat-resistant materials such as quartz or SiC. It should be noted that an O-ring (not shown) is provided between the manifold 38 and the outer tube 36 as a sealing component. Furthermore, by supporting the manifold 38 on a support portion (not shown) of the processing furnace 20, the reaction tube 32 is mounted vertically with the vertical direction as its axial direction.

[0030] (Gas supply system)

[0031] The processing gas supply system 40 is configured to supply processing gas (raw material gas) into the processing chamber. The processing gas supply system 40 includes a first processing gas supply system 42 and a second processing gas supply system 44.

[0032] The first processing gas supply system 42 consists of at least one component. Figure 1 The structure shown comprises a nozzle 80 (serving as the first gas supply nozzle), a gas supply pipe 90, a valve 100, an MFC 110, and a valve 120. It should be noted that... Figure 1 The nozzle 81, gas supply pipe 91, valve 101, MFC 111, and valve 121 shown are connected to the first processing gas supply system 42 as the second gas supply nozzle. In addition, the first processing gas supply source 130 can also be connected to the first processing gas supply system 42.

[0033] Nozzle 80 is connected to the peripheral wall of manifold 38 and communicates with the processing chamber 30. Therefore, the first processing gas is supplied to the processing chamber 30 via nozzle 80. A gas supply pipe 90 is connected to the upstream end of the nozzle 80 in the flow direction of the first processing gas. On the gas supply pipe 90, starting from the upstream side in the flow direction of the first processing gas, a first processing gas supply source 130, a valve 120, an MFC (mass flow controller) 110 (serving as a gas flow controller), and a valve 100 are sequentially arranged. It should be noted that nozzle 80 is an example of the first nozzle described in this disclosure.

[0034] The nozzle 81 penetrates the peripheral wall of the manifold 38, extends from the lower side of the processing chamber 30 towards the upper side, and communicates with the interior of the processing chamber 30. Specifically, the nozzle 81 forms an L-shape, penetrating the peripheral wall of the manifold 38 and extending horizontally, bending midway, and extending from the lower side of the processing chamber 30 towards the upper side along the axial direction of the reaction tube 32. Additionally, as... Figure 3 As shown, in the vertical portion 81A of the nozzle 81 extending from the lower side to the upper side of the processing chamber 30, a plurality of injection ports 81B are provided at intervals along the extending direction of the vertical portion 81A (in this embodiment, the axial direction of the reaction tube 32). The first processing gas supplied to the nozzle 81 is supplied into the processing chamber 30 through the plurality of injection ports 81B. Here, the injection ports 81B are respectively formed in the portions of the vertical portion 81A corresponding to at least the middle region 30B and the upper region 30A in the processing chamber 30, so the first processing gas can be directly supplied to the middle region 30B and the upper region 30A of the processing chamber 30. A gas supply pipe 91 is connected to the upstream end of the flow direction of the first processing gas of the nozzle 81. On this gas supply pipe 91, starting from the upstream side of the flow direction of the first processing gas, a first processing gas supply source 130, a valve 121, an MFC (mass flow controller) 111 as a gas flow controller, and a valve 101 are sequentially arranged. It should be noted that nozzle 81 is an example of the second nozzle in this disclosure. It should also be noted that nozzle 81 is not necessarily required in this disclosure. By providing nozzle 81 and supplying the first processing gas from nozzle 81, the processing uniformity of each wafer 200 can be improved.

[0035] MFC110, valve 100 and valve 120, and MFC111, valve 101 and valve 121 are each electrically connected to the controller 70 described later (see [link]). Figure 4 The controller 70 is configured to control MFC110, valve 100 and valve 120, and MFC111, valve 101 and valve 121 respectively, such that the flow rate of the first processing gas supplied to the processing chamber 30 becomes a predetermined flow rate at a predetermined time.

[0036] The second processing gas supply system 44 consists of at least one component. Figure 1 The system shown comprises a nozzle 82, a gas supply pipe 92, a valve 102, an MFC 112, and a valve 122, which serve as the first gas supply nozzle. Additionally, a nozzle 83, a gas supply pipe 93, a valve 103, an MFC 113, and a valve 123, which serve as the second gas supply nozzle, can be added to the second processing gas supply system 44. Furthermore, a second processing gas supply source 131 can be added to the second processing gas supply system 44.

[0037] Nozzle 82 is connected to the peripheral wall of manifold 38 and communicates with the processing chamber 30. Therefore, the second processing gas is supplied to the processing chamber 30 via nozzle 82. A gas supply pipe 92 is connected to the upstream end of nozzle 82 in the flow direction of the second processing gas. On the gas supply pipe 92, starting from the upstream side in the flow direction of the second processing gas, a second processing gas supply source 131, a valve 122, an MFC (mass flow controller) 112 (serving as a gas flow controller), and a valve 102 are sequentially arranged. It should be noted that nozzle 82 is an example of the first nozzle described in this disclosure.

[0038] The nozzle 83 penetrates the peripheral wall of the manifold 38, extends from the lower side of the processing chamber 30 toward the upper side, and communicates with the interior of the processing chamber 30. Specifically, the nozzle 83 is formed in an L-shape, penetrating the peripheral wall of the manifold 38 and extending horizontally, bending midway, and extending upward along the axial direction of the reaction tube 32 from the lower side of the processing chamber 30. Additionally, as... Figure 3As shown, in the vertical portion 83A of the nozzle 83 extending from the lower side to the upper side of the processing chamber 30, a plurality of injection ports 83B are provided at intervals along the extending direction of the vertical portion 83A (in this embodiment, the axial direction of the reaction tube 32). The second processing gas supplied to the nozzle 83 is supplied into the processing chamber 30 through the plurality of injection ports 83B. Here, the injection ports 83B are respectively formed in the portions of the vertical portion 83A corresponding to at least the middle region 30B and the upper region 30A in the processing chamber 30, so that the first processing gas can be directly supplied to the middle region 30B and the upper region 30A of the processing chamber 30. A gas supply pipe 93 is connected to the upstream end of the flow direction of the second processing gas of the nozzle 83. On this gas supply pipe 93, from the upstream side of the flow direction of the second processing gas, a second processing gas supply source 131, a valve 123, an MFC (mass flow controller) 113 as a gas flow controller, and a valve 103 are sequentially arranged.

[0039] It should be noted that nozzle 83 is an example of the second nozzle in this disclosure. Furthermore, nozzle 83 is not necessarily required in this disclosure. By providing nozzle 83 and supplying the second processing gas from nozzle 83, the processing uniformity of each wafer 200 can be improved.

[0040] MFC112, valves 102 and 122, and MFC113, valves 103 and 123 are each electrically connected to controller 70 (see [link]). Figure 4 The controller 70 is configured to control MFC112, valve 102 and valve 122, and MFC113, valve 103 and valve 123 respectively, such that the flow rate of the second processing gas supplied to the processing chamber 30 becomes a predetermined flow rate at a predetermined time.

[0041] (Clean gas supply system)

[0042] The clean gas supply system 50 is configured to supply clean gas into the processing chamber 30. For example... Figure 1 As shown, the clean gas supply system 50 has a first clean gas supply system 52 and a second clean gas supply system 54.

[0043] The first clean gas supply system 52 mainly consists of a nozzle 80, a gas supply pipe 94, a valve 104, an MFC 114, and a valve 124. Additionally, a nozzle 81, a gas supply pipe 95, a valve 105, an MFC 115, and a valve 125 can be added to the first clean gas supply system 52. Furthermore, a clean gas supply source 132 can also be added to the first clean gas supply system 52.

[0044] like Figure 1As shown, a gas supply pipe 94 for supplying clean gas to the processing chamber 30 is connected between the valve 100 and the nozzle 80 of the gas supply pipe 90. On the gas supply pipe 94, starting from the upstream side in the direction of clean gas flow, a clean gas supply source 132, a valve 124, an MFC (mass flow controller) 114 as a gas flow controller, and a valve 104 are arranged in sequence.

[0045] Between valve 101 and nozzle 81 of gas supply pipe 91, a gas supply pipe 95 is connected for supplying clean gas into processing chamber 30. On gas supply pipe 95, starting from the upstream side of the flow direction of clean gas, a clean gas supply source 132, valve 125, MFC (mass flow controller) 115 as a gas flow controller, and valve 105 are arranged in sequence.

[0046] MFC114, valves 104 and 124, and MFC115, valves 105 and 125 are each electrically connected to controller 70 (see [link]). Figure 4 The controller 70 is configured to control MFC114, valve 104 and valve 124, and MFC115, valve 105 and valve 125 respectively, such that the flow rate of the clean gas supplied to the processing chamber 30 becomes a predetermined flow rate at a predetermined time.

[0047] The second clean gas supply system 54 comprises at least a nozzle 82, a gas supply pipe 96, a valve 106, an MFC 116, and a valve 126. Additionally, a nozzle 83, a gas supply pipe 97, a valve 107, an MFC 117, and a valve 127 may be added to the second clean gas supply system 54. Furthermore, a clean gas supply source 132 may be added to the second clean gas supply system 54.

[0048] like Figure 1 As shown, a gas supply pipe 96 for supplying clean gas to the processing chamber 30 is connected between valve 102 and nozzle 82 of gas supply pipe 92. On gas supply pipe 96, starting from the upstream side in the direction of clean gas flow, a clean gas supply source 132, valve 126, MFC (mass flow controller) 116 as a gas flow controller, and valve 106 are arranged in sequence.

[0049] Between valve 103 and nozzle 83 of gas supply pipe 93, a gas supply pipe 97 for supplying clean gas into processing chamber 30 is connected. On gas supply pipe 97, starting from the upstream side in the direction of clean gas flow, a clean gas supply source 132, valve 127, MFC (mass flow controller) 117 as a gas flow controller, and valve 107 are arranged in sequence.

[0050] MFC116, valves 106 and 126, and MFC117, valves 107 and 127 are each electrically connected to controller 70 (see [link]). Figure 4 The controller 70 is configured to control MFC116, valve 106 and valve 126, and MFC117, valve 107 and valve 127 respectively, such that the flow rate of the clean gas supplied to the processing chamber 30 becomes a predetermined flow rate at a predetermined time.

[0051] With this configuration, clean gas is supplied from the upstream side (lower side) to the downstream side (upper side) of the processing chamber 30.

[0052] It should be noted that in this embodiment, multiple clean gas supply systems use one clean gas supply source, but this disclosure is not limited to this configuration, and each clean gas supply system may also use its own clean gas supply source.

[0053] (Inactive gas supply system)

[0054] In addition, the processing furnace 20 is equipped with an inactive gas supply system 58. This inactive gas supply system 58 is configured to supply inactive gas into the processing chamber 30.

[0055] The inactive gas supply system 58 comprises at least a nozzle 82, a gas supply pipe 98, a valve 108, an MFC 118, and a valve 128. A nozzle 83, a gas supply pipe 99, a valve 109, an MFC 119, and a valve 129 can be added to the inactive gas supply system 58. Furthermore, an inactive gas supply source 133 can also be added to the inactive gas supply system 58.

[0056] like Figure 1 As shown, a gas supply pipe 98 for supplying inactive gas into the processing chamber 30 is connected between valve 102 and nozzle 82 of gas supply pipe 92. On gas supply pipe 98, starting from the upstream side in the flow direction of inactive gas, inactive gas supply source 133, valve 128, MFC (mass flow controller) 118 as gas flow controller, and valve 108 are arranged in sequence.

[0057] Between valve 103 and nozzle 83 of gas supply pipe 93, a gas supply pipe 99 for supplying inactive gas into processing chamber 30 is connected. On gas supply pipe 99, starting from the upstream side of the flow direction of inactive gas, inactive gas supply source 133, valve 129, MFC (mass flow controller) 119 as gas flow controller, and valve 109 are arranged in sequence.

[0058] MFC118, valves 108 and 128, and MFC119, valves 109 and 129 are each electrically connected to controller 70 (see [link]). Figure 4The controller 70 is configured to control MFC118, valve 108 and valve 128, and MFC119, valve 109 and valve 129 respectively, such that the flow rate of the clean gas supplied to the processing chamber 30 becomes a predetermined flow rate at a predetermined time.

[0059] As an inert gas, nitrogen (N2) can be used, for example.

[0060] (Exhaust system)

[0061] In addition, such as Figure 1 As shown, the processing furnace 20 includes an exhaust system 140. This exhaust system 140 is configured to exhaust the atmosphere inside the processing chamber 30. Furthermore, the exhaust system 140 mainly consists of an exhaust pipe 141, a pressure sensor 142, an APC valve 143, and a vacuum pump 144.

[0062] The exhaust pipe 141 is connected to the peripheral wall of the manifold 38. Furthermore, the exhaust pipe 141 is disposed at the lower end of the cylindrical space 37 formed by the gap between the inner pipe 34 and the outer pipe 36, and communicates with the cylindrical space 37. With this configuration, the exhaust pipe 141 exhausts air from the processing chamber 30 via the cylindrical space 37.

[0063] On the side of the exhaust pipe 141 opposite to the connection side of the manifold 38, a vacuum pump 144, which serves as a vacuum exhaust device, is provided via a pressure sensor 142, which acts as a pressure detector, and an APC valve 143, which acts as a pressure adjustment device.

[0064] Vacuum pump 144 is configured to exhaust air in such a way that the pressure inside processing chamber 30 reaches a predetermined pressure (vacuum level). Controller 70 is electrically connected to APC valve 143 and pressure sensor 142. Controller 70 is configured to control APC valve 143 at a desired time based on pressure information detected by pressure sensor 142, so that the pressure inside processing chamber 30 reaches the desired pressure.

[0065] With the above configuration, the first processing gas supplied from the first processing gas supply system, the second processing gas supplied from the second processing gas supply system, the clean gas supplied from the clean gas supply system, and the inactive gas supplied from the inactive gas supply system each rise within the internal space of the inner tube 34 (within the processing chamber 30), flow out from the upper opening of the inner tube 34 into the cylindrical space 37, flow down in the cylindrical space 37, and are then exhausted from the exhaust pipe 141 (see...). Figure 2 ).

[0066] Below the manifold 38, a sealing cap 146, serving as a furnace opening cover, is provided to airtightly seal the lower opening of the manifold 38. This sealing cap 146 abuts against the lower end of the manifold 38 from a vertical downward direction. Furthermore, the sealing cap 146 is formed in a disc shape. Materials used to construct the sealing cap 146 include, for example, stainless steel or other metallic materials. Additionally, an O-ring (not shown) serving as a sealing member, abuts against the lower end of the manifold 38 on the upper surface of the sealing cap 146.

[0067] A support platform 149 for supporting the crystal boat 148 is provided on the sealing cover 146. The support platform 149 is made of a heat-resistant material. Examples of materials that make up the support platform 149 include quartz and silicon carbide (SiC). The support platform 149 functions as a heat insulation part to prevent heat from the heater 60 from being transferred to the manifold 38 side.

[0068] As described above, the crystal boat 148 is configured to arrange and maintain multiple wafers 200 in a horizontal orientation and with their centers aligned, forming a multilayer structure. The crystal boat 148 is made of a heat-resistant material such as quartz or silicon carbide.

[0069] Additionally, on the lower side of the sealing cover 146, there is a rotating mechanism (not shown) for rotating the crystal boat 148 and a crystal boat lift (not shown) for raising and lowering the crystal boat 148. The rotating mechanism can rotate the crystal boat 148 within the processing chamber 30 by rotating. Furthermore, the crystal boat lift can move the crystal boat 148 in and out of the processing chamber 30 by raising and lowering.

[0070] (Heater)

[0071] The heater 60, which serves as the heating element, is cylindrical (in this embodiment, it is cylindrical in shape). It is arranged to surround the reaction tube 32 radially outside the reaction tube 32. Furthermore, the heater 60 and the reaction tube 32 are arranged concentrically.

[0072] like Figure 1As shown, the heater 60 is configured to divide the processing chamber 30 into three or more regions in the direction of clean gas flow and heat each region separately. Specifically, the heater 60 of this embodiment is divided into three sections axially, which are arranged from top to bottom as heater section 60A, heater section 60B, and heater section 60C. Each of these heater sections 60A, 60B, and 60C is controlled separately by a controller 70. Specifically, the controller 70 is configured to adjust the heating temperature of each heater section by controlling the power supply to the heater wires provided in each heater section (e.g., thyristor on / off control). Furthermore, the area of ​​the processing chamber 30 heated by heater section 60A is the upper region 30A of the processing chamber 30, the area of ​​the processing chamber 30 heated by heater section 60B is the middle region 30B of the processing chamber 30, and the area of ​​the processing chamber 30 heated by heater section 60C is the lower region 30C of the processing chamber 30. It should be noted that the upper region 30A is the region of the processing chamber 30 located downstream of the clean gas flow direction, the middle region 30B is the region of the processing chamber 30 located midway along the clean gas flow direction, and the lower region 30C is the region of the processing chamber 30 located upstream of the clean gas flow direction. Here, the downstream side of the airflow direction within the processing chamber 30 refers to the side closest to the exhaust system that exhausts the atmosphere from the processing chamber 30, and the upstream side of the airflow direction refers to the side opposite to the downstream side. Furthermore, the midway side of the airflow direction refers to the area near the midpoint between the downstream and upstream sides. That is, the upstream, midway, and downstream sides of the gas flow may not correspond to the positions of the respective regions of the heater 60.

[0073] like Figure 1 As shown, a temperature sensor, serving as a temperature detector, is installed in the cylindrical space 37 to detect the temperature inside the reaction tube 32. Specifically, a temperature sensor 62A is installed in the area of ​​the cylindrical space 37 heated by the heater section 60A, a temperature sensor 62B is installed in the area of ​​the cylindrical space 37 heated by the heater section 60B, and a temperature sensor 62C is installed in the area of ​​the cylindrical space 37 heated by the heater section 60C.

[0074] The controller 70 is electrically connected to heater sections 60A, 60B, and 60C, as well as temperature sensors 62A, 62B, and 62C. The controller 70 is configured to control the power supply to each heater section of the heater 60 at a desired time based on temperature information detected by each temperature sensor, so that the temperature within the processing chamber 30 achieves the desired temperature distribution.

[0075] (Controller)

[0076] The controller 70 is configured in the form of a computer. For example... Figure 4As shown, the computer has a CPU (Central Processing Unit) 121A, RAM (Random Access Memory) 121B, storage device 73, and I / O port 74.

[0077] RAM 72, storage device 73, and I / O port 74 are configured to exchange data with CPU 71 via internal bus 75. An input / output device 76 configured as, for example, a touch panel is connected to the controller 70.

[0078] The storage device 73 may be composed of, for example, flash memory or HDD (Hard Disk Drive). The storage device 73 stores, in a readable manner, control programs that control the operation of the substrate processing apparatus, and process procedures that record the substrate processing steps, conditions, etc., as described later.

[0079] The process flow is a combination of steps in the substrate processing procedure described later, which enables the controller 70 to execute the process flow and obtain the specified results, and functions as a program. Hereinafter, the process flow, control program, etc., will also be referred to as a program.

[0080] In this disclosure, the term "program" is used in cases where only the process technology is involved, cases where only the control program is involved, or cases where both are involved. RAM 72 is configured as a memory area (working area) that temporarily holds programs, data, etc., read by the CPU 71.

[0081] On I / O port 74 are connected valves 100-109, MFC (mass flow controller) 110-119, valves 120-129, pressure sensor 142, APC valve 143, vacuum pump 144, heater section 60A-60C of heater 60, temperature sensors 62A-62C, a rotating mechanism (not shown), and a crystal boat lift (not shown).

[0082] CPU 71 is configured to read and execute control programs from storage device 73, and to read process data from storage device 73 based on inputs such as operation commands from input / output device 76.

[0083] CPU 71 is configured to control the flow rate adjustment of various gases performed by MFCs 110-119, the opening and closing of valves 100-109 and 110-119, and the opening and closing of APC valve 143 according to the read process flow. Furthermore, CPU 71 is configured to control the pressure adjustment performed by APC valve 143 based on pressure sensor 142, the start and stop of vacuum pump 144, and the temperature adjustment of heaters 60 (each heater section 60A-60C) based on temperature sensors 62A-62C. In addition, CPU 71 is configured to control the rotation and speed adjustment of the crystal boat 148 using a crystal boat rotation mechanism, and the lifting and lowering of the crystal boat 148 using a crystal boat lift.

[0084] The controller 70 is not limited to being configured as a dedicated computer; it can also be configured as a general-purpose computer. For example, by preparing an external storage device 77 storing the aforementioned program, and using the external storage device 77 to install programs on a general-purpose computer, the controller 70 of this embodiment can be configured. Examples of external storage devices include hard disks such as hard disks, optical disks such as CDs, optical discs such as MO disks, and semiconductor memories such as USB memories.

[0085] However, the means of supplying programs to a computer are not limited to the case where the supply is made via external storage device 77. For example, communication means such as the Internet or dedicated lines can also be used to supply programs without the external storage device 77. Storage device 73 and external storage device 77 constitute a computer-readable recording medium. Hereinafter, they will also be referred to together as recording medium. In this disclosure, the term recording medium is used in cases that include only storage device 73, only external storage device 77, or both.

[0086] Furthermore, the controller 70 of this embodiment is configured to control each heater section 60A to 60C of the heater 60 so that the processing chamber 30 is heated in such a way that the temperature difference (T2) between the region located upstream in the airflow direction (lower region 30C) and the adjacent region (middle region 30B) in the processing chamber 30 becomes greater than the temperature difference (T1) between the region located downstream in the airflow direction (upper region 30A) and the adjacent region (middle region 30B). Moreover, the controller 70 is configured to maintain the temperature state (T2>T1) within the heated processing chamber 30 while controlling the clean gas supply system 50 to supply clean gas into the processing chamber 30.

[0087] <Substrate Processing>

[0088] Next, refer to Figure 5The following substrate processing step, which is a step in the manufacturing process of a semiconductor device, will be described. This substrate processing step is performed sequentially as follows: a film formation step, which forms a film on the wafer 200; a cleaning step, which removes film-forming material adhering to the inner surface of the processing chamber 30; and a pre-coating step, which forms a film of a specified thickness on the inner surface of the processing chamber 30. It should be noted that, in the following description, the operation of each part constituting the substrate processing apparatus 10 is controlled by the controller 70.

[0089] (Moving-in process)

[0090] In the loading process S210, wafers 200 are loaded into the processing chamber 30. Specifically, firstly, multiple wafers 200 are loaded into the wafer boat 148 (wafer loading). Then, as... Figure 1 As shown, a crystal boat 148, holding multiple wafers 200, is raised and loaded into the processing chamber 30 using a crystal boat lift (not shown). In this state, the sealing cover 146 seals the lower end of the manifold 38 by means of an O-ring (not shown).

[0091] During the loading process S210, an inert gas (nitrogen in this embodiment) is supplied to the processing chamber 30 to purge it. Specifically, the inert gas supplied from the inert gas supply source 133 to the gas supply pipe 98 by opening valves 108 and 128 is controlled to a predetermined flow rate by MFC 118 and then supplied to the processing chamber 30 via the nozzle 82 through the gas supply pipe 98. Additionally, the inert gas supplied from the inert gas supply source 133 to the gas supply pipe 99 by opening valves 109 and 129 is controlled to a predetermined flow rate by MFC 119 and then supplied to the processing chamber 30 via the nozzle 83 through the gas supply pipe 99. By supplying the inert gas to the processing chamber 30 in this manner, the processing chamber 30 is purged. It should be noted that the supply of inert gas to the processing chamber 30 continues until all substrate processing steps are completed.

[0092] (Film forming process)

[0093] In the film formation process S220, a film formation process is performed by heating the processing chamber 30 and supplying processing gas into the processing chamber 30 to form a film on the wafer 200. Specifically, firstly, vacuum pump 144 is used to exhaust vacuum from the processing chamber 30 to achieve a predetermined film formation pressure (vacuum). At this time, the pressure inside the processing chamber 30 is measured by pressure sensor 142, and the APC valve 143 is controlled based on this measured pressure information. Additionally, the processing chamber 30 is heated to a predetermined temperature using heater 60. At this time, the temperature inside the processing chamber 30 is controlled based on the temperature information detected by temperature sensors 62A-62C, and the power supply to the heater sections 60A-60C of heater 60 is controlled based on the temperature information detected by temperature sensors 62A-62C (S221). Next, the rotation of the boat 148 and the wafer 200 is initiated using a rotation mechanism (not shown).

[0094] While maintaining a specified film-forming temperature and pressure within the processing chamber 30, the first processing gas and the second processing gas are supplied to the processing chamber 30 (S222). Specifically, the first processing gas, supplied from the first processing gas supply source 130 to the gas supply pipe 90 by opening valves 100 and 120, is controlled to a specified flow rate by MFC 110 and then supplied to the processing chamber 30 through the gas supply pipe 90 from the nozzle 80. Additionally, the first processing gas, supplied from the first processing gas supply source 130 to the gas supply pipe 91 by opening valves 101 and 121, is controlled to a specified flow rate by MFC 111 and then supplied to the processing chamber 30 through the gas supply pipe 91 from the nozzle 81. The first gas is supplied to the processing chamber 30 in this manner.

[0095] On the other hand, the second processing gas supplied from the second processing gas supply source 131 to the gas supply pipe 92 by opening valves 102 and 122 is supplied to the processing chamber 30 through the gas supply pipe 92 from the nozzle 82 after being controlled to a predetermined flow rate by MFC 112. Additionally, the second processing gas supplied from the second processing gas supply source 131 to the gas supply pipe 93 by opening valves 103 and 123 is supplied to the processing chamber 30 through the gas supply pipe 93 from the nozzle 83 after being controlled to a predetermined flow rate by MFC 113.

[0096] At this time, the inactive gas supplied to the processing chamber 30 functions as a dilution gas for the film-forming gases (the first processing gas and the second processing gas) or as a carrier gas to promote diffusion into the processing chamber 30. By controlling the supply flow rate of the inactive gas, the concentration and diffusion rate of the film-forming gases (the first processing gas and the second processing gas) can be controlled.

[0097] The film-forming gases (first processing gas and second processing gas) supplied to the processing chamber 30 rise within the inner tube 34 (within the processing chamber 30) and flow out from the upper opening of the inner tube 34 into the cylindrical space 37. Then, the film-forming gases flow down from the cylindrical space 37 and are exhausted through the exhaust pipe 141. As the film-forming gases pass through the processing chamber 30, they contact the surface of the wafer 200. At this time, a thin film is deposited on the surface of the wafer 200 through a thermal CVD reaction. If a film of a predetermined thickness is formed on the wafer 200 after a preset processing time, valves 100-103 and valves 120-123 are closed, respectively, stopping the supply of film-forming gases to the processing chamber 30.

[0098] Then, with valves 108, 128, 109, and 129 kept open, inactive gas is continuously supplied to the processing chamber 30 while exhausting gas from the processing chamber 30, thereby purging the processing chamber 30. After replacing the atmosphere in the processing chamber 30 with inactive gas, the opening of APC valve 143 is adjusted to restore the pressure in the processing chamber 30 to atmospheric pressure. Then, the power supply to heater 60 is stopped, and the temperature in the processing chamber 30 is cooled to the specified temperature (wafer removal temperature) (S223).

[0099] Examples of processing conditions for the film-forming process (S220) involved in this embodiment include:

[0100] Film-forming temperature: 600℃~850℃ (preferably around 650℃~800℃)

[0101] The supply flow rate of the first processing gas is 10 sccm to 2000 sccm (preferably 50 sccm to 200 sccm).

[0102] The supply flow rate of the second processing gas is 100 sccm to 10000 sccm (preferably 500 sccm to 2000 sccm).

[0103] Film-forming pressure: 1 Pa to 2666 Pa (preferably below 133 Pa).

[0104] By maintaining each processing condition constant at a certain value within its respective range, a film (silicon nitride film) with a thickness of, for example, 10 nm to 200 nm is formed on the wafer 200.

[0105] It should be noted that silicon-containing gases can also be used as the first processing gas. For example, dichlorosilane (SiH2Cl2, abbreviated as DCS) gas can be cited as a silicon-containing gas.

[0106] It should be noted that nitrogen-containing gases can also be used as the second processing gas. For example, ammonia (NH3) can be used as a nitrogen-containing gas.

[0107] (Transfer process)

[0108] In the removal process S230, the processed wafer 200 is removed from the processing chamber 30. Specifically, after the wafer 200 undergoes film deposition, the rotation of the wafer boat 148 and the wafer 200, which is operated by a rotating mechanism, is stopped. Next, the sealing cover 146 is lowered using a wafer boat lift, opening the lower end of the manifold 38, and the wafer boat 148, holding the processed wafer 200, is moved outside the reaction tube 32 (wafer boat unloading). Then, the processed wafer 200 is removed from the wafer boat 148 (wafer removal).

[0109] It should be noted that in the film deposition process (S220), a film (silicon nitride film) is formed on the wafer 200 by a film deposition gas, but the same film deposition gas is also used to form a film on the inner surface of the inner tube 34 (in other words, the inner surface of the processing chamber 30). That is, the film forming material adheres to the inner surface of the processing chamber 30. Therefore, when the film deposition process is repeated, the thickness of the deposit (film forming material) adhering to the inner surface of the processing chamber 30 increases. Here, when the thickness of the deposit reaches a predetermined thickness, the cleaning process S260, which will be described later, is performed. Specifically, the increase in film thickness for each film deposition process is calculated in advance, and it is determined whether the film thickness (cumulative film thickness) after multiple film deposition processes has reached a predetermined thickness (S240). If it is determined in S240 that the film thickness after multiple film deposition processes has reached a predetermined thickness, the cleaning process S260 is performed.

[0110] (Empty crystal boat loading process)

[0111] In the empty wafer boat loading process S250, an empty wafer boat 148, i.e., a wafer boat 148 without wafers 200, is raised using a wafer boat elevator and loaded into the processing chamber 30 (wafer boat loading). In this state, the sealing cap 146 seals the lower end of the manifold 38 with an O-ring. It should be noted that the empty wafer boat 148 can be filled with a dummy wafer (not shown) that is not a finished product wafer.

[0112] (Cleaning process)

[0113] In the cleaning process S260, the processing chamber 30 is heated while maintaining the temperature inside the heated processing chamber 30, and a cleaning gas is supplied to the processing chamber 30 to remove deposits containing film-forming material adhering to the inner surface of the processing chamber 30. This is achieved by dividing the processing chamber 30, in the direction of the supplied cleaning gas flow, into three or more regions, such that the temperature difference T2 between the lower region 30C (located upstream in the flow direction) and the adjacent middle region 30B is greater than the temperature difference T1 between the upper region 30A (located downstream in the flow direction) and the adjacent middle region 30B. Specifically, firstly, vacuum exhaust is performed using a vacuum pump 144 to achieve a predetermined cleaning pressure (vacuum level) inside the processing chamber 30, and then heating is performed using a heater 60 to achieve a predetermined cleaning temperature inside the processing chamber 30 (S261). It should be noted that S261 is an example of the heating process described in this disclosure.

[0114] Here, the heating method within the processing chamber 30 using heater 60 is described in detail.

[0115] First, the processing chamber 30 is heated in the following manner: the processing chamber 30 is divided into three regions in the direction of the clean gas flow, such that the temperature difference T2 between the lower region 30C and the middle region 30B is greater than the temperature difference T1 between the upper region 30A and the middle region 30B. Specifically, the heating temperatures of the heater section 60A of the heater 60 corresponding to the upper region 30A, the heater section 60B of the heater 60 corresponding to the middle region 30B, and the heater section 60C of the heater 60 corresponding to the lower region 30C are adjusted so that the temperature difference T2 is greater than the temperature difference T1, thereby heating the processing chamber 30. It should be noted that the temperature difference T2 is preferably set to be 5 to 50 times the temperature difference T1.

[0116] Alternatively, when heating the treatment chamber 30, the temperature of the lower region 30C within the treatment chamber 30 can be lower than the temperature of the upper region 30A.

[0117] Furthermore, when heating the processing chamber 30, the processing chamber 30 can be heated in such a way that the temperature of the lower region 30C within the processing chamber 30 becomes lower than the temperature of the middle region 30B. That is, the processing chamber 30 can be heated in such a way that the temperature of the region located upstream in the airflow direction becomes lower than the temperature of the region located downstream in the airflow direction. Alternatively, the processing chamber 30 can be heated in such a way that the temperature of the region located upstream in the airflow direction becomes lower than the temperature of the region located midstream in the airflow direction.

[0118] Next, the crystal boat 148 is rotated using a rotating mechanism. It should be noted that, in this disclosure, the crystal boat 148 may also be rotated without rotation.

[0119] Next, while maintaining the temperature state inside the heated processing chamber 30 (temperature difference T2 is greater than temperature difference T1), cleaning gas is supplied to the processing chamber 30 to remove deposits containing film-forming material adhering to the inner surface of the processing chamber 30. Specifically, while maintaining the processing chamber 30 at a predetermined cleaning temperature and a predetermined cleaning pressure, cleaning gas is supplied to the processing chamber 30. The cleaning gas supplied from the cleaning gas supply source 132 to the gas supply pipes 90 and 91 respectively by opening valves 104 and 124 and valves 105 and 125 is controlled to a predetermined flow rate by MFCs 114 and 115 respectively, and then supplied to the processing chamber 30 through nozzles 80 and 81 via gas supply pipes 94 and 91 respectively. Simultaneously, the clean gas supplied from the clean gas supply source 132 to the gas supply pipes 96 and 97 by opening valves 106, 126, 107, and 127, respectively, is controlled to a predetermined flow rate by MFCs 116 and 117, and then supplied to the processing chamber 30 via nozzles 82 and 83 through gas supply pipes 96 and 97 (S262). It should be noted that S262 is an example of the supply process described in this disclosure.

[0120] The supply amount of cleaning gas can be controlled such that the etching rate (etching speed) of the deposits adhering to the inner surface of the processing chamber 30 is lower on the upstream side of the airflow direction within the processing chamber 30 (in other words, the lower side of the processing chamber 30 (lower region 30C)) than on the downstream side of the airflow direction within the processing chamber 30 (in other words, the upper side of the processing chamber 30 (upper region 30A)). Specifically, by adjusting the supply ratio of cleaning gas from the upstream side of the airflow direction within the processing chamber 30 (in other words, the middle side of the processing chamber 30 (middle region 30B)) to the nozzles 81 and 83 relative to the nozzles 80 and 82 supplying cleaning gas from the upstream side of the airflow direction, the etching rate of the deposits on the lower side of the processing chamber 30 can be made lower than that on the upper side of the processing chamber 30. Furthermore, the supply amount of cleaning gas can also be adjusted so that the etching rate of the deposits on the upper side of the processing chamber 30 is substantially the same as that on the middle side of the processing chamber 30.

[0121] At this time, the inactive gas supplied to the processing chamber 30 functions as a dilution gas for diluting the clean gas, or as a carrier gas to promote diffusion into the processing chamber 30. By controlling the supply flow rate of the inactive gas, the concentration and diffusion rate of the clean gas can be controlled.

[0122] The cleaning gas supplied to the processing chamber 30 rises within the inner tube 34 (within the processing chamber 30), flows out from the upper opening of the inner tube 34 into the cylindrical space 37, flows down within the cylindrical space 37, and is exhausted from the exhaust pipe 141. As the cleaning gas passes through the processing chamber 30, it comes into contact with deposits accumulated within the processing chamber 30 (in this embodiment, this is a nitride film, etc. Here, the nitride film is, for example, a silicon nitride film), and removes the deposits through a thermochemical reaction. That is, the cleaning gas, activated by heating, becomes an etching agent, etching and removing the silicon nitride film, etc., which are deposits accumulated in the processing chamber 30. It should be noted that in this embodiment, nozzles 80 to 84, which supply film-forming gas to the processing chamber 30, are used as nozzles for supplying cleaning gas to the processing chamber 30. With this configuration, the silicon nitride film adhering to the nozzles 80 to 84 can also be removed efficiently. After the preset processing time has elapsed and the silicon nitride film has been removed, valves 104-107 and 124-127 are closed to stop the supply of cleaning gas to the processing chamber 30.

[0123] Then, while keeping valves 108, 128, 109, and 129 open, inactive gas is continuously supplied into the processing chamber 30, and exhaust gas is vented into the processing chamber 30, thereby purging the processing chamber 30 (S263).

[0124] It should be noted that the processing conditions for the cleaning step (S260) involved in this embodiment can be exemplified as follows:

[0125] Cleaning temperature: 300℃~500℃ (preferably around 350℃~450℃)

[0126] Clean gas supply flow rate: 1 sccm to 20,000 sccm (preferably 1 sccm to 10,000 sccm)

[0127] Cleaning pressure: 1 Pa to 60,000 Pa (preferably 5,000 Pa to 20,000 Pa).

[0128] It should be noted that, as a cleaning gas, a gas containing a halogen element, specifically a gas containing a fluorine element, is preferred. Examples of fluorine-containing gases include F2, HF, NF3, and CF4. It should be noted that the cleaning gas preferably contains at least one of F2, HF, NF3, and CF4. In this disclosure, an example of using NF3 gas is described as an example.

[0129] (Pre-coating process)

[0130] In the pre-coating process S270, a pre-coating process is performed by heating the processing chamber 30 and supplying processing gas into the processing chamber 30 to form a film on the inner surface of the processing chamber 30. Specifically, immediately after the cleaning process S260, with an empty wafer boat 148 (not loaded with wafers 200) being moved into the processing chamber 30 (cuplet loading), vacuum is exhausted using a vacuum pump 144 at a predetermined pre-coating pressure (vacuum level) within the processing chamber 30, and heating is performed using a heater 60 at a predetermined cleaning temperature within the processing chamber 30 (S271). Next, the wafer boat 148 is rotated using a rotating mechanism. It should be noted that the pre-coating temperature can be set lower than the film formation temperature in the film formation process S220.

[0131] Then, the supply of the first processing gas into the processing chamber 30 begins (S272). The first processing gas, supplied from the first processing gas supply source 130 to the gas supply pipes 90 and 91 by opening valves 100 and 120, and valves 101 and 121 respectively, is then supplied into the processing chamber 30 from nozzles 80 and 81 after being controlled to a predetermined flow rate by MFCs 110 and 111 respectively. At this time, the inactive gas supplied into the processing chamber 30 functions either as a dilution gas to dilute the first processing gas or as a carrier gas to promote diffusion into the processing chamber 30.

[0132] The first processing gas supplied to the processing chamber 30 rises within the inner tube 34 (within the processing chamber 30), flows out from the upper opening of the inner tube 34 into the cylindrical space 37, flows down in the cylindrical space 37, and is exhausted from the exhaust pipe 141. As the first processing gas passes through the processing chamber 30, it contacts the inner wall of the processing chamber 30, the surface of the crystal boat 148, etc. At this time, when using DCS gas as the first processing gas, a silicon layer (Si layer) of less than one atomic layer to several atomic layers is formed on their surfaces. At this time, the maximum pressure inside the processing chamber 30 when the first processing gas is supplied can be greater than the maximum pressure inside the processing chamber 30 during the film deposition process S220. After the silicon layer formation is completed after a preset processing time, valves 100 and 120, as well as valves 101 and 121, are closed, stopping the supply of the first processing gas to the processing chamber 30.

[0133] Then, while keeping valves 108, 128, 109, and 129 open, inactive gas is continuously supplied into the processing chamber 30, and exhaust gas is vented into the processing chamber 30, thereby purging the processing chamber 30 (S273).

[0134] Then, the supply of the second processing gas into the processing chamber 30 begins (S274). The second processing gas, supplied from the second processing gas supply source 131 to the gas supply pipes 92 and 93 by opening valves 102 and 122, and valves 103 and 123 respectively, is then supplied into the processing chamber 30 through nozzles 82 and 83 after being controlled to a predetermined flow rate by MFCs 112 and 113 respectively. At this time, the inactive gas supplied into the processing chamber 30 functions either as a dilution gas to dilute the second processing gas or as a carrier gas to promote diffusion into the processing chamber 30.

[0135] The second processing gas supplied to the processing chamber 30 rises within the inner tube 34 (within the processing chamber 30), flows out from the upper opening of the inner tube 34 into the cylindrical space 37, flows down in the cylindrical space 37, and is exhausted from the exhaust pipe 141. As the second processing gas passes through the processing chamber 30, it comes into contact with the silicon layer formed on the inner surface of the processing chamber 30 and the surface of the crystal boat 148. When NH3 gas is used as the second processing gas, the silicon layer is nitrided, forming a silicon nitride layer (SiN layer) of less than one atomic layer to several atomic layers. At this time, the maximum pressure inside the processing chamber 30 when the second processing gas is supplied can be greater than the maximum pressure inside the processing chamber 30 during the film deposition process S220. After the nitriding of the silicon nitride layer is completed after a preset processing time, valves 102 and 122, as well as valves 103 and 123, are closed, stopping the supply of the second processing gas to the processing chamber 30.

[0136] Then, while keeping valves 108, 128, 109, and 129 open, inactive gas is continuously supplied into the processing chamber 30, and exhaust gas is vented into the processing chamber 30, thereby purging the processing chamber 30 (S275).

[0137] The above steps S272 to S275 are performed as one cycle, and this cycle is repeated at least once, thereby forming a silicon nitride film (pre-coated film) of a specified thickness on the inner surface of the processing chamber 30 and the surface of the crystal boat 148 (S276). The above cycle is preferably repeated multiple times.

[0138] It should be noted that when using silicon-containing gas as the first processing gas and nitrogen-containing gas as the second processing gas, the supply amounts of the first and second processing gases can be adjusted such that the ratio of silicon (Si) contained in the pre-coated film is equal to or greater than the ratio of silicon (Si) contained in the silicon nitride film formed on the wafer 200 in the film formation process S220.

[0139] Examples of processing conditions for the pre-coating step (S270) involved in this embodiment include:

[0140] Pre-coating temperature: 600℃~850℃ (preferably around 650℃~800℃)

[0141] The first processing gas supply flow rate is 10 sccm to 2000 sccm (preferably 50 sccm to 200 sccm).

[0142] The second processing gas supply flow rate is 100 sccm to 10,000 sccm (preferably 500 sccm to 2,000 sccm).

[0143] Film-forming pressure: 1 Pa to 2666 Pa (preferably below 133 Pa).

[0144] By maintaining each processing condition constant at a certain value within its respective range, a silicon nitride film (pre-coated film) with a thickness of, for example, 10 to 100 nm is formed on the inner surface of the processing chamber 30 and the surface of the crystal boat 148.

[0145] After performing the above-described cycle a specified number of times to form a silicon nitride film (pre-coated film) of a specified thickness, valves 108, 128, 109, and 129 are kept open, and inactive gas is continuously supplied to the processing chamber 30 while exhausting gas from the processing chamber 30, thereby purging the processing chamber 30. After the processing chamber 30 is replaced with inactive gas, the opening of APC valve 143 is adjusted to restore the pressure in the processing chamber 30 to atmospheric pressure. Then, the power supply to heater 60 is stopped, and the temperature in the processing chamber 30 is cooled to a specified temperature (crystal boat removal temperature) (S277).

[0146] It should be noted that the example shown here is of forming a pre-coated film through a cyclic process, but it is not limited to this. A pre-coated film can also be formed by a CVD film formation process that simultaneously supplies a first process gas and a second process gas.

[0147] (Empty crystal boat removal process)

[0148] In the empty crystal boat removal process S280, the empty crystal boat is moved to the outside of the reaction tube 32. Specifically, after the pre-coating process S270, the rotation of the crystal boat 148 using the rotating mechanism is stopped, and the sealing cover 146 is lowered using the crystal boat lift, thereby opening the lower end of the manifold 38 and moving the empty crystal boat 148 from the lower end of the manifold 38 to the outside of the reaction tube 32 (crystal boat unloading). Then, the above-described loading process S210 and film formation process S220 are performed sequentially.

[0149] <program>

[0150] One embodiment of this disclosure relates to a program that causes a controller 70, which is a computer, to perform the following steps:

[0151] The heating step heats the processing chamber 30 in such a way that the processing chamber 30, to which the clean gas is supplied, is divided into three or more regions in the airflow direction, such that the temperature difference (T2) between the region located upstream in the airflow direction (lower region 30C) and the adjacent region (middle region 30B) becomes greater than the temperature difference (T1) between the region located downstream in the airflow direction (upper region 30A) and the adjacent region (middle region 30B); and

[0152] The supply step maintains the temperature within the processing chamber 30, which has been heated by the heating step, while supplying clean gas into the processing chamber 30.

[0153] Next, the function and effects of this embodiment will be explained.

[0154] During the film formation process immediately after cleaning, a phenomenon occurs where the film thickness formed on the wafer 200 becomes thinner (the so-called film thickness reduction phenomenon). This is due to the fluorine (F) from the fluorine-containing gas used in cleaning remaining inside the processing chamber 30. Specifically, the cleaning gas reacts with deposits adhering to the inner surface of the processing chamber 30, and the components of the cleaning gas, along with the components of the deposits, are discharged to the outside of the reaction tube 32. Inside the reaction tube 32, there are areas with thick and thin deposits, but the supply of cleaning gas is adjusted according to the areas with thicker deposits. Therefore, in areas with thin deposits, the deposits disappear during cleaning, and the components of the cleaning gas remain in an adsorbed state without being discharged, or the components of the cleaning gas react with the surface of components disposed within the reaction tube 32 (e.g., the crystal boat 148), and the components of the cleaning gas remain on the surface of the components disposed within the reaction tube 32. Fluorine, a component of the cleaning gas remaining in the reaction tube 32, reacts with the film-forming gas (e.g., at least one of DCS gas and NH3 gas) used in the processing (film formation) of the wafer 200. As a result, the amount of film-forming gas reaching the wafer 200 decreases. Consequently, the film formed on the wafer 200 becomes thinner. This thinning phenomenon is particularly noticeable when film-forming gas is supplied from the lower to the upper side of the reaction tube 32. Therefore, there is a market demand for a production process capable of suppressing film thickness reduction in the wafer 200 during the immediate post-cleaning film formation process. In other words, uniform processing of each wafer 200 is required.

[0155] Therefore, in the cleaning process of this embodiment, the processing chamber 30 is heated and maintained at this temperature while cleaning gas is supplied to the processing chamber 30. This is achieved by dividing the processing chamber 30 into three or more regions in the airflow direction, such that the temperature difference T2 between the lower region 30C and the adjacent middle region 30B within the processing chamber 30 becomes greater than the temperature difference T1 between the upper region 30A and the adjacent middle region 30B. Consequently, the cleaning rate (cleaning amount) in the lower region 30C within the processing chamber 30 is slower compared to the cleaning rates (cleaning amounts) of the upper region 30A and the middle region 30B. That is, by lowering the temperature of the lower region 30C of the processing chamber 30, the consumption of cleaning gas (reaction amount, decomposition amount, etc.) in the lower region 30C can be reduced. This reduces the amount of fluorine generated in the lower region 30C of the processing chamber 30, suppressing the residue of fluorine after cleaning. Furthermore, by setting the aforementioned temperature conditions (T2>T1), unreacted cleaning gas can be stably supplied to both the middle region 30B and the upper region 30A within the processing chamber 30. This improves the cleaning uniformity of the airflow direction in the processing chamber 30. Consequently, obstacles to subsequent film formation are reduced, and film thickness reduction in the wafer 200 can be suppressed immediately after cleaning. In other words, the film thickness of the wafer 200 is stabilized. Therefore, the processing of each wafer 200 becomes nearly uniform.

[0156] By using halogen-based gases as cleaning gases, the cleaning time for deposits adhering to the inner surface of the treatment chamber 30 can be shortened.

[0157] Furthermore, by using a fluorine-containing gas, specifically one or more of F2, HF, NF3, and CF4, as the cleaning gas, the cleaning time for films containing Si and N (silicon nitride films) can be shortened.

[0158] In this embodiment, nozzles 80 and 82 can supply cleaning gas to the processing chamber 30 from the lower region 30C toward the upper region 30A. Therefore, cleaning can be performed from upstream to downstream in the airflow direction of the processing chamber 30. In other words, cleaning can be performed from the lower side to the upper side of the processing chamber 30.

[0159] In this embodiment, nozzles 81 and 83 can supply cleaning gas to the processing chamber 30 in the middle region 30B (upstream side) and the upper region 30A (downstream side). Therefore, unreacted cleaning gas can also be reliably supplied in the middle region 30B and the upper region 30A. As a result, cleaning can be performed substantially uniformly from the upstream side to the downstream side of the airflow direction in the processing chamber 30. In addition, the controllability of the cleaning atmosphere (conditions) from the upstream side to the downstream side of the airflow direction in the processing chamber 30 can be improved, and F residue from the upstream side to the downstream side of the airflow direction can be suppressed.

[0160] Furthermore, in the pre-coating process of this embodiment, the pre-coating process is performed under the condition that a silicon nitride film containing a higher silicon content ratio than the silicon nitride film formed in the film deposition process is formed. Specifically, the condition is set such that the supply ratio of the first processing gas in the pre-coating process is higher than the supply ratio of the first processing gas in the film deposition process. Here, the supply ratio refers to the supply ratio of the first processing gas to the second processing gas, including at least one of the gas supply flow rate and the supply time. For example, the supply flow rate of the first processing gas in the pre-coating process is greater than the supply flow rate of the first processing gas in the film deposition process. By supplying the first processing gas and the second processing gas in the above manner, the fluorine remaining in the reaction tube 32 can be removed, and the reduction in film thickness during the film deposition process can be suppressed. It should be noted that the first processing gas used in the pre-coating process can be the same gas used in the film deposition process, or a gas with a different molecular structure can be used.

[0161] Furthermore, in the pre-coating process of this embodiment, since the pre-coating treatment is performed at a pressure lower than that of the film-forming treatment, the exposure (contact time) between the first processing gas and the residual F can be increased. As a result, the residual F reacts with the DCS and is discharged. Consequently, the amount of F remaining in the processing chamber 30 can be reduced, and the film thickness reduction rate can be improved.

[0162] On the other hand, in the film formation process, by increasing the pressure compared to the pre-coating process, the exposure (contact time) of the first processing gas and residual F can be reduced, and even if F remains, the film thickness reduction phenomenon during wafer processing can be suppressed.

[0163] Figure 6 The graph shown illustrates the relationship between the cumulative film thickness (the thickness of the accumulated deposits) in the treatment chamber 30 and the film thickness variation rate in each zone 30A to 30C when the cleaning method of the comparative example was implemented. In the cleaning method of this comparative example, the temperature of each zone 30A to 30C was kept at the same temperature. Furthermore, Figure 7 The graph shown illustrates the relationship between the cumulative film thickness in the treatment chamber 30 and the rate of change of film thickness in each region 30A–30C when the cleaning method of the embodiment is implemented. Figure 7 In the cleaning method shown, since the temperature of each region 30A to 30C is controlled such that temperature difference T2 > temperature difference T1, the film thickness variation rate of each region 30A to 30C relative to the cumulative film thickness is reduced within the processing chamber 30. That is, in the cleaning method of the embodiment, it is known that the processing chamber 30 can be cleaned uniformly from upstream to downstream in the airflow direction, and F residue on the upstream side in the airflow direction can be suppressed.

[0164] In the above embodiments, an example of using DCS gas as the first processing gas has been described, but this disclosure is not limited thereto. As the first processing gas (raw material gas), for example, monochlorosilane (SiH3Cl, abbreviated as MCS), trichlorosilane (SiHCl3, abbreviated as TCS), tetrachlorosilane (SiCl4, abbreviated as STC), hexachlorodisilane (Si2Cl6, abbreviated as HCDS), octachlorotrisilane (Si3Cl8, abbreviated as OCTS), and other chlorosilane gases may also be used. One or more of these may be used as the raw material gas.

[0165] In addition to chlorosilane gases, other raw material gases such as tetrafluorosilane (SiF4) and difluorosilane (SiH2F2), bromosilane (SiBr4) and dibromosilane (SiH2Br2), and iodosilane (SiI4) and diiodosilane (SiH2I2) can also be used as raw material gases. One or more of these can be used as raw material gases.

[0166] In addition to the above, gases containing Si and amino groups, i.e., aminosilane gases, can also be used as feedstock gases. An amino group is a monovalent functional group obtained by removing hydrogen (H) from ammonia, primary amines, or secondary amines, and can be represented as -NH2, -NHR, or -NR2. It should be noted that R represents an alkyl group, and the two Rs in -NR2 can be the same or different.

[0167] For example, tetra(dimethylamino)silane (Si[N(CH3)2]4, abbreviated as 4DMAS) gas, tri(dimethylamino)silane (Si[N(CH3)2]3H, abbreviated as 3DMAS) gas, bis(diethylamino)silane (Si[N(C2H5)2]2H2, abbreviated as BDEAS) gas, bis(tert-butylamino)silane (SiH2[NH(C4H9)]2, abbreviated as BTBAS) gas, and (diisopropylamino)silane (SiH3[N(C3H7)2], abbreviated as DIPAS) gas, etc., can be used as feedstock gases. One or more of these can be used as feedstock gases.

[0168] In the above embodiments, an example of using NH3 gas as the second processing gas has been described, but this disclosure is not limited thereto. For example, diazoxide (N2H2), hydrazine (N2H4), N3H8, and other hydrogen nitride-based gases may also be used as the second processing gas (reaction gas). One or more of these may be used as the reaction gas.

[0169] In addition to the above, gases containing nitrogen (N), carbon (C), and hydrogen (H) can also be used as reactants. For example, amine gases and organic hydrazine gases can be used as gases containing N, C, and H. Gases containing N, C, and H are also gases containing N, C, H, and both N and C.

[0170] In addition, as reactant gases, for example, ethylamine gases such as monoethylamine (C2H5NH2, abbreviated as MEA), diethylamine ((C2H5)2NH, abbreviated as DEA), and triethylamine ((C2H5)3N, abbreviated as TEA) can be used; methylamine gases such as monomethylamine (CH3NH2, abbreviated as MMA), dimethylamine ((CH3)2NH, abbreviated as DMA), and trimethylamine ((CH3)3N, abbreviated as TMA) can be used; and organohydrazine gases such as monomethylhydrazine ((CH3)HN2H2, abbreviated as MMH), dimethylhydrazine ((CH3)2N2H2, abbreviated as DMH), and trimethylhydrazine ((CH3)2N2(CH3)H, abbreviated as TMH) can be used. One or more of these can be used as reactant gases.

[0171] In the above embodiments, an example of film deposition using a batch-type substrate processing apparatus that processes multiple substrates at a time as a vertical device has been described. However, this disclosure is not limited to this and can also be appropriately applied to cases where film deposition is performed using a monolithic substrate processing apparatus that processes one or several substrates at a time.

[0172] Furthermore, in the above-described embodiment, an inactive gas is supplied to the processing chamber 30 between substrate processing steps, but this disclosure is not limited to this configuration. For example, the controller 70 may appropriately adjust the supply amount of the inactive gas when purging the processing chamber 30 or to dilute the gas.

[0173] Furthermore, in the above embodiment, the processing chamber 30 is divided into three areas, but this disclosure is not limited to this configuration. The processing chamber 30 may also be divided into three or more areas. For example, Figure 8 The diagram shows a substrate processing apparatus 150 that divides the processing chamber 30 into five regions. In this substrate processing apparatus 150, the heater 154 of the processing furnace 152 consists of five heater sections 154A to 154E, and temperature sensors are respectively arranged in the portions corresponding to the heating areas of each heater section. These heater sections 154A to 154E and each temperature sensor are electrically connected to a controller 70. Using such a substrate processing apparatus 150, cleaning can be performed more uniformly from the upstream to the downstream side of the airflow direction in the processing chamber 30. It should be noted that... Figure 8In the middle section, heater section 154E is located on the upstream side of the gas flow, heater section 154A is located on the downstream side of the gas flow, and heater section 154C is located on the midstream side of the gas flow.

[0174] Explanation of reference numerals in the attached figures

[0175] 10 Substrate processing apparatus

[0176] 30 Processing Room

[0177] 30A Upper Region (the region located downstream of the airflow direction)

[0178] 30B Middle Region (the region located on the midstream side of the airflow direction)

[0179] Region below 30°C (the region located upstream of the airflow direction)

[0180] 40. Gas supply system

[0181] 50 Clean Gas Supply System

[0182] 60 heater

[0183] 60A Heater Section

[0184] 60B Heater Section

[0185] 60C heater section

[0186] 70 Controller (Control Unit)

[0187] 80 nozzles

[0188] 150 Substrate Processing Device

[0189] 152 processing furnace

[0190] 154 heater

[0191] 200 chips

[0192] S210 Handling Process

[0193] S220 film formation process

[0194] S230 Transfer Process

[0195] S260 Cleaning Procedure

[0196] S270 Pre-coating process

Claims

1. A cleaning method, which is a method for cleaning the processing chamber where a film is deposited on a substrate, having the following characteristics: The heating process heats the processing chamber in such a manner that the processing chamber, to which clean gas is supplied, is divided into three or more zones in the airflow direction, such that a first temperature difference between the zone upstream in the airflow direction and its adjacent zone becomes greater than a second temperature difference between the zone downstream in the airflow direction and its adjacent zone; and The supply process involves supplying the cleaning gas into the processing chamber after the heating process. Furthermore, while supplying the clean gas into the processing chamber, the temperature state in the heated processing chamber is maintained such that the first temperature difference is greater than the second temperature difference.

2. The cleaning method as described in claim 1, wherein, In the heating process, the processing chamber is heated in such a way that the temperature of the region located upstream of the airflow direction in the processing chamber becomes lower than the temperature of the region located downstream of the airflow direction.

3. The cleaning method as described in claim 1, wherein, In the heating process, the processing chamber is heated in such a way that the temperature of the region located upstream of the airflow direction in the processing chamber becomes lower than the temperature of the region located midstream of the airflow direction.

4. The cleaning method as described in claim 2, wherein, In the heating process, the processing chamber is heated in such a way that the temperature of the region located upstream of the airflow direction in the processing chamber becomes lower than the temperature of the region located midstream of the airflow direction.

5. The cleaning method as described in claim 1, wherein, In the heating process, the processing chamber is heated in such a way that the etching rate of the deposits attached to the inner surface of the processing chamber becomes lower on the upstream side of the gas flow direction in the processing chamber than on the downstream side of the gas flow direction in the processing chamber.

6. The cleaning method as described in claim 2, wherein, In the heating process, the processing chamber is heated in such a way that the etching rate of the deposits attached to the inner surface of the processing chamber becomes lower on the upstream side of the gas flow direction in the processing chamber than on the downstream side of the gas flow direction in the processing chamber.

7. The cleaning method as described in claim 3, wherein, In the heating process, the processing chamber is heated in such a way that the etching rate of the deposits attached to the inner surface of the processing chamber becomes lower on the upstream side of the gas flow direction in the processing chamber than on the downstream side of the gas flow direction in the processing chamber.

8. The cleaning method as described in claim 1, wherein, In the heating process, the processing chamber is heated in such a way that the etching rate of the deposits attached to the inner surface of the processing chamber becomes substantially the same on the downstream side of the airflow direction in the processing chamber and on the midstream side of the airflow direction in the processing chamber.

9. The cleaning method as described in claim 1, wherein, The deposits adhering to the inner surface of the processing chamber include a nitride film. The clean gas contains halogen elements.

10. The cleaning method as described in claim 1, wherein, The deposits adhering to the inner surface of the processing chamber contain a film containing Si and N. The cleaning gas contains fluorine.

11. The cleaning method as described in claim 1, wherein, The clean gas contains at least one gas selected from the group consisting of F2, HF, NF3 and CF4.

12. The cleaning method as described in claim 1, wherein, The clean gas is supplied from the upstream side of the processing chamber toward the downstream side.

13. The cleaning method as described in claim 1, wherein, Upstream of the processing chamber, a gas supply nozzle capable of supplying clean gas is connected. The cleaning gas is supplied to the upstream side of the processing chamber through the gas supply nozzle.

14. The cleaning method as described in claim 13, wherein, In the processing chamber, a second gas supply nozzle capable of supplying the cleaning gas is connected downstream of the processing chamber, relative to the first gas supply nozzle which serves as the gas supply nozzle. The cleaning gas is supplied to the upstream side of the processing chamber through the first gas supply nozzle, and to the downstream side of the processing chamber further downstream than the first gas supply nozzle through the second gas supply nozzle.

15. The cleaning method as described in claim 14, wherein, The second gas supply nozzle has: a portion extending from the upstream side of the processing chamber toward the downstream side; and a plurality of injection ports spaced apart in the extending portion in the extending direction. The cleaning gas is supplied to the processing chamber from an extension of the second gas supply nozzle through multiple injection ports.

16. The cleaning method of claim 1, further comprising a pre-coating step of performing a pre-coating treatment, wherein a first gas containing a first element and a second gas containing a second element are supplied after the supply step, thereby forming a film on the inner surface of the processing chamber in which the ratio of the first element is greater than or equal to the ratio of the first element in the film formed on the substrate by the film-forming treatment.

17. The cleaning method of claim 16, wherein, The pressure in the treatment chamber during the pre-coating process is lower than the pressure in the treatment chamber during the film-forming process.

18. A method for manufacturing a semiconductor device, the method comprising: The loading process involves loading the substrate into the processing chamber; The film-forming process involves heating the processing chamber and supplying processing gas into the processing chamber to form a film on the substrate. The removal process involves removing the processed substrate from the processing chamber. and The removal process involves heating the processing chamber and supplying a cleaning gas into the heated processing chamber to remove deposits containing film-forming material adhering to the inner surface of the processing chamber. This is achieved by dividing the processing chamber, in the direction of the airflow of the cleaning gas, into three or more regions, such that a first temperature difference between the region upstream of the airflow direction and its adjacent region becomes greater than a second temperature difference between the region downstream of the airflow direction and its adjacent region. Furthermore, while supplying the clean gas into the processing chamber, the temperature state in the heated processing chamber is maintained such that the first temperature difference is greater than the second temperature difference.

19. A substrate processing apparatus, comprising: The processing chamber is where the substrate is processed; A processing gas supply system that supplies processing gas to the processing chamber; A clean gas supply system that supplies clean gas into the treatment chamber; A heating unit capable of dividing the processing chamber into three or more zones in the direction of the clean gas flow and heating each zone separately; and The control unit controls the heating unit, the processing gas supply system, and the cleaning gas supply system. The control unit is configured to control the heating unit to heat the processing chamber in such a way that the first temperature difference between the region located upstream of the airflow direction and the region adjacent to that region becomes greater than the second temperature difference between the region located downstream of the airflow direction and the region adjacent to that region. Furthermore, it is configured to control the cleaning gas supply system to supply the cleaning gas into the heated processing chamber. Furthermore, the control unit is configured to maintain a temperature state in which the first temperature difference in the heated processing chamber is greater than the second temperature difference while supplying the clean gas to the processing chamber.

20. A computer-readable recording medium having recorded a program that enables a substrate processing apparatus to perform the following steps using a computer: The heating step heats the processing chamber in such a way that the processing chamber, to which the clean gas is supplied, is divided into three or more zones in the airflow direction, such that a first temperature difference between the zone upstream in the airflow direction and its adjacent zone becomes greater than a second temperature difference between the zone downstream in the airflow direction and its adjacent zone; and The supply step involves maintaining a temperature state where the first temperature difference in the heated processing chamber is greater than the second temperature difference, while supplying the clean gas into the processing chamber that has been heated by the heating step.

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