Detection method, substrate processing system, and control program

Abstract

A detection method is provided for detecting the opening and closing of the lid of a substrate receiving container in which multiple substrates processed by a substrate processing system are housed in multiple layers. The substrate processing system includes a loading module for transferring the substrates to and from the substrate receiving container. The loading module includes a loading port for placing the substrate receiving container. The loading port has a port door. The loading port is configured such that, in a first state where the lid of the substrate receiving container abuts against and engages with the port door, and the lid of the substrate receiving container is open, the interior of the substrate receiving container is in communication with the interior of the loading module. The loading port is also configured to allow movement of the interior of the substrate receiving container when the lid is engaged. The exhaust section is equipped with an exhaust flow measuring unit that measures the flow rate of gas exhausted from the interior of the substrate receiving container, i.e., the exhaust flow rate. The detection method includes: step (a), changing from a first state to a second state in which the cover of the substrate receiving container is closed; step (b), in the second state, releasing the contact between the port door and the cover, and moving the substrate receiving container in a direction away from the port door; and step (c), during the execution of steps (a) and (b), continuously venting the interior of the substrate receiving container and measuring the exhaust flow rate, thereby evaluating whether the closure of the cover of the substrate receiving container was performed normally.

Description

Technical Field

[0001] This disclosure relates to a detection method, a substrate processing system, and a control program. Background Technology

[0002] Patent Document 1 discloses a wafer processing system equipped with an optical sensor that detects the state of the FOUP cover falling off when the FOUP containing multiple wafers is separated from the loading port and unloaded.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-061436 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The technology disclosed herein is used to detect the open and closed states of the lid of a substrate containing container.

[0008] Solution for solving the problem

[0009] One aspect of this disclosure is a detection method for detecting the opening and closing of the lid of a substrate receiving container in which multiple substrates processed by a substrate processing system are housed in multiple layers. The substrate processing system includes a loading module for transferring the substrates to and from the substrate receiving container. The loading module includes a loading port for placing the substrate receiving container. The loading port has a port door. The loading port is configured such that, in a first state where the lid of the substrate receiving container abuts against and engages with the port door, and the lid of the substrate receiving container is open, the interior of the substrate receiving container is in communication with the interior of the loading module. The loading port is configured to, in the state where the substrate receiving container is engaged, move the lid of the substrate receiving container... The exhaust section for venting gas from the interior of the substrate housing container includes a flow rate measuring unit for measuring the flow rate of gas discharged from the interior of the substrate housing container, i.e., the exhaust flow rate. The detection method includes: step (a), changing from a first state to a second state in which the cover of the substrate housing container is closed; step (b), in the second state, releasing the contact between the port door and the cover, and moving the substrate housing container away from the port door; and step (c), during the execution of steps (a) and (b), continuously venting gas from the interior of the substrate housing container and measuring the exhaust flow rate, thereby evaluating whether the closure of the cover of the substrate housing container was performed correctly.

[0010] Invention Effects

[0011] According to this disclosure, it is possible to detect the open / closed state of the lid of the substrate containing container. Attached Figure Description

[0012] Figure 1 This is a top view showing an outline of the structure of the wafer processing system.

[0013] Figure 2 This is a perspective view showing a structural example of a front-opening wafer transfer box and loading port.

[0014] Figure 3 This diagram shows an example of a wafer transfer box abutting against the wafer transport port at the loading position.

[0015] Figure 4 This is a top view showing a structural example of the bottom of a front-opening wafer transfer box.

[0016] Figure 5 This is a top view showing an example of the structure of the base and stage in the loading port.

[0017] Figure 6 This is an explanatory diagram illustrating an example of a gas system that supplies purge gas inside a front-opening wafer transport box and discharges gas from the front-opening wafer transport box.

[0018] Figure 7 This is a schematic cross-sectional view showing an example of a front-opening wafer transfer box with its cover open and closed.

[0019] Figure 8 This is a schematic cross-sectional view showing an example of a front-opening wafer transfer box with its cover open and closed.

[0020] Figure 9 This is a schematic cross-sectional view illustrating an example of a state when a front-opening wafer transfer box is being loaded or unloaded relative to the loading port.

[0021] Figure 10 It is a timing diagram showing a structural example of the detection method and a schematic curve of the exhaust flow rate measured in each step of a state example.

[0022] Figure 11 This is a schematic graph showing the exhaust flow rate measured in each process of other state examples. Detailed Implementation

[0023] In the manufacturing process of semiconductor devices, it is required to maintain the cleanliness of semiconductor wafers (hereinafter referred to as "wafers") and the various wafer processing devices that process the wafers. For this purpose, a method is used to maintain a high level of cleanliness inside a substrate housing container called a so-called front-opening unified pod (FOUP) that houses multiple wafers when transferring wafers from external wafer processing devices.

[0024] The aforementioned substrate container is configured to house multiple wafers in parallel layers, and to allow wafer transfer through an opening formed on one side of the substrate container. The interior of the substrate container is sealed with a highly clean nitrogen gas to prevent particulate contaminants from entering the substrate container.

[0025] The substrate receiving container has a cover that can be opened and closed to insert and remove wafers. The cover is opened when the substrate receiving container comes into contact with the loading port, allowing for wafer transfer with the loading module in this state. The cover is closed before the substrate receiving container is released from contact with the loading port.

[0026] When separating the substrate container, the lid may not close completely due to deformation of the substrate container or loosening of the locking key used to lock the lid in place with the main body of the substrate container. Patent Document 1 discloses a photosensitive sensor for detecting lid detachment during separation of the substrate container and subsequent unloading.

[0027] However, placing the sensor at the loading port increases the device cost. Furthermore, even when the cover is partially closed, it doesn't necessarily fall completely, making detection difficult for the optical sensor. Therefore, there is room for improvement in conventional wafer transport devices.

[0028] From this perspective, the inventors of the present invention, after in-depth research, conceived of the following method of the reference example: before separating the substrate receiving container, after locking the cover of the substrate receiving container, the opening and closing mechanism (port door) on the loading port side is retracted to detect opening and closing. In this method of the reference example, if the cover is not properly locked and thus not fully closed, when the port door is retracted, the locking key hooks the cover and causes the cover to fall off, thereby detecting the incomplete closure of the cover. When using other front-opening wafer transfer boxes that do not have the structure capable of supplying N2 gas in the front-opening wafer transfer box 31 of the embodiment described later, the detection method involved in the embodiment described later cannot be implemented. Therefore, from the viewpoint of being able to detect the incomplete closure of the cover, the method of the reference example is effective when performing opening and closing detection for such other front-opening wafer transfer boxes, but there are problems related to maintaining cleanliness in the event that the cover falls into the loading module.

[0029] In view of the aforementioned issues and methods of the reference examples, the technology disclosed herein detects the open / closed state of the lid of a substrate receiving container. The open / closed state of the lid includes not only a lid that has fallen off, but also a lid that is not fully closed.

[0030] The wafer processing system and the method for detecting the opening and closing of the cover, which is the substrate processing system according to this embodiment, will now be described with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, elements having substantially the same functional structure are omitted from repeated description by using the same reference numerals.

[0031] <Structure of a Wafer Processing System>

[0032] First, the structure of the wafer processing system, which is the substrate processing system according to this embodiment, will be described. Figure 1 This is a top view showing an outline of the structure of the wafer processing system 1. In the wafer processing system 1, desired processes such as film deposition and etching are performed on the wafer W, which serves as a substrate, under a reduced pressure atmosphere (vacuum atmosphere). Furthermore, the structure of the wafer processing system 1 disclosed herein is not limited to this and can be arbitrarily selected.

[0033] like Figure 1 As shown, the wafer processing system 1 has a structure in which an atmospheric pressure section 10 and a depressurization section 11 are connected as one unit via load-interlocking vacuum modules 20a and 20b. In the atmospheric pressure section 10, a front-opening wafer transfer box 31 (described later), which serves as a substrate receiving container capable of holding multiple wafers W, is transported under an atmospheric pressure atmosphere (atmospheric atmosphere), and wafers W are transported to the load-interlocking vacuum modules 20a and 20b. In the depressurization section 11, the wafers W are processed as desired under a depressurization atmosphere (vacuum atmosphere), and wafers W are transported to the load-interlocking vacuum modules 20a and 20b.

[0034] The loading interlock vacuum module 20a has a stage 21a for placing the wafer W inside. The loading interlock vacuum module 20a temporarily holds the wafer W on the stage 21a in order to transfer the wafer W from the loading module 30 (described later) of the atmospheric pressure section 10 to the transfer module 40 (described later) of the depressurization section 11.

[0035] The loading interlock vacuum module 20a is connected to the loading module 30 (described later) via gate valve 22a. Additionally, the loading interlock vacuum module 20a is connected to the transfer module 40 (described later) via gate valve 23a. These gate valves 22a and 23a ensure both airtightness and interconnectivity between the loading interlock vacuum module 20a, the loading module 30, and the transfer module 70.

[0036] The loading interlock vacuum module 20a is connected to a gas supply section (not shown) for supplying gas and a gas exhaust section (not shown) for discharging gas, configured to switch the internal atmosphere of the loading interlock vacuum module 20a between atmospheric pressure and reduced pressure using the gas supply section and the exhaust section. That is, the loading interlock vacuum module 20a is configured to allow appropriate transfer of wafer W between the atmospheric pressure section 10 (atmospheric pressure atmosphere) and the reduced pressure section 11 (reduced pressure atmosphere).

[0037] Furthermore, the loading interlock vacuum module 20b has the same structure as the loading interlock vacuum module 20a. That is, the loading interlock vacuum module 20b has a stage 21b for mounting the wafer W, a gate valve 22b on the loading module 30 side, and a gate valve 23b on the transfer module 40 side.

[0038] Furthermore, the number and configuration of the interlocked vacuum modules 20a and 20b are not limited to this embodiment and can be set arbitrarily.

[0039] The atmospheric pressure section 10 has a loading module 30 equipped with a wafer transfer device 33 and a loading port 32 for mounting a front-opening wafer transfer box 31 capable of holding multiple wafers W. Furthermore, the loading module 30 is also referred to as an EFEM (EpuipmentFront End Module).

[0040] The loading module 30 is constructed from a generally rectangular housing, the interior of which is maintained at a pressure higher than the ambient atmosphere outside the wafer processing system 1. Multiple, for example, three loading ports 32 are arranged side-by-side on one long side of the housing constituting the loading module 30. Figure 1The figure shows a loading port 32 on the left and center sides with a front-opening wafer transfer box 31, while the loading port 32 on the right side is not equipped with a front-opening wafer transfer box 31. Loading interlock vacuum modules 20a and 20b are arranged side-by-side on the other side of the long side of the housing constituting the loading module 30. Furthermore, the loading module 30 has a wafer transport device 33 that can move along its long side inside the housing. The wafer transport device 33 can transfer wafers W between the front-opening wafer transfer box 31 placed at the loading port 32 and the loading interlock vacuum modules 20a and 20b. Details of the structure of the front-opening wafer transfer box 31 and the loading port 32 will be described later.

[0041] The decompression unit 11 includes a transfer module 40 for transporting the wafer W and a processing module 41 as a substrate processing apparatus for performing the desired processing on the wafer W. The interiors of the transfer module 40 and the processing module 41 are maintained in a decompression atmosphere. Multiple processing modules 41, for example, are provided for the transfer module 40. Furthermore, the transfer module 40 is also referred to as a VTM (Vacuum Transfer Module).

[0042] The transfer module 40 consists of a housing that is polygonal in top view and hexagonal in the illustrated example. As described above, it is connected to the load-interlocking vacuum modules 20a and 20b via gate valves 23a and 23b. Specifically, load-interlocking vacuum modules 20a and 20b and four processing modules 41 are arranged on each side of the transfer module 40. Furthermore, the wafer W to be transferred to the load-interlocking vacuum module 20a is sequentially transferred by the transfer module 40 to one processing module 41 for the desired processing, and then transported out to the atmospheric pressure section 10 via the load-interlocking vacuum module 20b.

[0043] Inside the transfer module 40 is a wafer transfer device 50 that transfers wafer W between the load interlock vacuum modules 20a and 20b, the transfer module 40 and the processing module 41.

[0044] A stage 42 for mounting the wafer W is provided inside the processing module 41. The processing module 41 performs desired processes on the wafer W mounted on the stage 42, such as film deposition and etching. In addition, the processing module 41 is connected to a gas supply section (not shown) for supplying processing gas, purge gas, etc., and an exhaust section (not shown) for discharging gas.

[0045] In addition, the processing module 41 is connected to the transmission module 40 via a gate valve 43. This gate valve 43 ensures both airtightness between the transmission module 40 and the processing module 41 and allows for communication between them.

[0046] Furthermore, the number, configuration, and types of processing modules 41 provided in the transmission module 40 are not limited to this embodiment and can be arbitrarily set.

[0047] A control unit 60 is provided for the wafer processing system 1 described above. The control unit 60 processes computer-executable instructions that cause the wafer processing system 1 to execute the various processes described herein. The control unit 60 can be configured to control the various elements of the wafer processing system 1 to execute the various processes described herein. In one embodiment, part or all of the control unit 60 may be included in the wafer processing system 1. The control unit 60 may also include a processing unit, a storage unit, and a communication interface. The control unit 60 is implemented, for example, by a computer. The processing unit may be configured to perform various control actions by reading a program from the storage unit and executing the read program. The program may be pre-stored in the storage unit or retrieved via a medium when needed. The retrieved program is stored in the storage unit, and the processing unit reads and executes the program from the storage unit. The medium may be various computer-readable storage media or a communication line connected to the communication interface. The processing unit may be a CPU (Central Processing Unit). The storage unit can be transient or non-transient, and may include RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface can communicate with the wafer processing system 1 via a communication line such as a LAN (Local Area Network).

[0048] <Front-opening wafer transfer box and loading port>

[0049] Figure 2 This is a perspective view showing a structural example of a front-opening wafer transfer box 31 and a loading port 32. Figure 3 It is a cross-sectional view cut along a direction perpendicular to the long side of the loading module, and is a diagram showing an example of the state in which the open wafer transfer box 31 and the wafer transfer port 70 abut (connect) at the loading position. Figure 4 This is a top view showing a structural example of the bottom of the front-opening wafer transfer box 31. Figure 5 This is a top view showing an example of the structure of the base 71 and the stage 72 in the loading port 32.

[0050] like Figure 2As shown, the loading port 32 includes a wafer transfer port 70, a base 71, a stage (placement stage) 72 mounted on the base 71 for placing the front-opening wafer transfer box 31, and a port door 73 that closes the wafer transfer port 70. The stage 72 moves forward and backward along a guide rail 74 extending in the front-rear direction via a stage moving mechanism (not shown). Through the forward and backward movement of the stage 72, the front-opening wafer transfer box 31 moves between an unloading position (reverse position) and a loading position (forward position). The front-opening wafer transfer box 31 is shown in the unloading position. The front-opening wafer transfer box 31 is moved onto the stage 72 in the unloading position while being held by a suitable transfer device (not shown). Then, the stage 72 is moved forward, and the front-opening wafer transfer box 31 is connected to the loading module 30 in the loading position, enabling the transfer of wafers W using the wafer transfer device 33. The wall surface of the loading module 30, excluding the wafer transfer port 70, is referred to as the partition wall 75. The port door 73 is equipped with a locking key 76 that locks the front-opening wafer transfer box 31 to the cover 80, as described later.

[0051] like Figure 3 As shown, the front-opening wafer transfer box 31 has a box-like shape with a front opening and a cover 80 that seals the opening. Furthermore, in the following description, when the front-opening wafer transfer box 31 is connected to the wafer transport port 70, the cover 80 is connected to the port door 73. The bottom 31a of the front-opening wafer transfer box 31 is configured to be supported by a stage 72.

[0052] A desired engaging member (not shown) is provided on the stage 72, which engages (locks) the stage 72 and the front-opening wafer transfer box 31 at a desired position. A support mechanism corresponding to the mechanism of the engaging member is provided on the front-opening wafer transfer box 31. That is, "locking" the front-opening wafer transfer box 31 and the stage 72 means that the engagement control achieved by the mechanism of the engaging member of the stage 72 acting on the support mechanism of the front-opening wafer transfer box 31 is completed. Conversely, "releasing" means that the engagement control achieved by the mechanism of the engaging member of the stage 72 acting on the support mechanism of the front-opening wafer transfer box 31 is completed. The stage 72 may also have a desired positioning pin (not shown), configured to guide the front-opening wafer transfer box 31 to an accurate position during locking.

[0053] The cover 80 has a fitting member (not shown) configured to be hermetically sealed when the cover 80 is in close contact with the front-opening wafer transfer box 31. A keyhole (not shown) is provided at a position facing the locking key 76 when the cover 80 is in contact with the port door 73. The cover 80 and the front-opening wafer transfer box 31 have a desired locking mechanism (not shown), configured such that when the locking key 76 is engaged in the keyhole, the action of the locking key 76 moves the fitting member, thereby locking the cover 80 relative to the front-opening wafer transfer box 31. That is, "locking" the cover 80 relative to the front-opening wafer transfer box 31 means that the control of a series of actions to move the fitting member to lock the cover 80 relative to the front-opening wafer transfer box 31 is completed. Conversely, "unlocking" means that the control of a series of actions to move the fitting member to release the locked state of the cover 80 relative to the front-opening wafer transfer box 31 is completed. Furthermore, the port door 73 is configured to open and close freely via a drive mechanism (not shown). Therefore, by opening and closing the port door 73 with the port door 73 in contact with the cover 80 and the locking key 76 engaged in the keyhole, the cover 80 can be opened and closed.

[0054] The front-opening wafer transfer box 31 houses, for example, 25 wafers W processed by a wafer processing unit. Each wafer W is arranged horizontally and at equal intervals in multiple layers within the front-opening wafer transfer box 31.

[0055] like Figure 4 As shown, three gas supply ports 90 and one gas exhaust port 91 are provided at the bottom 31a of the front-opening wafer transfer box 31. In this embodiment, two of the gas supply ports 90 are located on the side opposite to the cover 80, and one is located on the side of the cover 80. The gas exhaust port 91 is located on the side of the cover 80.

[0056] like Figure 5 As shown, a through hole 100 is provided on the stage 72 at a position corresponding to the gas supply port 90 and gas exhaust port 91 provided on the front-opening wafer transfer box 31. Gas supply connectors 101 are provided on the base 71 at positions corresponding to the gas supply port 90 of the front-opening wafer transfer box 31. A flexible gas supply tube 102 is connected to the gas supply connector 101. A gas supply source (not shown) is connected to the other end of the gas supply tube 102, configured to supply dried purge gas, such as N2 gas, via the gas supply tube 102. Additionally, an exhaust connector 104 is provided on the base 71 at a position corresponding to the gas exhaust port 91 of the front-opening wafer transfer box 31. A flexible exhaust tube 105 is connected to the exhaust connector 104.

[0057] The gas supply connector 101 and the exhaust connector 104 are configured to be raised and lowered via a lifting mechanism (not shown) such as a cylinder. An annular sealing member (not shown) is provided at the front end of both the gas supply connector 101 and the exhaust connector 104. With this structure, by raising the gas supply connector 101, it can connect with the gas supply port 90 of the front-opening wafer transfer box 31 to supply purge gas into the front-opening wafer transfer box 31. Furthermore, by raising the exhaust connector 104, it can connect with the gas exhaust port 91 of the front-opening wafer transfer box 31 to exhaust gas from the front-opening wafer transfer box 31.

[0058] Figure 6 This is an explanatory diagram illustrating a structural example of a gas system configured to supply purge gas to and discharge gas from the front-opening wafer transfer box 31 according to this embodiment. A gas supply port 90 is connected via a gas supply pipe 102 to a gas supply source 110 that supplies gas, such as dry nitrogen, as the purge gas. A valve V1 is provided in the gas supply pipe 102 to control the supply and stop of gas from the gas supply source 110. The gas supply pipe 102 branches into two downstream of the valve V1. Each gas supply pipe 102 after the branch is provided with a shut-off valve V2 and a shut-off valve V3, respectively. A flow controller 111 is provided in each gas supply pipe 102 after the branch, and the flow controller 111 controls the supply of purge gas to each gas supply port 90 at a desired flow rate.

[0059] An exhaust mechanism 112 is connected to the gas exhaust port 91 via an exhaust pipe 105, enabling the exhaust of gas supplied from each gas supply port 90. A flow meter 120, serving as a flow measurement unit according to this embodiment, is provided in the exhaust pipe 105, capable of measuring the flow rate of the exhaust gas flowing through the exhaust pipe 105. The flow rate measured by the flow meter 120 is, for example, sent to the control unit 60.

[0060] return Figure 3 A distribution pipe 121 extending vertically upward within the front-opening wafer transfer box 31 is provided at two gas supply ports 90 located on the side opposite to the cover 80. In the distribution pipe 121, a slit-like opening (not shown) is formed at a height corresponding to the gap between each wafer W on the surface facing the wafer W, allowing gas supplied from the gas supply ports 90 to be evenly distributed between each wafer W. This creates an airflow inside the front-opening wafer transfer box 31 that flows uniformly from inside the box to the cover 80 and between the wafers W. Consequently, even when the cover 80 is open, this airflow prevents atmospheric air from inside the loading module 30 from flowing into the front-opening wafer transfer box 31.

[0061] Furthermore, the configuration of the gas supply port 90 and the gas exhaust port 91, and whether or not a distribution pipe 121 needs to be installed, are not limited to this embodiment. They can be set arbitrarily; for example, two gas supply ports 90 and two gas exhaust ports 91 can each be provided.

[0062] Furthermore, the number and configuration of the loading ports 32 are not limited to this embodiment and can be arbitrarily set. Alternatively, a processing module that performs desired processing on the wafer W under atmospheric pressure, such as an alignment process that adjusts the orientation of the wafer W in the horizontal direction, may be provided in the atmospheric pressure section 10.

[0063] Figure 7 , Figure 8 This is a schematic cross-sectional view showing an example of the state when the cover of the front-opening wafer transfer box 31 with the above-described structure is open and closed. When the cover 80 of the front-opening wafer transfer box 31 is open, as... Figure 7 As shown, first, the locking (unlocking) of cover 80 relative to the front-opening wafer transfer box 31 is released. Then, the composite structure formed by the port door 73 engaging with cover 80 is moved horizontally via a moving mechanism (not shown). Afterwards, as... Figure 8 As shown, the composite formed by the port door 73 contacting the cover 80 moves downward along the partition wall 75. This allows the wafer transport device 33, which becomes the loading module 30, to access the state of the wafer W inside the front-opening wafer transport box 31. Furthermore, when the cover 80 of the front-opening wafer transport box 31 is closed, the composite formed by the port door 73 contacting the cover 80 moves in the opposite direction to the release described above.

[0064] Figure 9 This is a schematic cross-sectional view illustrating an example of the loading or unloading state of the front-opening wafer transfer box 31 relative to the loading port 32. During unloading of the front-opening wafer transfer box 31, as... Figure 3 As shown, with the front-opening wafer transfer box 31 connected to the loading port 32 and the cover 80 open, the cover 80 is first closed and locked. Then, the front-opening wafer transfer box 31 is separated from the wafer transfer port 70, and the front-opening wafer transfer box 31 is moved to the unloading position (reverse position) by the stage 72 moving in a direction away from the port door 73. When loading the front-opening wafer transfer box 31, it is moved in the opposite direction. Additionally, as... Figure 9 As shown, the flexibly constructed gas supply pipe 102 and exhaust pipe 105 move in accordance with the movement of the front-opening wafer transfer box 31 while maintaining their connection with the gas supply connector 101 and exhaust connector 104, respectively.

[0065] <Method for detecting the opening and closing of the lid of a substrate housing container>

[0066] Next, the method for detecting the opening and closing of the cover 80 of the front-opening wafer transfer box 31 according to this embodiment will be described. Figure 10 This is a timing diagram illustrating a structural example of the detection method according to this embodiment, and a schematic graph showing the exhaust flow rate measured in each step. In the timing diagram, the horizontal axis represents time, and the vertical axis represents the state of each device. Similarly, in the exhaust flow rate graph, the horizontal axis represents time, and the vertical axis represents the exhaust flow rate.

[0067] In the detection method of this embodiment, the open / closed state of the cover 80 is detected during a continuous period from the state in which the front-opening wafer transfer box 31 is loaded onto the loading port 32 and the cover 80 is opened until the state in which the cover 80 is closed and the front-opening wafer transfer box 31 is unloaded from the loading port.

[0068] In the initial state ST0 before process ST1 begins, the front-opening wafer transfer box 31 is loaded onto the loading port 32 and the cover 80 is open, and the interior of the front-opening wafer transfer box 31 is connected to the interior of the loading module 30. This state of the front-opening wafer transfer box 31 is referred to as the first state. For example, Figure 7 or Figure 8 The state is the first state. In the first state, the gas supply connector 101 is connected to the gas supply pipe 102 and the exhaust connector 104 is connected to the exhaust pipe 105. Furthermore, purge gas is supplied to the front-opening wafer transfer box 31 at a desired supply flow rate via the gas supply connector 101 and the gas supply port 90, and the gas in the front-opening wafer transfer box 31 is discharged via the gas exhaust port 91 and the exhaust connector 104. The flow rate of the discharged gas flowing in the exhaust pipe 105 (hereinafter referred to as "exhaust flow rate") is measured by a flow meter 120 provided in the exhaust pipe 105. The exhaust flow rate measured in the initial state ST0 is the first flow rate Q1.

[0069] In process ST1, such as Figure 7 As shown, the composite structure formed by the port door 73 engaging with the cover 80 is moved to close the front-opening wafer transfer box 31. Then, the locking mechanism based on the locking key 76 is activated to lock the cover 80 and the front-opening wafer transfer box 31. Furthermore, the exhaust flow rate is continuously measured from before the execution of step ST1. The state of the front-opening wafer transfer box 31 after the cover 80 is closed and locked is referred to as the second state. The exhaust flow rate measured in the front-opening wafer transfer box 31 after it reaches the second state in step ST1 is called the second flow rate Q2. The closing and locking of the cover 80 are performed normally. Figure 10 In the example state, the second flow rate Q2 gradually decreases from the initial value of the first flow rate Q1, and then gradually approaches the third flow rate Q3, which is a stable value. Furthermore, regarding the second flow rate Q2, in... Figure 10 The curve is represented as a linear curve with a certain slope, but it is not limited to this, including cases where the curve becomes non-linear due to uneven descent. Furthermore, when the exhaust flow rate gradually approaches a value sufficiently close to the third flow rate Q3, it is defined as "the exhaust flow rate reaches the third flow rate Q3". The significance of the first flow rate Q1 to the third flow rate Q3 will be described later.

[0070] In step ST2, the cover 80 is separated from the port door 73, and the front-opening wafer transfer box 31 is moved to the unloading position in a direction away from the wafer transfer port 70. Additionally, the exhaust flow rate is continuously measured starting from step ST1. The exhaust flow rate measured in step ST3 is the third flow rate Q3.

[0071] In step ST3, the exhaust flow measurement is completed, and the connection between the gas supply connector 101 and the gas supply pipe 102, as well as the connection between the exhaust connector 104 and the exhaust pipe 105, is disconnected. After that, the engagement between the front-opening wafer transfer box 31 and the stage 72 is released.

[0072] Afterwards, the front-opening wafer transfer box 31 can be removed from the stage 72 and transported to other processing devices that perform other processing steps on the wafer W.

[0073] Here, the significance of the exhaust flow rates, namely the first flow rate Q1 to the third flow rate Q3, measured during the execution from the initial state ST0 to process ST2, will be explained. In the initial state ST0, the interior of the front-opening wafer transfer box 31 is connected to the interior of the loading module 30. As described above, the interior of the loading module 30 is maintained at a pressure higher than the ambient atmosphere outside the wafer processing system 1. Therefore, based on this pressure gradient, gas flows from the loading module 30 into the front-opening wafer transfer box 31, and the flow rate of the gas discharged from the front-opening wafer transfer box 31 becomes the relatively large first flow rate Q1.

[0074] In step ST1, the connection between the loading module 30 and the front-opening wafer transfer box 31 is severed by closing the cover 80. Therefore, the inflow of gas from the loading module 30 to the front-opening wafer transfer box 31 stops, and immediately after closing the cover 80, the gas remaining inside the front-opening wafer transfer box 31 is sequentially discharged. As a result, the amount of residual gas inside the front-opening wafer transfer box 31 gradually decreases, and consequently, the second exhaust flow rate Q2 gradually decreases. Subsequently, as the gas pressure inside the front-opening wafer transfer box 31 approaches equilibrium with the suction pressure in the exhaust mechanism 112 for exhaust, the exhaust flow rate reaches a stable third flow rate Q3.

[0075] exist Figure 10In the illustrated state example, during the execution of processes ST1 to ST3, the exhaust flow rate, after falling below a certain flow rate threshold Qt, does not exceed the threshold Qt again until process ST3 ends. In this case, it is evaluated that the front-opening wafer transfer box 31 was properly closed by the cover 80.

[0076] On the other hand, in other state examples, during the execution of processes ST1 to ST3, sometimes the exhaust flow rate exceeds the threshold Qt again after it has once fallen below a certain flow rate threshold Qt. Figure 11 This is a schematic graph showing the exhaust flow rate measured in each process step of this state example. Figure 11 In the diagram, the horizontal axis represents time, and the vertical axis represents exhaust flow rate.

[0077] exist Figure 11 In the illustrated state example, after the exhaust flow rate reaches the third flow rate Q3 in process ST1, the exhaust flow rate increases in process ST2, exceeding the threshold Qt. The reason for this flow rate change is as follows: First, in this state example, after the front-opening wafer transfer box 31 is closed by the cover 80 in process ST1, the cover 80 and the front-opening wafer transfer box 31 are not properly locked due to the loosening of the locking key, etc. In this state, later, when the cover 80 separates from the port door 73 in process ST2 and the front-opening wafer transfer box 31 moves for a period of time, the cover 80 is disengaged due to the locking key 76 hooking onto the keyhole of the cover 80, etc., and the front-opening wafer transfer box 31 changes from a closed state to an open state. When the front-opening wafer transfer box 31 is opened in the separated state, the interior of the front-opening wafer transfer box 31 is in communication with the surrounding atmosphere outside the wafer processing system 1. The ambient atmosphere is lower than the pressure inside the loading module 30, but higher than the pressure inside the front-opening wafer transfer box 31 when the exhaust flow rate from the front-opening wafer transfer box 31 is the third flow rate Q3. Furthermore, the ambient atmosphere is higher than the pressure inside the front-opening wafer transfer box 31 when the exhaust flow rate from the front-opening wafer transfer box 31 is the threshold value Qt. Therefore, when the interior of the front-opening wafer transfer box 31 is connected to the ambient atmosphere, the exhaust flow rate increases, resulting in a flow rate higher than the threshold value Qt.

[0078] For the reasons stated above, if the exhaust flow rate once falls below a certain flow rate threshold Qt and then exceeds the threshold Qt again, it is evaluated as a failure to properly close the cover 80. In the event of this evaluation, the control unit 60, for example, issues an alarm.

[0079] In one implementation, the closure of the cover 80 is detected without setting a threshold Qt for the exhaust flow rate. In this case, as an example, if the exhaust flow rate changes from decreasing to increasing after the cover 80 is separated from the port door 73 in step ST2, it is evaluated as the cover 80 not closing properly.

[0080] In addition, from one perspective, if the exhaust flow rate is found to have increased by a predetermined threshold during the execution of processes ST1 to ST3, it is evaluated as a failure to properly close the cover 80.

[0081] Furthermore, the threshold value Qt or the threshold value for the increase in exhaust flow rate can be predetermined through experiments or simulations based on factors such as the internal pressure of the loading module 30, the pressure of the surrounding atmosphere, the suction pressure in the exhaust mechanism 112 for exhaust, or the internal volume of the front-opening wafer transfer box 31. Alternatively, these determined values ​​can be stored in the control unit 60 and read in during the execution of each process.

[0082] Furthermore, in this embodiment, the exhaust flow rate is monitored by installing a flow meter 120 in the exhaust pipe 105, but this is not a limitation. For example, the flow meter 120 can be installed at any point on the exhaust line, such as in the exhaust mechanism 112. Additionally, if the flow meter 120 has the function of measuring pressure, the pressure can also be monitored.

[0083] According to the opening and closing detection method of the cover 80 of the front-opening wafer transfer box 31 in this embodiment as described above, there is no need to set up a separate sensor such as a light sensor for opening and closing detection. The opening and closing of the cover 80 can be detected by a simple structure such as a flow meter 120 installed in the exhaust pipe 105.

[0084] Furthermore, unlike the method described above where the port door 73 is retracted after the cover 80 is locked, the opening and closing of the cover 80 is detected after the port door 73 is engaged with the partition wall 75 and the cover 80 is separated. Therefore, even if the cover 80 falls off during the process, it will not fall into the loading module 30. Thus, when recovering the fallen cover 80, it is not necessary to open the loading module 30 to the ambient atmosphere, and the cleanliness of the loading module 30 is not compromised. Additionally, since it is not necessary to open the loading module 30 to the ambient atmosphere, the abnormal cover 80 and the front-opening wafer transfer box 31 can be quickly recovered from the ambient atmosphere, thereby suppressing a decrease in the overall productivity of the wafer processing system 1.

[0085] In addition, since there is no need for an additional step such as retracting the port door 73 after locking the cover 80, the time required for the process from separation to release can be shortened.

[0086] Furthermore, since the opening and closing of the cover 80 can be detected at the desired time point from the closing of the front-opening wafer transfer box 31 through the cover 80 until it is released, the opening and closing can be detected even at locations far from the loading position and outside the detection range of the sensor.

[0087] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The above embodiments can also be omitted, substituted, or modified in various ways without departing from the appended claims and their spirit. For example, the constituent elements of the above embodiments can be arbitrarily combined. Based on such arbitrary combinations, the functions and effects of each constituent element related to the combination can be obtained, and other functions and effects can be obtained that are clearly known to those skilled in the art based on the description herein.

[0088] Furthermore, the effects described in this specification are merely illustrative or exemplary and not limiting. That is to say, the technology disclosed herein can achieve the aforementioned effects and other effects that are clearly known to those skilled in the art based on the description in this specification, or can replace the aforementioned effects to achieve other effects that are clearly known to those skilled in the art based on the description in this specification.

[0089] Explanation of reference numerals in the attached figures

[0090] 1: Wafer processing system; 30: Loading module; 31: Front-opening wafer transfer box; 32: Loading port; 73: Port door; 80: Cover; 112: Exhaust mechanism; 120: Flow meter; W: Wafer.

Claims

1. A detection method for detecting the opening and closing of the lid of a substrate receiving container that houses multiple substrates processed by a substrate processing system in multiple layers. The substrate processing system includes a loading module for transferring the substrate to and from the substrate receiving container. The loading module has a loading port for placing the substrate receiving container. The loading port includes a port door, and the loading port is configured such that, in a first state where the cover of the substrate receiving container abuts against and engages with the port door, and the cover of the substrate receiving container is open, the interior of the substrate receiving container is in communication with the interior of the loading module. The loading port includes an exhaust section for venting air from the interior of the substrate receiving container when the substrate receiving container is engaged. The exhaust section includes a flow rate measuring unit for measuring the flow rate of gas discharged from the interior of the substrate receiving container, i.e., the exhaust flow rate. The detection method includes: Step (a) causes the first state to change to a second state in which the lid of the substrate receiving container is closed; Step (b): In the second state, the contact between the port door and the cover is released, and the substrate receiving container is moved away from the port door; and In step (c), during the execution of steps (a) and (b), the interior of the substrate receiving container is continuously vented and the venting flow rate is measured, thereby evaluating whether the closure of the lid of the substrate receiving container has been performed correctly.

2. The detection method according to claim 1, wherein, It also includes a step (d), in which the exhaust flow rate is compared with a predetermined threshold, and if the exhaust flow rate exceeds the threshold again after once falling below the threshold, it is evaluated as a failure to properly close the lid of the substrate receiving container.

3. The detection method according to claim 1, wherein, It also includes step (d), in which, if the exhaust flow rate increases, the increase in the exhaust flow rate is compared with a predetermined threshold for the increase, and if the increase in the exhaust flow rate exceeds the threshold for the increase, it is evaluated that the closing of the lid of the substrate receiving container has not been performed properly.

4. A substrate processing system comprising: A substrate housing container that houses multiple substrates in multiple layers; A loading module for transferring the substrate to and from the substrate receiving container; and Control Department wherein The substrate receiving container has a lid that hermetically seals the interior of the substrate receiving container. The loading module has a loading port for placing the substrate receiving container. The loading port includes a port door, and the loading port is configured such that, in a first state where the cover of the substrate receiving container abuts against and engages with the port door, and the cover of the substrate receiving container is open, the interior of the substrate receiving container is in communication with the interior of the loading module. The loading port includes an exhaust section for venting air from the interior of the substrate receiving container when the substrate receiving container is engaged. The exhaust section includes a flow rate measuring unit for measuring the flow rate of gas discharged from the interior of the substrate receiving container, i.e., the exhaust flow rate. The control unit performs control, which includes: Step (a) causes the first state to change to a second state in which the lid of the substrate receiving container is closed; Step (b): In the second state, the contact between the port door and the cover is released, and the substrate receiving container is moved away from the port door; and In step (c), during the execution of steps (a) and (b), the interior of the substrate receiving container is continuously vented and the venting flow rate is measured, thereby evaluating whether the closure of the lid of the substrate receiving container has been performed correctly.

5. The substrate processing system according to claim 4, wherein, The control unit performs control including a process (d), in which the exhaust flow rate is compared with a predetermined threshold, and if the exhaust flow rate exceeds the threshold again after once falling below the threshold, it is evaluated as a failure to properly close the lid of the substrate receiving container.

6. The substrate processing system according to claim 4, wherein, The control unit performs control including process (d), in which, if the exhaust flow rate increases, the increase in the exhaust flow rate is compared with a predetermined threshold for the increase. If the increase in the exhaust flow rate exceeds the threshold for the increase, it is evaluated as a failure to properly close the lid of the substrate receiving container.

7. A control program that enables a computer to control a substrate processing system to detect the opening and closing of a lid of a substrate receiving container that houses multiple substrates processed by the substrate processing system in multiple layers. The substrate processing system includes a loading module for transferring the substrate to and from the substrate receiving container. The loading module has a loading port for placing the substrate receiving container. The loading port includes a port door, and the loading port is configured such that, in a first state where the cover of the substrate receiving container abuts against and engages with the port door, and the cover of the substrate receiving container is open, the interior of the substrate receiving container is in communication with the interior of the loading module. The loading port includes an exhaust section for venting air from the interior of the substrate receiving container when the substrate receiving container is engaged. The exhaust section includes a flow rate measuring unit for measuring the flow rate of gas discharged from the interior of the substrate receiving container, i.e., the exhaust flow rate. The control program causes the computer to control the substrate processing system to perform control, which includes: Step (a) causes the first state to change to a second state in which the lid of the substrate receiving container is closed; Step (b): In the second state, the contact between the port door and the cover is released, and the substrate receiving container is moved away from the port door; and In step (c), during the execution of steps (a) and (b), the interior of the substrate receiving container is continuously vented and the venting flow rate is measured, thereby evaluating whether the closure of the lid of the substrate receiving container has been performed correctly.

8. The control program according to claim 7, wherein, The control program causes the computer to control the substrate processing system to perform control including a step (d), in which the exhaust flow rate is compared with a predetermined threshold, and if the exhaust flow rate once falls below the threshold and then exceeds the threshold again, it is evaluated as a failure to properly close the lid of the substrate receiving container.

9. The control program according to claim 7, wherein, The control program causes the computer to control the substrate processing system to perform control including a step (d), in which, if the exhaust flow rate increases, the increase in the exhaust flow rate is compared with a predetermined threshold for the increase, and if the increase in the exhaust flow rate exceeds the threshold for the increase, it is evaluated that the closing of the lid of the substrate receiving container has not been performed properly.

Images