Detection method, substrate processing system, and control program

Abstract

Provided is a detection method for detecting opening / closing of a lid of a substrate storage container for storing a plurality of substrates processed by a substrate processing system in multiple stages. The substrate processing system comprises a loader module for delivering the substrate to and from the substrate storage container. The loader module comprises a load port on which the substrate storage container is placed. The load port includes a port door, the lid of the substrate storage container is brought into contact with and locked to the port door, and in a first state in which the lid of the substrate storage container is opened, the inside of the substrate storage container and the inside of the loader module communicate with each other. The load port includes an exhaust part for exhausting the inside of the substrate storage container in a state in which the substrate storage container is locked, and the exhaust part is provided with a flow rate measurement unit that measures the exhaust flow rate, which is the flow rate of gas exhausted from the inside of the substrate storage container. The detection method includes: (a) a step for changing from the first state to a second state in which the lid of the substrate storage container is closed; (b) a step for cancelling the abutting of the port door and the lid from the second state, and moving the substrate storage container in a direction separating from the port door; and (c) a step for, during execution of step (a) and step (b), continuously exhausting the inside of the substrate storage container and measuring the exhaust flow rate, and thus evaluating whether or not closing of the lid of the substrate storage container was performed properly.

Description

DETECTION METHOD, SUBSTRATE PROCESSING SYSTEM, AND CONTROL PROGRAM

[0001] The present disclosure relates to a detection method, a substrate processing system, and a control program.

[0002] Patent Document 1 discloses a wafer processing system that is provided with an optical sensor that detects whether a FOUP lid has fallen off when a FOUP containing multiple wafers is undocked and unloaded from a load port.

[0003] Japanese Patent Application Publication No. 2020-061436

[0004] The technology according to the present disclosure detects whether the lid of a substrate container is open or closed.

[0005] One aspect of the present disclosure is a detection method for detecting opening and closing of a lid of a substrate storage container that stores multiple substrates in multiple stages to be processed in a substrate processing system, the substrate processing system including a loader module that transfers the substrates to and from the substrate storage container, the loader module including a load port on which the substrate storage container is placed, the load port including a port door, the lid of the substrate storage container abutting and engaging with the port door, and configured such that in a first state in which the lid of the substrate storage container is open, an interior of the substrate storage container and an interior of the loader module are in communication, and the load port is configured such that when the substrate storage container is in a state in which the lid is engaged, an interior of the substrate storage container communicates with an interior of the loader module ... The substrate storage container further includes an exhaust unit that exhausts the inside of the container, and the exhaust unit includes a flow rate measuring unit that measures an exhaust flow rate, which is the flow rate of gas exhausted from the inside of the substrate storage container. The detection method includes: (a) a step of changing the first state to a second state in which the lid of the substrate storage container is closed; (b) a step of releasing the abutment between the port door and the lid from the second state and moving the substrate storage container in a direction away from the port door; and (c) a step of continuously evacuating the inside of the substrate storage container and measuring the exhaust flow rate while the steps (a) and (b) are being performed, thereby evaluating whether the lid of the substrate storage container has been closed normally.

[0006] According to the present disclosure, it is possible to detect whether the lid of a substrate container is open or closed.

[0007] FIG. 1 is a plan view showing an outline of the configuration of a wafer processing system. FIG. 2 is a perspective view showing an example configuration of a FOUP and a load port. FIG. 3 is a diagram showing an example state in which the FOUP abuts against a wafer transfer port at the load position. FIG. 4 is a plan view showing an example configuration of the bottom of the FOUP. FIG. 5 is a plan view showing an example configuration of a base and a stage in the load port. FIG. 6 is an explanatory diagram showing an example configuration of a gas system that supplies purge gas to the inside of the FOUP and exhausts gas from the FOUP. FIG. 7 is a cross-sectional view showing a schematic example of a state when the lid of the FOUP is opened and closed. FIG. 8 is a cross-sectional view showing a schematic example of a state when the lid of the FOUP is opened and closed. FIG. 9 is a cross-sectional view showing a schematic example of a state when the FOUP is loaded or unloaded from the load port. FIG. 10 is a timing chart showing an example configuration of a detection method and a schematic graph of exhaust flow rates measured during each process in one example state. FIG. 11 is a schematic graph of exhaust flow rates measured during each process in another example state.

[0008] In the manufacturing process of semiconductor devices, it is necessary to maintain the cleanliness of semiconductor wafers (hereinafter referred to as "wafers") and various wafer processing equipment that processes the wafers. For this purpose, when transporting wafers from the outside to the wafer processing equipment, a method is adopted in which a high level of cleanliness is maintained inside a substrate storage container called a FOUP (Front-Opening Unified Pod) that stores multiple wafers.

[0009] The substrate container described above can accommodate multiple wafers in parallel rows, and is configured to allow wafers to be transferred through an opening formed on one side of the substrate container. The interior of the substrate container is filled with highly clean nitrogen gas or the like to prevent particles and other contaminants from entering the substrate container.

[0010] The substrate container has an openable lid for loading and unloading wafers. When the substrate container is docked to the load port, the lid is opened to transfer wafers to and from the loader module. The lid is closed before the substrate container is released from the load port (undocked).

[0011] When a substrate container is undocked, the lid may not be closed properly due to distortion of the substrate container, play in the latch key that latches the lid while locked to the body of the substrate container, etc. Patent Document 1 discloses providing an optical sensor to detect the lid falling off when the substrate container is undocked and subsequently unloaded.

[0012] However, providing a sensor on the load port increases the cost of the equipment. Also, when the lid is partially closed, it does not fall, making it difficult for an optical sensor to detect. Therefore, there is room for improvement in conventional wafer transport equipment.

[0013] From this perspective, the inventors conducted extensive research and came up with the method of the reference example, in which the lid of the substrate housing container is latched prior to undocking, and then the opening / closing mechanism (port door) on the load port side is retracted to detect the open / close state of the substrate housing container. With the method of the reference example, if the lid is not properly latched and is incompletely closed, the latch key catches on the lid when the port door is retracted, causing the lid to fall, thereby detecting the incomplete closure of the lid. The detection method of the embodiment described below cannot be implemented when using other FOUPs that do not have the configuration capable of supplying N2 gas, as in the FOUP 31 described in the embodiment described below. Therefore, from the perspective of being able to detect the incomplete closure of the lid, the method of the reference example is effective for detecting the open / close state of the other FOUPs, despite issues such as maintaining cleanliness when the lid falls into the loader module.

[0014] In view of the above-described problems and the method of the reference example, the technique disclosed herein detects whether a lid of a substrate container is open or closed. The open or closed state of the lid includes whether the lid is detached or not, as well as whether the lid is incompletely closed.

[0015] Hereinafter, a wafer processing system as a substrate processing system and a method for detecting the opening and closing of a lid according to the present embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0016] <Configuration of Wafer Processing System> First, the configuration of a wafer processing system as a substrate processing system according to this embodiment will be described. Fig. 1 is a plan view showing an outline of the configuration of a wafer processing system 1. In the wafer processing system 1, a desired process, such as a film formation process or an etching process, is performed on a wafer W as a substrate in a reduced pressure atmosphere (vacuum atmosphere). Note that the configuration of the wafer processing system 1 of the present disclosure is not limited to this and can be selected as desired.

[0017] 1, the wafer processing system 1 has a configuration in which an atmospheric pressure section 10 and a reduced pressure section 11 are integrally connected via load lock modules 20a and 20b. In the atmospheric pressure section 10, a FOUP 31 (described later) serving as a substrate container capable of accommodating a plurality of wafers W is transported under an atmospheric pressure atmosphere (air atmosphere), and the wafers W are then transported to the load lock modules 20a and 20b. In the reduced pressure section 11, the wafers W are subjected to desired processing under a reduced pressure atmosphere (vacuum atmosphere), and the wafers W are then transported to the load lock modules 20a and 20b.

[0018] The load lock module 20a is provided therein with a stage 21a on which a wafer W is placed. The load lock module 20a temporarily holds the wafer W on the stage 21a in order to transfer the wafer W transferred from a loader module 30 (described later) in the atmospheric pressure section 10 to a transfer module 40 (described later) in the decompression section 11.

[0019] The load lock module 20a is connected to a loader module 30 (described later) via a gate valve 22a. The load lock module 20a is also connected to a transfer module 40 (described later) via a gate valve 23a. These gate valves 22a and 23a ensure airtightness between the load lock module 20a and the loader module 30 and transfer module 40, while also allowing communication between them.

[0020] The load lock module 20a is connected to an air supply section (not shown) that supplies gas and an exhaust section (not shown) that exhausts gas, and is configured so that the interior can be switched between a normal pressure atmosphere and a reduced pressure atmosphere by the air supply section and the exhaust section. That is, the load lock module 20a is configured so that the wafer W can be appropriately transferred between the normal pressure section 10, which has a normal pressure atmosphere, and the reduced pressure section 11, which has a reduced pressure atmosphere.

[0021] The load lock module 20b has the same configuration as the load lock module 20a, i.e., it has a stage 21b on which the wafer W is placed, a gate valve 22b on the loader module 30 side, and a gate valve 23b on the transfer module 40 side.

[0022] The number and arrangement of the load lock modules 20a and 20b are not limited to those in this embodiment, but can be set arbitrarily.

[0023] The atmospheric pressure section 10 has a loader module 30 equipped with a wafer transfer device 33, and a load port 32 on which a FOUP 31 capable of storing a plurality of wafers W is placed. The loader module 30 is also referred to as an EFEM (Equipment Front End Module).

[0024] The loader module 30 is constructed with a substantially rectangular housing, and the interior of the housing is maintained at a pressure equal to or higher than the ambient atmosphere outside the wafer processing system 1. Multiple, e.g., three, load ports 32 are arranged side by side on one long side of the housing of the loader module 30. In FIG. 1 , FOUPs 31 are placed on the left and central load ports 32, while no FOUP 31 is placed on the right load port 32. Load lock modules 20a and 20b are arranged side by side on the other long side of the housing of the loader module 30. The loader module 30 also includes a wafer transfer device 33 that is movable in the longitudinal direction within the housing. The wafer transfer device 33 can transfer wafers W between the FOUP 31 placed on the load port 32 and the load lock modules 20a and 20b. The configurations of the FOUP 31 and the load ports 32 will be described in detail below.

[0025] The decompression unit 11 has a transfer module 40 that transfers the wafer W and a processing module 41 that serves as a substrate processing apparatus that performs desired processing on the wafer W. The interiors of the transfer module 40 and the processing module 41 are each maintained at a reduced pressure atmosphere. A plurality of processing modules 41, for example, four processing modules 41, are provided for the transfer module 40. The transfer module 40 is also referred to as a VTM (Vacuum Transfer Module).

[0026] The transfer module 40 is formed of a housing having an interior polygonal shape in a plan view, and in the illustrated example, a hexagonal shape in a plan view, and is connected to the load lock modules 20a and 20b via the gate valves 23a and 23b as described above. That is, the load lock modules 20a and 20b and four processing modules 41 are arranged on each side of the transfer module 40. The transfer module 40 sequentially transfers wafers W transferred to the load lock module 20a to one of the processing modules 41, where the wafers are subjected to the desired processing, and then transfers them to the atmospheric pressure section 10 via the load lock module 20b.

[0027] Inside the transfer module 40 , a wafer transfer device 50 is provided to transfer the wafer W between the load lock modules 20 a and 20 b , the transfer module 40 , and the processing module 41 .

[0028] A stage 42 on which a wafer W is placed is provided inside the processing module 41. The processing module 41 performs a desired process, such as a film formation process or an etching process, on the wafer W placed on the stage 42. The processing module 41 is connected to an air supply unit (not shown) that supplies a processing gas, a purge gas, etc., and an exhaust unit (not shown) that exhausts the gas.

[0029] The processing module 41 is connected to the transfer module 40 via a gate valve 43. The gate valve 43 ensures airtightness between the transfer module 40 and the processing module 41 while also allowing communication between them.

[0030] The number and arrangement of the processing modules 41 provided in the transfer module 40 and the types of processing performed by the processing modules 41 are not limited to those in this embodiment, but can be set arbitrarily.

[0031] The wafer processing system 1 described above is provided with a control unit 60. The control unit 60 processes computer-executable instructions that cause the wafer processing system 1 to perform the various processes described in this disclosure. The control unit 60 may be configured to control each element of the wafer processing system 1 to perform 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 include a processing unit, a storage unit, and a communication interface. The control unit 60 is realized, for example, by a computer. The processing unit may be configured to perform various control operations by reading a program from the storage unit and executing the read program. This program may be stored in the storage unit in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit and read from the storage unit by the processing unit for execution. 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 may be temporary or non-temporary and may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), a SSD (Solid State Drive), or a combination thereof. The communication interface may communicate with the wafer processing system 1 via a communication line such as a LAN (Local Area Network).

[0032] <Hoop and load port>

[0033] Fig. 2 is a perspective view showing an example of the configuration of the FOUP 31 and the load port 32. Fig. 3 is a cross-sectional view taken in a direction perpendicular to the longitudinal direction of the loader module, showing an example of the state in which the FOUP 31 abuts (docks) against the wafer transfer opening 70 at the loading position. Fig. 4 is a plan view showing an example of the configuration of the bottom of the FOUP 31. Fig. 5 is a plan view showing an example of the configuration of the base 71 and stage 72 in the load port 32.

[0034] As shown in FIG. 2 , each load port 32 includes a wafer transfer opening 70, a base 71, a stage (mounting table) 72 on which the FOUP 31 is placed, and a port door 73 that closes the wafer transfer opening 70. The stage 72 is moved forward and backward along rails 74 extending in the front-to-rear direction by a stage movement mechanism (not shown). The forward and backward movement of the stage 72 moves the FOUP 31 between an unload position (a retreated position) and a load position (an advanced position). The FOUP 31 is shown in the unload position. The FOUP 31 is held by a gripper (not shown) by an appropriate transfer device and transferred onto the stage 72 at the unload position. The stage 72 is then advanced, and at the load position, the FOUP 31 and the loader module 30 are connected, enabling the wafer W to be transferred by the wafer transfer device 33. The wall surfaces of the loader module 30 excluding the wafer transfer opening 70 are referred to as a partition wall 75. The port door 73 includes a latch key 76 that latches the hoop 31 and the lid 80 together, as will be described later.

[0035] 3, the FOUP 31 has a box-like shape with an opening at the front, and is provided with a lid 80 that seals the opening. In the following description, when the FOUP 31 is docked at the wafer transfer opening 70, the lid 80 is docked at the port door 73. The bottom 31a of the FOUP 31 is configured to be supported by the stage 72.

[0036] The stage 72 is provided with a desired locking member (not shown), which can lock (clamp) the stage 72 and the hoop 31 at a desired position. The hoop 31 is provided with a support mechanism corresponding to the mechanism of the locking member. In other words, when the hoop 31 is "clamped" to the stage 72, this means that the locking control by the action of the locking member mechanism of the stage 72 on the support mechanism of the hoop 31 has been completed. On the other hand, when the hoop 31 is "unclamped," this means that the control of release of the locking by the action of the locking member mechanism of the stage 72 on the support mechanism of the hoop 31 has been completed. The stage 72 may also be provided with a desired positioning pin (not shown), which can be used to guide the hoop 31 to a precise position during clamping.

[0037] The lid 80 includes a mating member (not shown) that allows the lid 80 and the hoop 31 to be airtightly closed when they are in close contact with each other. The lid 80 has a keyhole (not shown) that faces the latch key 76 when the lid 80 is docked to the port door 73. The lid 80 and the hoop 31 are equipped with a desired locking mechanism (not shown). When the latch key 76 is engaged with the keyhole, the latch key 76 moves the mating member, locking (latching) the lid 80 to the hoop 31. That is, "latching" the lid 80 to the hoop 31 refers to the completion of a series of controlled operations in which the mating member is moved to lock the lid 80 to the hoop 31. "Unlatching" refers to the opposite, that is, the completion of a series of controlled operations in which the mating member is moved to release the locked state of the lid 80 to the hoop 31. The port door 73 is configured to be freely opened and closed by a drive mechanism (not shown). Therefore, the lid 80 can be opened and closed by operating the port door 73 to open and close it while the port door 73 and the lid 80 are docked and the latch key 76 is fitted in the keyhole.

[0038] For example, 25 wafers W to be processed in the wafer processing apparatus are accommodated inside the hoop 31. The wafers W are arranged horizontally in multiple stages at equal intervals within the hoop 31.

[0039] 4, the bottom 31a of the FOUP 31 is provided with three gas supply ports 90 and one gas exhaust port 91. In this embodiment, two of the gas supply ports 90 are located on the side opposite the lid 80, and one is located on the lid 80 side. The gas exhaust port 91 is located on the lid 80 side.

[0040] 5 , the stage 72 is provided with through-holes 100 at positions corresponding to the gas supply ports 90 and gas exhaust ports 91 provided in the FOUP 31. The base 71 is provided with gas supply connectors 101 at positions corresponding to the gas supply ports 90 of the FOUP 31. Flexible gas supply pipes 102 are connected to the gas supply connectors 101. A gas supply source (not shown) is connected to the other end of the gas supply pipe 102, so that a dry purge gas, such as N2 gas, can be supplied via the gas supply pipe 102. The base 71 is also provided with an exhaust connector 104 at a position corresponding to the gas exhaust port 91 of the FOUP 31. A flexible exhaust pipe 105 is connected to the exhaust connector 104.

[0041] The gas supply connector 101 and the exhaust connector 104 are configured so that they can be raised and lowered by an elevating mechanism (not shown) such as an air cylinder. Ring-shaped seal members (not shown) are provided at the tips of the gas supply connector 101 and the exhaust connector 104. With this configuration, by raising the gas supply connector 101, the gas supply connector 101 communicates with the gas supply port 90 of the FOUP 31, making it possible to supply purge gas into the FOUP 31. Furthermore, by raising the exhaust connector 104, the exhaust connector 104 communicates with the gas exhaust port 91 of the FOUP 31, making it possible to evacuate the inside of the FOUP 31.

[0042] 6 is an explanatory diagram showing an example of the configuration of a gas system configured to supply purge gas to the FOUP 31 and exhaust gas from the FOUP 31 according to this embodiment. A gas supply source 110, which supplies, for example, dry nitrogen as a purge gas, is connected to the gas supply port 90 via a gas supply pipe 102. The gas supply pipe 102 is provided with a valve V1 that controls the start and stop of the supply of gas from the gas supply source 110. The gas supply pipe 102 branches into two downstream of the valve V1. Shut-off valves V2 and V3 are provided in each of the branched gas supply pipes 102. Each of the branched gas supply pipes 102 is provided with a flow rate controller 111 that controls the supply of purge gas to the respective gas supply ports 90 at a desired flow rate.

[0043] An exhaust mechanism 112 is connected to the gas exhaust port 91 via an exhaust pipe 105, and is capable of exhausting the gas supplied from each gas supply port 90. A flow meter 120 serving as a flow rate measurement unit according to this embodiment is provided in the exhaust pipe 105, and is 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 transmitted to, for example, the control unit 60.

[0044] 3 , the two gas supply ports 90 provided on the opposite side from the lid 80 are provided with distribution pipes 121 extending vertically upward within the FOUP 31. The distribution pipes 121 have, for example, slit-shaped openings (not shown) formed on the surface facing the wafers W at a height corresponding to the gaps between the wafers W, enabling the gas supplied from the gas supply ports 90 to be distributed evenly between the wafers W. This allows a gas flow to be formed inside the FOUP 31, flowing from the inside of the FOUP 31 toward the lid 80 and flowing evenly between the wafers W. As a result, even when the lid 80 is open, this gas flow prevents the atmosphere inside the loader module 30 from flowing into the inside of the FOUP 31.

[0045] The arrangement of the gas supply ports 90 and the gas exhaust ports 91, and whether or not distribution pipes 121 are provided are not limited to those in this embodiment. For example, any desired arrangement is possible, such as providing two gas supply ports 90 and two gas exhaust ports 91.

[0046] The number and arrangement of the load ports 32 are not limited to those in this embodiment and may be set as desired. The atmospheric pressure section 10 may also be provided with a processing module that performs a desired process on the wafer W under an atmospheric pressure atmosphere, such as a module that performs an alignment process to adjust the horizontal orientation of the wafer W.

[0047] 7 and 8 are cross-sectional views schematically illustrating exemplary states when the lid of the FOUP 31 having the above-described configuration is opened or closed. When the lid 80 of the FOUP 31 is opened, as shown in FIG. 7 , the lid 80 is first unlatched from the FOUP 31, and then the composite of the port door 73 and the lid 80 docked thereto is moved horizontally by a moving mechanism (not shown). Then, as shown in FIG. 8 , the composite of the port door 73 and the lid 80 docked thereto is moved downward along the partition wall 75. This enables the wafer transfer device 33 of the loader module 30 to access the wafers W inside the FOUP 31. When the lid 80 of the FOUP 31 is closed, the composite of the port door 73 and the lid 80 docked thereto is moved in the opposite direction to that during the above-described opening operation.

[0048] FIG. 9 is a cross-sectional view schematically illustrating an example of a state when the FOUP 31 is loaded or unloaded from the load port 32. When the FOUP 31 is unloaded, the FOUP 31 is docked to the load port 32 with the lid 80 open as shown in FIG. 3 , and the lid 80 is first closed and latched. The FOUP 31 is then undocked from the wafer transfer port 70, and the stage 72 moves in a direction away from the port door 73, thereby moving the FOUP 31 to the unload position, which is a retracted position. When the FOUP 31 is loaded, it is moved in the opposite direction. Also, as shown in FIG. 9 , the flexible gas supply pipe 102 and exhaust pipe 105 move following the movement of the FOUP 31 while remaining connected to the gas supply connector 101 and exhaust connector 104, respectively.

[0049] <Method for detecting opening / closing of lid of substrate housing container> Next, a method for detecting opening / closing of the lid 80 of the FOUP 31 according to this embodiment will be described. Fig. 10 is a timing chart showing an example of the configuration of the detection method according to this embodiment and a schematic graph of the exhaust flow rate measured during each process. In the timing chart, the horizontal axis represents time, and the vertical axis represents the state of each device. In the graph of the exhaust flow rate, the horizontal axis represents time, and the vertical axis represents the exhaust flow rate.

[0050] In the detection method according to this embodiment, the open / closed state of the lid 80 is detected during a continuous period from when the FOUP 31 is loaded onto the load port 32 and the lid 80 is open to when the lid 80 is closed and the FOUP 31 is unloaded from the load port.

[0051] In an initial state ST0 before the start of process ST1, the FOUP 31 is loaded onto the load port 32, the lid 80 is open, and the interior of the FOUP 31 is in communication with the interior of the loader module 30. This state of the FOUP 31 is referred to as a first state. For example, the state shown in FIG. 7 or FIG. 8 is the first state. In the first state, the gas supply connector 101 is in communication with the gas supply pipe 102, and the exhaust connector 104 is in communication with the exhaust pipe 105. Furthermore, purge gas is supplied into the FOUP 31 at a desired supply flow rate via the gas supply connector 101 and the gas supply port 90, and gas within the FOUP 31 is exhausted via the gas exhaust port 91 and the exhaust connector 104. Furthermore, a flow meter 120 provided in the exhaust pipe 105 measures the flow rate of exhaust gas flowing through the exhaust pipe 105 (hereinafter referred to as the "exhaust flow rate"). The exhaust flow rate measured in the initial state ST0 is a first flow rate Q1.

[0052] In step ST1, as shown in FIG. 7 , the docked composite of the port door 73 and the lid 80 is moved to close the FOUP 31. Then, the latch key 76 activates the locking mechanism described above to latch the lid 80 and the FOUP 31. The exhaust flow rate is continuously measured from before step ST1 is performed. The state of the FOUP 31 that is latched after being closed by the lid 80 is referred to as the second state. In step ST1, the exhaust flow rate measured in the FOUP 31 after entering the second state is the second flow rate Q2. In the example state shown in FIG. 10 where the lid 80 is normally closed and latched, the second flow rate Q2 gradually decreases from the first flow rate Q1 as an initial value and then asymptotically approaches a stable third flow rate Q3. Note that while the second flow rate Q2 is shown in FIG. 10 as a linear graph decreasing at a constant slope, this is not limited thereto and may be a nonlinear graph due to an uneven decrease. Furthermore, when the exhaust flow rate approaches a value sufficiently close to the third flow rate Q3, it is defined that the "exhaust flow rate has reached the third flow rate Q3." The significance of the first to third flow rates Q1 to Q3 will be described later.

[0053] In process ST2, the lid 80 is undocked from the port door 73, and the FOUP 31 is moved to the unload position in a direction away from the wafer transfer port 70. The exhaust flow rate is measured continuously from process ST1. The exhaust flow rate measured in process ST3 is a third flow rate Q3.

[0054] In step ST3, the measurement of the exhaust flow rate is completed, and the communication between the gas supply connector 101 and the gas supply pipe 102 and the communication between the exhaust connector 104 and the exhaust pipe 105 are cut off. Thereafter, the engagement between the hoop 31 and the stage 72 is released (unclamped).

[0055] Thereafter, the FOUP 31 may be removed from the stage 72 and transferred to another processing apparatus where another processing step is performed on the wafer W.

[0056] Here, the significance of the first to third flow rates Q1 to Q3, which are exhaust flow rates measured during execution of the above-mentioned processes from the initial state ST0 to step ST2, will be explained. In the initial state ST0, the interior of the FOUP 31 is in communication with the interior of the loader module 30. As described above, the interior of the loader module 30 is maintained at a pressure equal to or higher than the ambient atmosphere outside the wafer processing system 1. Therefore, based on this pressure gradient, gas flows from the loader module 30 into the FOUP 31, and the flow rate of gas exhausted from the FOUP 31 is a relatively large first flow rate Q1.

[0057] In step ST1, the lid 80 is closed, thereby blocking communication between the loader module 30 and the FOUP 31. This stops the flow of gas from the loader module 30 into the FOUP 31, and immediately after the lid 80 is closed, the gas remaining inside the FOUP 31 is sequentially exhausted. As a result, the amount of gas remaining inside the FOUP 31 decreases, and the second flow rate Q2 as the exhaust flow rate decreases accordingly. Thereafter, as the gas pressure inside the FOUP 31 approaches equilibrium with the suction pressure for exhaust in the exhaust mechanism 112, the exhaust flow rate reaches a stable value of the third flow rate Q3.

[0058] 10, once the exhaust flow rate falls below a certain threshold Qt during the execution of steps ST1 to ST3, it does not exceed the threshold Qt again until the end of step ST3. In such a case, it is determined that the FOUP 31 is normally closed by the lid 80.

[0059] On the other hand, in another example state, during execution of steps ST1 to ST3, the exhaust flow rate may fall below a certain flow rate threshold Qt and then exceed the threshold Qt again. Figure 11 is a schematic graph of the exhaust flow rate measured during each step in such an example state. In Figure 11, the horizontal axis represents time and the vertical axis represents the exhaust flow rate.

[0060] In the example state shown in FIG. 11 , after the exhaust flow rate reaches the third flow rate Q3 in process ST1, the exhaust flow rate increases and exceeds the threshold value Qt in process ST2. The reason for this flow rate change is believed to be as follows. First, in this example state, after the FOUP 31 is closed by the lid 80 in process ST1, the lid 80 and the FOUP 31 are not properly latched due to play in the latch key or the like. In this state, the lid 80 is undocked from the port door 73 in process ST2, and after the FOUP 31 moves for a while, the latch key 76 engages with a keyhole or the like in the lid 80, releasing the lid 80 and releasing the FOUP 31 from its closed state. When the FOUP 31 is opened in the undocked state, the interior of the FOUP 31 is connected to the ambient atmosphere outside the wafer processing system 1. The ambient atmosphere has a lower pressure than the interior of the loader module 30 but is higher than the pressure inside the FOUP 31 when the exhaust flow rate from the FOUP 31 is the third flow rate Q3. Furthermore, the pressure in the surrounding atmosphere is higher than the pressure inside the hoop 31 when the exhaust flow rate from the hoop 31 is at the threshold Qt. Therefore, when the inside of the hoop 31 is connected to the surrounding atmosphere, the exhaust flow rate begins to increase, and as a result, becomes higher than the threshold Qt.

[0061] For the reasons described above, if the exhaust flow rate exceeds the threshold Qt again after once falling below the threshold Qt, it is determined that the lid 80 has not been properly closed. If it is determined that the lid 80 has not been properly closed, the control unit 60 issues an alarm, for example.

[0062] In one embodiment, the closure of the lid 80 is detected without setting a threshold value Qt for the exhaust flow rate. In this case, as an example, if it is detected that the exhaust flow rate has changed from a decrease to an increase after the lid 80 is undocked from the port door 73 in step ST2, it is determined that the closure of the lid 80 was not performed normally.

[0063] Also, from one point of view, if it is measured that the exhaust flow rate has increased by a predetermined threshold value during the execution of steps ST1 to ST3, it is evaluated that the lid 80 has not been closed normally.

[0064] The threshold value Qt or the threshold value for the increase in the exhaust flow rate can be determined in advance by experiment or simulation based on the internal pressure of the loader module 30, the pressure of the surrounding atmosphere, the suction pressure for exhaust in the exhaust mechanism 112, or the internal volume of the FOUP 31. The determined values ​​may also be stored in the control unit 60 and read when each process is executed.

[0065] In addition, in this embodiment, the exhaust flow rate is monitored by providing the flow meter 120 in the exhaust pipe 105, but this is not a limitation. For example, the flow meter 120 may be provided anywhere on the exhaust line, and may be provided in the exhaust mechanism 112, for example. Furthermore, if the flow meter 120 has the function of measuring pressure, it may be configured to monitor this pressure.

[0066] According to the method for detecting the opening and closing of the lid 80 of the hoop 31 in this embodiment as described above, the opening and closing of the lid 80 can be detected by a simple configuration of providing a flow meter 120 in the exhaust pipe 105, without providing a separate sensor for detecting opening and closing, such as an optical sensor.

[0067] Furthermore, unlike the method of retracting the port door 73 after latching the lid 80 as described above, the opening and closing of the lid 80 is detected after the port door 73 engages with the partition wall 75 and the lid 80 is undocked, so even if the lid 80 falls off during processing, there is no risk of the lid 80 falling inside the loader module 30. Therefore, there is no need to expose the loader module 30 to the ambient atmosphere when recovering a fallen lid 80, and the cleanliness of the loader module 30 is not compromised. Furthermore, there is no need to expose the loader module 30 to the ambient atmosphere, so the lid 80 and FOUP 31 for which an abnormality has been detected can be quickly recovered from the ambient atmosphere, thereby suppressing a decrease in productivity of the wafer processing system 1 as a whole.

[0068] Furthermore, since there is no need for an additional step of retracting the port door 73 after latching the lid 80, the time required for the steps from undocking to unclamping can be reduced.

[0069] Furthermore, since the opening and closing of the lid 80 can be detected at any desired point between the closing and unclamping of the FOUP 31 by the lid 80, the opening and closing can be detected even at a position outside the detection range of the sensor, away from the load position.

[0070] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0071] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0072] REFERENCE SIGNS LIST 1 wafer processing system 30 loader module 31 FOUP 32 load port 73 port door 80 lid 112 exhaust mechanism 120 flow meter W wafer

Claims

1. A detection method for detecting opening and closing of a lid of a substrate housing container that houses multiple substrates in multiple stages to be processed in a substrate processing system, wherein the substrate processing system comprises a loader module that transfers the substrates between the substrate housing container and the loader module, the loader module comprising a load port on which the substrate housing container is placed, the load port comprising a port door, the lid of the substrate housing container abutting against and engaging with the port door, and configured such that in a first state in which the lid of the substrate housing container is open, the inside of the substrate housing container and the inside of the loader module are in communication, the load port comprising an exhaust unit that exhausts the inside of the substrate housing container when the substrate housing container is in an engaged state, the exhaust unit comprising a flow rate measuring unit that measures an exhaust flow rate that is the flow rate of gas exhausted from the inside of the substrate housing container, and the detection method comprises: (a) a step of changing from the first state to a second state in which the lid of the substrate housing container is closed; (b) releasing the abutment between the port door and the lid from the second state and moving the substrate container in a direction away from the port door; and (c) evaluating whether the lid of the substrate container has been closed normally by continuously evacuating the inside of the substrate container and measuring the exhaust flow rate while the steps (a) and (b) are being performed.

2. The detection method described in claim 1, further comprising the step of (d) comparing the exhaust flow rate with a predetermined threshold value, and if the exhaust flow rate falls below the threshold value once and then exceeds the threshold value again, evaluating that the lid of the substrate container was not closed normally.

3. The detection method described in claim 1, further comprising: (d) a step of, when the exhaust flow rate increases, comparing the amount of increase in the exhaust flow rate with a predetermined increase amount threshold, and, when the amount of increase in the exhaust flow rate exceeds the increase amount threshold, evaluating that the lid of the substrate container was not closed normally.

4. A substrate processing system comprising: a substrate storage container that stores a plurality of substrates in multiple stages; a loader module that transfers the substrates between the substrate storage container and the substrate storage container; and a control unit, wherein the substrate storage container has a lid that airtightly closes the interior of the substrate storage container; the loader module has a load port on which the substrate storage container is placed; the load port has a port door, and the lid of the substrate storage container is abutted against and engaged with the port door, and is configured such that in a first state in which the lid of the substrate storage container is open, the interior of the substrate storage container and the interior of the loader module are in communication with each other; the load port has an exhaust unit that evacuates the interior of the substrate storage container when the substrate storage container is engaged, and the exhaust unit has a flow rate measuring unit that measures an exhaust flow rate, which is the flow rate of gas exhausted from the interior of the substrate storage container; and the control unit performs the following steps: (a) changing the first state to a second state in which the lid of the substrate storage container is closed; (b) releasing the contact between the port door and the lid from the second state and moving the substrate container in a direction away from the port door; and (c) while performing the steps (a) and (b), continuously evacuating the inside of the substrate container and measuring the exhaust flow rate to evaluate whether the lid of the substrate container has been closed normally.

5. The substrate processing system of claim 4, wherein the control unit executes control that further includes the step of: (d) comparing the exhaust flow rate with a predetermined threshold value, and if the exhaust flow rate falls below the threshold value once and then exceeds the threshold value again, evaluating that the lid of the substrate container was not closed normally.

6. The substrate processing system of claim 4, wherein the control unit executes control that further includes the step of: (d) when the exhaust flow rate increases, comparing the amount of increase in the exhaust flow rate with a predetermined increase amount threshold, and when the amount of increase in the exhaust flow rate exceeds the increase amount threshold, evaluating that the lid of the substrate container was not closed normally.

7. A control program for causing a computer to control a substrate processing system to detect opening and closing of a lid of a substrate storage container which stores multiple substrates in multiple stages to be processed in the substrate processing system, wherein the substrate processing system comprises a loader module which transfers the substrate between the substrate storage container and the loader module, the loader module comprising a load port on which the substrate storage container is placed, the load port comprising a port door, the lid of the substrate storage container being abutted against and engaged with the port door, and configured such that in a first state in which the lid of the substrate storage container is open, the inside of the substrate storage container and the inside of the loader module are in communication, the load port comprising an exhaust unit which exhausts the inside of the substrate storage container when the substrate storage container is engaged, the exhaust unit comprising a flow rate measuring unit which measures an exhaust flow rate which is the flow rate of gas exhausted from the inside of the substrate storage container, and the control program comprises: (a) a step of changing from the first state to a second state in which the lid of the substrate storage container is closed; (b) releasing the abutment between the port door and the lid from the second state and moving the substrate container in a direction away from the port door; and (c) evaluating whether the lid of the substrate container has been closed normally by continuously evacuating the inside of the substrate container and measuring the exhaust flow rate while the steps (a) and (b) are being performed.

8. The control program of claim 7, which causes the computer to control the substrate processing system to execute control that further includes a step of comparing the exhaust flow rate with a predetermined threshold value, and if the exhaust flow rate falls below the threshold value once and then exceeds the threshold value again, evaluating that the lid of the substrate container was not closed normally.

9. The control program of claim 7, which causes the computer to control the substrate processing system to execute control that further includes a step of: (d) when the exhaust flow rate increases, comparing the amount of increase in the exhaust flow rate with a predetermined increase amount threshold, and when the amount of increase in the exhaust flow rate exceeds the increase amount threshold, evaluating that the lid of the substrate container was not closed normally.

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