Washing device, drying device and drying treatment method

Abstract

To provide a washing device for efficiently drying a treatment object after washing.SOLUTION: A washing device according to an embodiment of the present invention, comprises a washing treatment unit for washing a treatment object, a drying treatment unit for drying the treatment object and a control unit for controlling the washing treatment unit and the drying treatment unit to carry out the washing treatment and the drying treatment of the treatment object. The drying treatment unit includes a drying treatment tank capable of holding the treatment object therein and an exhaust device reducing the internal pressure of the drying treatment tank, and the control unit controls the exhaust device to carry out a first depressurization treatment of reducing the internal pressure of the drying treatment tank from the atmospheric pressure to a first pressure of 500 Pa or lower within one minute, during the drying treatment operation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a cleaning apparatus, a drying apparatus, and a drying method, and more particularly to a wafer container cleaning apparatus in which an object to be processed is a wafer container. [Background technology]

[0002] Conventionally, in the manufacturing process of semiconductor devices, wafer storage containers such as FOUPs (Front Opening Unified Pods) and FOSBs (Front Opening Shipping Boxes) are used as containers for storing (accommodating) semiconductor wafers. Wafer storage containers are periodically cleaned because the interior of the container may become contaminated when storing semiconductor wafers. Known cleaning devices for cleaning wafer storage containers include devices having a cleaning tank and a drying tank. For example, Patent Document 1 discloses a method in which the wafer storage container is cleaned in a cleaning tank by alternately repeating ultrasonic cleaning and high-pressure shower cleaning, and then the cleaned wafer storage container is dried in a drying tank by alternately repeating hot air heating and reduced-pressure drying. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-126678 Summary of the Invention [Problem to be solved by the invention]

[0004] As mentioned above, conventional wafer container cleaning equipment dries wafer containers using a drying process using reduced-pressure drying. Reduced-pressure drying is a drying method in which the object to be dried is placed in a reduced-pressure environment to lower the boiling point of moisture, such as water droplets, adhering to the surface of the object, thereby evaporating it. When drying wafer containers under reduced pressure, a vacuum is drawn in the processing tank in which the cleaned wafer containers are placed, and the drying process is carried out over a sufficient period of time until the moisture adhering to the containers is completely evaporated.

[0005] However, while conducting extensive research into drying processes using reduced pressure drying, the inventors noticed that, under certain conditions, water droplets may remain in the wafer container even after a sufficiently long period of reduced pressure drying. The inventors speculated that this was due to the freezing of water droplets in a reduced pressure environment. Specifically, they suspected that the temperature of the water droplets drops due to the heat of vaporization during the reduced pressure drying process, causing the entire water droplet to freeze, which then prevents the water droplets from evaporating.

[0006] Based on the above speculation, the inventors tried various methods, such as performing reduced pressure drying under conditions where water droplets would not freeze (for example, a pressure range where water droplets would not freeze), but there was still room for improvement in the efficiency of the wafer container cleaning device, such as further shortening the processing time.

[0007] An object of the present invention is to provide a cleaning apparatus that efficiently dries an object to be treated after cleaning. [Means for solving the problem]

[0008] A cleaning apparatus according to one embodiment of the present invention comprises a cleaning processing section that cleans an object to be treated, a drying processing section that dries the object to be treated, and a control section that controls the cleaning processing section and the drying processing section to perform the cleaning processing and drying processing of the object to be treated, wherein the drying processing section includes a drying processing tank capable of holding the object to be treated therein and an exhaust device that reduces the internal pressure of the drying processing tank, and during the drying processing, the control section controls the exhaust device to perform a first decompression processing that reduces the internal pressure of the drying processing tank from atmospheric pressure to a first pressure of 500 Pa or less within one minute.

[0009] A drying apparatus according to one embodiment of the present invention comprises a drying processing section that dries an object to be processed, and a control section that controls the drying processing section to perform a drying process on the object to be processed, wherein the drying processing section includes a drying processing tank capable of holding the object to be processed therein and an exhaust device that reduces the internal pressure of the drying processing tank, and during the drying process, the control section controls the exhaust device to perform a decompression process that reduces the internal pressure of the drying processing tank from atmospheric pressure to a pressure of 500 Pa or less within one minute.

[0010] A drying method according to one embodiment of the present invention includes placing an object to be dried inside a drying tank, and controlling an exhaust device connected to the drying tank to perform a first decompression process to reduce the internal pressure of the drying tank from atmospheric pressure to a first pressure of 500 Pa or less within one minute. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a plan view schematically showing the overall configuration of a wafer container cleaning apparatus according to a first embodiment. [Figure 2] 2 is a diagram schematically illustrating the configuration of a drying processing unit in the wafer container cleaning apparatus according to the first embodiment. FIG. [Figure 3] 10A and 10B are schematic diagrams for explaining the phenomenon in which water droplets adhering to a wafer container burst during reduced-pressure drying. [Figure 4]3A to 3C are views for explaining a drying process method performed in the wafer container cleaning apparatus according to the first embodiment. [Figure 5] FIG. 10 is a diagram schematically illustrating the configuration of a drying processing unit in a wafer container cleaning apparatus according to a second embodiment. [Figure 6] 6 is a view of the wafer container placed in the drying processing unit shown in FIG. 5, viewed from the opening side. [Figure 7] FIG. 10 is a diagram schematically illustrating the configuration of a drying processing unit in a wafer container cleaning apparatus according to a modified example of the second embodiment. [Figure 8] 8 is a view of the wafer container placed in the drying processing unit shown in FIG. 7, seen from the opening side. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a cleaning device according to one embodiment of the present invention will be described with reference to the drawings. However, the cleaning device can be implemented in many different forms, and should not be construed as being limited to the description of the example shown below. In the drawings referred to in this embodiment, the same parts or parts having similar functions are designated by the same reference numerals or the same reference numerals followed by alphabets, and repeated description thereof may be omitted.

[0013] In the specification and claims of this application, "up" refers to the direction vertically away from the installation surface (e.g., the factory floor) of the cleaning device when the cleaning device is installed in a state where it can be used normally, and "down" refers to the direction opposite to "up."

[0014] First Embodiment As an example of a cleaning apparatus according to an embodiment of the present invention, a wafer container cleaning apparatus will be described. However, the embodiment of the cleaning apparatus is not limited to a wafer container cleaning apparatus, and can be applied to cleaning apparatuses for cleaning other processing objects. For example, the cleaning apparatus can be applied to cleaning apparatuses for other purposes, such as a cleaning apparatus for cleaning containers that store glass substrates or a cleaning apparatus for cleaning medical instruments.

[0015] [Configuration of Wafer Container Cleaning Apparatus 100] FIG. 1 is a plan view schematically illustrating the overall configuration of a wafer container cleaning apparatus 100 according to a first embodiment. The wafer container cleaning apparatus 100 is installed, for example, in a semiconductor wafer manufacturing factory and cleans used wafer containers. The wafer container cleaning apparatus 100 of this embodiment includes a casing 10, a load port 20, a transfer mechanism 30, a disassembly / connection stage 40, a cleaning processing unit 50, a drying processing unit 60, an unload port 70, and a control unit 80. However, the configuration of the wafer container cleaning apparatus 100 is not limited to this example; some of the components shown in FIG. 1 may be omitted, or other components may be added.

[0016] The casing 10 is a housing that protects the wafer container cleaning apparatus 100. The casing 10 houses the above-mentioned transfer mechanism 30, disassembly / connection stage 40, cleaning processing section 50, and drying processing section 60. On the other hand, the load port 20 and unload port 70 are provided across the inside and outside of the casing 10. Although FIG. 1 shows an example in which the control section 80 is disposed inside the casing 10, it may also be disposed outside the casing 10.

[0017] The load port 20 is a component for loading a wafer container 90, which is an object to be cleaned, into the wafer container cleaning apparatus 100. The wafer container 90 is, for example, a FOUP or FOSB. The wafer container 90 is first placed in a portion of the load port 20 located outside the casing 10. When a loading gate 11 provided on the casing 10 opens, the wafer container 90 moves to a portion of the load port 20 located inside the casing 10. The wafer container 90 is moved by a transport device such as a slide conveyor (not shown). The loading gate 11 then closes, completing the loading of the wafer container 90.

[0018] The transfer mechanism 30 is a component that transfers the wafer storage container 90 to each component. The transfer mechanism 30 includes a transfer arm 31 and a gripping hand 32. The transfer mechanism 30 transfers the wafer storage container 90 to each component by extending, contracting, and rotating the transfer arm 31 while gripping the wafer storage container 90 with the gripping hand 32. Due to this configuration, the transfer mechanism 30 is also called a transfer robot.

[0019] The disassembly / connection stage 40 is a component that disassembles the wafer storage container 90 into a container body (also called a shell) 91 (see FIG. 2) and a lid (also called a door) 92, and connects the container body 91 and the lid 92. The wafer storage container 90, transported from the load port 20 by the transfer mechanism 30, is disassembled into the container body 91 and the lid 92 while being fixed on the disassembly / connection stage 40. After the wafer storage container 90 has completed the drying process in the drying process unit 60 (described later), the wafer storage container 90 is transported from the drying process unit 60 by the transfer mechanism 30 to the disassembly / connection stage 40, where the container body and the lid are reconnected.

[0020] The cleaning processing unit 50 is a component that performs cleaning processing on the wafer storage container 90. The cleaning processing unit 50 includes a cleaning processing tank 51 and a cleaning liquid tank 52. The cleaning processing tank 51 is configured to be able to hold the wafer storage container 90 therein, and is equipped with a cleaning nozzle (not shown) that sprays cleaning liquid onto the wafer storage container 90. The interior of the cleaning processing tank 51 has a rotatable structure, and the container body 91 and lid 92 of the wafer storage container 90 can each be rotated at a predetermined speed during cleaning. The cleaning liquid tank 52 is a tank that stores cleaning liquid (e.g., pure water) to be supplied to the cleaning nozzle.

[0021] After being held inside the cleaning processing tank 51, the wafer storage container 90 is cleaned using a cleaning liquid supplied from the cleaning liquid tank 52. Specifically, the cleaning processing of the wafer storage container 90 is performed by spraying the cleaning liquid onto the rotating wafer storage container 90 using the cleaning nozzle described above. In this embodiment, the container body 91 and lid 92 of the wafer storage container 90 are transported separately from the disassembly / connection stage 40 and held in the cleaning processing tank 51 in a separated state. For example, the container body 91 of the wafer storage container 90 is held inside the container body of the cleaning processing tank 51, and the lid 92 of the wafer storage container 90 is held inside the cleaning processing tank 51 attached to the lid of the cleaning processing tank 51.

[0022] The cleaning processing unit 50 is equipped with a drying means for preliminary drying, and is capable of subjecting the wafer storage container 90 after cleaning to a drying process. As described above, the interior of the cleaning processing tank 51 is rotatable, and by increasing the rotation speed, the wafer storage container 90 after cleaning can be subjected to a spin drying process. The cleaning processing unit 50 is also capable of supplying heated dry air into the interior of the cleaning processing tank 51, and by performing spin drying while spraying dry air, it is possible to remove most of the water droplets adhering to the wafer storage container 90. After the wafer storage container 90 has completed preliminary drying, the container body and lid are transported separately to the drying processing unit 60.

[0023] The drying processing unit 60 is a component that performs a drying process (main drying) on ​​the wafer storage container 90 by drying under reduced pressure. The drying processing unit 60 includes a drying processing tank 61, an exhaust device 62, and an air supply device 63. The drying processing tank 61 is configured to be able to hold the wafer storage container 90 therein and is airtight enough to create a reduced pressure environment (vacuum environment) inside. As with the cleaning processing unit 50 described above, the container body 91 and lid 92 of the wafer storage container 90 are separately held inside the drying processing tank 61 and are individually dried. The exhaust device 62 is a device that reduces the internal pressure of the drying processing tank 61 to create a reduced pressure environment. The air supply device 63 is a device that increases the internal pressure of the drying processing tank 61 to return it to an atmospheric pressure environment, etc. Specific configurations of the drying processing tank 61, the exhaust device 62, and the air supply device 63 will be described later.

[0024] After being held inside the drying process tank 61, the wafer storage container 90 is subjected to a drying process (vacuum drying) by being placed in a reduced pressure environment. Specifically, reduced pressure drying is performed by placing the wafer storage container 90 inside and then reducing the pressure inside the drying process tank 61 using the exhaust device 62. The wafer storage container 90 placed in the reduced pressure environment dries as moisture such as water droplets adhering to the surface evaporates and disappears. Once the drying process of the wafer storage container 90 is complete, the inside of the drying process tank 61 is returned to an atmospheric pressure environment by the air supply device 63.

[0025] The drying process of this embodiment involves rapidly cooling water droplets adhering to the wafer storage container 90 by reducing the internal pressure of the drying process tank 61 at a faster rate than in the past (reducing pressure at a rate at which water droplets do not freeze). Details of the drying process of this embodiment will be described later.

[0026] When the drying process of the wafer storage container 90 is completed in the drying process unit 60, the wafer storage container 90 is returned to the disassembly / connection stage 40, and the container body 91 and the lid 92 are connected again. After the connection of the container body 91 and the lid 92 is completed, the wafer storage container 90 is transported to the unload port 70 by the transport mechanism 30.

[0027] The unload port 70 is a component for unloading the wafer container 90 to the outside of the wafer container cleaning apparatus 100. The wafer container 90 is first placed in a portion of the unload port 70 located inside the casing 10. When the unload gate 12 provided on the casing 10 opens, the wafer container 90 moves to a portion of the unload port 70 located outside the casing 10. Thereafter, the unload gate 12 closes, completing the unloading of the wafer container 90.

[0028] The control unit 80 controls the operation of the wafer container cleaning apparatus 100. The control unit 80 includes an arithmetic unit 81 and a storage device 82. The arithmetic unit 81 is, for example, a CPU (Central Processing Unit). The storage device 82 is, for example, a ROM (Read Only Memory). In the control unit 80, the arithmetic unit 81 reads and executes a control program 82a stored in the storage device 82, thereby controlling the operation of each component of the wafer container cleaning apparatus 100. The control program 82a includes a set of instructions for executing various processes, such as cleaning, drying, and transport processes. The components constituting the control unit 80 are not limited to those shown in FIG. 1. For example, the control unit 80 may include other components, such as a large-capacity storage device such as a hard disk for storing various data and a communication interface for communicating with an external network.

[0029] [Configuration of Drying Processing Unit 60] 2 is a diagram schematically illustrating the configuration of the drying processing unit 60 in the wafer container cleaning apparatus 100 according to the first embodiment. As also illustrated in FIG. 1, the drying processing unit 60 includes a drying processing tank 61, an exhaust unit 62, and an air supply unit 63. However, the configuration of the drying processing unit 60 illustrated in FIG. 2 is merely an example and is not limited to this example. For example, the drying processing unit 60 may further include other components, such as a pressure sensor that detects the internal pressure of the drying processing tank 61 and an analyzer that measures the internal state of the drying processing tank 61 (e.g., the number of particles, the size of water droplets adhering to the wafer container 90, etc.).

[0030] The drying tank 61 includes a tank body 61a, a lid 61b, and a container mounting portion 61c. The wafer storage container 90 is disassembled into the container body 91 and the lid 92 prior to the cleaning process in the previous step, and these are held separately inside the drying tank 61. Specifically, the container body 91 is held on the container mounting portion 61c, and the lid 92 is held on the lid 61b of the drying tank 61. Inside the tank body 61a, the container body 91 is fixed onto the container mounting portion 61c with holders such as claws. Furthermore, the lid 92 of the wafer storage container 90 is fixed to the lid 61b of the drying tank 61 with holders such as claws, facing the container body 91. In practice, the container body 91 and lid 92 of the wafer storage container 90 are fixed to the container mounting portion 61c and lid 61b of the tank body 61a, respectively, and then the lid 61b is closed to the tank body 61a, resulting in the state shown in Figure 2.

[0031] The exhaust device 62 is connected below the tank main body 61a. The exhaust device 62 in this embodiment includes an exhaust pipe 62a, a pressure reducing device 62b, and a control valve 62c. The exhaust pipe 62a is connected to the interior of the drying treatment tank 61 and exhausts gas (e.g., water vapor) inside the tank main body 61a to the outside. The position to which the exhaust device 62 is connected is not limited to below the drying treatment tank 61, but it is preferable to connect the exhaust device 62 below the drying treatment tank 61 to prevent particles from adhering to the wafer storage container 90. This is because, with such a structure, gas generated inside the drying treatment tank 61 becomes a downward flow and moves downward.

[0032] The pressure reducing device 62b is a device that reduces the internal pressure of the drying treatment tank 61 (i.e., reduces the pressure) to form a vacuum. Specifically, the pressure reducing device 62b is a vacuum pump. The vacuum pump may be, but is not limited to, a dry pump, a mechanical booster pump, a turbomolecular pump, a rotary pump, or the like. In the example shown in FIG. 2, only one pressure reducing device 62b is shown, but a combination of multiple vacuum pumps may also be used as the pressure reducing device 62b.

[0033] The control valve 62c is a valve that controls the flow rate of gas flowing through the exhaust pipe 62a, and may be, for example, a vacuum valve such as a gate valve. The control valve 62c is controlled by the control unit 80 shown in Fig. 1. Specifically, in accordance with commands of a control program 82a executed by the control unit 80, the control valve 62c is controlled to be in an open state when a decompression process (vacuum drawing) is performed using the decompression device 62b.

[0034] The air supply device 63 is connected to the side of the drying treatment tank 61. The air supply device 63 increases (i.e., boosts) the internal pressure of the drying treatment tank 61 to release the vacuum. Specifically, the air supply device 63 has the role of supplying gas to the inside of the drying treatment tank 61, which is in a reduced pressure environment, and returning the internal pressure of the drying treatment tank 61 to atmospheric pressure or the like. The position at which the air supply device 63 is connected is not limited to the side of the drying treatment tank 61, but as mentioned above, it is preferable to connect the air supply device 63 so that a downward flow is formed inside the drying treatment tank 61.

[0035] The gas supply device 63 includes an air supply pipe 63a and a control valve 63b. The air supply pipe 63a is in communication with the interior of the drying treatment tank 61 and supplies gas (e.g., dry gas such as dry air or dry nitrogen) to the interior of the drying treatment tank 61. The control valve 63b controls the flow rate of the gas flowing through the air supply pipe 63a, and may be, for example, a vacuum valve such as a gate valve. The control valve 63b is controlled by the control unit 80 shown in FIG. 1, similar to the control valve 62c of the exhaust device 62.

[0036] The drying processing unit 60 described above performs drying processing under the control of the control unit 80. Specifically, after the post-cleaning processing wafer storage container 90 is held inside the drying processing tank 61, the exhaust device 62 is controlled to perform decompression processing to reduce the internal pressure of the drying processing tank 61, and drying processing is performed on the wafer storage container 90 by decompression drying. After the drying processing is completed, the air supply device 63 is controlled to perform pressure increase processing to increase the internal pressure of the drying processing tank 61, and the inside of the drying processing tank 61 is returned to an atmospheric pressure environment or the like.

[0037] The basic operation of the drying processing unit 60 has been described above, but the wafer container cleaning apparatus 100 of this embodiment is characterized by the specific content of the drying processing. The drying processing method for the wafer container 90 in the wafer container cleaning apparatus 100 of this embodiment will be specifically described below.

[0038] [Background to the invention] In the course of their research into drying processes using reduced pressure drying, the inventors discovered that when pressure is reduced rapidly, water droplets larger than a certain size (for example, millimeter-order size) tend to burst and scatter during the process (in other words, the water droplets burst). This phenomenon is explained schematically using Figure 3.

[0039] 3 is a schematic diagram illustrating the phenomenon in which water droplets 1 adhering to a wafer storage container 90 burst during reduced-pressure drying. The state shown at "t=t0" indicates the state before the reduced-pressure process begins, and the interior of the drying process tank 61 is in an atmospheric pressure environment at room temperature (25°C in this case). At this time, the wafer storage container 90 and the water droplets 1 adhering to it, which are in the same environment, are also at room temperature. Here, the state is shown in which water droplets 1 of a predetermined size or larger (for example, 1 mm or larger) are adhering to the surface of the wafer storage container 90.

[0040] The state shown at "t=t1" indicates the state after a predetermined time t1 has elapsed since the start of the decompression process, and the inside of the drying process tank 61 is in a decompression environment. When the decompression process is performed, the boiling point of the water droplets 1 decreases as the internal pressure of the drying process tank 61 decreases, thereby accelerating the evaporation of the water droplets 1, as indicated by the arrows. The water droplets 1 evaporate while absorbing heat (heat of vaporization) from their surroundings, so the temperature of the water droplets 1 also decreases as the internal pressure of the drying process tank 61 decreases. In other words, in the state shown at "t=t1," the water droplets 1 evaporate while their own temperature decreases as the internal pressure of the drying process tank 61 decreases.

[0041] The state shown at "t=t2" indicates the state after a predetermined time t2 (>t1) has elapsed since the start of the decompression process. In the state shown at "t=t2," the surface temperature of the water droplet 1 drops below 0°C due to the temperature drop caused by the decompression. In this state, only the surface of the water droplet 1 freezes, forming a thin ice film (hereinafter referred to as "frozen portion 2"), while the rest of the water droplet 1 remains liquid. However, whether the state shown at "t=t2" can be achieved is thought to depend on the size of the water droplet 1. In other words, if the size of the water droplet 1 is small, it is thought that the entire water droplet 1 will evaporate before the frozen portion 2 is formed, and the water droplet 1 will disappear. Therefore, the state shown at "t=t2" can be said to occur in water droplets 1 that are large enough that a liquid portion will remain when the frozen portion 2 is formed. According to the inventors' findings, water droplets on the order of millimeters (i.e., 1 mm or larger) can potentially reach the state shown at "t=t2."

[0042] The inventors speculate that the reason why the water droplets burst when a rapid depressurization process is performed is due to the freezing of the surface of the water droplets 1 described above. The temperature of the water droplets 1 decreases as the internal pressure of the drying process tank 61 decreases, and the greater the degree of decrease in internal pressure (i.e., the depressurization rate), the greater the degree of temperature decrease of the water droplets 1. Therefore, the inventors speculate that when the internal pressure of the drying process tank 61 is rapidly reduced, a temperature difference occurs between the surface and the interior of the water droplets 1 due to the sudden temperature drop, and the surface, which has reached 0°C, freezes. The reason for the temperature difference is speculated to be that the temperature of the surface of the water droplets 1 drops rapidly due to rapid evaporation caused by the depressurization, while the temperature inside the water droplets 1 does not drop as much as the surface due to heat conduction from the wafer storage container 90.

[0043] Furthermore, in the state shown at "t=t2", it is expected that the surface temperature of the water droplet 1 reaches 0°C and freezes, while the liquid inside the water droplet 1 continues to evaporate due to the pressure reduction. In other words, in the state shown at "t=t2", the water droplet 1 continues to expand in volume due to evaporation inside the freezing section 2, while the pressure from inside the freezing section 2 (pressure due to the volume expansion) increases as the internal pressure of the drying treatment tank 61 decreases.

[0044] The state shown at "t=t3" indicates the state after a predetermined time t3 has elapsed since the start of the decompression process. The inventors believe that the phenomenon of water droplet 1 bursting, as described above, occurs when frozen portion 2 can no longer withstand the increase in internal pressure. That is, as shown at "t=t3," when the internal pressure on frozen portion 2 increases further and frozen portion 2 can no longer withstand the pressure, frozen portion 2 is destroyed. As a result, the pressure that has built up inside frozen portion 2 is suddenly released, and water droplet 1 is thought to scatter into multiple ice fragments and multiple small water droplets.

[0045] As described above, the inventors speculate that the water droplets 1 adhering to the wafer storage container 90 are locally frozen only on the surface due to the rapid decompression process, and that the liquid portion continues to evaporate inside the frozen portion 2 formed on the surface. They further speculate that when the frozen portion 2 finally becomes unable to withstand the internal pressure and breaks down, the water droplets 1 break into multiple particles and burst as the pressure is released.

[0046] Based on the findings described above, the inventors came up with the idea of ​​utilizing the above-mentioned phenomenon of water droplets 1 bursting to change water droplets 1 larger than a predetermined size into smaller droplets, thereby eliminating poor drying caused by the entire water droplet freezing. A drying method according to one embodiment of the present invention based on this idea will now be described.

[0047] [Drying process configuration] 4 is a diagram for explaining the drying process method performed in the wafer container cleaning apparatus 100 according to the first embodiment. In FIG. 4, the horizontal axis represents time, and the vertical axis represents the internal pressure of the drying process tank 61. That is, FIG. 4 shows the change in the internal pressure of the drying process tank 61 over time in the drying process of this embodiment. The drying process method of this embodiment will be described below in order of the passage of time shown in FIG. 4.

[0048] The drying treatment method described below is carried out by the control unit 80 shown in Fig. 1 controlling the drying treatment unit 60. Specifically, in the control unit 80, the arithmetic unit 81 reads out and executes a control program 82a (here, a control program for controlling the drying treatment) from the storage device 82, thereby controlling the operations of the drying treatment tank 61, the exhaust device 62, and the air supply device 63.

[0049] 4, the internal pressure of the drying processing tank 61 is pressure P0 until time T1. In this embodiment, pressure P0 is atmospheric pressure. However, pressure P0 is not limited to atmospheric pressure and may be other pressures. In this embodiment, pressure P0 simply means the initial value of the internal pressure of the drying processing tank 61 immediately before the drying processing is performed.

[0050] Next, the control unit 80 controls the exhaust device 62 to perform a decompression process (hereinafter referred to as a "first decompression process") that rapidly reduces the internal pressure of the drying processing tank 61 from pressure P0 (atmospheric pressure) to pressure P1. Specifically, the control unit 80 opens the control valve 62c of the exhaust device 62 and operates the decompression device 62b to evacuate the inside of the drying processing tank 61. In FIG. 4, the process performed from time T1 to time T2 corresponds to the first decompression process.

[0051] The pressure P1 is 500 Pa or less (preferably 100 Pa or less, and more preferably 50 Pa or less). However, the pressure P1 may be a pressure that exceeds 500 Pa as long as the entire surface of the water droplets present inside the drying treatment tank 61 freezes when the internal pressure of the drying treatment tank 61 reaches the pressure P1. In this embodiment, the pressure P1 is set to 30 Pa.

[0052] In this embodiment, the internal pressure of the drying treatment tank 61 is reduced from atmospheric pressure (P0) to 30 Pa (P1) within one minute. In FIG. 4, time T2 is the time when the internal pressure of the drying treatment tank 61 reaches 30 Pa (P1), and the difference between time T1 when the first depressurization treatment starts and time T2 when the first depressurization treatment ends is one minute or less. The range of "within one minute" is set as an effective range for shortening the time required for the drying treatment. The drying treatment method of this embodiment is intended to rapidly reduce the internal pressure of the drying treatment tank 61 from atmospheric pressure to a pressure P1 of 500 Pa or less, and does not preclude depressurization over a period of more than one minute. However, as will be described later, if the first depressurization treatment is repeated multiple times, it is desirable to limit the time required for the first depressurization treatment to one minute or less.

[0053] As described above, in this embodiment, the first decompression process is performed to reduce the internal pressure of the drying processing tank 61 more rapidly than in the past, thereby causing the water droplets to explode as described with reference to Fig. 3. Specifically, as shown in Fig. 4, a decompression process is performed to reduce the internal pressure of the drying processing tank 61 from atmospheric pressure to 30 Pa within one minute. That is, in the drying processing method of this embodiment, the first decompression process is performed to cause water droplets of a predetermined size or larger (e.g., 1 mm or larger) adhering to the wafer storage container 90 to explode, changing them into multiple small water droplets less than 1 mm in size.

[0054] Next, after the internal pressure of the drying treatment tank 61 reaches pressure P1 through the first depressurization process, the control unit 80 controls the air supply device 63 to execute a pressure increase process (hereinafter referred to as the "first pressure increase process") to increase the internal pressure of the drying treatment tank 61 to pressure P2 of 80 kPa or higher. Specifically, the control unit 80 closes the control valve 62c while keeping the depressurization device 62b of the exhaust device 62 in operation, and opens the control valve 63b of the air supply device 63 to supply dry gas such as dry air into the drying treatment tank 61. The supply of gas into the drying treatment tank 61 increases the internal pressure of the drying treatment tank 61. In FIG. 4, the process executed between time T2 and time T3 corresponds to the first pressure increase process.

[0055] The water droplets (including fragments of the frozen portion 2) that burst during the first decompression process described above break into smaller droplets and adhere to the inner wall of the drying process tank 61 or to another portion of the wafer storage container 90 again. If the water droplets do not adhere to the wafer storage container 90 again, there is no problem in ending the drying process at that point. However, if the water droplets reattach, they must be removed. The scattered water droplets may contain fragments of ice (frozen portion), but frozen water droplets hardly evaporate even in a decompressed environment. Therefore, in the drying process method of this embodiment, a process is performed to temporarily return the internal pressure of the drying process tank 61 to near atmospheric pressure in order to return the frozen water droplets to a liquid (thaw).

[0056] In this embodiment, the pressure P2 is set to 80 kPa. The pressure P2 is set so that when the internal pressure of the drying tank 61 reaches pressure P2, the ice present inside the drying tank 61 will be sufficiently thawed. Therefore, the pressure may be lower than 80 kPa as long as it is a pressure that will thaw the ice present inside the drying tank 61. The pressure P2 may also be atmospheric pressure. If the pressure P2 is atmospheric pressure, no particularly precise control is required, and the drying tank 61 may simply be opened to the atmosphere. On the other hand, if it takes time to return the internal pressure of the drying tank 61 to atmospheric pressure, the pressure may only be increased to a pressure lower than atmospheric pressure in order to shorten the time required for the drying process.

[0057] As described above, the drying method of this embodiment includes a process in which water droplets of a predetermined size or larger are split by a first decompression process, and the resulting ice (frozen portions) fragments are returned to liquid form by a first pressure increase process subsequent to the first decompression process.

[0058] Next, after the internal pressure of the drying treatment tank 61 reaches pressure P2 through the first pressure increase process, the control unit 80 controls the exhaust device 62 to perform a decompression process (hereinafter referred to as a "second decompression process") to rapidly reduce the internal pressure of the drying treatment tank 61 from pressure P2 to pressure P1. Specifically, the control unit 80 closes the control valve 63b of the air supply device 63 and opens the control valve 62c of the exhaust device 62, causing the decompression device 62b to evacuate the interior of the drying treatment tank 61. In this embodiment, the internal pressure of the drying treatment tank 61 is reduced from 80 kPa (P2) to 30 Pa (P1) within one minute. In FIG. 4, the process performed between time T3 and time T4 corresponds to the second decompression process.

[0059] The second depressurization process is essentially the same as the first depressurization process. The difference between the first and second depressurization processes is the internal pressure of the drying process tank 61 at the start of the depressurization process. However, while the first depressurization process starts from atmospheric pressure, the second depressurization process starts at a pressure of 80 kPa or higher (including atmospheric pressure), so there is not much difference in the actual depressurization speed. Therefore, by performing the second depressurization process, like the first depressurization process, water droplets of a predetermined size or larger adhering to the wafer container 90 can be caused to burst and turn into multiple small water droplets or ice fragments.

[0060] The second depressurization process is a process that is performed preliminarily in case water droplets of a size equal to or larger than the predetermined size remain even after the first depressurization process. Therefore, if the water droplets attached to the wafer container 90 are sufficiently small by the first depressurization process, the second depressurization process can be omitted.

[0061] Next, after the internal pressure of drying processing tank 61 reaches pressure P1 through the second depressurization process, control unit 80 controls air supply device 63 to execute a pressure increase process (hereinafter referred to as the "second pressure increase process") to increase the internal pressure of drying processing tank 61 to pressure P2 of 80 kPa or higher. The second pressure increase process executed here (corresponding to the process executed between time T4 and time T5 in FIG. 4) is the same process as the first pressure increase process executed between time T2 and time T3. This second pressure increase process can return the ice fragments scattered inside drying processing tank 61 through the second depressurization process to a liquid state again.

[0062] Next, after the internal pressure of the drying treatment tank 61 reaches pressure P2 through the second pressure increase process, the control unit 80 controls the exhaust device 62 to perform a depressurization process (hereinafter referred to as a "third depressurization process") to reduce the internal pressure of the drying treatment tank 61 from pressure P2 to pressure P1. Specifically, the control unit 80 closes the control valve 63b of the air supply device 63 and opens the control valve 62c of the exhaust device 62, causing the depressurization device 62b to evacuate the drying treatment tank 61. However, in the third depressurization process, the internal pressure of the drying treatment tank 61 may be reduced from 80 kPa (P2) to a pressure (P3) of 500 Pa or less over a period of more than one minute. In FIG. 4, the process performed between time T5 and time T6 corresponds to the third depressurization process.

[0063] Unlike the first and second decompression processes, the third decompression process does not aim to freeze the entire surface of the water droplets and cause them to explode into smaller droplets. In other words, the third decompression process can be a conventional drying process using reduced pressure drying. In this case, the pressure P3 can be set to a pressure that does not cause the water droplets to freeze. For example, in this embodiment, the pressure P3 is set to 2 kPa. However, this is not limited to this example, and the pressure P3 can be set to any pressure that allows reduced pressure drying.

[0064] 4, the depressurization speed of the third depressurization process may be slower than that of the first depressurization process and the second depressurization process. However, from the viewpoint of shortening the time required for the entire drying process, it is preferable to make the time required for the third depressurization process (the time from time T5 to time T6) as short as possible. At the time when the third depressurization process is performed, the first depressurization process and at least one second depressurization process have already been performed, so it is highly likely that there are no water droplets larger than the aforementioned predetermined size in the wafer storage container 90. Therefore, regardless of the depressurization speed at which the third depressurization process is performed, it is considered that the water droplets will evaporate and disappear faster than they will freeze all at once.

[0065] As described above, the drying method of this embodiment performs a first decompression process in which decompression is performed at a rapid decompression rate and at least one second decompression process, and then performs a drying process using normal decompression drying, thereby making it possible to completely dry the wafer storage container 90 in a shorter time than conventional methods.

[0066] Finally, after the pressure reaches pressure P3 through the third depressurization process, the control unit 80 controls the air supply device 63 to perform a pressure increase process (hereinafter referred to as the "third pressure increase process") to increase the internal pressure of the drying process tank 61 to atmospheric pressure (P0). The third pressure increase process corresponds to the process performed between time T6 and time T7 in FIG. 4. When the internal pressure of the drying process tank 61 reaches atmospheric pressure, the drying process of this embodiment ends.

[0067] As described above, the wafer container cleaning apparatus 100 of this embodiment can perform a decompression process during the drying process, reducing the internal pressure of the drying tank 61 from atmospheric pressure (P0) or a pressure (P2) of 80 kPa or more to a pressure (P1) of 500 Pa or less within one minute. As a result, the wafer container cleaning apparatus 100 can change water droplets of a predetermined size or larger that adhere to the wafer container 90 during the drying process into multiple small water droplets that can be easily evaporated. In other words, this embodiment can provide a wafer container cleaning apparatus 100 that efficiently dries the wafer container 90, which is the processing object after cleaning.

[0068] Whether the water droplets 1 completely evaporate or the entire surface freezes and bursts as a result of the first and second decompression processes can vary depending on various factors, such as the size of the water droplets, the volume of the drying process tank 61, and the temperature of the wafer storage container 90. In this embodiment, the specific contents of the first and second decompression processes have been described as preferred aspects, but the decompression speed in the decompression processes can be adjusted as appropriate, taking into account the various factors described above.

[0069] In addition, in the exhaust device 62 of this embodiment, the control valve 62c is opened and closed while the pressure reducing device 62b is operating, but the present invention is not limited to this example. The pressure reducing device 62b may stop operating when the control valve 62c is closed, or may start operating when the control valve 62c is opened.

[0070] (Variation) In the first embodiment, an example was shown in which a second depressurization process was additionally performed after a first depressurization process, and finally a third depressurization process was performed. However, the drying process method performed by the wafer container cleaning apparatus 100 is not limited to this example. For example, a set of a second depressurization process and a subsequent second pressure increase process may be performed multiple times. If the water droplets adhering to the wafer container 90 are very large, there may be cases in which water droplets larger than a predetermined size remain even after the first depressurization process and the second pressure increase process are performed once each. In this case, it is effective to further perform a second depressurization process and a subsequent second pressure increase process, and repeatedly perform the second depressurization process and the second pressure increase process until the water droplets become sufficiently small.

[0071] Conversely, if there are no water droplets of a predetermined size or larger when the first depressurization process is completed, it is possible to omit the second depressurization process and directly perform the third depressurization process after the first pressure increase process. Of course, if there are no water droplets adhering to the wafer storage container 90 when the first depressurization process is completed, it is also possible to end the drying process at that point and open the drying process tank 61 to the atmosphere.

[0072] If necessary, the presence or absence of water droplets adhering to the wafer storage container 90 and the size of the water droplets may be visually observed through a window provided in the tank main body 61a of the drying processing tank 61, or an analytical device for detecting the presence or absence of water droplets and the size of the water droplets may be arranged in the drying processing unit 60.

[0073] Second Embodiment In the second embodiment, an example will be described in which the configuration of the drying processing unit in the wafer container cleaning apparatus is different from that in the first embodiment. Specifically, the wafer container cleaning apparatus of this embodiment differs from the first embodiment in that a heating device is provided inside the drying processing tank. Since the wafer container cleaning apparatus of this embodiment has a basic configuration similar to that of the wafer container cleaning apparatus 100 of the first embodiment, the description of this embodiment will focus on the structural differences. Components that are the same as those in the wafer container cleaning apparatus 100 of the first embodiment will be assigned the same reference numerals, and redundant description may be omitted.

[0074] Fig. 5 is a diagram schematically illustrating the configuration of a drying processing unit 65 in a wafer container cleaning apparatus according to the second embodiment. Fig. 6 is a diagram of a wafer container 90 arranged in the drying processing unit 65 shown in Fig. 5, viewed from the opening 91a side. The opening 91a is an opening for storing wafers in the container body 91.

[0075] 5 and 6, a plurality of heating devices 65a to 65e are provided inside the drying processing unit 65 of this embodiment. The plurality of heating devices 65a to 65e heat the wafer storage container 90 during the drying process. In this embodiment, the heating devices 65a to 65e are all infrared lamps, and the control unit 80 controls whether they are turned on (heated state) or off (non-heated state). However, the heating devices 65a to 65e are not limited to infrared lamps, and any means capable of heating the wafer storage container 90 may be used.

[0076] In this embodiment, the heating devices 65a and 65c are disposed near the upper corners of the container body 91 of the wafer storage container 90. Since the lid 92 of the wafer storage container 90 is disposed above the container body 91, the heating devices 65a and 65c have the role of heating the container body 91 as well as the role of heating the lid 92.

[0077] The heating devices 65b and 65d are disposed near the lower corners of the container body 91. Because a container mounting portion 61c for fixing the container body 91 is provided below the container body 91, the heating devices 65b and 65d not only heat the container body 91 but also heat the container mounting portion 61c. The container mounting portion 61c is equipped with a mechanism for fixing the container body 91, making its structure complex. For this reason, water droplets adhering to the container mounting portion 61c are difficult to remove by vacuum drying alone. In this embodiment, it is preferable to use the heating devices 65b and 65d to heat the container mounting portion 61c in addition to the wafer storage container 90 in order to improve the efficiency of the drying process.

[0078] The heating device 65e is disposed to face the opening 91a of the container body 91. Specifically, the heating device 65e is disposed near the opening 91a on the outside of the container body 91. The interior of the container body 91 (the portion that stores wafers) is provided with multiple storage compartments for holding wafers and has a more complex structure than the exterior. Therefore, water droplets adhering to the interior of the container body 91 tend to be more difficult to remove than from the exterior. Therefore, being able to heat the interior of the container body 91 with the heating device 65e is preferable in terms of improving the efficiency of the drying process. Note that, although an example is shown in FIGS. 5 and 6 in which the longitudinal direction of the heating device 65e extends in a direction substantially parallel to the upper surface of the container mounting portion 61c, the present invention is not limited to this example, and the longitudinal direction of the heating device 65e may extend in a direction substantially perpendicular to the upper surface of the container mounting portion 61c.

[0079] 5 and 6, in a plan view, the heating devices 65a to 65e are all configured to be disposed outside the container body 91. Therefore, when the container body 91 is placed on the container placing part 61c, the heating devices 65a to 65e do not interfere with the placement, and the time required for the drying process can be shortened.

[0080] As described above, in this embodiment, the wafer container 90 can be heated using the multiple heating devices 65a to 65e arranged inside the drying treatment tank 61. Heating the wafer container 90 can be performed in various ways. For example, the heating devices 65a to 65e may be used to heat the wafer container 90 during the first or second decompression treatment described in the first embodiment with reference to FIG. 4 . In this case, to prevent the water droplets from completely freezing during the first or second decompression treatment, the outputs of the heating devices 65a to 65e are adjusted so that the surface of the wafer container 90 is at room temperature (25°C) or a temperature range slightly higher than room temperature (e.g., a temperature range of 28°C to 35°C). The reason for maintaining the temperature of the wafer container 90 near room temperature is that if the temperature is raised too high, frozen portions may not form on the surface of the water droplets.

[0081] Furthermore, after the first or second decompression process is performed in the first embodiment, the heating devices 65a to 65e may be used to perform a drying process (heat drying) on ​​the wafer storage container 90 by heating. This drying process can be performed as an alternative to the third decompression process (drying process by decompression) in the first embodiment. That is, after the first decompression process (or the first and second decompression processes) is performed to cause water droplets of a predetermined size or larger adhering to the wafer storage container 90 to burst into multiple smaller droplets, the heating devices 65a to 65e can be used to heat and dry the scattered multiple droplets.

[0082] The heating devices 65a to 65e can also be used for both the heating process during the first depressurization process and the heating process during the final drying process. For example, in the first embodiment, the temperature of the wafer storage container 90 can be maintained near room temperature using the heating devices 65a to 65e while the first depressurization process and the second depressurization process are being performed, and then the set temperatures of the heating devices 65a to 65e can be increased to perform the final drying process.

[0083] Furthermore, the heating process on the wafer container 90 using the heating devices 65a to 65e may be performed in conjunction with the first pressure increase process, the second pressure increase process, or the third pressure increase process shown in Fig. 4. In this case, ice pieces adhering to the wafer container 90 can be more reliably thawed.

[0084] The control of the heating devices 65a to 65e described above is performed by the control unit 80. Regarding the control of the heating time, for example, the control unit 80 may control the lighting time of the heating devices 65a to 65e based on the elapsed time when the first depressurization process or the second depressurization process is controlled. Specifically, the control unit 80 may turn on the heating devices 65a to 65e when the first depressurization process or the second depressurization process is started, and may turn off the heating devices 65a to 65e when the first depressurization process or the second depressurization process is completed. Regarding the temperature control, a temperature sensor capable of detecting the temperature of the wafer storage container 90 may be disposed inside the drying process tank 61. In this case, the control unit 80 may perform feedback control, controlling the heating devices 65a to 65e based on the output of the temperature sensor so that the wafer storage container 90 is maintained at a predetermined temperature.

[0085] (Variation 1) In the example shown in Figures 5 and 6, a heating device 65e is placed outside and near the opening 91a to heat the inside of the container main body 91 of the wafer storage container 90, but the heating device 65e may also be placed inside the container main body 91.

[0086] Fig. 7 is a diagram schematically showing the configuration of a drying processing unit 65 in a wafer container cleaning apparatus according to a modified example of the second embodiment. Fig. 8 is a diagram showing a wafer container 90 arranged in the drying processing unit 65 shown in Fig. 7, viewed from the side of the opening 91a.

[0087] The example shown in FIGS. 7 and 8 is similar to the example shown in FIGS. 5 and 6 in that multiple heating devices 65a to 65e are provided. However, in the drying processing unit 65 according to this modification, the heating device 65e is disposed inside the container body 91. Specifically, as is clear from FIGS. 7 and 8, the heating device 65e is disposed at a position overlapping the container body 91 in a side view or a plan view. As described above, the inside of the container body 91 has a complex structure, and therefore, water droplets adhering thereto tend to be more difficult to remove than from the outer surface. In the configuration of this modification, the heating device 65e is disposed inside the container body 91, so that the inside of the container body 91 can be efficiently heated, thereby improving the efficiency of the drying process.

[0088] In this modified example, the heating device 65e is disposed on the line of movement when the container body 91 of the wafer storage container 90 is installed in the container body 61a of the drying processing tank 61, and therefore, the heating device 65e needs to be moved to a position away from the line of movement when the container body 91 is installed. For this reason, although not shown, a moving mechanism for moving the heating device 65e is provided inside the drying processing tank 61 of this modified example.

[0089] (Variation 2) The drying processing unit 65 of this embodiment may include a moving mechanism for individually moving the heating devices 65a-65e. That is, the drying processing unit 65 may be configured to change the position of each of the heating devices 65a-65e. In this case, the position of each of the heating devices 65a-65e can be changed to an appropriate position according to the size of the wafer storage container that is the target of the drying processing, thereby improving the efficiency of the drying processing.

[0090] Third Embodiment In the first and second embodiments, a wafer container cleaning apparatus has been described as an embodiment of the present invention, but the embodiments of the present invention are not limited to these examples. For example, the drying unit 60 described in the first embodiment or the drying unit 65 described in the second embodiment can also be implemented as an external drying unit. For example, the wafer container cleaning apparatus 100 of the first embodiment may be configured such that a drying unit having the functions of the drying unit 60 is externally connected to the wafer container cleaning apparatus having a configuration other than the drying unit 60. In this case, the wafer container cleaned in the cleaning unit 50 is transported to the external drying unit having the functions of the drying unit 60 and dried.

[0091] The cleaning device according to one embodiment of the present invention has been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiments (including variations; the same applies below), and can be modified as appropriate without departing from the spirit of the present invention. For example, even if a person skilled in the art appropriately adds, deletes, or modifies components based on each embodiment, this also falls within the scope of the present invention as long as the gist of the present invention is maintained. Furthermore, the configurations according to the above-described embodiments can be appropriately combined as long as there are no mutual contradictions, and technical matters common to each embodiment are included in each configuration even if not explicitly stated.

[0092] Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0093] 1...water droplet, 2...freezing section, 10...casing, 11...loading gate, 12...exporting gate, 20...load port, 30...transport mechanism, 31...transport arm, 32...grasping hand, 40...disassembly / connection stage, 50...cleaning section, 51...cleaning tank, 52...cleaning liquid tank, 60...drying section, 61...drying tank, 61a...tank main body, 61b...lid, 61c...container mounting section, 62...exhaust device, 62a ...exhaust pipe, 62b...pressure reducing device, 62c...control valve, 63...air supply device, 63a...air supply pipe, 63b...control valve, 65...drying processing unit, 65a to 65e...heating device, 70...unload port, 80...control unit, 81...arithmetic unit, 82...storage device, 82a...control program, 90...wafer storage container, 91...container main body, 91a...opening, 92...lid, 100...wafer storage container cleaning device

Claims

1. a cleaning processing unit that cleans the processing object; a drying processing unit that dries the processing object; a control unit that controls the cleaning processing unit and the drying processing unit to perform cleaning processing and drying processing of the processing object; Equipped with the drying processing unit includes a drying processing tank capable of holding the processing object therein and an exhaust device for reducing an internal pressure of the drying processing tank, In the drying process, the control unit controls the exhaust device to perform a first decompression process to reduce the internal pressure of the drying process tank from atmospheric pressure to a first pressure of 500 Pa or less within one minute.

2. the drying processing unit further includes an air supply device for increasing the internal pressure of the drying processing tank; 2. The cleaning apparatus according to claim 1, wherein after the internal pressure of the drying processing tank reaches the first pressure by the first decompression processing, the control unit controls the air supply device to execute a first pressure increase processing to increase the internal pressure of the drying processing tank to a second pressure of 80 kPa or more.

3. 3. The cleaning apparatus according to claim 2, wherein, after the internal pressure of the drying treatment tank reaches the second pressure by the first pressure increase process, the control unit controls the exhaust device to perform a second pressure decrease process to reduce the internal pressure of the drying treatment tank from the second pressure to the first pressure within one minute.

4. 4. The cleaning device according to claim 3, wherein after the internal pressure of the drying processing tank reaches the first pressure by the second decompression processing, the control unit controls the air supply device to execute a second pressure increase processing to increase the internal pressure of the drying processing tank to a second pressure of 80 kPa or more.

5. The cleaning apparatus according to claim 4 , wherein the control unit controls the exhaust device and the air supply device to repeatedly perform the second depressurization process and the second pressure increase process multiple times.

6. The cleaning apparatus according to claim 1 , wherein the drying processing section further includes a heating device disposed inside the drying processing tank for heating the object to be processed.

7. The cleaning apparatus according to claim 6 , wherein the control unit controls the heating device to perform a heating process for heating the object to be treated when the first depressurization process is performed.

8. The cleaning apparatus according to claim 6 , wherein the control unit controls the heating device to perform a heat treatment for heating the treatment object after performing the first depressurization treatment.

9. The cleaning apparatus according to claim 1 , wherein the first pressure is a pressure of 50 Pa or less.

10. The cleaning apparatus of claim 2 , wherein the second pressure is atmospheric pressure.

11. 2. The cleaning apparatus according to claim 1, wherein the object to be treated is a wafer container.

12. a drying processing section that dries the processing object; a control unit that controls the drying processing unit to perform drying processing on the processing object; Equipped with the drying processing unit includes a drying processing tank capable of holding the processing object therein and an exhaust device for reducing an internal pressure of the drying processing tank, In the drying process, the control unit controls the exhaust device to perform a decompression process to reduce the internal pressure of the drying process tank from atmospheric pressure to a pressure of 500 Pa or less within one minute.

13. The object to be dried is placed inside the drying tank. and performing a first decompression process to reduce the internal pressure of the drying tank from atmospheric pressure to a first pressure of 500 Pa or less within one minute by controlling an exhaust device connected to the drying tank.

14. 14. The drying method according to claim 13, further comprising: performing a first pressure increase process to increase the internal pressure of the drying tank to a second pressure of 80 kPa or more by controlling an air supply device connected to the drying tank after the internal pressure of the drying tank has reached the first pressure through the first decompression process.

15. 15. The drying method according to claim 14, further comprising: after the internal pressure of the drying tank reaches the second pressure by the first pressure increase process, controlling the exhaust device to perform a second pressure decrease process to reduce the internal pressure of the drying tank from the second pressure to the first pressure within one minute.

16. 16. The drying method according to claim 15, further comprising: performing a second pressure increase process to increase the internal pressure of the drying tank to a second pressure of 80 kPa or more by controlling an air supply device connected to the drying tank after the internal pressure of the drying tank reaches the first pressure through the second decompression process.

17. The drying method according to claim 16, further comprising controlling the exhaust device and the air supply device to repeatedly perform the second depressurization process and the second pressure increase process multiple times.

18. The drying method according to claim 13, further comprising controlling a heating device disposed inside the drying processing tank to perform a heating process for heating the object to be processed when the first decompression process is performed.

19. 14. The drying method according to claim 13, further comprising controlling a heating device disposed inside the drying tank to perform a heating process for heating the object to be treated after the internal pressure of the drying tank reaches the first pressure by the first decompression process.

20. The drying method according to claim 13 , wherein the first pressure is a pressure of 50 Pa or less.

21. The drying process according to claim 14, wherein the second pressure is atmospheric pressure.

22. The drying method according to claim 13, wherein the object to be processed is a wafer container.

Images