Cleaning device, drying device and drying treatment method

Abstract

The invention provides a cleaning device, a drying device and a drying processing method which can efficiently dry a processed object after cleaning. The cleaning apparatus includes: a cleaning processing unit configured to clean an object to be processed; a drying processing unit for drying the object to be processed; and a control unit that controls the cleaning processing unit and the drying processing unit to perform cleaning processing and drying processing of the object to be processed, the drying processing unit including 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. In the drying treatment, the control unit controls the exhaust device to execute a first pressure reduction treatment in which the internal pressure of the drying treatment tank is reduced from atmospheric pressure to a first pressure of 500 Pa or less within one minute.

Description

Technical Field

[0001] One embodiment of the present invention relates to a cleaning apparatus, a drying apparatus, and a drying method. In particular, one embodiment of the present invention relates to a wafer container cleaning apparatus in which a wafer container is used as a processing target. Background Art

[0002] Conventionally, in the semiconductor device manufacturing process, wafer storage containers such as front-opening unified pods (FOUPs) and front-opening shipping boxes (FOSBs) are used to store (contain) semiconductor wafers. Wafer storage containers can sometimes become contaminated during storage of semiconductor wafers, and therefore require regular cleaning. Known cleaning devices for cleaning wafer storage containers include a cleaning tank and a drying tank. For example, Patent Document 1 discloses a method of cleaning a wafer storage container by alternately repeating ultrasonic cleaning and high-pressure spray cleaning in a cleaning tank, followed by drying the cleaned wafer storage container by repeating hot air heating and reduced-pressure drying in a drying tank.

[0003] [Prior art literature]

[0004] [Patent Document]

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-126678 Summary of the Invention

[0006] [Problems to be solved by the invention]

[0007] As previously mentioned, conventional wafer container cleaning systems use reduced-pressure drying to dry wafer containers. Reduced-pressure drying is a drying method that places the object to be dried under a reduced-pressure environment, thereby lowering the boiling point of water droplets adhering to the surface of the object and causing it to evaporate. To dry a wafer container under reduced-pressure, the processing tank containing the cleaned wafer container is evacuated, and the drying process is continued for a sufficient period of time until all the water adhering to the container has evaporated.

[0008] However, during their repeated research into drying methods using reduced-pressure drying, the inventors of the present invention came to the attention of the following observation: even under specified conditions, even after a sufficiently long period of reduced-pressure drying, water droplets still remained in the wafer storage container. The inventors speculated that this might be due to freezing of the water droplets in the reduced-pressure environment. Specifically, they considered whether the temperature of the water droplets dropped during the reduced-pressure drying process due to the heat of vaporization, causing the entire water droplet to freeze, thereby hindering its subsequent vaporization.

[0009] Based on the above speculation, the inventors have devoted themselves to various attempts, such as implementing reduced pressure drying under conditions where water droplets will not freeze (for example, a pressure range where water droplets will not freeze), but there is still room for improvement in terms of improving the efficiency of the chip storage container cleaning device, such as further shortening the processing time.

[0010] One of the objects of the present invention is to provide a cleaning apparatus that can efficiently dry a cleaned object.

[0011] [Technical means to solve the problem]

[0012] A cleaning device according to one embodiment of the present invention includes: a cleaning processing unit for cleaning a processing object; a drying processing unit for drying the processing object; and a control unit for controlling the cleaning processing unit and the drying processing unit to perform cleaning and drying processing of the processing object, wherein the drying processing unit includes a drying processing tank capable of retaining the processing object therein, and an exhaust device for reducing the internal pressure of the drying processing tank. During the drying processing, the control unit controls the exhaust device to perform a first decompression processing, which is a processing for reducing the internal pressure of the drying processing tank from atmospheric pressure to a first pressure below 500 Pa within one minute.

[0013] A drying device according to one embodiment of the present invention includes: a drying processing unit for drying a processing object; and a control unit for controlling the drying processing unit to perform drying processing of the processing object, wherein the drying processing unit includes a drying processing tank capable of retaining the processing object therein, and an exhaust device for reducing the internal pressure of the drying processing tank. During the drying processing, the control unit controls the exhaust device to perform a decompression process, wherein the decompression process is a process for reducing the internal pressure of the drying processing tank from atmospheric pressure to a pressure below 500 Pa within one minute.

[0014] A drying treatment method according to one embodiment of the present invention includes: placing an object to be dried inside a drying treatment tank, controlling an exhaust device connected to the drying treatment tank to perform a first decompression treatment, wherein the first decompression treatment is a treatment for reducing the internal pressure of the drying treatment tank from atmospheric pressure to a first pressure below 500 Pa within one minute. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a plan view schematically showing the overall structure of the wafer storage container cleaning apparatus according to the first embodiment.

[0016] Figure 2 This is a diagram schematically showing the configuration of a drying process section in the wafer container cleaning apparatus according to the first embodiment.

[0017] Figure 3 This is a schematic diagram for explaining the phenomenon of water droplets adhering to a wafer storage container breaking up during reduced pressure drying.

[0018] Figure 4 It is a diagram for explaining the drying method performed in the wafer storage container cleaning apparatus according to the first embodiment.

[0019] Figure 5 This is a diagram schematically showing the configuration of a drying process section in a wafer container cleaning apparatus according to a second embodiment.

[0020] Figure 6 When viewed from the opening side, it is arranged Figure 5 FIG. 4 is a diagram of a wafer storage container in a drying process section.

[0021] Figure 7 This is a diagram schematically showing the configuration of a drying process section in a wafer container cleaning apparatus according to a modified example of the second embodiment.

[0022] Figure 8 When viewed from the opening side, it is arranged Figure 7 FIG. 4 is a diagram of a wafer storage container in a drying process section.

[0023] Explanation of Figure Numbers

[0024] 1: Water droplet 2: Freezing section 10: Housing 11: Inlet gate 12: Outlet gate 20: Loading port 30: Transfer mechanism 31: Transfer arm 32: Grasping hand 40: Disassembly / attachment platform 50: Cleaning section 51: Cleaning tank 52: Cleaning liquid storage tank 60: Drying section 61: Drying tank 61a: Tank body 61b: Cover 61c: Container placement section 62: Exhaust device 62a: Exhaust pipe 62b: Decompression device 62c : Control valve 63: Air supply device 63a: Air supply pipe 63b: Control valve 65: Drying processing unit 65a~65e: Heating device 70: Unloading port 80: Control unit 81: Calculation device 82: Storage device 82a: Control program 90: Wafer storage container 91: Container body 91a: Opening 92: Cover 100: Wafer storage container cleaning device P0~P3: Pressure t1, t2, t3: Specified time T1~T7: Time DETAILED DESCRIPTION

[0025] The following describes a cleaning device according to one embodiment of the present invention with reference to the accompanying drawings. However, the cleaning device can be implemented in a variety of different forms and is not limited to the following exemplary embodiments. Furthermore, in the drawings referenced in this embodiment, components having the same components or functions may be assigned the same reference numerals or letters following the same reference numerals, and duplicate descriptions thereof may be omitted.

[0026] In the specification and claims of the present application, "up" means the direction away from the installation surface of the cleaning device (such as the floor surface of a factory, etc.) in the vertical direction when the cleaning device is set to a state for normal use, and "down" means the direction opposite to "up".

[0027] <First embodiment>

[0028] As an example of a cleaning apparatus according to one embodiment of the present invention, a wafer container cleaning apparatus will be described. However, the cleaning apparatus is not limited to wafer container cleaning apparatuses and can also be applied to cleaning apparatuses for cleaning other processing objects. For example, the cleaning apparatus can also be applied to cleaning apparatuses for cleaning containers that hold glass substrates or cleaning apparatuses for cleaning medical instruments, among other purposes.

[0029] [Structure of Wafer Storage Container Cleaning Apparatus 100]

[0030] Figure 1This is a plan view schematically showing the overall structure of the wafer storage container cleaning device 100 of the first embodiment. The wafer storage container cleaning device 100 is, for example, arranged in a factory for manufacturing semiconductor wafers to clean used wafer storage containers. The wafer storage container cleaning device 100 of this embodiment includes a housing 10, a loading port 20, a conveying mechanism 30, a disassembly / attachment stage 40, a cleaning process unit 50, a drying process unit 60, an unloading port 70, and a control unit 80. However, the structure of the wafer storage container cleaning device 100 is not limited to this example, and the wafer storage container cleaning device 100 may be omitted. Figure 1 This is a part of the components shown, and other components may be added.

[0031] The housing 10 is a frame that protects the wafer storage container cleaning device 100. The housing 10 contains the aforementioned transfer mechanism 30, the disassembly / connection stage 40, the cleaning process unit 50, and the drying process unit 60. On the other hand, the loading port 20 and the unloading port 70 are provided across the interior and exterior of the housing 10. Figure 1 , an example in which the device is arranged inside the housing 10 is shown, but the device may be arranged outside the housing 10 .

[0032] The load port 20 is a component used to load wafer storage containers 90, which are objects to be cleaned, into the wafer storage container cleaning apparatus 100. The wafer storage container 90 is, for example, a FOUP or FOSB. The wafer storage container 90 is first placed in the portion of the load port 20 located outside the housing 10. When the loading gate 11 provided in the housing 10 is opened, the wafer storage container 90 is moved to the portion of the load port 20 located inside the housing 10. The wafer storage container 90 is moved using a transport device such as a slide conveyor (not shown). Subsequently, the loading gate 11 is closed, completing the loading of the wafer storage container 90.

[0033] The transport mechanism 30 transports the wafer storage container 90 to each component. It includes a transport arm 31 and a gripper 32. While gripping the wafer storage container 90 with the gripper 32, the transport mechanism 30 moves the transport arm 31 by extending or rotating it, thereby transporting the wafer storage container 90 to each component. Due to this configuration, the transport mechanism 30 is also referred to as a transport robot.

[0034] The disassembly / connection stage 40 is to disassemble the wafer storage container 90 into the container body 91 (also referred to as a shell) (see Figure 2) and a cover 92 (also referred to as a door), or a component connecting the container body 91 and the cover 92. The wafer storage container 90, which is transferred from the load port 20 by the transfer mechanism 30, is disassembled into the container body 91 and the cover 92 while being fixed on the disassembly / attachment stage 40. Furthermore, the wafer storage container 90, which has completed the drying process in the drying process section 60 described later, is transferred from the drying process section 60 to the disassembly / attachment stage 40 by the transfer mechanism 30, where the container body and the cover are reconnected.

[0035] The cleaning unit 50 is a component that performs cleaning on the wafer storage container 90. The cleaning unit 50 includes a cleaning tank 51 and a cleaning liquid storage tank 52. The cleaning tank 51 is configured to hold the wafer storage container 90 and includes a cleaning nozzle (not shown) that sprays cleaning liquid onto the wafer storage container 90. The interior of the cleaning tank 51 is configured such that the support portion that supports the wafer storage container 90 or the lid 92 can rotate independently. During the cleaning process, the container body 91 and the lid 92 of the wafer storage container 90 can each rotate at a predetermined speed. The cleaning liquid storage tank 52 is a storage tank that stores the cleaning liquid (e.g., pure water) supplied to the cleaning nozzle.

[0036] After being held within the cleaning tank 51, the wafer storage container 90 is cleaned using a cleaning liquid supplied from the cleaning liquid reservoir 52. Specifically, the cleaning process of the wafer storage container 90 is performed by spraying the cleaning liquid onto the rotating wafer storage container 90 using the aforementioned cleaning nozzle. In this embodiment, the container body 91 and lid 92 of the wafer storage container 90 are separately transported from the disassembly / attachment stage 40 and held in the cleaning tank 51 in a separated state. For example, the container body 91 of the wafer storage container 90 is held within the container body of the cleaning tank 51, while the lid 92 of the wafer storage container 90 is held within the cleaning tank 51 while being attached to the lid of the cleaning tank 51.

[0037] The cleaning unit 50 includes a drying unit for temporary drying, which can dry the cleaned wafer storage container 90. As previously mentioned, the interior of the cleaning tank 51 is rotatable. Therefore, by increasing the rotational speed, the cleaned wafer storage container 90 can be spin-dried. Furthermore, the cleaning unit 50 supplies heated dry air into the cleaning tank 51. This blows dry air while performing spin drying, substantially removing any water droplets adhering to the wafer storage container 90. After the temporary drying of the wafer storage container 90, the container body and lid are separately transported to the drying unit 60.

[0038] The drying processing section 60 is a component that performs a drying process (formal drying) on ​​the chip storage container 90 by means of reduced pressure drying. The drying processing section 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 chip storage container 90 inside, and has airtightness that can form a reduced pressure environment (vacuum environment) inside. Similar to the aforementioned cleaning processing section 50, the container body 91 and the cover 92 of the chip storage container 90 are separately held inside the drying processing tank 61, so that the drying process is performed separately. The exhaust device 62 is a device for reducing the internal pressure of the drying processing tank 61 to form a reduced pressure environment. The air supply device 63 is a device for increasing the internal pressure of the drying processing tank 61 and restoring it to an atmospheric pressure environment. The specific structure of the drying processing tank 61, the exhaust device 62 and the air supply device 63 will be described later.

[0039] After being held within the drying tank 61, the wafer container 90 is placed under a reduced pressure environment to undergo a drying process (reduced pressure drying). Specifically, reduced pressure drying is performed by placing the wafer container 90 within the drying tank 61 and then using the exhaust device 62 to reduce the pressure within the drying tank 61. Within the reduced pressure environment, moisture such as water droplets adhering to the surface of the wafer container 90 vaporizes, resulting in drying. After the drying process of the wafer container 90 is completed, the interior of the drying tank 61 is returned to atmospheric pressure via the air supply device 63.

[0040] The drying process of this embodiment includes reducing the internal pressure of the drying tank 61 at a faster rate than conventional methods (reducing the pressure to a rate that prevents water droplets from freezing), thereby rapidly cooling water droplets adhering to the wafer storage container 90. Details of the drying process of this embodiment will be described later.

[0041] In the drying process section 60, when the drying process of the wafer storage container 90 is completed, the wafer storage container 90 is returned to the disassembly / attachment stage 40, and the container body 91 and the lid 92 are reattached. The wafer storage container 90 with the container body 91 and the lid 92 fully attached is then transported by the transport mechanism 30 to the unloading port 70.

[0042] The unloading port 70 is a component used to unload the wafer storage container 90 outside the wafer storage container cleaning apparatus 100. The wafer storage container 90 is first placed in the portion of the unloading port 70 located inside the housing 10. When the unloading gate 12 provided in the housing 10 is opened, the wafer storage container 90 moves to the portion of the unloading port 70 located outside the housing 10. Subsequently, the unloading gate 12 is closed, completing the unloading of the wafer storage container 90.

[0043] The control unit 80 controls the operation of the wafer storage container cleaning device 100. The control unit 80 includes a computing device 81 and a storage device 82. The computing device 81 is, for example, a central processing unit (CPU). The storage device 82 is, for example, a read-only memory (ROM). In the control unit 80, the computing device 81 reads out the control program 82a stored in the storage device 82 and executes it, thereby controlling the operation of each component of the wafer storage container cleaning device 100. The control program 82a includes a command group for respectively executing various processes such as cleaning, drying, and conveying. The components constituting the control unit 80 are not limited to Figure 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 or a communication interface for communicating with an external network.

[0044] [Structure of Drying Processing Unit 60]

[0045] Figure 2 1 is a diagram schematically showing the structure of the drying processing unit 60 in the wafer storage container cleaning apparatus 100 according to the first embodiment. Figure 1 As shown in FIG, the drying treatment section 60 includes a drying treatment tank 61, an exhaust device 62 and an air supply device 63. Figure 2 The structure of the drying process unit 60 shown is merely an example and is not limited thereto. For example, the drying process unit 60 may further include other components such as a pressure sensor for detecting the internal pressure of the drying process tank 61, an analysis device for measuring the internal conditions of the drying process tank 61 (e.g., the number of particles or the size of water droplets attached to the wafer storage container 90), and the like.

[0046] The drying treatment tank 61 includes a tank body 61a, a cover 61b, and a container loading portion 61c. The chip storage container 90 is first decomposed into a container body 91 and a cover 92 before the cleaning process as a pre-process, and is held separately inside the drying treatment tank 61. Specifically, the container body 91 is held on the container loading portion 61c, and the cover 92 is held on the cover 61b of the drying treatment tank 61. Inside the tank body 61a, the container body 91 is fixed to the container loading portion 61c by a fixing frame such as a claw. Moreover, the cover 92 of the chip storage container 90 is fixed to the cover 61b of the drying treatment tank 61 relative to the container body 91 by a fixing frame such as a claw. In fact, after the container body 91 and the cover 92 of the chip storage container 90 are fixed to the container loading portion 61c and the cover 61b of the tank body 61a, respectively, the cover 61b is closed to the tank body 61a, thereby forming Figure 2 The status shown.

[0047] The exhaust device 62 is connected below the tank body 61a. In this embodiment, the exhaust device 62 includes an exhaust pipe 62a, a pressure reducing device 62b, and a control valve 62c. The exhaust pipe 62a communicates with the interior of the drying tank 61 and exhausts gas (e.g., water vapor) within the tank body 61a to the outside. The location where the exhaust device 62 is connected is not limited to below the drying tank 61. However, to prevent particles from adhering to the wafer storage container 90, etc., it is preferably connected below the drying tank 61. This is because, with this configuration, the gas generated within the drying tank 61 flows downward as a downflow.

[0048] The decompression 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 inside the drying treatment tank 61. Specifically, the decompression device 62b is a vacuum pump. As the vacuum pump, a dry pump, a mechanical booster pump, a turbomolecular pump, a rotary pump, etc. can be used, but it is not limited to these examples. In addition, Figure 2 In the illustrated example, only one decompression device 62 b is shown, but a plurality of vacuum pumps may be combined to serve as the decompression device 62 b.

[0049] The control valve 62c is a valve for controlling the flow rate of the gas flowing in the exhaust pipe 62a, and a vacuum valve such as a gate valve can be used. Figure 1 Specifically, when the decompression process (vacuuming) using the decompression device 62b is performed according to the command of the control program 82a executed by the control unit 80, the control valve 62c is controlled to be in the open state.

[0050] The gas supply device 63 is connected to the side of the drying tank 61. The gas supply device 63 increases the internal pressure of the drying tank 61 (i.e., boosts the pressure), thereby releasing the vacuum state within the drying tank 61. Specifically, the gas supply device 63 supplies gas to the interior of the drying tank 61, which is under a reduced pressure, thereby restoring the internal pressure of the drying tank 61 to atmospheric pressure. The location where the gas supply device 63 is connected is not limited to the side of the drying tank 61, but it is preferably connected to form a downward flow within the drying tank 61 as described above.

[0051] The gas supply device 63 includes a gas supply pipe 63a and a control valve 63b. The gas supply pipe 63a is connected to the interior of the drying treatment tank 61 and supplies gas (for example, dry air, dry nitrogen, or other dried gas) to the interior of the drying treatment tank 61. The control valve 63b is a valve that controls the flow rate of the gas flowing in the gas supply pipe 63a. For example, a vacuum valve such as a gate valve can be used. Similar to the control valve 62c of the exhaust device 62, the control valve 63b is Figure 1 The control unit 80 shown here controls it.

[0052] The drying unit 60 described above performs a drying process under the control of the control unit 80. Specifically, after the cleaned wafer storage container 90 is held within the drying tank 61, the exhaust device 62 is controlled to perform a decompression process to reduce the pressure within the drying tank 61, thereby performing a reduced-pressure drying process on the wafer storage container 90. After the drying process is completed, the air supply device 63 is controlled to perform a pressurization process to increase the pressure within the drying tank 61, thereby returning the interior of the drying tank 61 to atmospheric pressure.

[0053] The basic operation of the drying process section 60 is as described above, but the wafer storage container cleaning apparatus 100 of this embodiment has advantages in the specific content of the drying process. The following specifically describes the drying process method of the wafer storage container 90 in the wafer storage container cleaning apparatus 100 of this embodiment.

[0054] [Background of the Invention]

[0055] The present inventors have repeatedly studied the drying process using reduced pressure drying and have found that when a rapid reduced pressure process is performed, water droplets larger than a specified size (e.g., millimeter-level) may cause the water droplets to scatter like a shattering process (in other words, the water droplets may break up). Figure 3 To illustrate schematically.

[0056] Figure 3 This diagram illustrates the phenomenon of water droplets 1 adhering to wafer storage container 90 rupturing during reduced-pressure drying. The state indicated by "t = t0" represents the state before the start of the reduced-pressure process. The interior of drying tank 61 is at room temperature (here, 25°C) and atmospheric pressure. At this point, wafer storage container 90 and the water droplets 1 adhering to it, both exposed to the same environment, are also at room temperature. This diagram illustrates a state where water droplets 1 larger than a predetermined size (e.g., larger than 1 mm) are adhering to the surface of wafer storage container 90.

[0057] The state indicated by "t = t1" shows the state where the predetermined time t1 has elapsed since the start of the decompression process, and the interior of drying tank 61 has become a decompressed environment. As the decompression process is executed, the boiling point of water droplet 1 decreases as the internal pressure of drying tank 61 decreases, thereby promoting the vaporization of water droplet 1 as indicated by the arrow. As water droplet 1 vaporizes while depriving the surrounding environment of heat (heat of vaporization), the temperature of water droplet 1 also decreases as the internal pressure of drying tank 61 decreases. In other words, in the state indicated by "t = t1," water droplet 1 vaporizes while its own temperature decreases as the internal pressure of drying tank 61 decreases.

[0058] The state shown by "t=t2" indicates a state in which a predetermined time t2 (>t1) has passed since the decompression treatment was started. In the state shown by "t=t2", the surface temperature of the water droplet 1 becomes below 0°C due to the temperature drop accompanying the decompression. It can be considered that in this state, only the surface of the water droplet 1 is frozen to form a thin film of ice (hereinafter referred to as the "frozen portion 2"), and the portion of the water droplet 1 other than the frozen portion 2 remains in a liquid state. However, it is considered that whether the state shown by "t=t2" can be achieved depends on the size of the water droplet 1. In other words, it can be considered that if the size of the water droplet 1 is small, the water droplet 1 will be vaporized as a whole before the frozen portion 2 is formed, and the water droplet 1 will disappear. Therefore, it can be said that the state shown by "t=t2" occurs in a water droplet 1 of such a size that a liquid portion can remain at the time when the frozen portion 2 is formed. In the opinion of the present inventors, as long as the water droplet is of the millimeter order (i.e., a size of 1 mm or more), it is possible to reach the state shown by "t=t2".

[0059] The present inventors speculated that the reason why the water droplets burst when the rapid decompression treatment is performed may be the freezing of the surface of the water droplet 1. The temperature of the water droplet 1 decreases as the internal pressure of the drying treatment tank 61 decreases, but the greater the degree of decrease in internal pressure (i.e., the decompression rate), the greater the degree of decrease in the temperature of the water droplet 1. Therefore, the present inventors speculated that when the internal pressure of the drying treatment tank 61 is rapidly decompressed, a temperature difference is generated between the surface and the interior of the water droplet 1 due to the rapid temperature drop, and the surface freezes at 0°C. The reason for the temperature difference is speculated to be that on the surface of the water droplet 1, vaporization due to the decompression rapidly advances, thereby rapidly dropping the temperature. In contrast, the interior of the water droplet 1 does not experience the same temperature drop as the surface due to heat conduction from the chip storage container 90.

[0060] Furthermore, in the state shown at "t = t2", it is expected that the surface temperature of water droplet 1 reaches 0°C and freezes, while the interior of water droplet 1 continues to vaporize the liquid accompanied by reduced pressure. In other words, it can be considered that in the state shown at "t = t2", the volume expansion of water droplet 1 due to vaporization continues inside frozen portion 2, and the pressure on frozen portion 2 from the inside (the pressure accompanying the volume expansion) increases as the internal pressure of drying tank 61 decreases.

[0061] The state indicated by "t = t3" indicates the state after the predetermined time t3 has elapsed since the decompression process began. The present inventors believe that the aforementioned phenomenon of water droplet 1 rupturing occurs when frozen portion 2 cannot withstand the increased internal pressure. That is, as indicated by "t = t3," when the pressure on frozen portion 2 increases further from the inside and frozen portion 2 cannot withstand the pressure, frozen portion 2 is broken. As a result, it is believed that the increased pressure inside frozen portion 2 is suddenly released, causing water droplet 1 to break into multiple ice fragments or multiple small water droplets and scatter.

[0062] As described above, the inventors speculate that water droplet 1 attached to wafer storage container 90 freezes only partially on its surface due to the rapid decompression process, and that the liquid portion continues to vaporize within frozen portion 2 formed on the surface. Furthermore, they speculate that when frozen portion 2 eventually collapses due to the internal pressure, the pressure release causes water droplet 1 to break into multiple particles and rupture.

[0063] Based on the insights described above, the present inventors have devised the following concept: utilizing the aforementioned breakup phenomenon of water droplets 1 to transform water droplets 1 larger than a predetermined size into smaller droplets, thereby eliminating the drying defects caused by the freezing of the entire water droplet. The following describes a drying method according to one embodiment of the present invention based on this concept.

[0064] [Structure of Drying Treatment Method]

[0065] Figure 4 It is a diagram for explaining the drying method performed in the wafer storage container cleaning apparatus 100 according to the first embodiment. Figure 4 In FIG, the horizontal axis represents time, and the vertical axis represents the internal pressure of the drying tank 61. That is, Figure 4 The time variation of the internal pressure of the drying tank 61 in the drying process of this embodiment is shown. Figure 4 The time shown is explained in sequence.

[0066] The drying process described below is carried out by Figure 1The control unit 80 shown controls the drying process unit 60. Specifically, in the control unit 80, the computing device 81 reads a control program 82a (here, a control program for controlling the drying process) from the storage device 82 and executes it, thereby controlling the various operations of the drying process tank 61, the exhaust device 62, and the air supply device 63.

[0067] Figure 4 In the embodiment, the internal pressure of the drying tank 61 is at pressure P0 before 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 tank 61 immediately before the drying process begins.

[0068] Next, the control unit 80 controls the exhaust device 62 to perform a decompression process (hereinafter referred to as the "first decompression process") to rapidly reduce the internal pressure of the drying 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 interior of the drying tank 61. Figure 4 In FIG, the process executed during the period from time T1 to time T2 corresponds to the first decompression process.

[0069] Pressure P1 is 500 Pa or less (preferably 100 Pa or less, more preferably 50 Pa or less). However, pressure P1 may be any pressure at which the entire surface of water droplets within drying tank 61 freezes when the internal pressure of drying tank 61 reaches pressure P1, and may exceed 500 Pa. In this embodiment, pressure P1 is set to 30 Pa.

[0070] Furthermore, in this embodiment, the internal pressure of the drying treatment tank 61 is reduced from the atmospheric pressure (P0) to 30 Pa (P1) within one minute. Figure 4 In the embodiment, time T2 is the moment when the internal pressure of the drying treatment tank 61 reaches 30Pa (P1), and the difference between the moment T1 when the first decompression treatment is started and the moment T2 when the first decompression treatment is ended is less than one minute. In addition, the range of "within one minute" is set as a range that is effective in shortening the time required for the drying treatment. The drying treatment method of this embodiment refers to rapidly reducing the internal pressure of the drying treatment tank 61 from atmospheric pressure to a pressure P1 below 500Pa, and it does not matter if it takes more than one minute to perform the decompression. However, as described later, when the first decompression treatment is repeated multiple times, it is ideal to suppress the time required for the first decompression treatment to less than one minute.

[0071] As described above, in this embodiment, the first decompression process is performed to reduce the internal pressure of the drying tank 61 more rapidly than before, thereby generating a drying process using Figure 3 Specifically, the water droplet rupture phenomenon is described. Figure 4 As shown, a decompression process is performed to reduce the internal pressure of the drying tank 61 from atmospheric pressure to 30 Pa within one minute. That is, in the drying method of this embodiment, by performing the first decompression process, water droplets of a predetermined size or larger (e.g., a size of one millimeter or larger) adhering to the wafer storage container 90 are broken into a plurality of small water droplets of less than one millimeter in size.

[0072] Next, after the internal pressure of the drying tank 61 reaches pressure P1 through the first decompression process, the controller 80 controls the air supply device 63 to perform a pressurization process (hereinafter referred to as the "first pressurization process") to increase the internal pressure of the drying tank 61 to pressure P2, which is greater than 80 kPa. Specifically, the controller 80 closes the control valve 62c while the decompression device 62b of the exhaust device 62 is in operation, and opens the control valve 63b of the air supply device 63, thereby supplying dried gas such as dry air into the drying tank 61. The supply of gas into the drying tank 61 increases the internal pressure of the drying tank 61. Figure 4 , the process executed during the period from time T2 to time T3 corresponds to the first pressurizing process.

[0073] The water droplets (including the fragments of the frozen portion 2) that are broken by the aforementioned first decompression treatment become finer droplets and adhere to the inner wall of the drying treatment tank 61, or re-adhere to other parts of the chip storage container 90. If there is no water droplet re-adhering to the chip storage container 90, there is no problem even if the drying treatment is terminated at this point in time. However, if there is re-adherence of water droplets, the re-adhered water droplets must be removed. The scattered water droplets sometimes contain fragments of ice (frozen portion), but the frozen water droplets will hardly vaporize even if placed in a decompression environment. Therefore, in the drying treatment method of this embodiment, in order to restore the frozen water droplets to liquid (thaw), a process is performed to temporarily restore the internal pressure of the drying treatment tank 61 to near atmospheric pressure.

[0074] In this embodiment, the pressure P2 is set to 80 kPa. The pressure P2 is set to a pressure such that when the internal pressure of the drying tank 61 reaches the pressure P2, the ice inside the drying tank 61 is fully thawed. Therefore, as long as the pressure is such that the ice inside the drying tank 61 is thawed, the pressure may be lower than 80 kPa. Furthermore, the pressure P2 may be atmospheric pressure. If the pressure P2 is atmospheric pressure, no special fine control is required, and the drying tank 61 can simply be opened to the atmosphere. On the other hand, if it takes time for the internal pressure of the drying tank 61 to return to atmospheric pressure, in order to shorten the time required for the drying process, it may simply be pressurized to a pressure lower than atmospheric pressure.

[0075] As described above, the drying treatment method of this embodiment may include the following process: water droplets of a size larger than a specified size are split by a first decompression treatment, and the fragments of ice (frozen portion) generated at this time are restored to liquid again by a first pressurization treatment subsequent to the first decompression treatment.

[0076] Next, after the pressure inside the drying tank 61 reaches pressure P2 through the first pressurization process, the controller 80 controls the exhaust device 62 to perform a decompression process (hereinafter referred to as the "second decompression process"), rapidly reducing the pressure inside the drying tank 61 from pressure P2 to pressure P1. Specifically, the controller 80 closes the control valve 63b of the air supply device 63 and opens the control valve 62c of the exhaust device 62. This allows the decompression device 62b to evacuate the interior of the drying tank 61. In this embodiment, the pressure inside the drying tank 61 is reduced from 80 kPa (P2) to 30 Pa (P1) within one minute. Figure 4 In FIG, the process executed during the period from time T3 to time T4 corresponds to the second decompression process.

[0077] The second decompression process can be said to be essentially the same as the first decompression process. The difference between the first and second decompression processes lies in the internal pressure of drying tank 61 at the start of the decompression process. However, whereas the first decompression process begins at atmospheric pressure, the second decompression process begins at a pressure of 80 kPa or higher (including atmospheric pressure), resulting in no significant difference in the decompression rate. Therefore, similar to the first decompression process, the second decompression process can break up water droplets larger than a specified size adhering to wafer storage container 90, transforming them into multiple small droplets or ice fragments.

[0078] The second decompression process is a process to be performed in case water droplets larger than the predetermined size remain despite the first decompression process. Therefore, if the water droplets adhering to the wafer storage container 90 have become sufficiently small after the first decompression process, the second decompression process can be omitted.

[0079] Next, after the internal pressure of the drying tank 61 reaches the pressure P1 through the second decompression process, the control unit 80 controls the air supply device 63 to perform a pressurization process (hereinafter referred to as the "second pressurization process") to increase the internal pressure of the drying tank 61 to a pressure P2 of 80 kPa or more. Figure 4 The process performed from time T4 to time T5 is the same as the first pressurization process performed from time T2 to time T3. The second pressurization process can restore the ice fragments scattered inside the drying tank 61 by the second decompression process to liquid form.

[0080] Next, after the internal pressure of the drying tank 61 reaches pressure P2 through the second pressurization process, the controller 80 controls the exhaust device 62 to perform a decompression process (hereinafter referred to as the "third decompression process") to reduce the internal pressure of the drying tank 61 from pressure P2 to pressure P1. Specifically, the controller 80 closes the control valve 63b of the air supply device 63 and opens the control valve 62c of the exhaust device 62. The decompression device 62b then evacuates the drying tank 61. However, the third decompression process may take longer than one minute to reduce the internal pressure of the drying tank 61 from 80 kPa (P2) to a pressure (P3) below 500 Pa. Figure 4 Among them, the process executed during the period from time T5 to time T6 corresponds to the third decompression process.

[0081] Unlike the first and second decompression treatments, the third decompression treatment is not intended to freeze the entire surface of the water droplets and break them into smaller droplets. In other words, the third decompression treatment can be performed using conventional drying methods involving reduced pressure drying. In this case, the pressure P3 can be set to a level that prevents the water droplets from freezing. For example, in this embodiment, the pressure P3 is set to 2 kPa. However, this is not limiting; the pressure P3 can be set to any pressure that allows for reduced pressure drying.

[0082] Moreover, if Figure 4As shown, the third decompression process can also be performed at a slower rate than the first and second decompression processes. However, to shorten the overall drying process time, it is preferable that the time required for the third decompression process (from time T5 to time T6) be as short as possible. By the time the third decompression process is performed, the first decompression process and at least one second decompression process have already been performed, so it is highly likely that no water droplets larger than the predetermined size will be present in wafer storage container 90. Therefore, regardless of the decompression rate used in the third decompression process, it is believed that the water droplets will evaporate and disappear faster than if they were frozen all at once.

[0083] As described above, the drying method of this embodiment performs a first decompression treatment at a rapid decompression rate and at least one second decompression treatment, and then performs a normal drying treatment by means of reduced pressure drying, thereby enabling the chip storage container 90 to be completely dried in a shorter time than before.

[0084] Finally, after the pressure reaches the pressure P3 through the third decompression process, the control unit 80 controls the air supply device 63 to perform a pressurization process (hereinafter referred to as the "third pressurization process") to increase the internal pressure of the drying tank 61 to the atmospheric pressure (P0). The third pressurization process corresponds to the pressure in the Figure 4 The drying process of this embodiment is completed when the internal pressure of the drying tank 61 reaches the atmospheric pressure.

[0085] As described above, the wafer storage container cleaning apparatus 100 of this embodiment can perform a decompression process during the drying process, reducing the internal pressure of the drying process tank 61 from atmospheric pressure (P0) or a pressure of 80 kPa or higher (P2) to a pressure of 500 Pa or lower (P1) within one minute. Consequently, the wafer storage container cleaning apparatus 100 can convert water droplets larger than a predetermined size adhering to the wafer storage container 90 into a plurality of smaller droplets that readily evaporate and disappear during the drying process. Specifically, this embodiment provides a wafer storage container cleaning apparatus 100 that efficiently dries the wafer storage container 90, which is the object to be processed after cleaning.

[0086] Furthermore, whether the water droplets 1 completely vaporize or their entire surfaces freeze and break during the first or second decompression treatment may vary depending on various factors, such as the size of the water droplets, the volume of the drying tank 61, and the temperature of the installed wafer storage container 90. While the first and second decompression treatments are described in detail as preferred aspects in this embodiment, the decompression rate during the decompression treatments can be appropriately adjusted in consideration of the various factors described above.

[0087] Furthermore, while the exhaust device 62 of this embodiment shows an example in which the control valve 62c is opened and closed while the pressure reducing device 62b is kept in operation, the present invention is not limited to this example. The pressure reducing device 62b may be stopped when the control valve 62c is closed, or may be started when the control valve 62c is opened.

[0088] (Variation)

[0089] While the first embodiment illustrates an example in which a second decompression treatment is performed after the first decompression treatment, and finally a third decompression treatment is performed, the drying method performed by the wafer storage container cleaning apparatus 100 is not limited to this example. For example, a second decompression treatment and a subsequent second pressurization treatment may be combined into a set and repeated multiple times. If the water droplets adhering to the wafer storage container 90 are very large, there may be a situation in which, even after the first and second decompression treatments are performed sequentially, water droplets larger than a predetermined size may still remain. In this case, it is effective to further perform a second decompression treatment followed by a subsequent second pressurization treatment, and to repeat the second decompression treatment and the second pressurization treatment until the water droplets are sufficiently reduced in size.

[0090] Conversely, if no water droplets larger than a predetermined size are present at the time the first depressurization process is completed, the second depressurization process may be omitted and the third depressurization process may be performed directly after the first pressurization process. Of course, if no water droplets adhere to the wafer storage container 90 at the time the first depressurization process is completed, the drying process may be terminated at that time and the drying process tank 61 may be opened to the atmosphere.

[0091] As needed, the presence or absence of water droplets attached to the chip storage container 90 or the size of the water droplets can be visually inspected by the operator through a window provided in the tank body portion 61a of the drying processing tank 61, or an analysis device for detecting the presence or absence of water droplets or the size of the water droplets can be provided in the drying processing portion 60.

[0092] <Second embodiment>

[0093] In the second embodiment, an example is described in which the structure of the drying process section of a wafer storage container cleaning apparatus differs from that of the first embodiment. Specifically, the wafer storage container cleaning apparatus of this embodiment differs from the first embodiment in that a heating device is provided within the drying process tank. The basic structure of the wafer storage container cleaning apparatus of this embodiment is the same as that of the wafer storage container cleaning apparatus 100 of the first embodiment, so the description of this embodiment will focus on the structural differences. Components identical to those of the wafer storage container cleaning apparatus 100 of the first embodiment are sometimes denoted by the same reference numerals to omit duplicate descriptions.

[0094] Figure 5 This is a diagram schematically showing the configuration of a drying processing unit 65 in the wafer container cleaning apparatus according to the second embodiment. Figure 6 The device is arranged in the opening 91a as viewed from the side of the opening 91a. Figure 5 FIG. 1 is a diagram of a wafer storage container 90 in the drying process section 65. The opening 91a is a storage port for storing wafers in the container body 91.

[0095] like Figure 5 and Figure 6 As shown, in this embodiment, a plurality of heating devices 65a to 65e are provided within the drying process section 65. These 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 infrared lamps, and their lighting (heating state) and non-lighting (non-heating state) are controlled by the control section 80. However, the heating devices 65a to 65e are not limited to infrared lamps; any device capable of heating the wafer storage container 90 may be used.

[0096] In this embodiment, the heating devices 65a and 65c are arranged near the upper corners of the container body 91 of the wafer storage container 90. The lid 92 of the wafer storage container 90 is arranged above the container body 91. Therefore, the heating devices 65a and 65c not only heat the container body 91 but also heat the lid 92.

[0097] Heating devices 65b and 65d are positioned near the lower corners of the container body 91. Below the container body 91, a container mounting portion 61c is provided for securing the container body 91. Therefore, heating devices 65b and 65d not only heat the container body 91 but also the container mounting portion 61c. The container mounting portion 61c includes a mechanism for securing the container body 91, making its structure complex. Consequently, water droplets adhering to the container mounting portion 61c are difficult to remove using reduced-pressure drying alone. As in this embodiment, heating devices 65b and 65d heat the container mounting portion 61c in addition to the wafer storage container 90, which is preferred for improving drying efficiency.

[0098] The heating device 65e is arranged to face the opening 91a of the container body 91. Specifically, the heating device 65e is arranged near the opening 91a on the outside of the container body 91. The interior of the container body 91 (the part for storing the wafers) is provided with a plurality of storage parts for holding the wafers, and the structure is more complex than the outer surface. Therefore, there is a tendency that it is more difficult to remove the attached water droplets inside the container body 91 than on the outer surface. Therefore, it is preferable to heat the interior of the container body 91 by the heating device 65e in terms of improving the efficiency of the drying process. In addition, Figure 5 and Figure 6 , an example is shown in which the long side direction of the heating device 65e extends in a direction approximately parallel to the upper surface of the container loading portion 61c, but the present invention is not limited to this example. The long side direction of the heating device 65e may also extend in a direction approximately perpendicular to the upper surface of the container loading portion 61c, or may extend in any other direction.

[0099] and, Figure 5 and Figure 6 In the illustrated example, the heating devices 65a to 65e are all arranged outside the container body 91 in a plan view. Therefore, when the container body 91 is placed on the container mounting portion 61c, the heating devices 65a to 65e do not become an obstruction to the installation, and the time required for the drying process can be shortened.

[0100] As described above, in this embodiment, the plurality of heating devices 65a to 65e arranged inside the drying tank 61 can be used to heat the wafer storage container 90. The heating treatment of the wafer storage container 90 can be performed in various forms. For example, in the first embodiment, the plurality of heating devices 65a to 65e can be used to heat the wafer storage container 90. Figure 4 During the first or second decompression treatment described above, the heating devices 65a to 65e can also be used to heat the wafer storage container 90. To prevent the entire water droplet from completely freezing during the first or second decompression treatment, the output of the heating devices 65a to 65e is adjusted so that the surface of the wafer storage container 90 is at room temperature (25°C) or a temperature slightly higher than room temperature (e.g., between 28°C and 35°C). The reason for maintaining the temperature of the wafer storage 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.

[0101] Furthermore, in the first embodiment, after the first or second decompression treatment is performed, the heating devices 65a to 65e may be used to dry the wafer storage container 90 by heating (heat drying). This drying process can be performed as an alternative to the third decompression treatment (drying by decompression) in the first embodiment. Specifically, after the first decompression treatment (or the first and second decompression treatments) is performed to break water droplets larger than a predetermined size adhering to the wafer storage container 90 into a plurality of smaller droplets, the heating devices 65a to 65e may be used to heat and dry the scattered water droplets.

[0102] Furthermore, the heating devices 65a to 65e may be used for both the heating during the first decompression process and the heating during the final drying process. For example, in the first embodiment, the temperature of the wafer storage container 90 may be maintained at approximately room temperature using the heating devices 65a to 65e during the first and second decompression processes. Subsequently, the set temperatures of the heating devices 65a to 65e may be increased to perform the final drying process.

[0103] Furthermore, the heating treatment of the wafer storage container 90 using the heating devices 65a to 65e can also be performed with Figure 4 The first pressurization process, the second pressurization process, or the third pressurization process shown is performed together. In this case, the ice flakes attached to the wafer storage container 90 can be thawed more reliably.

[0104] The control of the heating devices 65a-65e described above is performed by the control unit 80. Regarding heating time control, for example, the control unit 80 may control the lighting time of the heating devices 65a-65e based on the elapsed time during the control of the first or second decompression process. Specifically, the control unit 80 may activate the heating devices 65a-65e upon the start of the first or second decompression process and deactivate the heating devices 65a-65e upon the completion of the first or second decompression process. Furthermore, for temperature control, a temperature sensor capable of detecting the temperature of the wafer storage container 90 may be disposed within the drying tank 61. In this case, the control unit 80 may also perform feedback control, that is, control the heating devices 65a-65e based on the output of the temperature sensor to maintain the wafer storage container 90 at a predetermined temperature.

[0105] (Variation 1)

[0106] Figure 5 and Figure 6In the example shown, the following example is shown, that is, in order to heat the interior of the container body 91 of the chip storage container 90, the heating device 65e is arranged outside and near the opening 91a, but the heating device 65e can also be arranged inside the container body 91.

[0107] Figure 7 This 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. Figure 8 The device is arranged in the opening 91a as viewed from the side of the opening 91a. Figure 7 FIG. 1 is a diagram of a wafer storage container 90 in the drying process section 65 shown.

[0108] Figure 7 and Figure 8 The example shown is the same as Figure 5 and Figure 6 The example shown is similar in that a plurality of heating devices 65a to 65e are provided. However, in the drying processing unit 65 of this modified example, the heating device 65e is arranged inside the container body 91. Specifically, as shown in FIG. Figure 7 and Figure 8 As clearly shown, the heating device 65e is positioned so as to overlap the container body 91 when viewed from the side or from above. As previously mentioned, the interior of the container body 91 has a complex structure, making it more difficult to remove adhered water droplets than from the exterior surface. This modification places the heating device 65e inside the container body 91, effectively heating the interior of the container body 91 and improving the efficiency of the drying process.

[0109] In this modified example, the heating device 65e is positioned on the line of motion when the container body 91 of the wafer storage container 90 is installed in the tank body 61a of the drying tank 61. Therefore, when installing the container body 91, the heating device 65e must be moved to a position offset from the line of motion. Therefore, although not shown in the figure, a moving mechanism for moving the heating device 65e is provided within the drying tank 61 of this modified example.

[0110] (Variation 2)

[0111] The drying process section 65 of this embodiment may also include a movement mechanism for individually moving the plurality of heating devices 65a-65e. In other words, the drying process section 65 may include a structure that allows the positions of the heating devices 65a-65e to be changed. In this case, the positions of the heating devices 65a-65e can be adjusted to suit the size of the wafer storage container being dried, thereby improving the efficiency of the drying process.

[0112] <Third embodiment>

[0113] While the first and second embodiments describe a wafer storage container cleaning apparatus as one embodiment of the present invention, the present invention is not limited to this example. For example, the drying process section 60 described in the first embodiment or the drying process section 65 described in the second embodiment may also be implemented as an external drying device. For example, in the wafer storage container cleaning apparatus 100 of the first embodiment, a configuration may be employed in which a drying device having the function of the drying process section 60 is externally connected to a wafer storage container cleaning apparatus having a structure other than the drying process section 60. In this case, the wafer storage container cleaned in the cleaning process section 50 is transported to the external drying device having the function of the drying process section 60 for drying.

[0114] The above describes a cleaning device according to an embodiment of the present invention with reference to the accompanying drawings, but the present invention is not limited to the aforementioned embodiments (including variations, the same below), and can be appropriately changed without departing from the scope of the present invention. For example, an embodiment in which a person skilled in the art appropriately adds, deletes, or changes the design of the constituent elements based on each embodiment is included within the scope of the present invention as long as it has the purpose of the present invention. Furthermore, the structures of the aforementioned embodiments can be appropriately combined as long as they do not contradict each other, and the common technical matters in each embodiment are included in each structure even if there is no explicit description.

[0115] Even if the effects are different from the effects brought about by the forms of the aforementioned embodiments, the effects that are clear based on the description of this specification or the effects that can be easily predicted by those skilled in the art can of course be understood as the effects brought about by the present invention.

Claims

1. A cleaning device comprising: The cleaning processing unit cleans the processing object; A drying treatment unit for drying the treatment object; as well as a control unit that controls the cleaning unit and the drying unit to perform cleaning and drying of the object to be processed, The drying treatment section includes a drying treatment tank capable of holding the treatment object therein, and an exhaust device for reducing the internal pressure of the drying treatment tank. During the drying process, the control unit controls the exhaust device to perform a first decompression process that reduces the internal pressure of the drying tank from atmospheric pressure to a first pressure of 500 Pa or less within one minute.

2. The cleaning device according to claim 1, wherein the drying process section further comprises an air supply device for increasing the internal pressure of the drying process tank. After the internal pressure of the drying tank reaches the first pressure through the first depressurization process, the control unit controls the gas supply device to perform a first pressurization process that increases the internal pressure of the drying tank to a second pressure of 80 kPa or higher.

3. A cleaning device according to claim 2, wherein the control unit controls the exhaust device to perform a second decompression process after the internal pressure of the drying treatment tank reaches the second pressure through the first pressurization process, and the second decompression process reduces the internal pressure of the drying treatment tank from the second pressure to the first pressure within one minute.

4. A cleaning device according to claim 3, wherein the control unit controls the air supply device to perform a second pressurization process after the internal pressure of the drying treatment tank reaches the first pressure through the second decompression process, and the second pressurization process increases the internal pressure of the drying treatment tank to a second pressure of more than 80 kPa. 5 . The cleaning device 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 pressurization process, respectively, a plurality of times. 6 . The cleaning apparatus according to claim 1 , wherein the drying process section further includes a heating device for heating the process object inside the drying process tank. 7 . The cleaning apparatus according to claim 6 , wherein the control unit controls the heating device to perform a heating process for heating the treatment object when performing the first decompression process. 8 . The cleaning apparatus according to claim 6 , wherein the control unit controls the heating device to perform a heating process for heating the treatment object after performing the first decompression process. 9 . The cleaning device according to claim 1 , wherein the first pressure is a pressure of 50 Pa or less.

10. The cleaning device according to claim 2, wherein the second pressure is atmospheric pressure. The cleaning apparatus according to claim 1 , wherein the object to be processed is a wafer storage container.

12. A drying device comprising: A drying treatment section for drying the treated object; as well as a control unit that controls the drying unit to perform drying processing on the processing object, The drying treatment section includes a drying treatment tank capable of holding the treatment object therein, and an exhaust device for reducing the internal pressure of the drying treatment tank. During the drying process, the control unit controls the exhaust device to perform a decompression process that reduces the internal pressure of the drying tank from atmospheric pressure to a pressure of 500 Pa or less within one minute.

13. A drying method comprising: The object to be dried is placed inside the drying tank. An exhaust device connected to the drying tank is controlled to perform a first decompression process that reduces the internal pressure of the drying tank from atmospheric pressure to a first pressure of 500 Pa or less within one minute.

14. The drying method according to claim 13, comprising: After the internal pressure of the drying tank reaches the first pressure through the first decompression process, the air supply device connected to the drying tank is controlled to perform a first pressurization process, which increases the internal pressure of the drying tank to a second pressure of 80 kPa or more.

15. The drying method according to claim 14, comprising: After the internal pressure of the drying tank reaches the second pressure through the first pressurization process, the exhaust device is controlled to perform a second decompression process, which reduces the internal pressure of the drying tank from the second pressure to the first pressure within one minute.

16. The drying method according to claim 15, comprising: After the internal pressure of the drying tank reaches the first pressure through the second decompression process, the air supply device connected to the drying tank is controlled to perform a second pressurization process, which increases the internal pressure of the drying tank to a second pressure of more than 80 kPa.

17. The drying method according to claim 16, comprising: The exhaust device and the air supply device are controlled to repeatedly perform the second depressurization process and the second pressurization process, respectively, a plurality of times.

18. The drying method according to claim 13, comprising: When the first decompression process is performed, a heating device disposed inside the drying process tank is controlled to perform a heating process for heating the process object.

19. The drying method according to claim 13, wherein after the internal pressure of the drying tank reaches the first pressure by the first decompression treatment, a heating device arranged inside the drying tank is controlled to perform a heating treatment for heating the treatment object. 20 . The drying method according to claim 13 , wherein the first pressure is 50 Pa or less. The drying method 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.

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