Wafer storage container cleaning device

Abstract

Clean the outer surface of the wafer storage container door. [Solution] The wafer storage container cleaning apparatus according to the embodiment comprises a cleaning tank for cleaning at least the door of a wafer storage container which has a container body having a storage space for storing wafers and a door that closes an opening in the container body leading to the storage space, a cage-shaped door holder provided in the cleaning tank for housing the door, a rotary drive unit provided in the cleaning tank for rotatably supporting the door holder, and a cleaning nozzle for supplying cleaning liquid to the door held by the door holder.

Description

Technical Field

[0001] Embodiments of the present invention relate to a wafer storage container cleaning device.

Background Art

[0002] In the semiconductor manufacturing process, for example, in the process of wafer transfer between processes such as a resist coating process, an exposure and development process, an etching (film formation) process, a resist stripping process, and a cleaning process, a FOUP (Front Opening Unified Pod) is used. A FOUP is a wafer storage container including a FOUP main body (shell) having an opening and a door capable of opening and closing the opening of the FOUP main body.

[0003] Each time a FOUP is used to a certain extent, it is cleaned by a FOUP cleaning device. The FOUP cleaning device includes a cleaning tank for cleaning the FOUP. The cleaning tank includes a box-shaped cleaning tank main body having an opening and a lid capable of opening and closing the opening of the cleaning tank main body. In such a cleaning tank, the door of the FOUP is cleaned in a state where the outer surface is adsorbed and held by a holding portion provided, for example, inside the lid of the cleaning tank. Here, the outer surface of the door refers to the surface located on the outside when the door is attached to the FOUP main body.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Such cleaning tanks lack consideration for providing space on the outer side of the door, resulting in the inability to adequately clean the outer surface of the door. Furthermore, the outer surface of the door, which is held in place by the tank's holding mechanism, is covered by the suction and not exposed. Therefore, cleaning this suctioned portion is difficult. On the other hand, in order to ensure a higher level of cleanliness of the FOUP, it is sometimes necessary to thoroughly clean the outer surface of the door. However, the aforementioned cleaning tanks cannot meet this requirement. The same applies to wafer storage container cleaning equipment that cleans wafer storage containers other than FOUPs (e.g., FOSB (Front Opening Shipping Box)).

[0006] The problem that the embodiments of the present invention aim to solve is to provide a wafer storage container cleaning apparatus that can improve the cleanliness of the wafer storage container. [Means for solving the problem]

[0007] A wafer storage container cleaning apparatus according to an embodiment of the present invention comprises a cleaning tank for cleaning at least the door of a wafer storage container, which includes a container body having a storage space for storing wafers and a door that closes an opening in the container body leading to the storage space, A cage-shaped door holder is provided inside the washing tank to house the door, A rotary drive unit is provided in the washing tank and rotatably supports the door holding portion, A cleaning nozzle that supplies cleaning fluid to a door held in a door retaining section, It is equipped with. [Effects of the Invention]

[0008] According to embodiments of the present invention, the cleanliness of the wafer storage container can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a plan view showing an example of the configuration of a wafer storage container cleaning apparatus according to an embodiment. [Figure 2] Figure 2 is a front view showing an example of a door retaining part provided on the lid of a washing tank. [Figure 3] Figure 3 is a side view showing an example of a door retaining part provided on the lid of a washing tank. [Figure 4] Figure 4 is a plan view showing an example of a door retaining mechanism. [Figure 5] Figure 5 is a bottom view showing an example of a door retaining mechanism. [Figure 6] Figure 6 is a front cross-sectional view showing the top of the washing tank. [Modes for carrying out the invention]

[0010] <First Embodiment> Hereinafter, a wafer storage container cleaning apparatus according to the first embodiment of the present invention will be described with reference to Figures 1 to 6.

[0011] The wafer storage container cleaning apparatus 1 according to this embodiment, shown in Figure 1, is installed, for example, in a factory that manufactures semiconductor wafers, and is used for cleaning wafer storage containers 20 and drying the cleaned wafer storage containers 20.

[0012] Furthermore, the wafer storage container 20 shown in Figure 1 is, for example, a FOUP or FOSB, and comprises a container body (shell) 20a and a door 20b. The container body 20a has a hexahedral shape and has a storage space inside for storing wafers. The container body 20a also has a rectangular opening on one side that communicates with the storage space. The door 20b is attached to the opening of the container body 20a. That is, the door 20b can be disassembled and connected to the container body 20a, and when connected to the container body 201, it closes the opening. The container body 20a is also provided with a flange 20c. The flange 20c is the part that is gripped (held) when the wafer storage container 20 is transported by an OHT (Overhead Hoist Transport) or robot 3, and is formed in the shape of a rectangular plate.

[0013] The wafer storage container cleaning apparatus 1 has a casing 11 that forms a horizontally elongated rectangle in plan view as shown in Figure 1 and defines the outer shape of the apparatus. The wafer storage container cleaning apparatus 1 also includes a load port 2 for loading wafer storage containers 20 into the casing 11, a robot 3, a buffer (disassembly / assembly stage) 4, a cleaning tank 5, a drying tank 6, and an unload port 7 for unloading wafer storage containers from the casing 11, all of which are located inside the casing 11. The wafer storage container cleaning apparatus 1 also includes a control device 8 that controls the load port 2, robot 3, buffer 4, cleaning tank 5, drying tank 6, and unload port 7.

[0014] The load port 2 is located on one of the two short sides of the casing 11. The load port 2 has an external portion located outside the casing 11 and an internal portion located inside the casing 11. The load port 2 loads the wafer storage container 20, which is placed on the external portion of the casing 11, into the internal portion of the casing 11. The load port 2 also includes an opening 2a for loading the wafer storage container 20 from the external portion to the internal portion through the casing 11, a shutter 2b for opening and closing the opening 2a, and a sliding device (not shown) for moving the wafer storage container 20 from the external portion to the internal portion.

[0015] Robot 3 is positioned approximately in the center of the casing 11 and transports the wafer storage container 20 within the casing 11. Robot 3 is a so-called vertical articulated robot and is equipped with an arm 3a having multiple joints and a hand 3b provided at the tip of the arm 3a. The hand 3b is equipped with a body chuck (not shown) for gripping the flange 20c of the wafer storage container 20 and a door chuck (not shown) for gripping the door 20b separated from the container body 20a on its own.

[0016] Buffer 4 is adjacent to the load port 2 and the robot 3 within the casing and is arranged closer to the load port 2. Buffer 4 has the function of placing the wafer storage container 20, separating the door 20b from the container body 20a of the wafer storage container 20, or attaching the door 20b to the container body 20a. That is, buffer 4 includes a latch key 4a and can operate the latch mechanism built into the door 20b to lock / unlock the door 20b with respect to the container body 20a.

[0017] The cleaning tank 5 is arranged on the opposite side of the load port 2 across the robot 3 within the casing 11. The cleaning tank 5 is a tank for cleaning the wafer storage container 20. As shown in FIG. 6, the cleaning tank 5 includes a box-shaped cleaning tank body 5a having an opening at the upper end and a lid 5b provided at the opening of the cleaning tank body 5a and capable of opening and closing the opening. The cleaning tank 5 includes a rotatable table (not shown) for supporting the container body 20a within the cleaning tank body 5a and a rotatable door holding portion 50 for holding the door 20b on the back surface of the lid 5b (the surface inside the cleaning tank 5). Further, as shown in FIG. 2, the cleaning tank 5 includes a plurality of cleaning liquid nozzles 5c for supplying cleaning liquid to the container body 20a and the door 20b within the cleaning tank body 5a and a plurality of gas nozzles 5d for supplying drying gas to the container body 20a and the door 20b after cleaning with the cleaning liquid. Here, the cleaning nozzle 5c supplies, for example, pure water as the cleaning liquid. Also, the gas nozzle 5d supplies, for example, clean dry air (CDA (Clean Dry Air)) as the gas. Note that the drying of the container body 20a and the door 20b by the gas supplied from the gas nozzle 5d is a preliminary drying for removing the cleaning liquid adhering to the container body 20a and the door 20b. The configuration of the door holding portion 50 will be described later.

[0018] The drying tank 6 is arranged adjacent to the robot 3 and the buffer 4 within the casing 11. It is a tank for vacuum drying (main drying) the wafer storage container 20. That is, the vacuum tank 6 is equipped with a vacuum pump (not shown), and in a state where the container body 20a and the door 20b are accommodated, by making the interior into a predetermined vacuum state, the moisture adhering to the container body 20a and the door 20b is removed and dried.

[0019] The unload port 7 is arranged adjacent to the load port 2 on one of the two short sides of the casing 11. The unload port 7 carries out the wafer storage container 20 placed on the inner part of the casing 11 to the outside of the casing 11. The unload port 7, similar to the load port 2, includes an opening 7a, a shutter 7b, and a slide device (not shown).

[0020] The control device 8 comprehensively controls the load port 2, the robot 3, the buffer 4, the cleaning tank 5, the drying tank 6, and the unload port 7, and controls the operation of the wafer storage container cleaning device 1. The control device 8 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), and a communication interface. These are connected via an internal bus.

[0021] The CPU executes various processes while using the storage area of the RAM as a temporary storage area for data used in various processes. The ROM and the HDD store programs for executing the processes of each part, various databases and various tables used when executing the processes of each part, etc.

[0022] Next, the door retaining part 50 will be described with reference to Figures 2 to 6. The door retaining part 50 is a cage-shaped member that has a space for accommodating the door 20b. This door retaining part 50 is supported by the rotating shaft 61 of the rotary drive unit 60 provided on the lid 5b of the washing tank 5. That is, the rotary drive unit 60 is provided on the upper surface of the lid 5b, and the rotating shaft 61 penetrates the lid 5b and extends to the lower surface (inner surface) of the lid 5b. The axis 61X of the rotating shaft 61 is aligned vertically when the lid 5b is closed. The door retaining part 50 is supported at the tip (lower end) of this rotating shaft 61. Here, a cage shape is a structure that has gaps (spaces) through which liquids and gases can pass, without the outer surface being covered by walls, like a container made by weaving long, thin materials such as bamboo or wire. Such a cage-shaped door retaining part 50 generally has the outer shape of a flattened rectangular parallelepiped.

[0023] The door holding part 50 also comprises a holding part body 51 supported by a rotating shaft 61, a pair of support plates 52 (52A, 52B) provided at a predetermined distance from the holding part body 51, and a plurality of cylindrical connecting parts 53 that connect the holding part body 51 and the support plates 52. The holding part body 51 corresponds to a member that constitutes one of the flat surfaces of the flat rectangular parallelepiped's outer shape. The pair of support plates 52 correspond to members that constitute another of the flat surfaces. The plurality of connecting parts 53 correspond to members that constitute the side surfaces of the flat rectangular parallelepiped's outer shape.

[0024] The retaining body 51 is formed in a roughly rectangular shape, larger than the outer shape of the door 20b when viewed from above. In other words, the retaining body 51 has a rectangular outer shape with long sides and short sides, similar to the door 20b. This retaining body 51 is formed by cutting out roughly triangular sections in four places along each side of a rectangular plate-like member, leaving the outer periphery and diagonally located sections intact. Therefore, as shown in Figure 4, the retaining body 51 has roughly triangular openings 51a along each side. The retaining body 51 is fixed to the rotation axis 61 such that each side is perpendicular to the axis 61X of the rotation axis 61, or in other words, the direction of the axis 61X of the rotation axis 61 intersects perpendicularly with the plane (one of the flat surfaces) enclosed by the long and short sides of the retaining body 51. In other words, the retaining body 51 is supported in a horizontal position.

[0025] As shown in Figure 5, the pair of support plates 52 (52A, 52B) are elongated plate-shaped members having the same length as the length of the main body 51 in the long side direction. The support plates 52A and 52B are positioned to match the position of the long side of the main body 51. The pair of support plates 52A and 52B are provided such that the spacing between them is smaller than the length of the door 20b in the short side direction. In other words, the width of the pair of support plates 52A and 52B is set so that the spacing between them is smaller than the length of the door 20b in the short side direction.

[0026] As described above, the connecting portion 53 is formed in a cylindrical shape and connects the holding portion body 51 and the support plate 52. The connecting portion 53 is also formed to be longer than the thickness dimension of the door 20b. This creates a space between the holding portion body 51 and the support plate 52 that can accommodate the door 20b. In this embodiment, three connecting portions 53 are provided for each support 52A, 52B in the same positional relationship. Two of the three connecting portions 53 are provided near both ends of the long side of the holding portion body 51. The remaining connecting portion 53 is provided near the end of the short side of the holding portion body 51. As a result, the short side opposite to the short side on which the connecting portion 53 is provided becomes the opening 50a for inserting and removing the door 20b from the door holding portion 50. Here, among the connecting parts 53, the connecting part 53 provided on the longer side is designated with the reference numeral "53a", and the connecting part 53 provided on the shorter side is designated with the reference numeral "53b".

[0027] Of the six connecting parts 53 provided in this manner, the four connecting parts 53a located on the long side of the holding part body 51 function as guides that guide the long side of the door 20b when inserting or removing the door 20b into or removing it from the door holding part 50. More specifically, as shown in Figure 5, when the door 20b is positioned such that the center line 20L between the two long sides of the door 20b intersects the axis 61X of the rotation axis 61, the four connecting parts 53 are arranged so that there is a slight gap between them and the long sides of the door 20b. This slight gap is, for example, a gap that can tolerate transport errors by the robot 3 when inserting or removing the door 20b into or removing it from the door holding part 50, and dimensional errors of the door 20b including the types of wafer storage containers 20. By arranging the connecting parts 53a in this manner, the door 20b can be guided when inserting or removing the door 20b into or removing it from the door holding part 50, and movement in the direction along the short side of the housed door 20b can be restricted.

[0028] Furthermore, the two connecting portions 53b provided on the short side of the holding body 51 function as restrictors that control the position of the door 20b in the direction along its long side. More specifically, the two connecting portions 53b are positioned such that the distance along the long side direction relative to the axis 61X of the rotation shaft 61 is a predetermined length longer than half the length of the door 20 in the long side direction. This allows the holding body 51 to accommodate the door 20b such that the position of the center of gravity 20G of the door 20b is located on the connecting portion 53b side relative to the axis 61X of the rotation shaft 61, in other words, it is positioned eccentrically on the opposite side from the opening 50a. Here, the predetermined length should be such that when the door holding body 50 is rotated by the rotation drive unit 60, a centrifugal force of the required magnitude acts on the door 20b, pressing the door 20b against the connecting portion 53b. However, during cleaning of the door 20b housed in the door holding section 50, it is sufficient that the door 20b remains stably pressed against the connecting section 53b without moving towards the opening 50a side, so there is no need to make it longer than necessary. For example, a range of a few millimeters to a little over ten millimeters would suffice.

[0029] Furthermore, the pair of support plates 52A and 52B are equipped with support portions 52a that support the door 20b. One support portion 52a is positioned on each end of the support plates 52A and 52B in the longitudinal direction. More specifically, it is positioned near the connecting portion 53a, but inside the connecting portion 53a. The contact portion of the support portion 52a with the door 20b is formed as a curved surface, for example, a hemispherical curved surface, making it difficult to scratch the surface of the door 20b by contact with the door 20b. Instead of a hemispherical shape, it may be configured as a rotatable roller shape or a ball shape, etc.

[0030] A retaining portion 51b is provided so as to be roughly opposite to the support portion 52a. The retaining portion 51b is provided on the holding portion body 51. The retaining portion 51b functions as a restricting portion that restricts the upward movement of the door 20b supported on the support portion 52a. Therefore, the retaining portion 51b is provided such that the distance between its lower end and the support portion 52a in the vertical direction (in the direction of the axis 61X of the rotation axis 61) is slightly larger than the thickness dimension of the door 20b. The tip of the retaining portion 51b is formed in a hemispherical shape. Note that "slightly larger" means large enough to allow for, for example, transport errors by the robot 3 when the robot 3 moves the door 20b in and out of the door holding portion 50, and dimensional errors of the door 20b including the types of wafer storage containers 20.

[0031] The door 20b is housed in the door holding section 50 in a horizontal position with its inner surface facing downwards and its outer surface facing upwards. The inner surface of the door 20b is the surface that faces the inside of the container body 20a (the wafer storage space side) when the door 20b is attached to the container body 20a. On the other hand, the outer surface of the door 20b is the surface that faces the outside when the door 20b is attached to the container body 20a.

[0032] Furthermore, in order to clean the door 20b housed in the door holding section 50, the cleaning tank 5 is equipped with cleaning liquid nozzles 5c and gas nozzles 5d arranged as follows: a cleaning liquid nozzle 5c1 that supplies cleaning liquid from the bottom (inner) side, a cleaning liquid nozzle 5c2 that supplies cleaning liquid from the side side, and a cleaning liquid nozzle 5c3 that supplies cleaning liquid from the top (outer) side to the door 20b housed in the door holding section 50. In addition, the cleaning tank 5 is equipped with a gas nozzle 5d1 that supplies gas from the bottom (inner) side, a gas nozzle 5d2 that supplies gas from the side side, and a gas nozzle 5d3 that supplies gas from the top (outer) side to the door 20b housed in the door holding section 50.

[0033] Multiple cleaning solution nozzles 5c1 are arranged in a row and facing upward on a horizontally extending rod-shaped support member (not shown). The multiple cleaning solution nozzles 5c1 are arranged to be able to rotate horizontally as a single unit within the cleaning tank 5 by the swinging of the support member. This rotational movement allows the multiple cleaning solution nozzles 5c1 to move between a standby position and a cleaning solution supply position. The standby position is a position where the cleaning solution nozzles 5c1 do not interfere with the container body 20a when the container body 20a is loaded into or unloaded from the cleaning tank 5.

[0034] The cleaning fluid nozzle 5c2 is positioned to face horizontally, opposite the side of the door 20b housed in the door retaining section 50. The cleaning fluid nozzle 5c2 is supported by a support member (not shown) on the lid 5b. Since the door retaining section 50 rotates during cleaning, at least one cleaning fluid nozzle 5c2 is sufficient, but multiple nozzles may be provided.

[0035] The cleaning fluid nozzle 5c3 is provided to supply cleaning fluid to the outer surface of the door 20b housed in the door holding part 50 from an oblique upward direction. That is, the cleaning fluid nozzle 5c3 is provided above the door 20b housed in the door holding part 50, in other words, at a height between the outer surface of the door 20b and the inner surface of the lid 5b. The cleaning fluid nozzle 5c3 is provided so that the direction of discharge (injection) of the cleaning fluid is directed toward a position on the axis 61X of the rotation axis 60 on the outer surface of the door 20b. Such a cleaning fluid nozzle 5c3 is supported by the lid 5b by a support member (not shown). Although at least one cleaning fluid nozzle 5c3 is sufficient, multiple nozzles may be provided.

[0036] The gas nozzles 5d1, 5d2, and 5d3 can be installed in the same configuration as the cleaning fluid nozzles 5c1, 5c2, and 5c3, respectively.

[0037] These cleaning solution nozzles 5c1, 5c2, 5c3 and gas nozzles 5d1, 5d2, 5d3 are connected to the cleaning solution supply unit 5e and the gas supply unit 5f. Specifically, the cleaning solution nozzle 5c1 is connected to the cleaning solution supply unit 5e via an on / off valve 5e1, the cleaning solution nozzle 5c2 via an on / off valve 5e2, and the cleaning solution nozzle 5c3 via an on / off valve 5e3, each by a liquid supply pipe. The cleaning solution supply unit 5e is, for example, a tank for storing cleaning solution. The gas nozzle 5d1 is connected to the gas supply unit 5f via an on / off valve 5f1, the gas nozzle 5d2 via an on / off valve 5f2, and the gas nozzle 5d3 via an on / off valve 5f3, each by an intake pipe. The gas supply unit 5f may be a gas tank in which gas is stored, or it may be supplied from piping of factory equipment. The gas tank may be dedicated to the wafer storage container cleaning apparatus 1, or it may be shared with other equipment.

[0038] Next, the operation of the wafer storage container cleaning apparatus 1 will be described. The operation of the wafer storage container cleaning apparatus 1 is controlled by the control device 8.

[0039] First, the wafer storage container 20 to be cleaned is transported by the OHT and placed on the outer part of the load port 2. Once the wafer storage container 20 is placed on the outer part of the load port 2, the operation of the load port 2 moves the wafer storage container 20 from the outer part to the inner part of the load port 2. In other words, the wafer storage container 20 is brought into the casing 11.

[0040] When the wafer storage container 20 is loaded, the flange 20c of the wafer storage container 20 is grasped by the body chuck provided on the hand portion 3b of the robot 3, and the wafer storage container 20 on the load port 2 is transported by the robot 3 onto the buffer 4. At this time, the wafer storage container 20 is placed on the buffer 4 with the opening side facing downward. More specifically, the door 20b is in contact with the buffer 4, and the latch key 4a of the buffer 4 is placed so as to engage with the latch mechanism of the door. In this state, the latch key 4a of the buffer 4 is activated, and the latch mechanism of the door 20b is unlocked. This makes the wafer storage container 20 separable into the container body 20a and the door 20b. After this, the robot 3 transports the wafer storage container 20 to the cleaning tank 5, leaving the door 20b on the buffer 4 and transporting the container body 20a. The container body 20a, which has been transported to the washing tank 5, is placed on a table (not shown) inside the washing tank body 5a with its opening facing downwards. In this case, the control device 8 pre-opens the lid 5b of the washing tank 5.

[0041] Once the container body 20a has been transported to the washing tank 5, the door 20b on the buffer 4 is grasped by the door chuck on the hand portion 3b of the robot 3. The door 20b is grasped by the center of its short side from a direction along its long side. The door 20b is then transported by the robot 3 to the door holding portion 50 provided on the lid 5b of the washing tank 5. At this time, the lid 5b of the washing tank 5 is open in a nearly vertical position, and the door holding portion 50 is positioned in a rotational position with the opening 50a facing upwards. In this state, the robot 3 inserts the door 20b into the door holding portion 50 from the opening 50a so that its long side faces vertically. At this time, since the door chuck of the robot 3 is grasping the center of the short side of the door 20b, it passes between the pair of support plates 52A and 52B of the door holding portion 50 and does not interfere with the door holding portion 50. The door 20b, housed within the door holding section 50, has its position restricted along its longer side by the connecting section 53b and its position restricted along its shorter side by the connecting section 53a. In this stored state, the center of gravity of the door 20b is eccentrically positioned toward the connecting section 53b with respect to the axis 61X of the rotation axis 61.

[0042] When the container body 20a and door 20b are brought into the washing tank 5, the washing tank 5 (rotation drive unit 60, washing liquid supply unit 5e, gas supply unit 5f) performs a washing process on the container body 20a and door 20b, and after washing is complete, a preliminary drying process is performed on the container body 20a and door 20b to remove the washing liquid. For example, the washing process is performed by supplying washing liquid for a predetermined time while the container body 20a and door 20b are rotated at a predetermined rotational speed. The rotation of the container body 20a is performed by a rotation mechanism (not shown), and the rotation of the door 20b is performed by rotating the door holding unit 50 by the rotation drive unit 60. After the washing process is completed, the preliminary drying process is similarly performed by supplying gas for a predetermined time while the container body 20a and door 20b are rotated at a predetermined rotational speed. At this time, the rotational speed may be the same or different for the washing process and the preliminary drying process.

[0043] When the aforementioned door holding part 50 rotates, the door 20b is pressed towards the connecting part 53b by centrifugal force because its center of gravity is eccentrically positioned toward the connecting part 53b with respect to the axis 61X of the rotation axis 61.

[0044] In the aforementioned cleaning process, the timing for starting the supply of cleaning solution from each cleaning solution nozzle 5c1, 5c2, and 5c3 is set to the same timing, and the timing for stopping the supply is also set to the same timing. Similarly, in the preliminary drying process, the timing for starting the supply of gas from each gas nozzle 5d1, 5d2, and 5d3 is set to the same timing, and the timing for stopping the supply is also set to the same timing.

[0045] Furthermore, in this cleaning process, the cleaning liquid supplied from each cleaning liquid nozzle 5c1, 5c2, and 5c3 reliably reaches not only the inner surface of the door 20b, which is the bottom surface, but also the sides of the door 20 and the outer surface of the door 20b, which is the top surface, through the gap in the cage-shaped door holding part 50. Similarly, in the pre-drying process, the gas supplied from each gas nozzle 5d1, 5d2, and 5d3 reliably reaches the inner surface, sides, and outer surface of the door 20b.

[0046] Once the preliminary drying process is complete, the supply of gas from the gas nozzles 5d1, 5d2, and 5d3 is stopped, and the rotation of the container body 20a and the door 20b is stopped. When stopping the rotation of the door 20b, the stopping position of the door holder 50 is controlled so that when the lid 5b is opened, the opening 50a of the door holder 50 faces upward. The stopping position of the door holder 50 can be controlled, for example, by providing a detector that detects the rotational position of the rotation axis 61 of the rotation drive unit 60, and determining the orientation of the opening 50a of the door holder 50 based on the value detected by this detector.

[0047] Once the washing and pre-drying processes in the washing tank 5 are complete, the lid 5b of the washing tank 5 is opened. After this, the robot 3 removes the container body 20a from the washing tank body 5a and transports it to the drying tank 6. Next, the door 20b is removed from the door holding unit 50 and transported to the drying tank 6.

[0048] Once the container body 20a and door 20b have been transported into the drying chamber 6, a vacuum pump (not shown) in the drying chamber 6 is activated, and the inside of the drying chamber 6 is brought to a predetermined vacuum state. This vacuum state is then maintained for a predetermined time, during which time any moisture adhering to the container body 20a and door 20b is removed and they are dried (final drying).

[0049] Once drying in the drying tank 6 is complete, the robot 3 transports the door 20b and the container body 20a to the buffer 4 in the order of door 20b, then container body 20a. The door 20b is placed on the buffer 4 so that its latch mechanism engages with the latch key 4a of the buffer 4, and the container body 20a is placed on the buffer 4 so that its opening covers the door 20b which was placed on the buffer 4 earlier. In this state, the latch key 4a of the buffer 4 is activated, locking the latch mechanism of the door 20b and attaching the door 20b to the container body 20a.

[0050] Once the door 20b is attached to the container body 20a, the robot 3 transports the wafer storage container 20 to the inner part of the unload port 7. Subsequently, the unload port 7 moves the wafer storage container 20 from the inner part to the outer part of the unload port 7. In other words, the wafer storage container 20 is removed from the casing 11. After this, the above operation is repeated each time a wafer storage container 20 to be cleaned is transported to the load port 2.

[0051] As described above, according to this embodiment, the door holding part 50 provided in the washing tank 5 is of the cage type, and the structure is such that the outer surface and sides of the housed door 20b are not covered by the wall and have gaps. More specifically, the holding part body 51, which is a member facing the outer surface of the door 20b, is hollowed out in a roughly triangular shape, leaving the outer circumference and diagonally opposite parts, and has an opening 51a. In addition, the connecting parts 53 (53a, 53b), which are members located corresponding to the sides of the door 20b, are cylindrical members and have a space between them. Furthermore, the pair of support plates 52 (52A, 52B), which are members located corresponding to the inner surface of the door 20b, are spaced apart and are configured to support both ends of the long side of the door 20b. As a result, the parts of the door 20b other than both ends of the long side are exposed.

[0052] Because the door holding portion 50 is formed in this cage shape, the cleaning liquid and gas can easily reach not only the inner surface of the door 20b housed in the door holding portion 50 (the surface facing downwards inside the cleaning tank 5), but also the outer surface opposite to the inner surface and the side surfaces located between the inner and outer surfaces. Therefore, the outer surface and side surfaces of the door 20b can also be easily cleaned and partially dried. As a result, the cleanliness of the wafer storage container 20 can be improved.

[0053] Furthermore, the door holder 50 is positioned such that the center of gravity of the door 20b housed in the door holder 50 is eccentrically located on the opposite side of the door opening 50a of the door holder 50 from the rotation axis 61 of the rotation drive unit 60 that rotates the door holder 50. As a result, when the door holder 50 is rotated, the door 20b housed in the door holder 50 is subjected to a force caused by centrifugal force that directs it away from the opening 50a. In other words, the door 20b is pressed by centrifugal force against the connecting part 53b of the connecting part 53 that connects the holding part body 51 and the support plate 52 of the door holder 50, which restricts the position of the door 20b in the direction along the long side. Since the connecting part 53b is located on the opposite side of the opening 50a of the door holder 50, it is possible to prevent the door 20b from moving towards the opening 50a during the cleaning and pre-drying processes that are performed while the door holder 50 is rotating. This eliminates the need for a mechanism in the door retaining section 50 to prevent the door 20b from slipping out of the opening 50a, thus simplifying the configuration of the door retaining section 50.

[0054] Furthermore, the door holding mechanism 50 supports the door 20b with support portions 52a provided on a pair of support plates 52 (52A, 52B), and separates the surfaces of the support plates 52A and 52B from the surface (inner surface) of the door 20b. As a result, the contact area between the door holding portion 50 and the door 20b is reduced, allowing cleaning fluid to penetrate through the gap between the support plates 52A and 52B and the door 20b. Therefore, it becomes possible to clean the door 20b more effectively and improve the cleanliness of the door 20b.

[0055] Furthermore, the contact area between the support portion 52a and the door 20b is formed as a hemispherical curved surface. This makes it possible to further reduce the contact area between the door holding portion 50 and the door 20b.

[0056] In the first embodiment described above, the door holding part 50 was described as being installed so as to be perpendicular to the rotation axis 61 along the vertical direction of the rotary drive unit 60, that is, in a horizontal state, when the lid 5b of the washing tank 5 is closed. It was described as being installed so as to support the door 20b housed in the door holding part 50 in a horizontal state. However, the door holding part 50 does not necessarily have to be installed horizontally, nor does the door 20b have to be supported horizontally. For example, the door holding part 50 may be installed on the rotation axis 61 at an angle with respect to the rotation axis 61 along the vertical direction. However, in this case, it is preferable that the angle between the upper surface of the holding part body 51 of the door holding part 50 (one of the flat surfaces of the door holding part 50, which has a flat rectangular parallelepiped outer shape) and the axis 61X of the rotation axis 61 be larger on the connecting part 53b side, which is opposite to the opening 50a, than on the opening 50a side of the door holding part 50. In this way, even when the rotation of the door holding part 50 is stopped, the inclination of the door holding part 50 allows a force to be applied to the door 20b housed in the door holding part 50 in the direction toward the connecting part 53b, in other words, a force toward the direction toward away from the opening 50a. Therefore, the effect of making it difficult for the door 20b to slip out of the opening 50a during washing or pre-drying can be further improved.

[0057] Furthermore, as mentioned above, when the door holding part 50 is tilted, it is not necessarily required that the center of gravity of the door 20b housed in the door holding part 50 be eccentric with respect to the axis 61X of the rotation shaft 61. As long as the tilt of the door holding part 50 as described above prevents the door 20b from coming out of the opening 50a during washing or pre-drying, the center of gravity of the door 20b housed in the door holding part 50 may be on the axis 61X of the rotation shaft 61. In other words, if the door holding part 50 is tilted with respect to the rotation shaft 61 to the extent that it prevents the door 20b from coming out of the opening 50a during washing or pre-drying, the center of gravity of the door 20b housed in the door holding part 50 may be on the axis 61X of the rotation shaft 61.

[0058] Furthermore, it was explained that during cleaning, the timing for starting and stopping the supply of cleaning solution from each cleaning solution nozzle 5c1, 5c2, and 5c3 is set to be the same, and during pre-drying, the timing for starting and stopping the supply of gas from each gas nozzle 5d1, 5d2, and 5d3 is also set to be the same. However, each timing may be different, or some may be set to be the same timing and others to be different timings, and can be set as appropriate. In other words, it should be set as appropriate according to the conditions of the cleaning process and the pre-drying process.

[0059] Although embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0060] 1. Wafer storage container cleaning device 2 Load Ports 2a opening 2b shutter 3 Robots 3a Arm section 3b Hand section 4 buffers 4a Latch key 5. Washing tank 5a Washing tank body 5b Lid 5c (5c1, 5c2, 5c3) Cleaning solution nozzle 5d (5d1, 5d2, 5d3) Gas Nozzle 5e Cleaning fluid supply unit 5e1, 5e2, 5e3, 5f1, 5f2, 5f3 On / Off Valves 5f Gas supply unit 6 Drying tank 7 Unload Ports 7a opening 7b shutter 8 Control device 11 Casing 20 wafer storage containers 20a Container body 20b Door 20c flange 20G center of gravity 20L center line 50 Door retaining part 50a Inlet / Outlet 51 Holding part body 51a opening 51b Retaining part 52(52A, 52B) Support plate 52a Support part 53(53a, 53b) Connection part 60 Rotary drive unit 61 Rotation axis 61X axis

Claims

1. A cleaning tank for cleaning at least the door of a wafer storage container, which comprises a container body having a storage space for storing wafers and a door that closes an opening in the container body leading to the storage space, A cage-shaped door holder is provided inside the washing tank to house the door, A rotary drive unit is provided in the washing tank and rotatably supports the door holding portion, A cleaning nozzle that supplies cleaning fluid to a door held in a door retaining section, A wafer storage container cleaning device equipped with [a specific feature].

2. The aforementioned door retaining part is The door is housed in the door holding section such that the center of gravity of the door housed in the door is eccentric with respect to the rotation axis of the rotary drive section. The wafer storage container cleaning apparatus according to claim 1, wherein the opening for the door is located on the opposite side of the rotation axis from the center of gravity of the door when viewed from a direction along the rotation axis.

3. The wafer storage container cleaning apparatus according to claim 2, wherein the rotation drive unit is provided in the cleaning tank such that the rotation axis is aligned in the vertical direction.

4. The wafer storage container cleaning apparatus according to claim 3, wherein the door holding part is supported on the rotation shaft so that the housed door is in a horizontal position.

5. The aforementioned door retaining part is A holding body having a rectangular outer shape in plan view, supported on the rotation axis such that the sides forming the outer shape are perpendicular to the rotation axis, A support plate for supporting the door is provided at a distance from the main body of the holding part that allows the door to be accommodated, The wafer storage container cleaning apparatus according to claim 3, further comprising a plurality of columnar connecting parts that connect the holding part body and the support plate.

6. The wafer storage container cleaning apparatus according to claim 5, wherein the plurality of connecting parts include a connecting part that functions as a guide for the door that is inserted into and removed from the opening, and a connecting part that functions as a restricting part that restricts the position of the door in the direction in which the door is inserted into and removed from the opening.

7. The wafer storage container cleaning apparatus according to claim 6, wherein the support plate has two plate portions that are separated to the left and right when viewed from the side of the loading / unloading opening, and each portion is connected to the main body of the holding part via the connecting part.

8. The support plate has a plurality of support parts that support the door, The wafer storage container cleaning apparatus according to any one of claims 5 to 7, wherein the support portion has a curved surface at the contact portion with the door.

9. The wafer storage container cleaning apparatus according to claim 1, wherein a plurality of cleaning nozzles are provided in the door housed in the door holding portion, so as to face the inner surface which is the inner surface when the opening of the main body is closed, the outer surface which is the surface opposite to the inner surface, and the side surface located between the inner surface and the outer surface.

10. The cleaning tank comprises a box-shaped cleaning tank body with an open top and a lid that can open and close the opening of the cleaning tank body. The wafer storage container cleaning apparatus according to claim 5, wherein the rotational drive unit is provided on the upper surface of the lid.

11. The system further includes a control device for controlling the aforementioned rotary drive unit, The lid is configured to be able to be opened and closed by swinging relative to the washing tank body. The wafer storage container cleaning apparatus according to claim 10, wherein the control device controls the stopping position of the door holding part when stopping the rotation of the door holding part so that the loading / unloading opening faces upward when the lid is opened.

12. The door holding portion has a generally flattened rectangular parallelepiped shape, with the rotation shaft of the rotary drive unit connected to one of its flattened surfaces, and one of its side surfaces formed as an opening for inserting and removing the door. The wafer storage container cleaning apparatus according to claim 1, wherein the door holding portion is connected to the rotating shaft such that the angle between the flat surface of the door holding portion and the rotating shaft is larger on the side of the door holding portion opposite to the opening than on the side of the opening.

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