Patent Publication Number: US-2023135865-A1

Title: Cleaning systems and methods for semiconductor substrate storage articles

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a divisional application of application Ser. No. 16/119,465, filed Aug. 31,2018 (now U.S. Pat. No. 11,167,322); which is a divisional application of application Ser. No. 15/031,334, filed Apr. 22,2016, (now U.S. Pat. No. 10,065,222), which is the National Stage of International Application No. PCT/IB2014/065458, having an International Filing Date of 20 Oct. 2014, which designated the United States of America, and which International Application was published under PCT Article 21(2) as WO Publication No. 2015/059615 A1, and which claims priority from, and the benefit of U.S. Application No. 61/894,883, filed 23 Oct. 2013, the disclosures of which are incorporated herein by reference in their entireties. 
     This application is related to U.S. application Ser. No. 14/517,900, filed 19 Oct. 2014, which claims priority from, and the benefit of U.S. Application No. 61/894,883, filed 23 Oct. 2013, the disclosures of which are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND 
     Production of semiconductor devices requires cleanliness of substrates as well as articles used for storing and transferring these substrates. Presence of particulates and other contaminant can negatively impact production yields. The transport of the semiconductor substrates is typically carried out in special articles or, more specifically, containers, such as cassettes, carriers, trays, Front Opening Unified Pod (FOUP), Front-Opening Shipping Box (FOSB), Standard Mechanical Interface (SMIF), MAC (Multi Application Carrier), pods, and boxes. For example, a FOUP typically includes one or more comb-like guiding structures positioned inside a shell for supporting substrates. The FOUP also includes a door that can be removed from the shell and allow a substrate handling robot to access the substrates from the shell. 
     FOUPs and other articles used for storing and transferring semiconductor substrates need to be periodically cleaned in order to prevent contamination of substrates and to maintain the standard of cleanliness needed for the substrates. The FOUPs and other articles can be cleaned using special cleaning and drying equipment. As the cleanliness requirements become more stringent, the number of cleaning cycles and complexity of each cycle increases. For example, a FOUP may need to be cleaned after each individual use in order to prevent cross contamination. 
     Overall, it is desirable to shorten the time needed for cleaning FOUPs and other articles used for storing and transferring substrates. At the same time, mechanical complexity of the FOUPs and other articles increases in order to accommodate new substrate handling systems and perform new functions. For example, a FOUP door is engaged with a FOUP body using a complex set of moving parts provided with the FOUP door. Furthermore, FOUP doors and bodies may include numerous openings used for engagement these components and for coupling to these components using, for example, substrate handling equipment. These openings may complicate drying with trapped cleaning and/or other liquids. 
     SUMMARY 
     In some embodiments, the present invention discloses methods and systems for cleaning various articles, such as semiconductor substrate storage articles including containers, such as FOUP container doors and bodies. The FOUP containers and other similar articles often have openings, such as cavities or gaps, that may trap cleaning liquids during the cleaning process. Some of the trapped liquid may not be removed during the drying process, especially for high aspect ratio openings. The described cleaning system can include processes and components to prevent liquids from entering the hard-to-dry openings, thus can facilitate the drying process. 
     In some embodiments, the openings can be protected with a gaseous flow, for example, during the wet cleaning process. The gaseous flow can minimize or prevent the liquid from entering the openings, or can expel any liquid from the openings. The gaseous flow can assist in cleaning the openings, for example, through the gaseous flow or through a combination of liquid entering the openings and expelled by the gaseous flow. 
     In some embodiments, contact points can be provided for engaging the article and partially or completely covering these openings. The contact points may be also used for supporting the article and for pressurizing the openings in the article with a gas. The gas may be supplied through one or more contact points. It prevents liquids from getting into the openings if even the openings are not completely sealed. The pressurization may be maintained through the entire wet portion of the cleaning process. The article may be rotated within the cleaning system while cleaning and/or other liquids or gases are dispensed through a set of spraying nozzles. Spraying nozzles may move to enhance cleaning of the article. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1 A-  1 B  illustrate a prior art cleaning process. 
         FIG.  2    illustrates a schematic cleaning system according to some embodiments. 
         FIGS.  3 A- 3 F  illustrate various configurations for cleaning articles according to some embodiments. 
         FIGS.  4 A- 4 D  illustrate various configurations of openings in an article according to some embodiments. 
         FIG.  5    illustrates a flow chart for article cleaning according to some embodiments. 
         FIGS.  6 A- 6 B  illustrate a rotating cleaning system according to some embodiments. 
         FIG.  7    illustrates a flow chart for cleaning an article according to some embodiments. 
         FIGS.  8 A- 8 B  illustrate perspective views of a FOUP container according to some embodiments. 
         FIGS.  9 A- 9 B  illustrate a schematic representation of a FOUP door according to some embodiments. 
         FIGS.  10 A- 10 B  illustrate a schematic representation of a FOUP body according to some embodiments. 
         FIG.  11    illustrates a schematic cleaning system according to some embodiments. 
         FIGS.  12 A- 12 B  illustrate schematic cleaning processes for a container lid according to some embodiments. 
         FIGS.  13 A- 13 D  illustrate schematic view of an assembly supporting a FOUP door for cleaning according to some embodiments. 
         FIG.  14    illustrates a schematic view of an assembly supporting a FOUP body for cleaning according to some embodiments. 
         FIG.  15    illustrates a drive mechanism for supporting an article according to some embodiments. 
         FIG.  16    illustrates another schematic cleaning system according to some embodiments. 
         FIGS.  17 A- 17 B  illustrate schematic views of another assembly supporting a FOUP door for cleaning according to some embodiments. 
         FIGS.  18  and  19 A- 19 C  illustrate various contact points for engaging an article during a cleaning process according to some embodiments. 
         FIGS.  20 A- 20 D  illustrate schematic configurations for cleaning nozzles according to some embodiments. 
         FIG.  21    illustrates a flow chart for cleaning an article according to some embodiments. 
         FIG.  22    illustrates another flow chart for cleaning an article according to some embodiments. 
         FIG.  23    illustrates an example of FOUP door support before cleaning according to some embodiments. 
         FIG.  24    illustrates an example of FOUP body support before cleaning according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented concepts. The presented concepts may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail so as to not unnecessarily obscure the described concepts. While some concepts will be described in conjunction with the specific embodiments, it will be understood that these embodiments are not intended to be limiting. 
     In some embodiments, the present invention discloses systems and methods for cleaning articles. The cleaning process can include a wet cleaning, e.g., cleaning with a liquid, such as cleaning chemicals and water. The cleaning process can include a drying step, removing the liquids from the articles surfaces. The articles can have openings, such as gaps, cavities, holes, enclosures, apertures, orifices, or any other types of openings that can trap and retain liquid. For example, the openings can include a long narrow hole passing through the article. The openings can include a large cavity with a small aperture which accepts a bolt mechanism. The articles can be a semiconductor container that is configured to store one or more substrates such as wafers or reticles. 
     In some embodiments, the cleaning process can protect the openings from trapping and/or retaining liquid during the wet cleaning process. The protection can facilitate the subsequent drying process, since there can be minimal or no liquid in areas that are difficult to dry. The protection can be in the form of a gaseous flow, for example, from a gas nozzle directed toward the openings. The protection can be in the form of a blocking component, which partially or completely covers the openings to minimize or to prevent liquid from entering the openings. 
     In some embodiments, the present invention discloses methods and systems for cleaning semiconductor substrate storage containers and other articles, such as cassettes, holders, FOUPs, and MACs. While references are often made to FOUPs, one having ordinary skills in the art would understand that the described methods and systems can be also applied to other articles. In some embodiments, multiple different articles may be cleaned together or sequentially using the same cleaning apparatus. For example, the cleaning apparatus may be used for cleaning a body and a door of a FOUP unit in dissembled state. The FOUP unit may be provided for cleaning in its assembled state. The apparatus may disassemble, clean, dry, and re-assembly the FOUP unit. Furthermore, the apparatus may include certain inspection features to verify cleanness of an article after the cleaning is completed. 
       FIGS.  1 A -IB illustrate an prior art cleaning process. An article  110  can be subjected to a cleaning process, for example, through nozzle  120  delivering cleaning liquid  125 . The article  110  can have openings at the surface, such as through hole  170 , gap  175 , or cavity  177 . During the liquid cleaning process, liquid droplets  130  and  135  can retain on the surfaces of the articles, including the inner surfaces of the openings  170 ,  175 , and  177 . For openings having high aspect ratio or blockage, the liquid droplet, e.g., droplet  135 , can be trapped in the openings and can remain after a drying process to dry the article, e.g., to remove the liquid from the surfaces of the article. 
     The trapped liquid, e.g., liquid droplets that remain on the article even after the drying process, can contaminate the article. For example, the liquid droplets can be released from the article and contaminate a substrate. Alternatively, the liquid droplets can attract particulates, which can contaminate the article. 
     In some embodiments, the present invention discloses methods and system for cleaning articles without, or with minimum, liquid remained on the articles, even in trappable-liquid openings. The openings can be blocked, for example, by a physical cover or by a gaseous flow blockage, to prevent liquid droplets from being trapped in the openings or to prevent liquid droplets from being retained in the openings after a drying process. 
       FIG.  2    illustrates a schematic cleaning system according to some embodiments. An article  210  can be subjected to a cleaning process, for example, through nozzle  220  delivering cleaning liquid  225 . Other cleaning process can be used, such as submerging the article to a liquid bath, or flowing liquid to the article until the article is submerged in a liquid. In the following description, liquid nozzles delivering liquid flows are shown for cleaning the articles, but the invention is not so limited, and can include other liquid cleaning processes, such as submerging the article in a liquid bath, or flowing an ultrasonic liquid, or ultrasonic treating the article. Further, a cleaning process can include washing the article for removing contaminates or particulates at the surfaces of the article. Thus chemical washing or water rinsing can be used. 
     The article  210  can have openings at the surface, such as through hole  270 , gap  275 , or cavity  277 . The openings  270 ,  275 , and  277  can be configured to provide blockage of liquid  225  from entering or from retaining in the openings. A nozzle  250  can be placed in a vicinity of the opening  270 , and can deliver a gaseous flow  240  to the opening  270 . The gaseous flow  240  can be positioned in one end of the openings  270  in a general direction of the liquid flow, for example, to prevent the liquid from entering the opening. The gaseous flow  240  can be positioned in another end of the openings  270  in an opposite direction of the liquid flow, for example, to push any liquid away from the opening. The gas flow  240  can assist in cleaning the opening  270 , for example, by dislodging any particulates in the openings while minimizing or preventing liquid from being trapped in the opening, e.g., retaining in the opening after a drying process. 
     Contact points can be used to block the openings to prevent liquids from entering the openings. A contact point  257  can be used to block the opening  277 , sealing the openings from the liquid environment. A contact point  255  together with a gaseous flow  245  can be used to block the opening  275 . The contact point  255  can be placed in the vicinity of the opening  275 , totally or partially blocking the opening. The gas flow  245  can assist in cleaning the opening  275 , for example, by dislodging any particulates in the openings while minimizing or preventing liquid from being trapped in the opening, e.g., retaining in the opening after a drying process. Thus during the cleaning, liquid droplets  230  can retain on the surfaces of the articles, while no droplets or minimal droplets can stay inside the openings  270 ,  275 , and  277 . The absence of liquid droplets inside the openings can significantly simplify the subsequent drying process. 
       FIGS.  3 A- 3 F  illustrate various configurations for cleaning articles according to some embodiments. An article  310  can have an opening  370 , which is subjected to a cleaning process, for example, by a liquid flow from a nozzle  320 . In  FIG.  3 A , a nozzle  350  carrying a gas flow  340  can be directed toward the opening. The nozzle  350  can be placed perpendicular to the opening, blocking the opening. In  FIG.  3 B , nozzle  351  can form an angle with the opening surface, delivering a gas flow  341  at and near the opening. In  FIG.  3 C , a contact point  352  partially blocks the opening, together with a gas flow  342  to create a pressurized area at the vicinity of the opening. The partial blockage of contact point  352  can minimize particles due to contacting surface. In  FIG.  3 D , a contact point  353  blocks the opening, together with a gas flow  343  to create a pressurized area at the vicinity of the opening. In  FIG.  3 E , a contact point  354  having curve surface can be used to partially block the opening, with the gas flow  344  radially flowing toward the opening. In  FIG.  3 F , a contact point  355  partially blocks the opening, with an optional gas flow  345  from inside of the opening. 
       FIGS.  4 A- 4 D  illustrate various configurations of openings in an article according to some embodiments. In general, the opening can capture liquid droplets in a wet cleaning process, which are not easily removed during a subsequent drying process. For example, the opening can have a small aperture, for example, less than a few mm gap, such as less than 1 or 2 mm gap. The opening can have high aspect ratio, for example, greater than 10:1 (e.g., the depth is ten times the size of the opening), such as greater than 20:1 or 50:1. 
     An article  410  can have an opening  470  in the form of a hole passing through the article, e.g., from one surface to an opposite surface. The size of the opening  470  can be small or the aspect ratio of the opening can be high, which prevent any trapped liquid droplets in the opening from being removed during a drying process. An article  412  can have an opening  472 , which is configured to contain a bolt  482 . The bolt  482  can slide in and out of the opening  472 , for example, to lock the article  412  with a mating article. The gap between the bolt and the opening can be small, thus any liquid droplets trapped in the inside volume of the opening can be difficult to remove. An article  414  can have an opening  474  in the form of a cavity having a smaller opening that the cavity volume. With the small aperture, trapped liquid droplets can be blocked from being removed at the aperture. An article  416  can have an opening  476  at the interface of two connecting walls. The opening  476  can be used to reduce the weight and material of the article at the reinforced corner. 
       FIG.  5    illustrates a flow chart for article cleaning according to some embodiments. Operation  500  provides an object. The object can have a liquid-trappable opening, e.g., an opening that can retain liquid droplets even after a drying process. For example, the opening can include a high aspect ratio cavity or gap. Operation  510  flows a gas in a vicinity of the opening, e.g., the high aspect ratio cavity or gap, to minimize liquid entering the opening or to push out any entered liquid. Alternatively, the opening can be blocked, pressurized with a gas, or partially or completely blocks together with flowing a gas. Operation  520  flows a liquid toward the object or cleans the object with a liquid. 
     In some embodiments, the present invention discloses systems and methods for cleaning articles, including cleaning with a liquid and then drying the object. The article can be cleaned while rotating for a complete surface cleaning process. A rotation mechanism can be used with supports for holding the article, together with liquid nozzles for delivering liquid to the article. A gas source can be coupled to the rotation mechanism to deliver gas flows to the article, for example, at openings of the article that need to be covered to prevent or to minimize wetting at the hard-to-dry openings. 
       FIGS.  6 A- 6 B  illustrate a rotating cleaning system according to some embodiments. A rotation mechanism  645  can include supports  660 , which can hold an article  610  or  615 . A liquid source  620  can deliver a liquid flow to the article for cleaning or for rinsing. 
     A gas source  640  can be coupled to the rotating mechanism, for example, through a rotatable seal. Gaseous nozzles or contact points  650  and  655  can be coupled to the support  660  to block openings  670  and  675 . Gaseous nozzle  655  can deliver a gas flow to the opening  675 . Gaseous nozzle  650  can form a contact point with the article at the opening  670  for generating a high flow high pressure area at the opening area, preventing liquid from entering the opening. As shown, the cleaning process is performed by liquid nozzle  620 . Other cleaning mechanisms can be used, such as a liquid bath, or the liquid nozzle  620  flowing liquid to form a liquid bath for submerging the article. 
       FIG.  7    illustrates a flow chart for cleaning an article according to some embodiments. Operation  700  provides an object to be cleaned, wherein the object has an opening, such as a high aspect ratio cavity or gap. Operation  710  mounts the object to a rotating mechanism. The rotating mechanism can accept a gas flow, which can lead to a gas nozzle. Operation  720  aligns the gas nozzle with the opening, e.g., the high aspect ratio cavity or gap of the object. The gas nozzle can be placed in a vicinity of the opening, or the gas nozzle can totally or partially block the entrance to the opening. Operation  730  flows a gas to the gas source, which delivers the gas to the gas nozzle. Operation  740  flows a liquid toward the object for cleaning. Operation  750  rotates the object. 
     In some embodiments, the present invention discloses systems and methods for cleaning semiconductor containers, such as wafer containers or reticle containers. The following description uses FOUP as an example of semiconductor container, but other kinds of containers can be equally applicable. 
     A brief description of FOUP containers is provided to better illustrated various features of the cleaning apparatus. As noted above, a FOUP includes a FOUP door which mates with a 
     FOUP body to provide a sealed, ultraclean interior environment in which wafers may be stored and transferred. The wafers are supported either in a cassette which may be inserted into the body, or to shelves mounted to the interior of the body. 
       FIGS.  8 A- 8 B  illustrate perspective views of a FOUP container according to some embodiments.  FIG.  8 A  shows a perspective view from a top side  850  and  FIG.  8 B  shows a perspective view from a bottom side  855  of a FOUP  800 . The FOUP  800  can include a FOUP door  802  coupled to a FOUP body  801 . The FOUP can have some openings which can trap and retain liquid during a cleaning process. The openings can be configured so that it can be nearly impossible to remove the trapped liquid or can take a long drying time or special drying components. For example, the FOUP door  802  can have a latching mechanism  820  for locking the FOUP door  802  with the FOUP body  801 . The mechanism  820  can have opening leading to an inner cavity that houses the locking mechanism. The FOUP body  801  can have some pass through holes  810 . 
       FIGS.  9 A- 9 B  illustrate a schematic representation of a FOUP door according to some embodiments.  FIG.  9 A  shows a schematic top view and  FIG.  9 B  shows a schematic side view of a FOUP door  900  illustrating various openings within FOUP door  900 . FOUP door  900  includes multiple latch plates  906  that slide within openings  908 . Latch plates  906  are connected to latch hubs  905  that control the position and movement of latch plates  906 . Specifically, two latch hubs  905  are shown within internal cavity  904  of FOUP door  900 . Each latch hub  905  is configured to actuate two opposite latch plates  906  in this example. When latch hub  905  is turned, it moves latch plates  906  within openings  908 . Latch plates  906  can extend outside of openings  908  for engaging with, e.g., the FOUP body. In order to disengage FOUP door  900  from the FOUP shell, latch plates  906  are retracted back into openings. The latch plate  906  can be slightly smaller than the opening  908  so that the latch plate can slide through. The gap in the opening  908  from the latch plate  906  to the FOUP door material surrounding the latch plate can be small, for example, less than 10×, less than 20×, or less than 50× the length of the latch plate. For example, the gap can be less than 2 mm, less than 1 mm, or less than 0.5 mm. The latch plate can be greater than 50 mm, greater than 20 mm, or greater than 10 mm. 
     When FOUP door  900  is sprayed with a cleaning liquid or submerged into the cleaning liquid, the liquid may get into openings  908  and eventually into internal cavity  904 . If that happens, it may be extremely difficult to remove the liquid from internal cavity  904  and/or openings  908 . At the same time, it is not desirable to use FOUP door  900  until all liquid is removed. In some embodiments, openings  908  are protected when FOUP door  900  is exposed to liquids. In addition to openings  908  extending into internal cavity  904 , FOUP door  900  or some other similar articles may include external cavity  910 , which may also trap liquids. For purposes of this disclosure, any cavity, recess, or other surface feature capable of trapping liquid is referred to an opening. 
     In some embodiments, the present invention discloses protecting openings that can trap and retain liquid after a reasonable drying process. For example, the openings  908  can trap liquid into the internal cavity  904 . The trapped liquid can be retained within the cavity  904  even after prolong drying time, such as spin dry or heated dry, since the openings  908  can have high aspect ratio and small aperture size, leading to low escape probability of the trapped liquid. The opening  910  can trap also liquid, but since the aspect ratio is small, the trapped liquid can be removed in a normal drying process such as a spin dry, a vacuum dry or a heated dry process. 
     Some or all openings may be protected by a gas flow, or covered by contact points while the article is being cleaned. The same contact points may be used to support the article during the cleaning process. Alternatively, support points can be used for support the article, while the contact points are configured to protect the openings. Gas flow can be provided to the contact points, for example, to pressurize the openings and/or cavities, such that the cleaning liquid does not enter these openings and/or cavities even if the seal is not completely formed between the contact point and the article. In some embodiments, an opening may be pressurized to between about 1-100 kPa relative to the pressure inside the cleaning chamber. 
     It should be noted that any openings of an article being cleaned may be covered using methods and systems provided herein. For example, a FOUP body may have high aspect ratio holes for reducing FOUP weight, which can retain liquid even after a drying process. These holes may be covered with contact points or protected by a gas flow. 
       FIGS.  10 A- 10 B  illustrate a schematic representation of a FOUP body according to some embodiments.  FIG.  10 A  shows a perspective view and  FIG.  10 B  shows a cut away view of a FOUP body  1010  illustrating various openings within FOUP body  1010 . The FOUP body  1010  can have through holes  1070  at corners of the FOUP body, running from the top face to the bottom face. At the corner of the FOUP body, reinforced features can be added to connect the side walls of the FOUP. The reinforced features can strengthen the structure of the FOUP, but at the expense of weight increase. Through holes  1070  can reduce the weight without affecting the structural integrity of the FOUP body. During the cleaning of the FOUP body, the through holes  1070  can be protected with a gas flow or a contact point to prevent or minimize the liquid entering the through holes, leading to a simplified drying process. 
       FIG.  11    illustrates a schematic cleaning system according to some embodiments. A cleaning system  1100  includes a cleaning chamber  1101  and cover  1103 . Cover  1103  may be removed from cleaning chamber  1101  during loading and unloading of article  1104  (such as a FOUP body) and article  1105  (such as a FOUP door) for cleaning. Cover  1103  may be positioned over cleaning chamber  1101  to isolate the internal environment of cleaning chamber  1101  from the external environment during cleaning. This isolation can reduce the losses of cleaning and drying liquids and gases and, in general, to maintain different conditions in the internal environment in comparison to the external environment. A seal may be provided at the interface between cover  1103  and cleaning chamber  1101 . In some embodiments, cover  1103  may be movable, while cleaning chamber  1101  may remain stationary. Alternatively, cover  1103  may be stationary, while cleaning chamber  1101  may be movable. In some embodiments, both cover  1103  and cleaning chamber  1101  are movable. Overall, cover  1103  may move relative to cleaning chamber  1101  at least in the Z direction, such that when cover  1103  is raised over cleaning chamber  1101  and/or cleaning chamber  1101  lowered relative to cover  1103  an external article handling system (not shown) can access and remove articles  1104  and  1105  after cleaning and/or position new articles for cleaning. 
     Cover  1103  may serve as a supporting base for multiple support arms  1102 A and  1102 B and/or drive mechanism  1106 . In some embodiments, a main portion of drive mechanism  1106  is positioned on the external side of cover  1103 , while multiple support arms  1102 A and  1102 B are provided on the internal side of cover  1103 . 
     This orientation of drive mechanism  1106  protects drive mechanism  1106  from cleaning and/or liquids as well as protects the internal environment from contamination that drive mechanism  1106  may cause. In some embodiments, drive mechanism  1106  position on the internal side of cover such that no moving parts protrude through the cover. 
     In some embodiments, article  1104  is movable with respect to spaying nozzles  1112 . It should be noted that article  1104  may or may not be movable with respect to cleaning chamber  1101 . For example, spaying nozzles  1112  may be movable relative to cleaning chamber  1101  and article  1104 , while article  1104  may be stationary relative to cleaning chamber  1101 . Alternatively, spaying nozzles  1112  may be stationary relative to cleaning chamber  1101 , while article  1104  may be movable relative to cleaning chamber  1101  and spraying nozzles  1112 . Article  1104  may be also supported and, in some embodiments, moved by support arms  1102 A and  1102 B or some other devices that may be attached to support arms  1102 A and  1102 B, directly to shaft  1107  of drive mechanism  1106  or some other drive. 
     Drive mechanism  1106  may include a drive shaft  1107  that is attached to multiple support arms  1102 A and  1102 B in order to rotate support arms  1102 A and  1102 B inside cleaning chamber  1101 . Drive mechanism may be also used to move multiple support arms  1102 A and  1102 B relative to each other when, for example, engaging article  1105 . This configuration may be referred to as movable supporting arm. For example, support arms  1102 A and  1102 B may tilt relative to drive shaft  1107  in order to engage or disengage article  1105 . Alternatively, support arms  1102 A and  1102 B may remain stationary when engaging or disengaging article  1105 . It should be noted that both types of support arms  1102 A and  1102 B (i.e., movable and stationary) are rotated within chamber  1101  during cleaning of article  1105  such that all sides of article  1105  are exposed to different spraying nozzles  1112 . 
     Drive mechanism  1106  may be controlled by signals received from a system controller  1108 . Controller  1108  may be also configured to control operations of various other components, such as spraying nozzles  1112 , gas delivery line, cover moving mechanism, and others. 
     Controller  1108  may include one or more memory devices and one or more processors with a central processing unit (CPU) or computer, analog and/or digital input/output connections, stepper motor controller boards, and the like. In some embodiments, controller  1108  executes system control software including sets of instructions for controlling timing of operations, temperatures and flow rates of cleaning and/or other liquids, temperatures and/or flow rates of drying gases, ultrasonic nozzle operations, and other parameters. Other computer programs and instruction stored on memory devices associated with controller may be employed in some embodiments. 
     As noted above, the rotation of supporting arms  1102 A and  1102 B is provided by drive mechanism  1106 , which may include an electrical motor, a pneumatic motor, or some other type of motor. The motor may be coupled to a gear box to provide desired rotational speed. In some embodiments, the rotation speed may be between about 1 RPM and 100 RPM or, more specifically, between about 5 RPM and 25 RPM, e.g., between about 8 RPM and 10 RPM. 
     The rotation may start after engaging article  1104  with supporting arms  1102 A and  1102 B or, more specifically, with contact points attached to ends of supporting arms  1102 A and  1102 B. The rotation continues during dispensing of a cleaning liquid and/or rinsing liquid onto article  1105  and, in some embodiments, during drying of article  1105  within cleaning chamber  1101 . As noted above, the rotation allows exposing different portions of article  1105  to different spraying nozzles  1112  provided within cleaning chamber  1101 . Furthermore, the rotation may be used to provide additional or different shear forces when the cleaning liquid hits that the surface of article  1105 , which may provide additional cleaning action and help to dislodge particles from the surface. Another function of this rotation involves removing liquid droplets from article by creating a centrifugal force. 
     The contact points attached to the ends of supporting arms  1102 A and  1102 B engage article  1105  and, in some embodiments, cover one or more openings of article  1105 . As such, the contact points are used to prevent liquids from getting into the openings. This may be referred to as sealing of the openings. In some embodiments, the contact points include a flexible material to improve sealing at the interface with article  1105 . Furthermore, the size of the contact points may be larger than the size of the openings to accommodate some misalignment. 
     Contamination of openings in article  1105  may be also prevented by pressurizing these openings. For example, at least one of the contact points may be used to supply a gas into a corresponding opening of article  1105 . This supply of gas may pressurize this opening and, in some embodiments, other openings if these other openings are internally coupled and can received the gas through the article and from the opening that faces the gas supplying contact point. In some embodiments, multiple contact points and even all contact points engaged with article  1105  may be configured to supply gas. The gas may be supplied to the contact points through one or more gas flow channels provided within the supporting arms. In some embodiments, the gas supplied to a contact point is also used to move this contact point with the respect to the remaining portion of the support arm. 
     When article  1104  and, in some embodiments, article  1105  are positioned within cleaning chamber, a set of spraying nozzles  1112  can be used to direct cleaning and/or other liquids onto the articles. Spraying nozzles  1112  can deliver cleaning liquid, rinsing liquid (e.g., deionized water), and other types of liquid (e.g., surfactant and metal removal agent) designed for cleaning and decontaminating the article. In some embodiments, liquids may be mixed and delivered together with gases (e.g., a carrier gas). The amount of liquid and/or carrier gases can be carefully controlled, for example, to form fine droplets and aerosol gas bubbles together with the carrier gas. 
     In some embodiments, spraying nozzles  1112  may be also used to deliver drying liquids (e.g., isopropanol alcohol) and drying gases to the surfaces of the article. For example, fast evaporating liquid, such as alcohol and other liquids low boiling temperature and high vapor pressure, may be used for cleaning and/or to adsorb other cleaning liquids that may remain on the surface of the article. Some examples of carrier gases and/or drying gases include nitrogen, air, argon, and other inert gases. 
     In some embodiments, temperature of carrier and/or drying liquid and gases may be specifically controlled to assist with cleaning and drying, e.g., evaporating rinsing liquids from the surface of articles  1104  and  1105 . For example, the temperature may be between about 40° C. and 80° C., such as about 60° C. Lower temperatures may be less effective for cleaning and drying, while higher temperatures may be damaging to the article being cleaned and/or components of cleaning apparatus  1100 . In some embodiments, liquid vapors can be removed from cleaning chamber by fast exhaust and low chamber pressure, for example, by purging with dry gas and/or by maintaining a vacuum pressure inside the cleaning chamber during the liquid cleaning cycle. 
     High flow rate may be used for effective cleaning. In some embodiments, a flow rate through each nozzle may be between about 0.1 liters per minute to about 10 liters per minute. Furthermore, ultrasonic nozzles may be used for additional cleaning efficiency. 
     In some embodiments, spraying nozzles  1112  can be positioned near surfaces of articles  1104  and  1105 , in particular near corners, such as inner comers and outer comers. For flat articles, such as a FOUP door, the spraying nozzles may be posited next to flat surfaces and/or around the ends. For partially enclosed articles, such as a FOUP shell, the sparing nozzles may be positioned both inside and outside of these articles. In some embodiments, the partially enclosed articles may be positioned such their openings face downward to allow removal of the cleaning liquid from the container by gravity. 
     The number of nozzles and the locations of the nozzles are designed to simplify apparatus design and to maximize effective cleaning. Specifically, the number and location of the spraying nozzles may be designed to effectively distribute the liquid being dispensed onto the article surfaces. For example, some spray nozzles may be located in high positions in order to spray generally downward, i.e., in the direction of the gravity. Some nozzles may point toward the comers of the article for effective cleaning. 
     A brief description of a process for loading articles  1104  and  1105  into cleaning chamber  1101  will now be presented to provide better understanding of various features and design considerations of cleaning system  1100 . In some embodiments, articles  1104  and  1105  are provided to system  1100  as separate components that have previously disassembled, e.g., a FOUP cover removed from a FOUP shell. Cover  1103  of system  1100  may be raised together with supporting arms  1102 A and  1102 B and other components. Alternatively or in addition to raising cover  1103 , chamber  1101  may be lowered relative to cover  1103 . The transfer system may then load article  1104  onto supports (not shown) provided within cleaning chamber  1101 . In some embodiments, these supports may be removed from within cleaning chamber  1101  for ease of loading. As noted above, the supports may be attached to supporting arms  1102 A and  1102 B or other components of drive mechanism  1106 . 
     Article  1105  may be aligned relative to supporting arms  1102 A and  1102 B such that minimal travel of supporting arms  1102 A and  1102 B is needed to engage article  1105 . This alignment may involve movement of the transfer system that supports article  1105  (and, in some embodiments, article  1104 ) prior to engaging this article with supporting arms  1102 A and  1102 B and/or movement of cover  1103 . Cover  1103  may move in the Z direction and, in some embodiments, in the X and Y directions. The process proceed with engaging article  1105  with supporting arms  1102 A and  1102 B, which may involve moving portions of supporting arms  1102 A and  1102 B in the X direction. At this point, the transfer system may disengage and retrieve. Cover  1103  may be then lowered onto chamber  1101  and/or chamber  1101  raised to cover  1103 . Cover  1103  may be sealed relative to chamber  1101  at this point to prevent cleaning liquids and gases from escaping. 
     The process may then proceed with cleaning articles  1104  and  1105  inside cleaning chamber  1101 . Specifically, cleaning articles  1104  and  1105  may move relative to spraying nozzles  1112  while spraying nozzles  1112  deliver cleaning liquids onto articles  1104  and  1105 . The process may also involve rinsing and drying of articles  1104  and  1105  prior to disengaging cover  1103  from cleaning chamber  1101 . Cover  1103  is lifted relative to cleaning chamber  1101  in order to gain access to articles  1104  and  1105 . In some embodiments, one or both articles  1104  and  1105  are lifted together with cover  1103 . To disengage article  1105  from supporting arms  1102 A and  1102 B, at least portions of supporting arms  1102 A and  1102 B are moved in the X direction. Cover  1103  may be then placed onto cleaning chamber  1101 . 
     In some embodiments, supporting arms  1102 A and  1102 B may be in a form of a shelf that can form one or more support planes for holding articles  1104  and  1105 . Each supporting plane may be formed by one or more components. In these embodiments, supporting arms  1102 A and  1102 B may be stationary at least during engagement of articles  1104  and  1105  may be slid into the shelf by the transfer system. Nevertheless, supporting arms  1102 A and  1102 B may rotate relative to spraying nozzles within the plane formed by the X and Y axes and more along the Z axis. 
       FIGS.  12 A- 12 B  illustrate schematic cleaning processes for a container lid according to some embodiments.  FIG.  12 A  shows a schematic illustration of a nozzle configuration  1220  including two spraying nozzles  1224  and  1226  positioned at the corners of an article  1222  during cleaning and/or drying of this article. Specifically, a center line  1223  of spraying nozzle  1224  is shown to coincide with corner  1223  such that the flow of liquid or gas discharged from nozzle  1224  may be split between two different surfaces of article  1222 . Overall, positioning nozzles  1224  and  1226  at the corners of article  1222  allow each nozzle to cover at least portions of two different surfaces of article  1222 . Furthermore, comers tend to be more prone to contamination than, e.g., flat surfaces, and may be harder to clean if a nozzle is directed to one surface and not the other. In some embodiments, nozzles  1224  and  1226  may pivot to ensure that at some point their center lines (e.g., center line  1223  of spraying nozzle  1224 ) will pass through the comers (e.g., comer  1223 ). 
       FIG.  12 B  shows a schematic illustration of another nozzle configuration  1230  that includes four spraying nozzles  1234 A-B and  1236 A-B, in accordance with some embodiments. All four spraying nozzles  1234 A-B and  1236 A-B are connected to manifold  1238  that may be used to support all nozzles and deliver liquid and/or gas to all nozzles. Manifold  1238  can be positioned at various distances and angles relative to article  1232 . For example, manifold  1238  may extend parallel to the surface of the article. In some embodiments, manifold  1238  may be positioned vertically to improve liquid draining from manifold  1238 . In some embodiments, one or more nozzles may be pivoted with respect to supporting manifold. 
     Spraying nozzles may be distributed on a manifold to cover different comers and surfaces. For example, two spraying nozzles  1234 A and  1234 B are positioned at the comers of article  1232 , while two other spraying nozzles  1236 A and  1236 B are directed at one surface of this article. The nozzles may be positioned to provide complete coverage of the surface and to ensure complete cleaning of that surface. In some embodiments, an article and nozzles are moved with respect to each other to ensure complete coverage of surfaces and, in some embodiments, to direct liquid and/or gas at different angles to the surface. 
     In some embodiments, nozzles deliver liquid and/or gas at an angle other than the normal relative to the surface being (i.e., provide some angle flow), which results in a shear force onto the surface to dislodge particles and other contaminants from the surface. Furthermore, the angle flow can provide a greater surface coverage. In some embodiments, the nozzle may turn relative to the surface being cleaned in order to cover more surface area and/or clean the surface with different shear and other forces. 
     A cleaning liquid supplied through the nozzles may include additives, such as surfactant, detergent, or contamination/metal removal agents. These additives may be added into the water or other liquid, for example, by aspiration or pumping. The contamination/metal removal agent can be a metal removal agent, such as a chelating agent. A high alkaline detergent may be used in place of the surfactant. UV light can be added, for example, to aid removal of contamination. After completing cleaning and/or contamination removal, the article is then rinsed using a rinsing liquid, such as DI water. Cyclic cleaning/rinsing processes can be performed for effective cleaning. The cleaning liquid can be collected for recycling. 
     In some embodiments, the nozzles dispense small liquid droplets to aid in the subsequent drying process. In addition, purged gas or liquid spray can be provided to break droplets into even smaller ones. In the areas where the quid tend consolidated (such as bottoms), gas or liquid spray can be provided to break large liquid accumulations into smaller droplets, such as by blowing the liquid away. 
     Furthermore, the nozzle may be used for delivering dry air, inert or non-reactive gas. For example, after loading the article, the air within the process chamber can be evacuated and replaced with a process gas, such as inert (e.g., argon) or non-reactive gas (e.g., nitrogen). In some embodiments, the chamber is purged during liquid cleaning. The chamber may be sealed and maintained at sub-atmospheric pressure, for example, to aid in removing liquid vapor within the process chamber ambient. The reduced pressure can be less than 100 Torr, such as less than 10 Torr and even less than 1 Torr. In some embodiments, the liquid or gases supplied through the nozzles can be heated to increase the volatility. Heated liquid can be recycled to reduce energy cost. In addition, the article and the process chamber can also be heated, for example, by IR or UV lamps. 
     After cleaning, the container can be rinsed. Optional gas purge, such as hot air flow, can be utilized to further reduce the amount of liquid remaining on the container surfaces. The nozzles can also be configured to provide liquid for cleaning, liquid for rinsing, and gas for pushing liquid away from the container surface. 
     In some embodiments the cleaning system can include an assembly for supporting, rotating, and/or moving the article while this article is being cleaned. The assembly can include a rotatable seal to accept a stationary gas source inlet while delivering a rotating gas flow to the rotating article. 
       FIGS.  13 A- 13 D  illustrate schematic view of an assembly supporting a FOUP door for cleaning according to some embodiments.  FIG.  13 A  shows a schematic side view of an assembly 
       1300  for cleaning a FOUP door. This assembly  1300  may be used for supporting a FOUP door 
       1301  and/or some other articles, e.g., a FOUP body. The configuration of the assembly may change depending on the article being supported. 
     Assembly  1300  may include a cover  1303 , a drive mechanism  1306 , and multiple supporting arms  13   02 A and  1302 B connected to drive mechanism  1306  using drive shaft  1307 . Assembly  1300  may be referred to as a cover assembly as cover  1303  may be used for support of all other components. Drive mechanism  1306  may include a motor  1304  for rotating drive shaft  1307  and slip support  1316  (e.g., bearing) for supporting drive shaft  1307  relative to non-moving parts, such as cover  1303  or a case of drive mechanism  1306 . In some embodiments, drive shaft  1307  has a gas flow channel  1302  that extends into one or more supporting arms (e.g., supporting arm  1302 A). The gas may be supplied into gas flow channel  1302  from a stationary gas supply line  1310 , which may be connected to gas flow channel  1302  using a slip coupling  1308 . It should be noted that gas flow channel  1302  is different from channels connected to spraying nozzles. 
     Each supporting arm includes a contact point for engaging with an article. Supporting arm  1302 A includes contact point  1306 A, while supporting arm  1302 B includes contact point  1306 B. Other supporting arms and contact points can be used. Two opposite contact points  1306 A and  1306 B are configured to move relative to each other at least along the X axis. When article  1301  is provided and aligned with contact points  1306 A and  1306 B, contact points  1306 A and  1306 B are further away from each other than when contact points  1306 A and  1306 B engage article  1301 . This may be referred to as open and closed positions of contact points  1306 A and  1306 B. The travel between open and closed positions of contact points  1306 A and  1306 B may be between about 10 millimeters and mm and 100 millimeters. 
     Contact points  1306 A and  1306 B may be moved relative to each other by moving one or both contact points  1306 A and  1306 B relative to their supporting arms  1302 A and  1302 B and/or by moving supporting arms  1302 A and  1302 B relative to, e.g., drive shaft  1307 . For example, supporting arms  1302 A and  1302 B may pivot relative to drive shaft  1307  resulting in a scissor-like action. In the same or other embodiments, ends of supporting arms  1302 A and  1302 B include one or more actuators for moving one or both contact points  1306 A and  1306 B relative to supporting arms  13   02 A and  1302 B. The actuators may be driven pneumatically, hydraulically, or electrically. 
     The number of contact points  1306 A and  1306 B may be defined by the number of openings in an article that is being cleaned. In some embodiments, each opening has a corresponding contact point. For example, a FOUP door may have four openings, each having a separate latch plate. An assembly used to support this FOUP door may include four contact points, each being aligned and engaged with the separate opening. In other embodiments, one contact points may be used to cover multiple openings. Some contact points may be load bearing contact points (i.e., to support the weight of the article that is being cleaned), while other may be used to cover the opening and without supporting any weight of the article. 
       FIGS.  13 B- 13 D  show schematic top views of different assemblies, each including a drive and multiple supporting arms, in accordance with some embodiments. Specifically,  FIG.  13 B  shows a configuration  1320  in which each one of contact points  1326 A- 1326 D is attached to a separate supporting arm, i.e., contact point  1326 A is attached to supporting arm  1324 A, contact point  1326 B is attached to supporting arm  1324 B, contact point  1326 C is attached to supporting arm  1324 C, and contact point  1326 D is attached to supporting arm  1324 D. Furthermore, from an article engagement standpoint, contact point  1326 A and contact point  1326 B are opposite to each other and so are contact point  1326 C and contact point  1326 D. In this configuration, contact point  1326 A is configured to move relative to contact point  1326 B, while contact point  1326 C is configured to move relative to contact point  1326 D to engage an article  1321 . In some embodiments, contact point  1326 A can be moved relative to contact point  1326 C, e.g., to align these contact points  1326 A and  1326 C relative to openings in article  1321 . In a similar manner, contact point  1326 C can be moved relative to contact point  1326 D. 
     Supporting arms  1324 A- 1324 D may be attached to a pair of cross-bars  1322 A and  1322 B. Specifically, supporting arms  1324 A and  1324 B may be attached to cross-bar  1322 A, while supporting arms  1324 C and  1324 D may be attached to cross-bar  1322 B. In some embodiments, movement of cross-bars  1322 A and  1322 B determines movement of contact points  1326 A- 1326 D in the Y direction, which may be used to align opening in article  1321  with contact points  1326 A- 1326 D. In the same or different embodiments, supporting arms  1324 a and  1324 B can move relative to cross-bar  1322 A determining movement of contact points  1326 A and  1326 B in the X direction, and supporting arms  1324 C and  1324 D can move relative to cross-bar  1322 B determining movement of contact points  1326 C and  1326 D in the X direction. In other embodiments, cross-bars  1322 A and  1322 B are not movable relative to the drive shaft and/or supporting arms  1324 A- 1324 D are not movable relative to cross-bars  1322 A and  1322 B. 
       FIG.  13 C  illustrates a configuration  1330  that include two supporting arms  1334 A and  1334 B, each attached to two contact points, in accordance with certain embodiments. 
     Specifically, contact points  1336 A and  1336 C are attached to supporting arm  1334 A, while contact points  1336 B and  1336 D are attached to supporting arm  1334 B. Supporting arm  1334 A is attached to the drive shaft  1337  by a cross-bar  1332 A, while supporting arm  1334 B is attached to the drive shaft by a cross-bar  1332 B. Tilting of cross-bars  1332 A and  1332 B relative to the drive shaft may be used to move supporting arms  1334 A and  1334 B and as a result contact points  1336 A- 1336 D in the X direction, e.g., to engage and release article  1331 . 
       FIG.  13 D  illustrates yet another configuration  1340 , in which each supporting arm is directly attached to drive shaft  1347  and supports a separate contact point. Specifically, contact points  1346 A is attached to supporting arm  1344 A, contact points  1346 B is attached to supporting arm  1344 B, contact points  1346 C is attached to supporting arm  1344 C, while contact points  1346 D is attached to supporting arm  1344 D. Supporting arms  1344 A- 1344 D may tilt relative to the drive shaft in order to move contact points  1346 A- 1346 D in the X direction, e.g., to engage and release article  1341 . 
       FIG.  14    illustrates a schematic view of an assembly supporting a FOUP body for cleaning according to some embodiments. An assembly  1400  may be used for supporting a FOUP body  1401 . The configuration of the assembly may change depending on the article being supported. Assembly  1400  may include a cover, a drive mechanism  1406 , and multiple supporting arms connected to drive mechanism  1406  using drive shaft. Drive mechanism  1406  may include a motor for rotating drive shaft and slip support (e.g., bearing) for supporting drive shaft relative to non-moving parts. In some embodiments, drive shaft has a gas flow channel  1402  that extends into one or more supporting arms. The gas may be supplied into gas flow channel  1402  from a stationary gas supply line  1410 , which may be connected to gas flow channel  1402  using a slip coupling. It should be noted that gas flow channel  1402  is different from channels connected to spraying nozzles. The supporting arm includes a contact point  1406  for engaging with an opening  1499  of the article. 
       FIG.  15    illustrate a drive mechanism for supporting an article according to some embodiments. The drive mechanism can include a motor for rotating the article, together with a stationary gas inlet for accepting a gas flow from a gas source. A rotating seal, such as a slip ring, can be included to deliver the gas flow to the rotating article, for example, at the openings of the article. 
       FIG.  16    illustrates another schematic cleaning system according to some embodiments. A cleaning system can include support arm  1670  for holding a FOUP body  1610  and a FOUP door  1615  for cleaning. Support arm  1670  can be coupled to a drive mechanism  1645 , which can accept a gas source inlet  1640 . The FOUP body  1610  and door  1615  can be movable with respect to spaying nozzles  1690 . Gas nozzles or contact points  1620  and  1625  can be coupled to the FOUP door  1615  and body  1610  for protecting openings in the FOUP door  1615  and body  1610 . 
       FIGS.  17 A- 17 B  illustrate schematic views of another assembly supporting a FOUP door for cleaning according to some embodiments.  FIG.  17 A  shows a schematic side view and  FIG.  17 B  shows a schematic top view of an assembly for cleaning a FOUP door  1701 . 
     The assembly may include a cover  1703 , a drive mechanism  1706 , and multiple supporting arms connected to drive mechanism  1706  using a drive shaft. Drive shaft  1707  has a gas flow channel  1702  that extends into one or more supporting arms supporting the FOUP door. The gas may be supplied into gas flow channel  1702  from a stationary gas supply line  1710 , which may be connected to gas flow channel  1702  using a slip coupling. 
     The supporting arm includes support points  1726 A and  1726 B for engaging with an article. The support arm can include contact points  1706 A and  1706 B for protecting openings in the FOUP door. 
       FIGS.  18  and  19 A- 19 C  illustrate various contact points for engaging an article during a cleaning process according to some embodiments.  FIG.  18    is a schematic cross-sectional view of a contact point  1800  engaging an article  1820  during cleaning and drying of article  1820 , in accordance with some embodiments. Contact point  1800  includes a stem  1802  that is attached to a supporting arm (not shown) and a body  1804 . Body  1804  may be expanded in the Y-Z plane relative to stem  1802  to provide a larger footprint and be able to cover larger openings. At the same time, the smaller profile of stem  1802  in the Y-Z plane minimizes interferences within the cleaning chamber. 
     Body  1804  may include a sealing member  1806  that actually comes in contact with article  1820 . Sealing member  1806  defines a sealing area  1807 , which is typically larger opening  1822  in article  1820 . In some embodiments, the largest dimension (e.g., a diagonal of a rectangle or a large diameter of an oval) of sealing area  1807  is at least about  1 . 5  times greater than the corresponding largest dimension if opening  1822 . In some embodiments, this ratio is at least about  2  and even at least about  4 . Large sealing areas simplify alignment process while ensuring the seal. At the same time, portions of articles covered by these larger seals are not cleaned. 
     Sealing member  1806  may be made from a suitable soft polymer that may compress when contact point is engaged. Some examples of such materials include butyl, EPDM, neoprene, nitrile, SBR, silicone, vinyl, and YITON(™). In some embodiments, sealing member  1806  should provide sufficient friction when engage with article  1820  so that article  1820  does not slide out. At the same time, materials used for sealing member  1806  should not generate particles and serve as contamination sources. 
     As noted above, some if not all contact points may be gas supplying contact points.  FIG.  18    illustrates an example of a gas supplying contact point  1800 . Stem  1802  may include a gas flow channel  1803  for delivering gas into body  1804 . Body  1804  may have a diffuser plate  1808  for uniform distribution of this gas into opening  1822  of the article. The uniform distribution may prevent additional contamination. This gas flow may create a pressurize environment within opening  1822  and inside article  1820  in comparison to the cleaning chamber environment. In some embodiments, the difference in pressure is between about 1 kPa to 100 kPa. This difference in pressure may help to prevent from liquid getting into sealing area  1807  when, e.g., a seal is not complete. 
     A contact point that is not a gas supplying contact point may also include a stem, body, and a sealing member as described above. However, the non-gas supplying contact point may not have a gas flow channel or a diffuser plate. The gas supplying contact points may be used in combination with non-gas supplying contact points when, for example, an article may allow for a gas to flow from one opening to another through internal cavities of the article. In some embodiments, a contact point includes an alignment device (not shown) for aligning the sealing member with the opening. 
     Some contact points may be actuated pneumatically.  FIGS.  19 A- 19 C  show schematic cross-sectional views of a contact point  1900  movable relative to its supporting arm  1910  by a supply of gas, in accordance with some embodiments. In fact, the gas used to actuate contact point  1900  may be also used to pressurize opening  1922  in article  1920  that is being engage by contact point  1900 . 
     Contact point  1900  may include a stem  1902 , a body  1904 , and a spring  1906 . Stem  1902  can slip within body  1904  in the X direction. Furthermore, stem  1902  can slip within supporting arm  1910 . The position of stem  1902  relative to body  1904  and supporting arm  1910  is determined by the force balance exerted by spring  1906  and pressure of the supplied gas. For example, spring  1906  controls extension of stem  1902  into cavity  1905  of body  1904 . When the pressure inside stem  1902  is low, spring  1906  pushes stem  1902  out of cavity  1905  in the direction opposite of the X direction. As the pressure inside stem  1902  increases, the force caused by this pressure overcomes the force of spring  1906  and stem  1902  starts extending into cavity  1905 . Stem  1902  may include gas release aperture  1908 , which allows the gas to escape from stem  1902  when aperture  1908  extends into cavity  1905  as, e.g., shown in  FIG.  19 C . On the other hand, when stem  1902  is retracted and gas release aperture  1908  is blocked by body  1904 , then the gas cannot escape from stem  1902 . Different positions of stem  1902  and operations of contact point will now be described in more details. 
     The position illustrated in  FIG.  19 A  may be referred to as a retracted position. In this position, stop  1903  of stem  1902  is in contact with supporting arm  1910 , while stem  1902  is retracted into body  1904  such that gas release aperture  1908  is blocked by body  1904 . The gas pressure inside stem  1902  may be the lowest in this position. In fact, the pressure inside stem  1902  may be reduced below the pressure outside of stem  1902  in order, e.g., to retract stem  1902  into support arm  1910 . 
     As the pressure builds up inside stem  1902 , stem  1902  can be slightly pushed out of supporting arm  1910  until body  1904  engages article  1920 . Article  1920  effectively acts as a positive stop for body  1904 . The force with which body  1904  engages article  1920  depends on pressure inside stem  1902  (relative to the pressure outside of stem  1902 ) and the cross-sectional area of stem in the Y-Z plane. This position of contact point  1900  may be referred to as a partially extended position and is illustrated in  FIG.  19 B . In this position, the gas from the stem may not be supplied into cavity  1905  since gas release aperture  1908  is still blocked by body  1904 . The pressure inside stem  1902  at this stage is still not sufficient to overcome the force of spring  1906  and stem  1902  does not extend sufficiently into cavity  1905  for gas to escape. 
     The process may continue with building up the pressure inside stem  1902 , and, at some point, stem  1902  extends into cavity far enough that the gas can escape from gas release aperture  1908  and into cavity  1905 . The pressure of the gas inside stem  1902  should be enough to overcome the force of spring  1906  and spring is compressed during this part of the process. This position is illustrate in  FIG.  19 C  and may be referred to as a fully extended position. In this position, gas release aperture  1908  is not blocked by body  1904 , which allows the gas to escape from stem  1902  and into cavity  1905 . As such, the gas that is used to actuate contact point  1900  is also used to pressurize opening  1922  within article  1920 . 
     Depending on the size of gas release aperture  1908  and the gas flow, contact point  1900  may stay in a fully extended position while the gas is being supplied. In some embodiments, gas release aperture  1908  may be partially blocked by body  1904  such that the gas only escapes through a portion of gas release aperture  1908 . This position may be referred to as an equilibrium position in which compression of spring  1906  (corresponding to partial blocking of gas release aperture  1908 ) is balanced by the pressure within stem  1902 . Any change in the gas flow may move stem  1902  into a new equilibrium position, i.e., corresponding to more opened gas release aperture  1908  when the flow is increased and less opened gas release aperture  1908  when the flow is decreased. As such, the engagement force and pressurization inside opening  1922  may be controlled by the gas flow through stem  1902  and support arm  1910 . It should be noted that the equilibrium position may be also influenced by the pressurization within the opening that may try to push stem  1902  back into body. 
     The process of going back from the fully extended position to the partially extended position and eventually into the retracted position is completed by reducing the gas flow and/or pressure through supporting arm  1910  and stem  1902 . When the pressure inside stem  1902  cannot overcome the force exerted by compressed spring  1906 , spring  1906  expands (as illustrated by transition from  FIG.  19 C  to  FIG.  19 B ) and pulls stem  1902  from cavity  1905 . In order to retract stem  1902  into supporting arm (as illustrated by transition from  FIG.  19 B  to  FIG.  19 A ), the pressure inside stem  1902  may be further reduced such that the entire contact point  1900  is shift away from article  1920 . 
       FIGS.  20 A- 20 D  illustrate schematic configurations for cleaning nozzles according to some embodiments. When an object is rotated around an axis, it outer most point (i.e., the most distant point from the axis) defines a circular rotational boundary. This boundary only coincides with outer surfaces of round cylindrical objects that are rotated around their center axis. All other types of objects and/or off-axis rotation have boundaries that extend away from the outer surfaces of these objects. As such, positioning spraying nozzles outside of the circular rotational boundary may cause in insufficient cleaning of some parts of an article as illustrated in  FIGS.  20 A- 20 B . Specifically,  FIGS.  20 A- 20 B  illustrate FOUP door  2002  rotated around its own center  2004  such that corners  2008  define circular rotational boundary  2006 . Spraying nozzle  2010  is positioned outside of this boundary  2006 . When a corner  2008  of FOUP door  2002  faces spraying nozzle  2010  as shown in  FIG.  20 A , the distance between corner  2008  and spraying nozzle  2010  is small. However, when FOUP door  2002  turns and side  2009  of FOUP door  2002  faces spraying nozzle  2010 , the distance between side  2009  and spraying nozzle  2010  is significantly larger. As such, side  2009  may be cleaned less effectively in comparison to comer  2008 . 
     Stationary objects cannot be positioned within rotational boundary as these objected will be crashed into by a rotating article. However, an object may be moved in and out of the rotational boundary during rotation of an article without crashing one into another. Returning to the above described examples, when corner  2008  passes spraying nozzle  2010 , nozzle  2010  may start moving towards boundary  2006  and even into boundary  2006  as, e.g., shown in  FIG.  20 C . The motion of nozzle  2010  is synchronized with the rotation of FOUP door  2002 . The amount of travel may depend on the shape of an article that is being rotated. In some embodiments, the distance between spraying nozzle  2010  and a point on FOUP door  2002  to which spraying nozzle is directed remains substantially the same during rotation of FOUP door  2002 . As such spraying nozzle  2010  may move with variable speed if FOUP door  2002  is rotated with a constant speed and vice versa. 
     Once spraying nozzle  2010  is protruded into boundary  2006 , it needs to be retracted from the boundary at least once during rotation of an article. In some embodiments, spraying nozzle  2010  may be retracted from and inserted back into boundary multiple times during one rotation. For example, FOUP door  2002  has four corners and spraying nozzle  2010  has to be retracted from boundary every time a new corners passes spraying nozzle  2010  (assuming rotation around the center of FOUP door  2002 ).  FIG.  20 D  illustrates retracted spraying nozzle  2010  as corner  2012  passes nozzle  2010 . Spraying nozzle  2010  maybe then extended into boundary  2006  after corner  2012  is past nozzle  2010  as so on. 
     In some embodiments, a rotated article may be surrounded by multiple spraying nozzles surrounding the article. One or more of these nozzles is configured to move in and our relative to the rotational axis. In some embodiments, all nozzles are movable relative to the rotational axis. Nozzles may also move in other directions, e.g., parallel to the rotational axis. In some embodiments, spraying nozzles may turn relative to their attachment points. 
       FIG.  21    illustrates a flow chart for cleaning an article according to some embodiments. Operation  2100  loads a body and a lid of a container to a cleaning chamber. Operation  2120  aligns a gas nozzle to a portion of the lid and/or the body. The gas nozzle can be disposed in a vicinity of the portion. The gas nozzle can totally or partially blocks the portion of the lid and/or the body. Operation  2130  flows a gas to the gas nozzle. Operation  2140  flows a liquid toward the body and lid for cleaning. Operation  2150  rotates the body and lid during cleaning. 
       FIG.  22    illustrates another flow chart for cleaning an article according to some embodiments. For example, the cleaning system may be used for cleaning FOUP doors. Method  2200  may commence with providing the article into the cleaning system during operation  2202 . Various examples of articles and cleaning systems are described above. The article may be separated from other articles being cleaned in the same chamber. For example, a FOUP cover may be separated from a FOUP shell. The article may be provided or, more specifically, positioned within the cleaning system using a transfer system. The cleaning system may be in an open state. For example, a cover may be raised relative to the cleaning chamber such that the transfer system has access to supporting arms and other components of the system. The articles may be supported by the transfer system up until operation  2206  during which the contact points engage with the article. 
     Method  2200  may proceed with align at least one contact point with at least one opening on the article during operation  2204 . In some embodiments, each contact point is aligned with a separate opening. Furthermore, one contact point may be used to cover multiple openings in the article. Operation  2204  may involve moving contact points with respect to each other and/or with respect to an article. 
     Method  2200  may proceed with engaging contact points with article during operation  2206 . As described above, this operation may involve moving contact points relative to supporting arms and/or moving the supporting arms relative to the drive shaft. After operation  2206 , the article is supported by the contact points and external handling systems may be retrieved from the cleaning system. 
     Method  2200  then continues with rotating the article relative to the set of spraying nozzles during operation  2208 . In some embodiment, the set of spraying nozzles are stationary, while the article is movable. In other embodiments, the article is stationary, while the spraying nozzles are movable. Furthermore, both the article and the spraying nozzles may be movable. 
     At some point after engaging the contact points, dispensing of the cleaning liquid may be initiation as reflected by operation  2210 . The dispensing of the liquid may start prior or after stating the rotation of the article. Overall, operations  2208  and  2210  proceeds in parallel for a period of time. Operation  2210  also involved supplying a gas into the opening in the article thereby pressurizing these and, in some embodiments, other openings. Pressurization helps to prevent liquid getting into openings. Operation  2210  may also involve dispensing of the rinsing liquid. The rinsing liquid may be dispensed in a manner similar to the cleaning liquid. 
     After dispensing of cleaning and/or cleaning liquid is completed, method  2200  may proceed with drying the article during operation  2212 . The article may still rotate during this operation. In fact, operation  2212  may involve spin drying such that the article is rotated at a faster speed than, e.g., during previous operations. In some embodiments, operation  2212  involves flowing drying gases into the cleaning chamber. The drying gases may be flow through the spraying nozzles used for the cleaning liquid. 
     Once the article is sufficiently dried, the contact points may be disengaged from the article during operation  2214 . Supply of the gas into the article may also be discontinued at this point as there is low risk of any liquids getting into the article. As such, the openings of the article are effectively sealed through the entire wet portion of the cleaning process. 
     At this point, the article may be supported by an external handling mechanism that may extend into the cleaning chamber. Operations  2202 - 2212  may be repeated for another article as reflected by the decision bock  2216 . 
       FIG.  23    illustrates an example of FOUP door support before cleaning according to some embodiments. A FOUP door  2310  can be mounted to a support frame  2390 , which can be placed in a cleaning chamber. Contact points  2350  can be placed in a vicinity of the openings of the FOUP door, for example, at the latch plate of the latch mechanism. The contact points  2350  can protect the openings from having liquid trapped and retained in the openings, and thus can simplify the drying process. Opposite elements  2355  can be used for supporting the FOUP door or for protecting the opposite latch plates. For example, the opposite elements can be contact points similar to the contact points  2350 . The opposite elements can be a support point, or a different kind of contact points. 
       FIG.  24    illustrates an example of FOUP body support before cleaning according to some embodiments. A body  2410  can be mounted to a support frame  2490 , which can be placed in a cleaning chamber. Contact points  2450  can be placed in a vicinity of the openings of the FOUP body, for example, at the through holes at the corners of the FOUP body. The contact points  2450  can protect the openings from having liquid trapped and retained in the openings, and thus can simplify the drying process. 
     In some embodiments, the present invention discloses a system for cleaning semiconductor substrate storage containers. The system can include a cleaning chamber. The system can also include multiple supporting arms positioned within the cleaning chamber. The system can also include multiple contact points for engaging an article and for supporting an article during cleaning of the article. The article can be a front opening unified pod (FOUP) door. At least one of the multiple contact points can be attached to a support arm. The multiple contact points can include a gas supplying contact point. At least one contact point is configured to move relative to the article for engaging the article. At least one contact point is attached to a movable supporting arm. The movable supporting arm can be movable relative to the article for engaging the article with the at least one contact point. At least one contact point is attached to a stationary supporting arm. The at least one contact point can be movable relative to the stationary supporting arm for engaging the article with the at least one contact point. The at least one contact point can be the gas supplying contact point. At least two contact points are configured to move relative to the article for engaging the article. The contact point can include a seal for engaging the article. The contact point can be gas supplying contact point. The gas supplying contact point can be configured to align with an opening in the article. The gas supplying contact point can include an gas flow channel for supplying a gas to the opening in the article. The gas supplying contact point can be driven by the gas supplied through the gas flow channel. The gas flow channel can extend through a supporting arm attached to the gas supplying contact point. The gas flow channel can extend through a drive shaft, wherein the drive mechanism comprises a slip coupling for connecting the gas flow channel in the drive shaft to an external gas supply. 
     The system can also include a drive mechanism, which can include a drive shaft attached to the multiple supporting arms, The drive mechanism can be configured to rotate the multiple supporting arms within the cleaning chamber. The drive mechanism can be configured to rotate the multiple supporting arms at a rotational speed of between about 5 RPM and 25 RPM. 
     The system can also include a set of spraying nozzles for dispensing a cleaning liquid onto the article. At least one spraying nozzle in the set of spraying nozzles can be configured to move in and out relative to the drive shaft. The movement of the at least one spraying nozzle can be synchronized with the rotation of the multiple supporting arms within the cleaning chamber. The movement of the at least one spraying nozzle can be configured to maintain a substantially constant distance of the at least one spraying nozzles and the article. 
     The system can also include a cover for positioning over and closing the cleaning chamber during cleaning of the article. The cover can support the drive mechanism and the multiple supporting arms. 
     The system can also include a support for a FOUP body for cleaning together with the FOUP door. The support for the FOUP body can be attached to the multiple supporting arms. 
     The system can also include a system controller, which can include a set of instructions for align at least the gas supplying contact point with the openings in the article; engaging each contact point with the article; rotating the article relative to the set of spraying nozzles; and dispensing the cleaning liquid from the set of spraying nozzles while supplying the gas into the opening of the article. 
     In some embodiments, the present invention discloses a system for cleaning semiconductor containers. The system can include a cleaning chamber, a support structure, a contact point, and a set of spraying nozzles. The support structure is configured to support a container door, wherein the support structure is configured to be positioned within the cleaning chamber. The contact point can be configured for protecting a latch opening of the container door. The contact point can be configured to engage with the latch opening. The contact point can include a gas channel configured to flow a gas to the latch opening. The set of spraying nozzles can be configured for dispensing a cleaning liquid onto the container door. 
     The support structure can be configured to support a container body. The system can include a second contact point for protecting an opening of the container body. The second contact point can be configured to engage with the opening of the container body. The second contact point can include a second gas channel configured to flow a gas to the opening of the container body. The system can include a set of second spraying nozzles for dispensing a cleaning liquid onto the container body. 
     The gas flow channel can extend through a drive shaft. The drive mechanism can include a slip coupling for connecting the gas flow channel in the drive shaft to an external gas supply. 
     The contact point can be coupled to the support structure. The contact point can include a gas inlet for accepting a gas to the gas channel. 
     The system can include a drive mechanism comprising a drive shaft attached to the support structure. The drive mechanism can be configured to rotate the support structure within the cleaning chamber. The drive mechanism can be configured to rotate the support structure at a rotational speed of between about  5  RJPM and 25 RPM. At least one spraying nozzle in the set of spraying nozzles is configured to move in and out relative to the drive shaft. The movement of the at least one spraying nozzle can be synchronized with the rotation of the multiple supporting arms within the cleaning chamber. The movement of the at least one spraying nozzle can be configured to maintain a substantially constant distance of the at least one spraying nozzles and the article. 
     The system can include a gas conduct. The gas conduit can be coupled to a gas source at the drive mechanism. The gas conduit can be couple to the gas inlet of the contact point. The system can include a cover for positioning over and closing the cleaning chamber during cleaning of the article. The cover can support the drive mechanism and the support structure. The contact point can be configured to move relative to the container door for engaging the container door. The contact point can be attached to a supporting arm, wherein the movable supporting arm is movable relative to the contact point for engaging the contact point with the container door. The contact point can include a seal for engaging the article. 
     In some embodiments, the present invention discloses a method for cleaning semiconductor substrate storage containers having an opening. The cleaning system can include multiple supporting arms, multiple contact points, and a set of spraying nozzles. At least one of the multiple contact points being attached to each of the multiple support arms. The contact points can include comprise a gas supplying contact point. The gas supplying contact point can include an gas flow channel for supplying a gas to the opening in the article. 
     The method can include providing an article into a cleaning system; align the gas supplying contact point with the opening of the article; engaging each contact point with the article; rotating the article relative to the set of spraying nozzles; and dispensing the cleaning liquid from the set of spraying nozzles while supplying a gas into the opening in the article. 
     In some embodiments, the present invention discloses a method for cleaning an article. The method can include protecting an opening of the article with a gas flow; and cleaning the article with a liquid. The method can further include rotating the article. The method can further include loading the article in a cleaning chamber, and aligning the gas flow with the opening. The method can further include align the contact point with the opening of the. article; and engaging the contact point with the article. 
     The opening can include a cavity. The cavity can have an aperture at a surface of the article. A dimension of the aperture can be smaller than a dimension of the cavity. The opening can include an object. The object can be configured to be slidable in the opening. The object can be positioned in the opening with a gap, wherein the length of the object is at least 10×, 20×, or 50× greater than the gap. The opening can include a hole. The hole can have an aperture at a surface of the article. The hole can have a depth. The ratio of the depth and a dimension of the aperture can be higher than 10:1, 20:1, or higher than 50:1. 
     Protecting the opening can include supplying the gas flow into the opening. Protecting the opening can include applying the gas flow toward the opening to minimizing liquid entering the opening. Protecting the opening can include blocking the opening from being exposed to the liquid. Protecting the opening can include pressurizing the opening with the gas flow. Protecting the opening can include applying a contact point at the opening, and applying the gas flow to the contact point. 
     Cleaning the article can include flowing a liquid toward the article. Cleaning the article can include submerging the article in a liquid. 
     In some embodiments, the present invention discloses a method for cleaning a semiconductor container. The method can include loading a container door to a cleaning chamber; protecting a latch opening of the container door with a contact point; and flowing a liquid toward the container door while supplying a gas flow into the gas inlet of the contact point. The contact point can be configured to channel a gas from a gas inlet to the latch opening. The method can further include rotating the container door, aligning and engaging the contact point with the opening, and/or draining the liquid from the cleaning chamber. 
     Cleaning the container body can include flowing a liquid toward the container body while protecting an opening of the container body with a gas flow. The latch opening can include a latch element. The latch element can be configured to be slidable in the latch opening. The latch element can be positioned in the opening with a gap. The length of the latch element can be at least 10×, 20×, or 50× greater than the gap. 
     Protecting the latch opening can include sealing the latch opening with the contact point. Protecting the latch opening can include applying the contact point near the latch opening without touching the container door. Protecting the opening can include pressurizing the contact point with the gas flow. 
     Although the foregoing concepts have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and apparatuses. Accordingly, the present embodiments are to be considered as illustrative and not restrictive.