Side storage pods, equipment front end modules, and methods for operating the same

Electronic device processing assemblies including an equipment front end module (EFEM) with at least one side storage pod attached thereto are described. The side storage pod has a side storage container. In some embodiments, an exhaust conduit extends between the chamber and a pod plenum that can contain a chemical filter proximate thereto. A supplemental fan may draw purge gas from the pod plenum through the chemical filter and route the gas through a return duct to an upper plenum of the EFEM. Methods and side storage pods in accordance with these and other embodiments are also disclosed.

TECHNICAL FIELD

The present disclosure relates to electronic device manufacturing, and more specifically to equipment front end modules, side storage pods, and methods for operating the same.

BACKGROUND

Electronic device manufacturing systems may include multiple process chambers arranged around a mainframe housing having a transfer chamber and one or more load lock chambers configured to pass substrates into the transfer chamber.

Processing of substrates in semi-conductor component manufacturing may be carried out in multiple tools, where the substrates travel between the tools in substrate carriers such as front end unified pods (FOUPs). Exposure of the substrates to certain environmental conditions during processing may degrade the substrates. For example, exposure to humidity during processing of substrates may degrade chip components fabricated on the substrates.

Accordingly, improved assemblies, apparatus, and methods for controlling the environmental conditions of substrates during processing are desired.

DETAILED DESCRIPTION

Reference will now be made in detail to the example embodiments of this disclosure, which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts throughout the several views. Features of the various embodiments described herein may be combined with each other, unless specifically noted otherwise.

Electronic device manufacturing may involve exposing substrates to different chemicals during a plurality of processes. In between different processes being applied to the substrates, the substrates may undergo outgassing. Some processes applied to the substrates may cause the substrates to outgas corrosive chemicals, such as fluorine, bromine, and/or chlorine. If these chemical components are not removed from the environment and the substrates, the gasses may cause defects on the substrates.

According to one or more embodiments of the disclosure, electronic device processing assemblies and methods adapted to improve substrate processing are provided. The apparatus, assemblies, and methods described herein may provide efficiency and/or processing improvements in the processing of substrates by controlling environmental exposure to the substrates, and, in particular, conditions within one or more side storage pods coupled to a body of an equipment front end module (hereinafter “EFEM”). One or more side storage containers may be configured to be receivable within a side storage pod and may include substrate holders (e.g., shelves) that receive and support substrates, such as during idle periods before and/or after processes are applied to the substrates.

Purge gas may flow from the EFEM chamber into a side storage container where the purge gas flows past substrates located therein. In some embodiments, the purge gas may be exhausted from the rear of the side storage container and passed through a chemical filter. The filtered gas may then be recirculated into the EFEM chamber. In some embodiments, the recirculation path of the gas may pass through an access door to the EFEM, which may reduce and/or minimize the space occupied by the recirculation path. Such a side storage container configuration may reduce harmful effects of substrate outgassing within the side storage container because the purge gas recirculated into the EFEM chamber from the side storage container is filtered by the chemical filter (e.g., removing unwanted chemicals). In addition, the substrates are exposed to a controlled gas environment within the EFEM, which may be relatively dry and/or have relatively low O2levels.

Further details of example embodiments of side storage pods, electronic device processing assemblies, apparatus such as EFEMs including a side storage pod, and methods of operating EFEMs are described with reference toFIGS.1-7herein.

FIG.1illustrates a schematic diagram of an example embodiment of an electronic device processing assembly100according to one or more embodiments of the present disclosure. The electronic device processing assembly100may include a mainframe housing101having housing walls defining a transfer chamber102. A transfer robot103(shown as a dotted circle) may be at least partially housed within the transfer chamber102. The transfer robot103may be configured to place and extract substrates to and from destinations via operation of arms (not shown) of the transfer robot103. Substrates as used herein may mean articles used to make electronic devices or circuit components, such as semiconductor wafers, silicon-containing wafers, patterned or un-patterned wafers, glass plates, masks, or the like.

The motion of the various arm components of the transfer robot103may be controlled by suitable commands to a drive assembly (not shown) containing a plurality of drive motors of the transfer robot103as commanded from a controller106. Signals from the controller106may cause motion of the various components of the transfer robot103. Suitable feedback mechanisms may be provided for one or more of the components by various sensors, such as position encoders, or the like.

In the embodiments shown inFIG.1, the transfer chamber102in the depicted embodiment may be square or slightly rectangular in shape. However, other shapes are possible, such as hexagonal, octagonal, and the like. Transfer chamber102may include a first facet102A, second facet102B opposite the first facet102A, a third facet102C, and a fourth facet102D opposite the third facet102C. In some embodiments, the transfer robot103may be adept at transferring dual substrates at the same time to and from process chamber sets. The first facet102A, second facet102B, third facet102C, and fourth facet102D may be planar and entryways into the chamber sets that may lie along the respective facets, for example. However, other suitable shapes of the mainframe housing101, transfer chamber102, and/or facets102A-102D, and/or other numbers of facets and/or process chambers are possible.

The destinations for the transfer robot103may be a first process chamber set108A,108B, coupled to the first facet102A and which may be configured and operable to carry out a process on the substrates delivered thereto. The process may be any suitable process such as plasma vapor deposition (PVD) or chemical vapor deposition (CVD), etch, annealing, pre-clean, metal or metal oxide removal, or the like. Other processes may be carried out on substrates therein.

The destinations for the transfer robot103may also be a second process chamber set108C,108D that may be opposed from the first process chamber set108A,108B. The second process chamber set108C,108D may be coupled to the second facet102B and may be configured to carry out any suitable process on the substrates, such as any of the processes mentioned above. Likewise, the destinations for the transfer robot103may also be a third process chamber set108E,108F coupled to the third facet102C that may be opposed from a load lock apparatus112. The third process chamber set108E,108F may be configured to carry out any suitable process on the substrates, such as any of the processes mentioned above.

Substrates may be received into the transfer chamber102from an EFEM114, and also exit the transfer chamber102, to the EFEM114, through the load lock apparatus112that is coupled to a wall (e.g., a rear wall) of a body114B of the EFEM114. The load lock apparatus112may include one or more load lock chambers (e.g., load lock chambers112A,112B, for example). Load lock chambers112A,112B that are included in the load lock apparatus112may be single wafer load locks (SWLL) chambers, multi-wafer chambers, or combinations thereof, for example.

In some embodiments, the EFEM114may include a EFEM body114B comprising an enclosure having walls (such as a front wall, a rear wall, and side walls, a top wall, and a bottom wall, for example) forming an EFEM chamber114C. One or more load ports may be provided in a wall (e.g., front wall) of the EFEM body114B and may be configured to receive and dock one or more substrate carriers116(e.g., FOUPs) thereat. Three substrate carriers116are shown, but more or less numbers of substrate carriers116may be docked with the EFEM114.

EFEM114may include a suitable load/unload robot117(shown dotted) of conventional construction within the EFEM chamber114C thereof. The load/unload robot117may be configured and operational, once a door of a substrate carrier116is opened, to extract substrates from the substrate carrier116and feed the substrates through the EFEM chamber114C and into the one or more load lock chambers112A,112B of the load lock apparatus112.

The load/unload robot117also may be configured and operational, once the door of a substrate carrier116is opened, to extract substrates from the substrate carrier116and feed the substrates into a side storage pod120while the substrates sit idle awaiting processing. In some embodiments, the side storage pod120may be coupled to a side wall114S of the EFEM body114B. The load/unload robot117may further be configured to extract substrates from and load substrates into the side storage pod120prior to and/or after processing in one or more of the process chambers108A-108F. In some embodiments, the load/unload robot117may be a high-Z robot configured to access substrates stacked greater than26high, or even fifty-two high or higher, in the side storage pod120.

In the depicted embodiment, the EFEM chamber114C may be provided with environmental controls providing an environmentally-controlled atmosphere therein. In particular, an environmental control apparatus118may be coupled to the EFEM114and may be operational to monitor and/or control environmental conditions within the EFEM chamber114C. In some embodiments, and at certain times, the EFEM chamber114C may receive a purge gas (e.g., inert and/or non-reactive gas) therein, such as argon (Ar), nitrogen (N2), or helium (He), from a purge gas supply118A. In other embodiments, or at other times, air (e.g., dry filtered air) may be provided from an air supply118B. In some embodiments, the environmental conditions within the EFEM chamber114C may be present in the interiors of side storage containers124and224(FIG.2) located within and part of the side storage pod120. The side storage containers124,224receive substrates such as substrates435(FIG.4). In some embodiments, the side storage pod120may have substrate holders located therein to receive substrates435without the use of side storage containers.

In more detail, the environmental control apparatus118may control at least one of: 1) relative humidity (RH), 2) temperature (T), 3) an amount of O2, and/or 4) an amount of purge gas, within the EFEM chamber114C. Other environmental conditions of the EFEM114may be monitored and/or controlled, such as gas flow rate into the EFEM chamber114C, or pressure in the EFEM chamber114C, or both, or flow rate or pressure in the side storage pod120or conduits interconnected therewith.

In some embodiments, environmental control apparatus118includes the controller106. Controller106may include suitable processor, memory, and electronic components for receiving inputs from various sensors and controlling one or more valves or fans to control the environmental conditions within the EFEM chamber114C and the side storage pod120. Environmental control apparatus118may, in one or more embodiments, monitor relative humidity (RH) by sensing RH in the EFEM chamber114C with an environmental monitor130. Any suitable type of environmental monitor130that measures relative humidity may be used, such as a capacitive-type sensor. The RH may be lowered by flow of a suitable amount of the purge gas from the purge gas supply118A of the environmental control apparatus118into the EFEM chamber114C. As described herein, the inert and/or non-reactive gas from the purge gas supply118A may be argon, N2, helium, another non-reactive gas, or mixtures thereof. In some embodiments, compressed bulk inert gases having low H2O levels (e.g., purity≥99.9995%, H2O≤5 ppm) may be used as the purge gas supply118A in the environmental control apparatus118, for example. Other H2O levels may be used.

In another aspect, the environmental monitor130may measure a plurality of environmental conditions. For example, in some embodiments, the environmental monitor130may measure the relative humidity value as discussed above. In one or more embodiments, the pre-defined reference relative humidity value may be less than 1000 ppm moisture, less than 500 ppm moisture, or even less than 100 ppm moisture, depending upon the level of moisture that is tolerable for the particular process being carried out in the electronic device processing assembly100or particular substrates exposed to the environment of the EFEM chamber114C.

The environmental monitor130may also measure a level of oxygen (O2) within the EFEM114. In some embodiments, a control signal from the controller106to the environmental control apparatus118initiating a flow of a suitable amount of the purge gas from the purge gas supply118A into the EFEM chamber114C may take place to control the level of oxygen (O2) to below a threshold O2value. In one or more embodiments, the threshold O2value may be less than 50 ppm, less than 10 ppm, or even less than 5 ppm, depending upon the level of O2that is tolerable (not affecting quality) for the particular process being carried out in the electronic device processing assembly100or particular substrates exposed to the environment of the EFEM114. In some embodiments, the environmental monitor130may sense the level of oxygen in the EFEM chamber114C to ensure it is above a safe threshold level to allow entry into the EFEM chamber114C.

The environmental monitor130may also measure the absolute or relative pressure within the EFEM114. In some embodiments, the controller106may control the amount of flow of the purge gas from the purge gas supply118A into the EFEM chamber114C to control the pressure within the EFEM chamber114C.

In some embodiments, the environmental control apparatus118of the electronic device processing assembly100may include an air supply118B coupled to the EFEM114. The air supply118B may be coupled by suitable conduits and one or more valves to the EFEM chamber114C. The air supply118B can be used to purge the EFEM of the purge gas prior to servicing the EFEM114.

In the depicted embodiments herein, the controller106may include a processor, memory, and peripheral components adapted to receive control inputs (e.g., relative humidity and/or oxygen, etc.) from the environmental monitor130and execute a closed loop or other suitable control scheme. In one embodiment, the control scheme may change a flow rate of the purge gas being introduced into the EFEM114to achieve a predetermined environmental condition therein. In another embodiment, the control scheme may determine when to transfer substrates into the EFEM chamber114C.

The side storage pod120attached to the EFEM body114B may store substrates under specific environmental conditions. For example, the side storage pod120may store the substrates in the same environmental conditions as are present in the EFEM chamber114C, except for flow rate. In some embodiments, the side storage pod120may be fluidly coupled to the EFEM chamber114C and may receive gas (e.g., purge gas) from the EFEM chamber114C. The side storage pod120may include exhaust conduits134A,134B that exhaust gas from the side storage pod120, which further enables the substrates stored in the side storage pod120to be constantly exposed to the desired environmental conditions.

A first side storage container124may be received in the side storage pod120. A second side storage pod container224substantially identical to the first side storage container124may also be included in the side storage pod120. The description of the first side storage container124is applicable to the second side storage pod container224. In some embodiments, the side storage pod120may receive one or more vertically-aligned and/or stacked side storage containers124,224.

In more detail, the first side storage container124may include an opening126that faces and interfaces with the EFEM chamber114C and an exhaust plenum128located opposite the opening126. The exhaust plenum128may be coupled to the first exhaust conduit132that may couple to an exhaust duct128exterior to the side storage pod120. Purge gas within the interior of the first side storage container124may be prevented from entering the interior130of the side storage pod120via appropriate seals.

In some embodiments, the first exhaust conduit132may include a first external exhaust conduit134A. A second conduit134(only the external portion134A shown inFIG.1) may be coupled between a second side storage container (224inFIG.2) and the return duct129. Both the first external exhaust conduit132A and the second external exhaust conduit134B may be located partially or fully within a cover136. In some embodiments, the cover136, rather than the first external exhaust conduit132A and the second external exhaust conduit134A may exhaust the exhaust gas from the side storage containers124,224. In other embodiments, the first external exhaust conduit131A and the second external exhaust conduit134A may pass through the interiors130,230of the side storage pod120.

Additional reference is made toFIG.2, which illustrates a side, cross-sectional, elevation view of the EFEM114including the side storage pod120coupled to the EFEM body114B. The side storage pod120may include the first chamber130that receives the first side storage container124and the second chamber230that receives a second side storage container224.

Both the first external exhaust conduit134A and the second external exhaust conduit134A may be connected to a pod plenum240that receives the exhausted purge gas from the first side storage container124and the second side storage container224. The plenum240may be attached to or be a portion of the side storage pod120, for example. In some embodiments, the side storage pod120is removably attached to the EFEM body114B. In one or more embodiments, purge gas may be drawn from the plenum240by a fan264located proximate to the upper plenum262of the EFEM114. A supplemental fan141located, for example, in a plenum exhaust port241may supplement the purge gas flow through the side storage pod120. Funnel142located between the supplemental fan141and the pod plenum240may direct the purge gas to the return duct129, for example. Other configurations of the return duct129and pod plenum240are possible. In some embodiments, the gas flow through each of the side storage containers124,224of the side storage pod120is greater than about 100 cfm, or from about 150 cfm to about 200 cfm (4.25 cmm to 5.0 cmm), or even from about 150 cfm to about 175 cfm (4.25-5.67 cmm), although other flows may be used. The high flow rate is thought to aid in disassociating unwanted chemical components (e.g., halogen containing components) from the substrates stored in the side storage containers124,224.

A filter248may be provided in the purge gas flow path generated by the fans264,140. For example, the filter248may be located proximate to the pod plenum240so that all the purge gas drawn into the pod plenum240passes through the filter248. Other filter locations in the side storage pod120may be used. Optionally, the supplemental fan141may be provided in the portion of the return duct129. In some embodiments, the filter248may be a chemical filter that filters one or more chemical components that are carried in the purge gas that have been outgassed by a substrate in the side storage pod120and/or in EFEM chamber114C after application of a fabrication process thereto. In some embodiments, the filter248can operationally filter chlorine, bromine, and/or fluorine. In some embodiments, the filter248may filter base gasses, such as ammonia (NH3) (e.g., to less than or equal to about 5.0 ppb or another target filter level). In some embodiments, the filter248may filter acidic gasses, such as fluorine (F), chlorine (Cl), bromine (Br), acetate (OAc), nitrogen dioxide (NO2), nitrate (NO3), phosphate (PO4), hydrogen fluoride (HF), and hydrochloric acid (HCl) (e.g., to equal to or less than about 1.0 ppb or another target filter level). In some embodiments, the filter248may be an activated carbon filter. In other embodiments, the filter248may be a particulate filter or include a chemical filter and a particulate filter. The particulate filter is fine enough and operable to remove particles that may cause defects on the substrates.

In some embodiments, a heater250may be located in the gas flow generated by the fan140. The heater250may heat the exhausted purge gas to a predetermined temperature as the exhaust gas is recirculated into the EFEM114. In some embodiments, the heat generated by the heating elements250e(e.g., resistive or infrared heating elements) of the heater250may be used as a reactant and/or to change the relative humidity in the EFEM114and/or the side storage pod120. Further, the added heat may aid in improving the disassociation of chemical components from the substrates stored in the side storage pod120. In some embodiments, the heater250may heat the purge gas to a temperature greater than or equal to 5° C. above ambient temperature outside of the EFEM114, or even a temperature greater than or equal to 10° C. above ambient, or to a temperature from 5° C. above ambient to 25° C. above ambient in some embodiments.

The supplemental fan140may be operated to assist flow the purge gas (e.g., filtered gas) through return duct to the top of the EFEM114where it is recirculated back into the EFEM114, and may be a variable speed fan enabling a desired flow rate through the side storage containers124,224to be achieved.

For example, as shown inFIGS.2and3, one or both of the exhaust conduits132,134can include along their length a suitable sensor139A,139B. The sensor139A,139B can be a flow sensor (such as a pitot or other tube sensor, a thermister, and the like) to enable a signal in lines labeled A and B to be sent to the controller106. The controller106can then process the signals from A, B and send a control signal in control line labeled C to control the rotational speed of the supplemental fan141to achieve a desired flow rate through the side storage containers124,224. Any suitable control scheme can be used, such as Proportional-Integral-Derivative (PID) control. In some embodiments, the sensors139A,139B can be pressure sensors whose readings can be correlated to flow rate through the side storage containers124,224. Other suitable location for the sensors may be used, such as in the plenum240, or in the return duct129. In particular, the one or more sensors139A,139B can be located at any suitable location along an exhaust flow path from the one or more side storage containers124,224where a good estimate of flow from the one or more side storage containers124,224can be obtained.

In more detail, the recirculation of purge gas can flow through the return duct129that may extend between the funnel142and an access door156to the EFEM chamber114C. In some embodiments, the return duct129may bend to fit through tight confines within the EFEM114. For example, the return duct129may route around the load/unload robot117so as not to interfere with the operation of the load/unload robot117. The return duct129may also route through the EFEM114in such a way as not to block operations associated with the substrate carriers116, such as substrate carrier door openers (not shown). The return duct129may have a first section129A that extends from the funnel142toward an opposed side of the EFEM114. The first section129A may, for example, direct the purge gas away from the plenum240and towards the robot117. A second section129B of the return duct129interconnected to the first section129A through diversion portion129D diverting around the robot117may extend toward the access door156. The various sections may extend below load ports115associated with the substrate carriers116, for example.

A return duct129may include duct section260that may extend through the access door156. By extending the return duct129through the access door156, the space occupied by the duct129is reduced and/or kept minimal. The duct portion260in the access door156may couple to an upper plenum262located on the top of the EFEM114. The fan264may assist in forcing the purge gas from the return duct129into the upper plenum262. In some embodiments, the upper plenum262may include or be coupled to outlets that cause a laminar gas flow through the EFEM chamber114C and back into the side storage pod120. Additional chemical and/or particulate filters may be located proximate to the plenum262.

In some embodiments, a portion of the purge gas within EFEM chamber11C may be exhausted from EFEM114through exhaust ports114P. One exhaust ports114P is shown, but there may be many exhaust ports for entry of purge gas into the return duct129. In some embodiments, a small portion of the purge gas within EFEM chamber114C may be exhausted from EFEM114. For example, an exhaust valve266may be provided at a suitable location to exhaust a portion of gas from EFEM chamber114C. In some embodiments, about 150 L/min of the gas may be exhausted from EFEM114. Other amounts of gas may be exhausted.

In these or other embodiments, a source of supplement gas, such as from purge gas supply118A, may be employed to provide additional purge gas to EFEM114to replace the gas that is exhausted through exhaust valve266. For example, the same amount of gas exhausted by exhaust valve266may be introduced to upper plenum262using a gas flow valve270. Other amounts of gas may be introduced. In some embodiments, exhaust valve266and/or gas flow valve270may be controlled by controller106or another controller. Purge gas supply118A may include, for example, an inert and/or non-reactive gas such as Ar, N2, He, or the like.

FIG.3illustrates a front elevation view of the EFEM114and a side elevation view of an embodiment the side storage pod120. The side storage pod120depicted inFIG.3may include a first door350and a second door352. The first door350and the second door352may form a seal with end portions of the side storage pod120. For example, the first door350and the second door352may be hinge-type doors including hinges (not shown) or removable panel doors (e.g., screwed-on sealed panel doors) that enable access to the interiors130,230of the side storage pod120, yet sealing them when closed. In some embodiments, a single door may be used in place of the first door350and the second door352. A suitable O-ring, gasket, or other seal on the first door350and the second door352or on the end portions may form hermetic seals of the side storage pod120. In some embodiments, the first door350may form a first sealed compartment that is separated from and separately sealable from a second sealed compartment sealed by the second door352. The first side storage container124may be received in the interior130of the first sealed compartment and the second side storage container224may be received in the interior230of the second sealed compartment230. Other types of doors may be used to access the interiors130,230of the side storage pod120.

Additional reference is now made toFIG.4, which illustrates a partial cut-away view of the side storage pod120. The side storage pod120may have an interface side415located opposite the first door350and the second door352. A panel416having a first side417and a second side418may be attached to the interface side415of the side storage pod120. Specifically, the first side417of the panel416may be attached to the interface side415of the side storage pod120. The second side418of the panel416may be attached to a surface420of a side wall of the EFEM body114B located on the exterior of the EFEM114. The panel416may form a hermetically-sealed interface between the interior of the EFEM chamber114C and the interior of the side storage pod120as described below. In some embodiments, the panel416may be integrally formed with the side storage pod120or the EFEM114. Other suitable connections to the EFEM body114B may be used.

The first interior chamber130may include the first exhaust conduit132coupled to the first side storage container124and the second chamber230may include the second exhaust conduit134coupled to the second side storage container224. The first exhaust conduit132may be coupled to external exhaust conduit portion132A (FIGS.1and3). The second exhaust conduit134may couple to the second external exhaust conduit portion134A (FIGS.1and3).

Other embodiments of side storage pods may include a larger number of chambers, such as three or more vertically-stacked chambers or side by side chambers, or both. In some embodiments, the side storage pod120may include a single chamber. As shown, plurality of substrates435are transferable between the first side storage container124and the EFEM chamber114C and the second side storage container224and the EFEM114. For example, the load/unload robot117may transfer substrates435between the EFEM chamber114C and the first side storage container124and/or the second side storage container224before and/or after processing in the one or more process chambers108A-108F (FIG.1). In some embodiments, the first side storage container124and the second side storage container224may each receive twenty-six substrates435. More or fewer substrate storage locations may be provided in each side storage container. The first side storage container124and the second side storage container224may maintain the substrates435under specific environmental conditions during their storage. For example, the substrates435may be exposed to the purge gas that is within the EFEM chamber114C as described above. The environmental conditions may be controlled to provide exposure to less than preselected thresholds of water and/or O2, or other conditions as specified above, and gas flow rate and/or temperature.

Additional reference is now made toFIG.5, which illustrates a side, cross-sectional view of the first side storage container124. The second side storage container224(FIG.2) may be substantially similar or identical to the first side storage container124and configured to seal against an interface portion500of panel416. The first side storage container124may have a pod opening516that is located adjacent a panel opening502of panel416, which is located adjacent an interface opening504of EFEM114, to form a single opening into the interior of the first side storage container124. The panel opening502may be the same approximate size as the pod opening516, for example. A pod recess518may be formed in an upper flange524of side storage container124and may extend around the periphery of the pod opening516. A pod seal520may be received within the pod recess518. The pod seal520prevents gas from leaking past the interface portion500of the panel416. In some embodiments, the pod seal520may be a pliable material, such as an elastomer-based material, that contacts the pod recess518and the interface portion500. In some embodiments, the pod seal520is a pliable tube that may deform to form a seal between the pod recess518and the interface portion500. Other types of seals may be used to seal the first side storage container124and the interface portion500.

The second side418of the panel416may have a panel recess525formed therein that extends around the periphery of the panel opening502. A panel seal526may be received within the panel recess525to prevent the exchange of gas between the panel416and the surface420of the side wall of the body114B of the EFEM114. In some embodiments, the panel seal526may be a flat seal and may be made of ethylene propylene diene monomer (EPDM) rubber or another suitable sealing material. In some embodiments, the panel seal526may be about 10-12 mm deep and have a compression of about 4-6 mm. Other types of sealing mechanisms and materials may be used to form a seal between the surface420and the panel416.

The interior of the first side storage container124may include a plurality of substrate holders530configured to support substrates435thereon. The substrate holders530may be vertically-stacked shelves formed onto the lateral sides of the first side storage container124and may include a top substrate holder532and a bottom substrate holder534. The substrate holders530may be spaced a distance from each other that enables gas flow around (e.g., above and below) substrates435received by and supported on the substrate holders530and allows access by the end effector of the robot117. Specifically, purge gas entering the interior of the first side storage container124from the EFEM chamber114C (FIG.1) by way of the panel opening502, the interface opening126, and the pod opening516may flow around and/or across the substrates435received on the substrate holders530. Accordingly, the substrates435are maintained at desired environmental conditions, such as those present in the EFEM chamber114C, but also at a desired target purge gas flow rate in the first side storage container124.

A rear portion540of the first side storage container124may include openings543that fluidly couple the interior of the first side storage container124with the exhaust plenum128. The exhaust plenum128may be configured to provide the above-described gas flow around the substrates435received on the substrate holders530. In some embodiments, the exhaust plenum128may have a height that extends vertically between the top substrate holder532and the bottom substrate holder534. In one or more embodiments, the exhaust duct128may have a width that is approximately the width of the substrates435. For example, the width of exhaust duct128may be about 250 mm to 350 mm for a 300 mm wafer. The exhaust duct128may include an exhaust port544configured to be coupled to the first exhaust conduit132(FIG.4).

In some embodiments, the openings543may be in an exhaust baffle564may be in the purge gas flow path between the substrates435and the exhaust plenum128. Reference is made toFIG.6, which illustrates a front elevation view of an example embodiment of the exhaust baffle564. Other exhaust baffle configurations may be used. The exhaust baffle564may include a plurality of round holes comprising the openings543(a few labeled) that aid in balancing purge gas flow through the first side storage container124. In some embodiments, the holes543may have small diameters D61at the bottom of the exhaust baffle564and large diameters D62toward the top of the exhaust baffle564. The holes543with the smaller diameters D61may be proximate the exhaust port544to balance the gas flow. For example, the larger diameters D62may be between about 15 mm and 17 mm in some embodiments. The smaller diameter holes may range in diameter D61from about 7 mm to about 9 mm in some embodiments. Other hole diameters and/or hole arrangements and patterns may be used.

In the embodiment ofFIG.6, the holes543may be arranged as a two-dimensional array wherein the diameters of the holes543progressively decrease from the top of the exhaust baffle564toward the bottom of the exhaust baffle564. In some embodiments, adjacent pairs of rows of holes543have the same diameters. For example, a first pair of rows662may have holes543having a first diameter and a second pair of rows664may have holes543having a second larger diameter.

FIG.7illustrates another embodiment of an exhaust baffle764that may be used in side storage containers where the exhaust port544is located at a height of about half the vertical distance of the exhaust plenum128of the side storage pod120. As shown inFIG.7, the holes with smaller diameters are located proximate the location of the exhaust port544, which balances the purge gas flow through the side storage pod.

The exhaust baffle564may substantially balance the purge gas flow, so that all substrates on the substrate holders530are exposed to approximately the same purge gas flow (e.g., within 25% of the flow of each other or less, such as 15% or less different).

Gas flow through the interior of the first side storage container124enters the pod opening516, passes over and/or around the substrates435supported on the substrate holders530, flows through the exhaust baffle564, enters the exhaust plenum128, and is exhausted via the exhaust port544. The purge gas flow configuration enables the substrates435received in the substrate holders530to be in the same environmental conditions as the EFEM114, yet at a higher flow rate.

As shown inFIGS.1and2, exhausted purge gas from the exhaust conduits132,134enters the pod plenum240(FIG.2) where it may be heated by the heater250. The exhaust gas can further be filtered by the filter248to remove certain chemicals as described above. The supplemental fan141forces the exhaust gas into the duct129in concert with fan264to recirculate the purge gas back into the upper plenum262of the EFEM114as described above.

The foregoing description discloses example embodiments of the disclosure. Modifications of the above-disclosed apparatus, assemblies, and methods which fall within the scope of the disclosure will be readily apparent to those of ordinary skill in the art. Accordingly, while the present disclosure has been disclosed in connection with example embodiments, it should be understood that other embodiments may fall within the scope of the disclosure, as defined by the claims.