WO2015066484A1

WO2015066484A1 - A modular reticle pod system

Info

Publication number: WO2015066484A1
Application number: PCT/US2014/063448
Authority: WO
Inventors: Anthony M. Tieben; Brian Wiseman; Steve P. KOLBOW; David L. Halbmaier; John Lystad
Original assignee: Entegris, Inc.
Priority date: 2013-10-31
Filing date: 2014-10-31
Publication date: 2015-05-07
Also published as: TW201523126A

Abstract

A modular system for construction of reticle pods having door assemblies and cover assemblies. The modular system can accommodate cover portions of various and differing constructions within a common frame portion, thereby reducing tooling and inventory requirements. In one embodiment, the cover portion is fabricated from a polymer material. In another embodiment, the cover portion is fabricated from a metallic material and mates with a door assembly that has a metallic door panel, so that the resident reticle is within a metallic encapsulation for static dissipation and contaminant control. In various embodiments, a viewing window can be included with the cover portion to enable visual verification of the presence of a reticle within the pod assembly. Wash slots extending through the cover portion provide enhanced cleaning. A seal in the door assembly is in a groove open upwardly and downwardly.

Description

A MODULAR RETICLE POD SYSTEM

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 61/898,435 filed October 31, 2013, U.S. Provisional Patent Application No. 61/917,1 14, filed December 17, 2013, and U.S. Provisional Application Serial No. 62/067,368, filed October 22, 2014, the disclosures of which are hereby incorporated by reference herein in their entirety.

FIELD OF THE DISCLOSURE

The disclosure relates generally to a container for storage, transport, shipping and processing of fragile devices such as photomasks, reticles and wafers, and more particularly to a modular system for utilizing selected components and materials of construction within a common platform that provides ease of manufacture and enhanced cleaning capabilities.

BACKGROUND OF THE INVENTION

Integrated circuit devices are commonly manufactured using a process known as photolithography. In photolithography, a photoresist layer is first deposited on a wafer substrate. Radiant energy, such as ultraviolet light, is then projected onto the photoresist layer through a template in the form of a mask or reticle having the desired pattern. The photoresist layer is then developed to remove either the exposed portions or the unexposed portions, to form a resist mask on the substrate. The resist mask can then be used to protect underlying areas during later deposition or etching processes.

An important component of the photolithographic apparatus is the reticle, which provides the pattern and layout corresponding to the various integrated circuit features. Typically, the reticle is a transparent glass plate with a layer of opaque or semi-opaque material coated thereon forming the pattern. It is critically important that the surfaces of the reticle, especially the coated surface, be protected from damage or contamination, since any such defects or contamination may be projected onto the photoresist layer during exposure, thus leading to a finished integrated circuit device of unacceptably diminished or even unusable quality.

Typically, containers for holding and protecting reticles are provided with standardized mechanical interfaces that allow automatic manipulation of the container by processing machinery. The reticle containers or pods, have a base or door and a cover that has a skirt that extends around a periphery of the door with latches in the skirt that latch to the door periphery. The reticle seats on the door and when the cover is latched thereto an interior region is defined that contains the reticle. An elastomeric seal typically extends between the cover and door when the two are joined thereby sealing the juncture between the two. Such containers generally hold photomasks of up to 200mm and are designated standard mechanical interface pods, or SMIF-Pods. Even with such a controlled environment, migration of particulates that may be present inside the controlled environment is still possible due to pressure changes of the air trapped in the controlled environment or turbulence of the trapped air brought on by rapid movements of the container and/or by disturbing the trapped air volume. For example, thin walled SMIF pods may experience wall movement due to altitude related pressure changes causing the trapped air inside the controlled environment to be displaced. Temperature changes can set up convection currents within the container. Dimensional changes of the container and its components due to pressure fluctuations can lead to compromising the sealing between cover and door of the carrier and incursion of particulates within the carrier.

Those skilled in the art will appreciate that particulate contaminants are but one half of the equation. Equally important are gas-phase contaminants or airborne molecular contaminants (AMC) due to ambient air venting or leaking into or getting trapped in a hermetically sealed system. For example, at a suitable dew point temperature, the moisture in the air will condense out of the air and some of it may get deposited onto the reticle. Even with a perfectly sealed container, there is the possibility of air entering into the system when the reticle is removed from and replaced within the container during processing. Water vapor condensing onto the patterned surface of the reticle can interfere with the optics just as a solid particulate would. Other sources of gas-phase or vapor contamination that are believed to be significant are solvent residues resulting from reticle/pod cleaning operations during the photomask lifecycle, chemical agents generated by out-gassing from the structural components of the carrier and chemical agents that enter into the carrier from the ambient atmosphere by breaching the hermetic sealing arrangement between the carrier shell and the carrier door.

Efforts directed at reducing contamination have included using dual containment in reticle pods, that is an inner pod and an outer pod. See for example U.S. 8,613,359 and 7,607,543, both owned by the owner of the instant application and incorporated herein by reference. These pods are mechanically complicated resulting in less than optimum cleaning and drying capabilities and also less than optimum manufacturing and assembly costs.

Multiple contamination species are thought to be the largest contributors to gas- phase contamination. These include NH3 (ammonia), S02 (sulphur dioxide), H20 (moisture) and condensable organics C6-C10. It is believed that moisture or water is one of the key ingredients required for haze and crystal growth. Essentially, water combines with some of the aforementioned contaminants to form the salts are generally clubbed together under the rubric of crystal growth. Controlling such haze and crystal growth has included use of desiccants and/or aggressive purging and effectively cleaning of reticle pods. Such cleaning includes washing and drying of the reticle pod.

Where components are assembled in conventional substrate containers such as reticle pods, there are entrapment areas, particularly where planar surfaces of one component engages a planar surface of another component and the engagement region is more than a few millimeters wide and particularly where there is no easy exit path for entrapped water. One solution is to manufacture as much of the reticle pod as possible as a single unitary molded component, and then there are no junctures as compared to where components are assembled. There are difficulties associated with this practice, such as complicated and expensive molds, difficulty in molding components without excessive warpage or shrinkage. And obviously, parts that move with respect to one another, such as latch components, cannot be unitarily molded.

It has been shown that an effective way of controlling or reducing contaminants in reticle pods is to reduce the volumetric area of the interior region, the containment, of the reticle. This minimizes the surface area defining the interior region and minimizes the quantity of air (or other gas(es) in the air and thus the quantity of potential contaminants. In a conventional reticle pod, formal industry standards, SEMI standards, exist that control dimensions of surfaces. For particular size reticles, the standards require certain exterior dimensions that dictate the size of the reticle pod, particularly the cover assembly. It is difficult to provide a reduced interior volume when the exterior dimensions are provided that have significant separation from the interior footprint of the reticle and still have a unitary cover. In certain types of reticle pods a secondary containment is provided that has minimal interior space, see for example 8,613,359 and 7,607,543, both owned by the owner of the instant application. It would be beneficial to improve on these configurations by reducing the number of parts, providing better washability and driability characteristics, providing options in assembly, for example, substitution of components.

It is known that moisture may permeate into polymer walls and other polymer portions of reticle pods. When a reticle pod is not being purged the moisture permeating out of the polymer walls into the interior of reticle pods and contribute to the hazing issues. Critical to these efforts is a reticle pod that seals hermetically to limit entry of contaminants including moisture laden air. Also, eliminating the polymer walls is a solution. Providing reticle containment with metal walls is known, see for example, U.S. 8,613,359. Some customers and some applications do not want or need the metal walls for the containment. Heretobefore, providing a reticle pod with a metal reticle containment was significantly more expensive than polymer reticle containment. A way to offer the option of a metal reticle containment or a polymer containment without a great price differential and with interchangeability would be welcome by the industry.

SUMMARY OF THE DISCLOSURE

A reticle pod has a door assembly with fixtures for seating a reticle thereon and a cover assembly that covers and encloses the reticle, seals to the door assembly and extends around and latches to a periphery of the door. In embodiments, the door assembly is formed of an outer frame and a unitary internal lattice, the lattice supporting a door panel that partially defines the reticle containment surface. The door panel periphery is spaced from the outer frame defining a seal receiving slot that is open on a top side and a bottom side. A continuous seal that extends around the perimeter is inserted in the slot. In embodiments, a cover assembly comprises an exterior support frame portion and an interior cover portion rigidly mounted thereto. The interior cover portion having a top wall, and four contiguous and unitary side walls. The lower edge of the sidewalls defining a sealing surface for engaging the continuous seal. Whereby the door panel, cover portion, and seal define the reticle interior containment surface. In embodiments, the exterior surface of the cover portion being spaced from the exterior support frame portion substantially over the entirety of the exterior surface except for bosses and standoffs extending from the exterior support frame portion.

Various disclosed embodiments provide a modular reticle pod system comprising a door for holding a reticle and a cover attachable thereto, wherein the materials of cover components and door components can be chosen for a particular application or customer, but within a framework that enables use of common components. Specifically the reticle containment formed from a cover portion(in the cover assembly) and a door panel (on the door assembly) may be selected from an inventor for assembly of a custom reticle pod. For example, certain reticle pod carriers may utilize a entirely polymer cover with viewing windows for readily determining whether a reticle is contained therein, and a polymer door panel; whereas other reticle pod carriers may utilize a cover with a metallic cover portion defining a reticle containment, over a base with a metallic panel for better electrostatic dissipation and no permeability of the walls of the reticle containment. Various embodiments disclosed herein enable modular implementation of different cover and base characteristics within a common framework, thereby reducing the need for extra tooling, parts and inventory. Also, different robotic flanges are available or the flange may be replaced by a manual handle.

Structurally, in one embodiment, a modular reticle pod system comprises a cover assembly including a cover portion disposed within an exterior support or frame portion, the cover portion having an exterior surface, the exterior surface defining a continuous peripheral portion, the continuous peripheral portion being positioned at and spaced from the frame portion proximate the opening, the frame portion including beam members that extend over the exterior surface of the cover portion. The cover portion is axially and laterally offset from the frame portion to define a gap between the frame portion and the exterior surface of the cover portion. This provides an exit path for washing fluids to escape and allow complete and quick drying after washing. The modular reticle pod system can further comprise a door assembly including a base portion dimensioned to form a closure over the opening of the frame portion, the door assembly including pedestal portions mounted to the base portion for suspension of a reticle over the base portion and lateral retainer portions mounted to the base portion for lateral retention of the reticle over the base portion, the door assembly including a continuous seal member proximate a perimeter of the base portion for engagement with the cover assembly to form a hermetic seal between the cover assembly and the door assembly.

In some embodiments, a latching assembly is disposed within the frame portion, the latching assembly including latches that extend laterally into the opening to engage and secure the door assembly within the opening of the frame portion. In various embodiments, a corner retention member is disposed on an interior surface of the cover portion for engagement with a corner of the reticle. In one embodiment, the cover the cover portion is metallic. The cover portion can also include viewing windows. The cover portion can also be formed of a polymer material and includes reinforcing ribs that span a top portion of the cover portion.

A feature and advantage of embodiments of the invention is a door assembly of a reticle pod that has a door panel secured to a frame by fasteners and wherein a lower surface of the door panel is substantially exposed through voids in the frame thereby providing enhanced washability and driability of the door. A further feature and advantage of embodiments is the groove for the seal member that seals between the cover portion and the door panel is open upwardly and downwardly, thereby provide enhanced washability and driability in that there are no closed ends for trapping cleaning fluids or water.

A feature and advantage of embodiments of the invention is a cover assembly of a reticle pod that has a top wall and four side walls defining an interior and an open downwardly facing side, the cover portion fastened to a support frame by fasteners and wherein each of the side walls is exposed through voids in the support frame thereby providing enhanced washability and driability of the door. In embodiments, the top wall is exposed through one or more of the voids thereby providing enhanced washability and driability of the door. In embodiments a gap is defined between each side wall and the support frame and an open pathway extends between one of the voids, each gap to below the cover assembly, thereby defining a plurality of wash slots and drying slots that extend entirely through the cover assembly from above to below. In embodiments, the gap extends the majority of the length of each side wall. In embodiments, the gap extends the entire length of each sidewall. In embodiments, the gap extends entirely around the periphery of the cover portion defined by the sidewalls.

A feature and advantage of embodiments of the invention is a reticle pod with a door assembly for seating the reticle and a cover assembly that extends over and covers the reticle and extends down around the outer periphery of the door and latches thereto. The reticle pod having an inner containment comprising a cover portion which is part of the cover assembly and a door panel that is part of the door assembly and a seal sandwiched between the cover portion and the door panel. In embodiments, the only contact between the door assembly and the cover assembly, when a reticle is contained therein is at the seal and the latches system. A feature and advantage of embodiments of the invention includes a reticle containment in a standard reticle pod configuration that is minimal in volume and that therefore reduces contamination issues. In embodiments, the volume of the containment defined by the cover portion, the seal member, and the door panel is less than 900,000 cubic mm. In embodiments the volume is less than 1.4 million cubic mm. In embodiments, less than 1.2 million cubic mm. All of which are substantially less than the containment in a conventional reticle pod. These volumes are similar to volumes of dual containment EUV reticle pods, that have a seperable inner metal pod. However, the expense and thus the cost of manufacturing the reticle pods according to the inventions herein is far below that of the EUV reticle pods.

A feature and advantage of embodiments of the invention is providing a reticle pod with a metal reticle containment that has simplicity allowing pricing to be comparable to similarly configured reticle pod with a polymer reticle containment. An advantage of embodiments is being able to provide the option of a metal reticle containment or a polymer containment without a increase in complexity and thus without an expected great price differential and with interchangeability.

Feature and advantages of embodiments of the invention is a reduced volume reticle pod with enhanced washability and driability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is an exploded view of a reticle pod system in an embodiment of the disclosure with the cover portion having a robotic flange to be attached thereto;

FIG. IB is a view of a cover portion and door assembly attachable thereto with the cover portion having a manual handle option;

FIGS. 2 and 3 are perspective views of a frame portion of FIGS. 1A-1B in an embodiment of the disclosure;

FIG. 4 is an enlarged perspective view of a latch assembly of FIG. 1 in an embodiment of the disclosure;

FIG. 5A is a perspective view of a cover assembly in an embodiment of the disclosure;

FIG. 5B is a perspective view of a cover assembly in an embodiment of the disclosure; FIG. 6 is an upward perspective view of a cover assembly with a cover portion and reticle engagement features therein;

FIGS. 7 and 8 are perspective views of an alternative cover portion of a reticle pod system in an embodiment of the disclosure;

FIG. 9 is an elevation view of the cover assembly of FIG. 1 in an embodiment of the disclosure;

FIG. 9A is an enlarged partial view of the cover assembly of FIG. 9;

FIG. 9B is a sectional view of the cover assembly of FIG. 9 taken at line 9B-9B;

FIG. 10A is an exploded view of the door assembly of FIG. 1 in an embodiment of the disclosure;

FIG. 10B is a partial exploded view of the door assembly of FIG. 1 viewed from below the door;

FIG. 1 1 is a top perspective view of the door assembly of FIGS. 10A and 10B;

FIG. 12 is an elevation view of the door assembly of FIG. 11;

FIG. 13 is a sectional view of the door assembly of FIG. 1 1 ; and

FIG. 14 is an enlarged, sectional view of the door assembly of FIG. 13 illustrating the groove for the seal member that is open above and below the groove.

FIG. 15 is an exploded view of the top side of a modular door assembly with the door panel in place in an embodiment of the disclosure;

FIG. 16 is a partial sectional view of the modular door assembly of FIG. 14.

FIG. 17A is a cross sectional view of a cover assembly and door assembly separated;

FIG. 17B is a cross sectional view of the cover assembly and door assembly of FIG. 18A coming into engagement;

FIG. 17C is a cross sectional view of the cover assembly and door assembly of

FIG. 18A engaged and latched;

FIG. 18 is a schematic illustration of a facility with inventories of the modular components described herein for constructing the modular reticle pods according to the inventions herein; and FIG. 19 is a graph of the robustness of the enclosure in maintaining low humidity after a purge of modular reticle pods according to the invention(s) herein.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIGS. 1A-3, exploded and assembled views of a reticle pod assemblies 30 and cover assemblies 32 are depicted. The reticle pod assembly 30 includes a cover assembly 32 and a door assembly 34. The cover assemblies 32 includes a liner or cover portion 36 disposed within a frame portion 38, and can include a robotic flange 42 attached to the frame portion 38. In one embodiment, a pair of latch assemblies 44 are disposed on opposing sides of the frame portion 38, each latch assembly 44 including a pair of latch members 46 which can be biased (e.g., spring loaded) inward defining the latched position.

The cover portions 36 include a top portion 52 with a top wall 53 from which can depend a continuous lateral side portion 54 defining four side walls 55. In one embodiment, a lip portion 56 is located distal to the top portion 52 that flares outwardly, that is, extends radially outward from the lateral side portion 54 and is continuous. The lip portion provides a planar or substantially planar sealing surface 57 that faces and confronts the door when the cover assembly is assembled with the door assembly. The top portion 52 and the lateral side portion 54 define an exterior surface 58 and an interior surface 59. In one embodiment, the top portion 52 includes one or more viewing windows 62, and can also include corner retention members 64 that are coupled to the interior of the cover portion 36. The cover portion may The sidewalls may have a slight draft from the top portion to facilitate manufacture and cleaning. Additionally, the corners between the top portion and side wall are radiused an eighth of an inch or more and the corners between the side walls a similar amount or slightly larger. The cover assembly 32 is mounted to the door assembly 34 along a central axis 66.

The door assembly 34 includes a base portion 72 to which is mounted a plurality of reticle engagement features 73 that include pedestal portions 74 and lateral retainer portions 76. A continuous seal member 78 can be mounted within a groove 82. In one embodiment, structure defining a plurality of holes 84 can pass through a top surface 86 of the base portion 72. Filter elements (not depicted) can be mounted in the holes 84, enabling the pressure within the reticle pod 30 to attain equilibrium with the surrounding environment. The base portion 72 can also define perimeter recesses 87 which are part of the latching system and engage with and cooperate with the latch members 46 of the latch assemblies 44. Further details of the door are discussed below with respect to FIGS. 10A- 17C.

Referring to FIGS. 2 and 3, the support frame portion 38 of the cover assembly is depicted in isolation in an embodiment of the disclosure. The frame portion 38 includes lower structure having an outer rectangular frame 88 that defines an opening 90. The outer rectangular frame 88 can define mounting recesses 92 into which the latch assemblies 44 are mounted. The mounting recesses 92 can each include a pair of guide rails 94 which straddle a catch 96. In one embodiment, an upper structure 98 extends upwards from the rectangular frame 88. The upper structure 98 can include a pair of opposed lifting flanges 100, and can also include beam portions 102 that span the outer rectangular frame 92. The beam portions 102 can define through holes configured as fastener apertures 104 that include bosses or spacer pads 106 that depend from interior surfaces 108 of the beam portions 102. The beam portions 102 can also include bosses 1 12 that extend upward, each defining an aperture 114 therethrough. The upper structure can define apertures or voids 116 which provides access for washing and drying to the outer or exterior surface 58 of the cover portion.

Referring to FIG. 4, one latch assembly 44 is depicted in isolation in an embodiment of the disclosure. The latch assembly 44 includes a body portion 122 with the latch members 46 extending from opposing ends of the body portion 122. Each latch member 46 can be biased with a spring element 124 that causes an engagement portion 126 of each latch member 46 to extend laterally in the same direction relative to the body portion 122. Generally, the latch members will have a normal position extending inwardly to latch to the door in recesses 87. The latch members may be deflected outwardly utilizing the apertures 127 by robotic means allowing separation, such as lowering of the door. Recesses 129 allow outward travel of the latch members 46 beyond the outer periphery 130 of the rectangular frame 88. In one embodiment, a tab portion 132 extends from the body portion 122, the tab portion 132 including a detent 134 formed on an outer surface thereof, the tab portion 132 and body portion 122 defining a pair of slots 136 therebetween.

Referring to FIGS. 2-6, an assembly of the cover assembly 32 is depicted in an embodiment of the disclosure. In assembly, the cover portion 36 can be secured to the frame portion 38 using fasteners 138 that pass through the fastener apertures 104 and spacer pads 106 of the frame portion 38. Referring to FIG. 5B, the robotic flange 42 can be secured to the bosses 1 12 of the beam portions 102 with bolts (not depicted) that pass through apertures 114. The bolts can be secured to the cover assembly 32 using acorn nuts 140. Referring to FIG. 5 A, rather than securing a robotic flange, a manual handle 142 may be attached utilizing the same apertures. The molds may be designed with mold inserts that may be removed that allow the parallel and opposite flanges 141 to be unitary with the frame portion as desired and as part of the modularity of embodiments of the invention.

Each latch assembly 44 can be positioned at the mouth of the respective mounting recess 92 so that the slots 136 are aligned with the guide rails 94. The latch assembly 44 is then pushed into the mounting recess 92 so that the slots 136 slide over the guide rails 94. This action causes the tab 132 to depress toward the body portion 122 of the latch assembly 44 until the detent 134 snaps into the catch 96, thereby securing the latch assembly 44 within the outer rectangular frame 92.

Referring to FIGS. 7 and 8, a homogenous and unitary cover portion 150 is depicted in an embodiment of the invention. The homogenous cover portion 150 can be made, for example, of a metallic material such as stainless steel and may be formed by conventional metal forming such as stamping. The cover portion may be injection molded of materials conventional in the art of substrate containers relating to semiconductor processing. The cover portion 150 can include many of the same aspects as the cover portion 36, which are indicated with like-numbered numerical references. To complement a metallic cover portion, the base portion 72 can also include a metallic laminate disposed thereon to establish a metallic top surface 86.

Referring to FIGS. 9, 9A and 9B, the cover assembly 32 is depicted in an embodiment of the disclosure. The spacer pads 106 provide an axial offset between the cover portion 36 and the frame portion 38 to define an axial gap 162 therebetween. The lip portion 56 can be dimensioned to provide a lateral offset between the cover portion 36 or 150 and the frame portion 38 to define a lateral gap 164 therebetween.

Functionally, the axial and lateral gaps 162 and 164 enable the cover assembly 32 to be washed and dried effectively (i.e., without trapping liquid therebetween). The gaps along with the voids The viewing windows 62 enable the contents of the reticle pod to be viewed from the outside, generally to inform whether the reticle pod assembly 30 contains a reticle. The cover portion with the windows may be formed by overmolding as disclosed in U.S. Pat. No. 8,734,698, which is owned by the owner of the instant application, said patent is incorporated by reference herein.

Referring to FIGS. 10A through 16, aspects of the door assembly 34 are depicted in an embodiment of the invention. In the depicted embodiment, a plurality of fixtures 170 each include a pedestal portion 74 and a lateral retainer portion 76, the fixture 170 including a boss 172 and an alignment pin 174 that are pressed into corresponding apertures 176 and 178 of the base portion 72. In one embodiment, the continuous seal member 78 includes an axially-extending lip 182 that is pressed into the groove 82. A lateral portion 184 of the continuous seal member 78 extends radially outward from the axially extending lip 182 and can be canted upwards.

Functionally, the pedestal portions 74 support a reticle 184 above the top surface 86 of the base portion 72 of the door assembly 34. The lateral retainer portion 76 capture reticle 184 about its edges to prevent lateral movement of the reticle 184 within the reticle pod assembly 30. The latches 46 of the latch assemblies 44 can be actuated outward to enable the cover assembly 32 to slide over the periphery of the door assembly 34, then released so that the engagement portions 126 of the latches 46 are biased inward to register within the perimeter recesses 87 of the base portion 72, thereby securing the door assembly 34 to the cover assembly 32. When the cover assembly 32 is secured to the door assembly 34, the corner retention members 64 are also brought into contact with the reticle 184 proximate the corners to further secure the reticle 184 in position both axially and laterally. The lateral portion 184 of the continuous seal member 78 is captured between the cover assembly 32 and the door assembly 34 to provide a hermetic seal therebetween.

Referring to FIGS. 14 through 16, a modular door assembly 200 is depicted in an embodiment of the disclosure. The modular door assembly 200 includes a door panel 202 fastened to a base configured as a frame, illustrated as a skeletal frame 204 with a plurality of fasteners 243, such as screws. The skeletal frame is configured as a grid work or lattice. The door panel 202 includes a first or interior face 212 and a second or exterior face 214 that is opposite the interior face 212, and a perimeter 216 that bridges the interior and exterior faces 212 and 214. The door panel 202 can be of a solid (homogeneous) metallic or non-metallic material, or a composite (non-homogeneous) and may be a simple square (or rectangular) panel with rounded corners. The door panel 202 can also define a plurality through holes 218 that pass through the interior face 212 and exterior face 214 for mounting of filters and/or purging appurtenances 220. In embodiments of the invention alternate door panels of different materials and/or configurations are provided.

The skeletal frame 204 includes an outer frame portion 222 and an inner lattice portion 224, the outer frame portion 222 defining an opening 226, the inner lattice portion 224 comprising a plurality of cross members 228 and traversing the opening 226 and defining a plurality of voids 232. In embodiments, the inner lattice portion 224 is integrally formed with the outer frame portion 222 by injection molding. The inner lattice portion has an upper surface 225 that is recessed below the upper surface 226 of the outer frame portion, thus defining a door panel recess 227. The inner lattice portion 224 can include a plurality of kinematic coupling receptacles 234a, 234b, and 234c (referred to collectively as kinematic coupling receptacles 234) that are dimensioned and spaced for engagement with the kinematic coupling of exterior handling equipment. In various embodiments, there are three such kinematic coupling receptacles 234a, 234b and 234c. In one embodiment, two of the kinematic coupling receptacles 234 (e.g., 234a and 234b) define a circular opening 236, while one of the kinematic coupling receptacles 234 (e.g., 234c) define an oval opening 238.

In various embodiments, the inner lattice portion 224 also includes a plurality of fastener receptacles 242. The fastener receptacles 242 can be configured to accept fasteners for securing the door panel 202 to the skeletal frame 204 and/or for securing appurtenances to the interior face 212 of the door panel 202.

The cross members 228 can be characterized as having contact edges 244 that contact the exterior face 214 of the door panel 202. The contact edges 244 can be substantially planar (as depicted), or can define a profile that reduces contact area between the cross members 228 and the exterior face 214; examples of such profiles include a radiused edge, or spaced protrusions distributed along the lengths of the cross members 228.

The modular door assembly 200 can also be configured with a seal such as the continuous seal member 78 having the axially-extending flange portion 182 and the lateral portion 184. In one embodiment, the door panel 202 and the outer frame portion 222 cooperate to define a continuous groove 252 that passes from the interior face 212 to the exterior face 214 of the door panel 202. In this embodiment, the axially-extending flange portion 182 of the continuous seal member 78 is captured within the groove 252 between the perimeter 216 of the door panel 202 and the outer frame portion 222 of the skeletal frame 204. The axially-extending flange portion 182 can be dimensioned to provide an interference fit within the groove 252 for retention of the continuous seal member 78. In one embodiment, an edge 254 of the axially-extending flange portion 182 (downward facing in the depiction of FIG. 16) faces and is exposed to the inner lattice portion 224 of the skeletal frame 204. In one embodiment, the edge 254 can be substantially flush with exterior face 214 of the door panel 202.

The outer frame 222 can include an inclined shoulder 256 that, in assembly, substantially faces the lateral portion 184 of the continuous seal member 78. In one embodiment, the inclined shoulder 256 slopes away from the lateral portion 184 of the continuous seal member 78 in a direction that is radially outward from a central axis 258 of the door assembly 200.

The door panel 202 can be configured with mounting apertures 262 and alignment apertures 264 that accommodate the boss portions 172 and the alignment pins 174, respectively, of the fixtures 170. In one embodiment, one or more of the boss portions 172 can be threaded and aligned with a corresponding one of the fastener receptacles 242. In another embodiment (not depicted), there is no boss portion; instead, the base of the fixture 170 includes a through hole that is aligned with a corresponding mounting aperture 262 and fastener receptacle 242, all sized for a clearance fit with a fastener.

In assembly, the door panel 202 is placed within the skeletal frame 204. In one embodiment, fasteners (not depicted) are fed through one or more of the fastener receptacles 242 and threaded into the door panel 202; in another embodiment, one or more of the fixtures 170 are disposed in the corresponding apertures 262, 264 and the fasteners threaded into the boss portions 172; in still another embodiment, the fastener is fed through the fixture 170, mounting aperture 262, and fastener receptacle 242 and terminated on one end with a nut (not depicted). The fasteners can be tightened slightly to provide a spaced fit between the door panel 202 and the skeletal frame 204 and to define the groove 252. The axially-extending flange portion 182 of the continuous seal member 78 can then be inserted into the groove 252 to aid in centering the door panel 202 within the opening 226 of the outer frame portion 222. The fasteners can then be fully tightened to secure the door panel 202 to the skeletal frame 204 and to secure the continuous seal member 78 within the groove 252. In embodiments, tolerances are such that no such adjustment is needed. Functionally, the boss portion 172 (or, in the absence of a boss, the fastener) laterally secures a given fixture 170 to the interior face 212 of the door panel 202. The mounting boss 172 can be dimensioned to provide a friction fit within the mounting aperture 262 to also prevent axial movement (i.e., movement parallel to the central axis 66). For embodiments where the boss portion 172 includes internal threads, the accompanying fastener captures the fixture 170 to prevent axial movement. The alignment pin 174 disposed in the alignment aperture 264 ensures proper alignment of the fixture 170, and also prevents rotation of the fixture 172 over time.

Various aspects of the modular door assembly 200 help to augment the drying process after the door is washed for faster and more thorough drying. For embodiments where the door panel 202 is of a homogeneous material (e.g., solid metal or solid polymer), there are no laminate layers which can entrap moisture from the washing process. The voids 232 within the skeletal frame 204 provide access to the contact areas between the skeletal frame 204 and the door panel 202 for drying purposes. In embodiments, the exterior surface of the cover portion and side walls has a cumulative total surface area and the engagement contact area where the cover portion is secured to the frame 204 at bosses or otherwise, and the contact areas (if any) where there are standoffs engaging the cover portion has a total contact area. In embodiments the ratio of total contact area of the top portion and side walls to the cumulative total surface area is less than .08 or less, that is, 8% or less. In such an embodiment, 92% or more of the cumulative surface area is not in contact, "non-engaged", with the frame portion. In other embodiments, the ratio is less than .05, or 5%. In such an embodiment, 95% or more of the cumulative surface area is not in contact, "non-engaged", with the frame portion. In other embodiments, the ratio is .03 or less, that is less than 3%. In such an embodiment, 97% or more of the cumulative surface area is not in contact, "non-engaged", with the frame portion. In other embodiments, the ratio is .01 or less, that is less than 1%. In such an embodiment, 99% or more of the cumulative surface area is not in contact, "non- engaged", with the frame portion. In other embodiments, the ratio is .005 or less, that is less than .5%. In such an embodiment, 99.5% or more of the cumulative surface area is not in contact, "non-engaged", with the frame portion. In each of the above embodiments, the entirety of the outside surfaces of the side walls may be non-engaged with the frame portion. A similar minimization of the engagement of the door panel with the door frame portion is provided. In embodiments the total surface area of the lower side of the door panel the area engaged by the door frame is less than 20%, or stated differently, 80% or more of the downwardly facing surface of the door panel is exposed through the door frame. In another embodiment, the total surface area of the lower side of the door panel the area engaged by the door frame is less than 15%, or stated differently, 85% or more of the downwardly facing surface of the door panel is exposed through the door frame. These ratios provide enhance washability and driability to the door assemblies.

For embodiments that implement reduced area structures (e.g., contact edges 244 having radiused edges or spaced protrusions distributed along the lengths of the cross members 228), access to the contact areas are further enhanced. The groove or slot 252, being accessible from both the interior face 212 and the exterior face 214 during the drying operation, also enhances drying, as there is no gland for entrapment of moisture. Accordingly, the door assembly 200 can be readily dried after a washing process without need for disassembly of the door assembly 200. The seal can be removed if desired for replacement or washing.

Referring to FIGS 17A-17C, features of embodiments of the invention are illustrated. FIG. 17A illustrates the reticle pod open with the cover assembly on processing equipment 257, and the door in the equipment on an elevator 259. The elevator is being raised to close the reticle pod as indicated by the arrow 261. The voids 1 16 are positioned proximate the cover portion 36 in the frame portion of the cover assembly 32. The cover portion has the gaps 162, 164 between it and the frame portion 38. The void in combination with the gaps define a wash slot 262, indicated generally by the dashed line in FIG 17A. The wash slot 262 extends through the vertical thickness of the cover assembly from above the cover assembly to below the cover assembly.

FIG. 17A further shows a threaded fastener 242 extending through the frame portion, the cover portion 36, a robotic flange 42, into a reticle engagement feature 73. The cover portion, in this embodiment is formed of metal and is sandwiched between the engagement feature 73 and the boss 260. The lip portion 56 has the sealing surface for engagement with the seal member 78. The door assembly 200 has a door panel 202 seated in the top side recess FIG. 17B shows the door assembly moving into engagement with the cover assembly. FIG. 17C illustrates the seal member deflected and sandwiched between the lip of the cover portion and the shoulder 256 of the outer frame 222. An inner reticle containment 266 is thus formed and defined by the cover portion, the door panel 202, and the seal member 78, and the containment is supported by an outer framework 258. FIG. C also illustrates that the reticle pods as disclosed herein, when closed, both the door assembly and cover assembly seat on the same datum level 271 with the cover assembly surrounding the door assembly whereby the door is not exposed above the datum level.

The door assembly 200 has the door frame 204 with the door panel 202, formed of metal and seated in the door panel recess 227 or receiving region, defined by the top of the inner lattice portion 224 being lower than the top of the outer frame portion 222.

FIG. 18 illustrate utilization of the reticle pod systems described herein in a facility 300. Inventory 310 of frame portions 38, metal cover portion inventory 312, polymer cover portions inventory 314, the metal cover portions and polymer cover portions both configured to be received by the frame portions, door frame inventory 320, metal door panel inventory 322, polymer door panel inventory 324, both the metal door panels and polymer door panels sized to be received by the door frames, reticle engagement fixtures inventories 330, fastener inventories 332, seal member inventory 334. The inventories can be utilized to construct assembled reticle pods and maintain an inventory 338 of same in the facility. Moreover, orders 340 may be received from customers resulting in the assembly and shipping of reticle pods 342 constructed from the inventories 310, 312, 314, 320, 322, 324, 330, 332, 334.

Embodiments of the invention include maintaining inventories of components and assembling select components into desired or ordered configurations. Each assembly providing the advantageous washing and drying characteristics as described above. Moreover, the assembled modular reticle pods have been demonstrated to maintain superior low relative humidity in the interior environment after purging as illustrated by FIG. 19.

Use of "substantially" herein means "more than 50% unless in context the meaning is obviously different.

Each of the additional figures and methods disclosed herein can be used separately, or in conjunction with other features and methods, to provide improved containers and methods for making and using the same. Therefore, combinations of features and methods disclosed herein may not be necessary to practice the invention in its broadest sense and are instead disclosed merely to particularly describe representative and preferred embodiments of the instant invention.

Various modifications to the embodiments of the inventions may be apparent to one of skill in the art upon reading this disclosure. For example, persons of ordinary skill in the relevant art will recognize that the various features described for the different embodiments of the inventions can be suitably combined, un-combined, and re-combined with other features, alone, or in different combinations, within the spirit of the invention. Likewise, the various features described above should all be regarded as example embodiments, rather than limitations to the scope or spirit of the inventions. Therefore, the above is not contemplated to limit the scope of the inventions.

Persons of ordinary skill in the relevant arts will recognize that the inventions may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the inventions may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the inventions may comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art.

Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein.

References to "embodiment(s)", "embodiment(s) of the disclosure", and "disclosed embodiment(s)" contained herein refer to the specification (text, including the claims, and figures) of this patent application that are not admitted prior art.

For purposes of interpreting the claims for the embodiments of the inventions, it is expressly intended that the provisions of 35 U.S.C. 1 12(6) are not to be invoked unless the specific terms "means for" or "step for" are recited in the respective claim.

Claims

CLAIMS What is claimed is:

1. A reticle pod providing an outer support framework and an inner containment module, the reticle pod comprising:

a door assembly and a cover assembly, the cover assembly sized to conform to a periphery of the door,

the cover assembly comprising a support frame sized to the outer peripheral margins of the door assembly and further comprising an inwardly positioned unitary cover portion having a top wall and four downwardly depending side walls with an open downwardly facing side, the cover portion fastened to the support frame;

the door assembly comprising a support frame defining the outer peripheral margins of the door assembly and further comprising a door panel sized to close the open side of the four sided portion with an open downwardly facing side, the cover portion fastened to the support frame; and

a seal member positioned at a perimeter of the door panel.

2. The reticle pod of claim 1 wherein each side wall of the cover portion has an open pathway extending entirely through the cover assembly.

3. A reticle pod with a door assembly and a cover assembly, the door assembly comprising a support frame with a central lattice portion supported by an outer peripheral frame and a door panel fastened to the central lattice portion, and wherein the door panel has a downwardly facing surface and substantially all of the downwardly facing surface is exposed through the central lattice.

4. The reticle pod of claim 3 wherein at least 80% of the downwardly facing surface area of the door panel is exposed through the lattice portion.

5. The reticle pod of any one claim of 3 to 4 wherein a seal member is positioned between the door panel and the outer peripheral frame, and wherein the seal member is substantially exposed downwardly through the door assembly.

6. The reticle pod of any one claim of 3 to 4 wherein the door panel is attached to the central lattice portion with one of threaded fasteners and rivets.

7. The reticle pod of claim 6 wherein the door panel is sandwiched between the central lattice portion and a reticle engaging fixture.

8. A reticle pod with a modular door assembly comprising:

a skeletal frame including an outer frame portion and an inner lattice portion including a plurality of cross members, said inner lattice portion traversing said outer frame portion, said inner lattice portion defining a plurality of coupling receptacles and a plurality of fastener receptacles, said plurality of coupling receptacles being dimensioned and arranged for interfacing with equipment; and

a door panel including a upwardly facing first face, a downwardly facing second face opposite said first face, and a perimeter that bridges said first face and said second face, said skeletal frame being attached to said second face of said of said door panel with a plurality of fasteners, each of said plurality of fasteners being disposed in a respective one of said plurality of fastener receptacles.

9. The reticle pod of claim 8, wherein said outer frame portion and said inner lattice portion of said skeletal frame are integrally formed.

10. The reticle pod of claim 8, wherein said skeletal frame comprises a polymer material and said door panel is solid metallic.

1 1. The reticle pod of claim 8, further comprising a reticle engaging fixture mounted to said first face of said door panel.

12. The reticle pod of claim 8, wherein the skeletal frame defines a door panel recess and the door panel is seated in the recess.

13. The reticle pod of claim 8, wherein the outer frame is spaced from the door panel thereby defining a seal member slot.

14. The reticle pod of claim 13 wherein the seal member slot is mostly opened downwardly and totally open upwardly.

15. The reticle pod of claim 14 wherein a seal member extending at an oblique angle outwardly is positioned in the seal member groove.

16. The modular door assembly of claim 8, wherein a seal member is disposed between said outer frame portion and said perimeter of said door panel.

17. The modular door assembly of claim 16, wherein said seal member includes an axially-extending flange portion that forms a seal between said seal member and said perimeter of said door portion.

18. The modular door assembly of claim 18, wherein an edge of said axially-extending flange portion is exposed to said voids of said inner lattice portion of said skeletal frame.

19. The reticle pod system of any one of claims 8-18, wherein the downwardly facing side of the door panel has a cumulative surface area, and wherein the portion of the cumulative surface area engaged by the frame portion is less than 20% of the cumulative surface area.

20. The reticle pod system of any one of claims 8-18, wherein the downwardly facing side of the door panel has a cumulative surface area, and wherein the portion of the cumulative surface area engaged by the frame portion is less than 15% of the cumulative surface area.

21. A reticle pod system, comprising a door assembly and a cover assembly with an open bottom, the door sized to fit within the cover assembly; wherein the cover assembly including a cover portion disposed within a frame portion, said cover portion having a top wall with four side walls unitary with and depending therefrom, the cover portion being mounted to said frame portion, wherein said cover portion is axially and laterally offset from said frame portion to define a gap between said frame portion and said exterior surface of said cover portion.

22. The reticle pod system of claim 21, wherein the door assembly including a base portion dimensioned to form a closure within said opening of said frame portion, said door assembly including pedestal portions mounted to said base portion for suspension of a reticle over said base portion and lateral retainer portions mounted to said base portion for lateral retention of said reticle over said base portion, said door assembly including a continuous seal member proximate a perimeter of said base portion for engagement with said cover assembly to form a hermetic seal between said cover assembly and said door assembly.

23. The reticle pod system of claim 22, further comprising a latching assembly disposed within said frame portion, said latching assembly including latches that extend laterally into said opening to engage and secure said door assembly within said opening of said frame portion.

24. The reticle pod system of any one of claims 21-23, wherein said cover portion is comprised of one of stamped metal or an injection molded polymer.

25. The reticle pod system of any one of claims 21-23, wherein said frame portion includes a void, and the cover portion includes a viewing window, and wherein the viewing window is positioned at the void of the frame portion whereby a reticle seated on the door is viewable through the viewing window.

26. The reticle pod system of any one of claims 21-23, wherein said frame portion includes a plurality of voids, and the plurality of voids and the gap define a plurality of wash slots extending through cover assembly from above the cover assembly to below the cover assembly.

27. The reticle pod system of any one of claims 21-23, wherein the cover system is mounted to the frame portion exclusively at the top wall of the cover portion.

28. The reticle pod system of any one of claims 21-23, wherein the top wall and four side walls of the top cover have a cumulative surface area, and wherein the portion of the cumulative surface area engaged by the frame portion is less than 5%

29. The reticle pod system of claim 28 wherein the portion of the cumulative surface area engaged by the frame portion is less than 1%.

30. A method of providing reticle pods to end users, the reticle pods comprising a door assembly and a cover assembly, the method comprising:

maintaining an inventory of framing portions;

maintaining an inventory of metal cover portions that fit into the framing portions; maintaining an inventory of polymer cover portions that fit into the framing portions;

maintaining an inventory latching portions that assemble with the framing portions;

maintaining an inventory of reticle engaging fixtures; assembling pursuant to a customer order or an inventory filling order a cover assembly with a selected one of the metal cover portion or polymer cover portion;

maintaining an inventory of door components.

assembling the door assembly according the customer order or the inventory filling order.

31. The method of claim 30 further comprising maintaining an inventory of door frame portions;

maintaining an inventory of metal door panels sized to fit into the door frame portions;

maintaining an inventory of polymer door panels sized to fit into the door frame portions;

assembling pursuant to a customer order or an inventory filling order a door panel with a selected one of the metal door panel or polymer door panel.

32. The method of claim 30 or 31 further comprising assembling the cover assembly by sandwiching the cover portion between the frame portion and a reticle engagement fixture with a fastener.

33. The method of claim 30 or 31 further comprising assembling the door assembly by sandwiching the door panel between the door frame portions and a reticle engagement fixture with a fastener.

34. A method of assembling a door assembly of a reticle pod comprising selecting one of at least two different door panels and attaching the selected door panel to a skeletal frame and sandwiching the door panel between the skeletal frame and a reticle engagement fixture using a fastener.

35. A method of assembling a cover assembly of a reticle pod comprising selecting one of at least two different cover portions and attaching the selected cover portion to a skeletal frame.

36. The method of claim 35 further comprising assembling the cover assembly by sandwiching the cover portion between the frame portion and a reticle engagement fixture with a fastener.

37. A reticle pod comprising a door assembly with fixtures for holding a reticle and a top cover assembly comprised of a cover portion secured within an outer support frame, the outer support frame latchable to the door assembly;

the cover portion having a top portion and four unitary sidewalls depending therefrom, the top wall being closed and continuous, except for openings where components are attached, a gap provided between the framework and each of the sidewalls of the cover portion, the gap providing an open pathway extending from below the top cover to above the top cover;

the door assembly having a seal member in a groove, the groove open upwardly and downwardly.

38. A reticle pod comprising a door assembly with fixtures for holding a reticle and a top cover assembly comprised of a cover portion secured within an outer support frame, the outer support frame latchable to the door assembly;

the cover portion having a top portion and four unitary sidewalls depending therefrom, the top wall being closed and continuous, except for openings where components are attached, a gap provided between the framework and each of the sidewalls of the cover portion, the gap providing an open pathway extending from below the top cover to above the top cover.

39. A reticle pod comprising a door assembly with fixtures for holding a reticle and a top cover assembly comprised of a cover portion secured within an outer support frame, the outer support frame latchable to the door assembly;

the cover portion having a top portion and four unitary sidewalls depending therefrom, the top wall being closed and continuous, except for openings where components are attached,

a plurality of wash slot extending through the vertical thickness of the cover portion.

40. A reticle pod providing an outer support framework and an inner containment module, the reticle pod comprising:

the cover assembly comprising a support frame defining the outer peripheral margins of the door assembly and further comprising an inwardly positioned unitary cover portion having a top wall and four downwardly depending side walls with an open downwardly facing side, the cover portion fastened to the support frame;

the door assembly comprising a support frame defining the outer peripheral margins of the door assembly and further comprising a door panel sized to close the open side of the four sided portion with an open downwardly facing side, the cover portion fastened to the support frame;

a seal member positioned at a perimeter of the door panel.

41. The reticle pod of claim 40 wherein each side wall of the cover portion has an open pathway extending entirely through the cover assembly.

42. A reticle pod with a reduced reticle containment volume, the reticle pod comprising:

a cover assembly comprising a metal cover portion having a top wall and four side walls depending therefrom and defining an open bottom side for receiving the reticle, the metal cover portion attached to a frame portion, the metal cover portion outwardly and upwardly physically exposed with respect to the frame portion for cleaning;

a door assembly comprising a door frame with a central lattice portion, a metal door panel sized to close the open bottom side of the cover portion fixed to the frame portion on the central lattice portion, a downwardly facing surface of the door panel substantially exposed through the central lattice portion.

43. The reticle pod of claim 42, wherein the exposure of the downwardly facing surface of the door panel is greater than 80%.

44. The reticle pod of claim 42, wherein the cover portion is physically exposed outwardly and upwardly through a plurality of voids in the frame portion, and wherein the plurality of voids are each part of a wash slot extending through the door assembly.

45. The reticle pod of any one of claim 42, 43, and 44, wherein the four walls of the cover portion are not contacting the frame portion.

46. The reticle pod of one of claim 42, 43, and 44, wherein the cover portion has an exterior surface of a cumulative surface area and wherein the engagement between the surface of the cover portion compared to the cumulative surface area is less than 3%,

47. The reticle pod of one of claim 42, 43, and 44, wherein mounting of the door panel to the frame is exclusively by fasteners extending between the frame portion, the door panel, and one or more reticle engagement fixtures.

48. The reticle pod of one of claim 42, 43, and 44, wherein mounting of the cover portion to the frame is exclusively by fasteners extending between the frame, the door panel, and one or more reticle engagement fixtures.

49. The reticle pod of one of claim 42, 43, and 44, wherein the door panel and frame define a seal member slot and a seal member is positioned therein.

50. The reticle pod of claim 49 wherein the seal member slot is substantially open upwardly and downwardly.

51. A reticle pod system at a supply facility, the system comprising:

an inventory of a plurality of frame portions sized to receive a cover portion, an inventory of door frames sized to be received within each of the plurality of frame portions, each door frame with a receiving region sized for a door panel;

an inventory of metal door panels sized for being received in the door frames; an inventory of polymer door panels sized for being received in the door frame, the polymer door panels interchangeable with the metal door panels;

an inventory of metal cover portions sized for being received in the frame portion; an inventory of polymer cover portions sized for being received in the frame portion, the polymer cover portions interchangeable with the polymer cover portions/

52. The reticle pod system of claim 51 further comprising an inventory of seal members sized to be received in a seal member slot defined by an installed door panel and the frame into which it is installed.

53. A method of manufacturing modular reticle pods comprising drawing from the inventories of claim 1 upon receipt of an order from a customer.

54. A method of maintaining a supply of modular reticle pods in inventory comprising selecting components from the inventories of claim 51 and manufacturing modular reticle pods therefrom and storing the manufactured modular reticle pods in inventory pending receipt of customer orders.