WO2015095357A1

WO2015095357A1 - A low energy seal for a substrate carrier

Info

Publication number: WO2015095357A1
Application number: PCT/US2014/070904
Authority: WO
Inventors: Anthony M. Tieben; Brian Wiseman; Steven P. Kolbow; David L. Halbmaier; John Lystad
Original assignee: Entegris, Inc.
Priority date: 2013-12-18
Filing date: 2014-12-17
Publication date: 2015-06-25
Also published as: TW201524867A

Abstract

A substrate carrier with a low energy seal. In various embodiments, the low energy seal provides a seal line between a housing assembly and a door assembly of the substrate carrier, the seal being actuated by a force that is less than the weight of the housing assembly. In some embodiments, the low energy seal can provide a low threshold pressure relief mechanism that vents gas from an interior chamber of the substrate carrier to ambient when the pressure of the chamber exceeds the ambient pressure. In various embodiments, a venting structure is formed on the low energy seal to provide pressure relief between the interior chamber and ambient during disengagement of the housing assembly from the door assembly.

Description

A LOW ENERGY SEAL FOR A SUBSTRATE CARRIER

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/917,641, filed December 18, 2013, and of U.S. Provisional Application No. 61/985,627, filed April 29, 2014, the disclosures of which are hereby incorporated by reference herein in their entirety.

FIELD OF THE DISCLOSURE

The disclosure is directed generally to substrate carriers, and more specifically to a seal system for substrate carriers.

BACKGROUND

Semiconductor substrates are typically transported in substrate carriers that are equipped to interface with processing equipment such as load ports. For larger substrate carriers (e.g., 200 mm wafers and larger), the processing equipment usually includes hold downs that secure the substrate carrier and maintain a hermetic seal between a housing assembly of the carrier and a door assembly of the carrier. However, for smaller substrate carriers (e.g., 150 mm reticle pods), processing equipment typically does not include external seal hold downs. Without such external seal hold downs, the seal integrity of the substrate carrier is often compromised during processing operations.

What is needed is a substrate carrier that enables a hermetic seal between the housing assembly and the door assembly without the aid of mechanical hold downs.

SUMMARY OF THE DISCLOSURE

Various embodiments of the disclosure include a low energy seal member that can effect a hermetic seal between a housing assembly and a door assembly of a substrate carrier, where the only actuation force is provided by the weight of the housing assembly. In one embodiment, the actuation force required is only a fraction of the weight of the housing assembly, because the weight of the housing assembly is also allocated for distribution to other force couplings, such as retention of the substrate.

In addition to providing a hermetic seal under low contact forces, the low energy seal can also provide a low threshold for relief when the pressure internal to the substrate carrier exceeds the ambient pressure. The ability to relieve pressure can further enable purging of the substrate carrier without the need for a separate purge exhaust port. During prototype testing, it was found that, surprisingly, the low energy seal of certain embodiments disclosed herein provided sealing with such efficacy that the seal would not readily release or "crack" when attempting to open the substrate carrier. That is, rather than the housing assembly separating from the door assembly, the entire carrier assembly would lift off or partially lift off the load port, the cover and door assemblies being held together by suction because of the steadfastness of the low energy seal.

To remedy the suction problem, a variety of seal venting arrangements are disclosed herein. The seal venting arrangements facilitate fluid communication between the interior chamber of the substrate carrier and the ambient surroundings during disengagement of the housing assembly and the door assembly. The fluid communication equalizes or reduces the pressure difference between the interior chamber and the ambient surroundings, eliminating or reducing the suction that otherwise maintains coupling between the door and the housing assemblies. This enables the seal between the door assembly and the housing assembly to "crack" so that the housing assembly can be lifted away from the door assembly without aid of external retention.

In various embodiments, the venting arrangement is effected by irregularities in the body of the seal, such as through-passages (e.g., apertures or slits) that enable venting of the chamber and cracking of the seal. In some embodiments, the venting arrangement is effected by irregularities in the seal surfaces (e.g., creases, notches, or local depressions) that facilitate cracking of the seal at a predetermined localized area of the seal. In certain embodiments, the venting arrangement is effected by a separate mechanism that selectively grips the seal during opening of the substrate carrier to effectively peel the seal away from its contact line. Despite the presence of these venting arrangements, the above- outlined embodiments can be configured to enable a hermetic seal when the housing and closure are fully engaged.

Structurally, various embodiments of a substrate carrier are disclosed, the carrier comprising a housing assembly including a cover portion having a top portion and a continuous side portion that depends from the top portion, the continuous side portion defining a proximal plane of the cover portion. A door assembly cooperates with the housing assembly to define a chamber for housing a substrate when in a fully engaged configuration, the door assembly being concentric about a central axis and defining a distal face. A seal member can be disposed between the housing assembly and the door assembly, the seal member defining a seal line between the housing assembly and the door assembly when the housing assembly and the door assembly are in the fully engaged configuration. In various embodiments, the seal member defines a venting structure for passage of gas therethrough when the housing assembly and the door assembly are disengaged from the fully engaged configuration. In various embodiments, the seal member is sealingly mounted to the door assembly and extends in a distal direction from the distal face. In some embodiments, the housing assembly restricts flow through the venting structure of the seal when the housing assembly and the door assembly are in the fully engaged configuration; in other embodiments, the housing assembly blocks flow through the venting structure of the seal when the housing assembly and the door assembly are in the fully engaged configuration.

The seal member can include a lateral web portion that extends radially outward to a peripheral edge of the seal member. In one embodiment, the peripheral edge of the seal member is in contact with the housing assembly and the door assembly when the housing assembly and the door assembly are in the fully engaged configuration. Various embodiments of the seal member include a lip portion that defines the peripheral edge of the seal member, the lip portion having an axial thickness greater than an axial thickness of the lateral web portion.

In various embodiments, the seal member defines a distal plane and the venting structure defines a local depression of the peripheral edge relative to the distal plane. The structure defining the depression can, in certain embodiments, be one of a crease and a notch.

In certain embodiments, a local depression is defined when the housing assembly and the door assembly are disengaged and is removed when the housing assembly and the door assembly are in the fully engaged configuration. The local depression can be defined by a hold down, for example an external seal hold down mounted to the door assembly, or a unitary seal hold down that is unitary with the seal member. The unitary seal hold down can include a stem portion extending proximally from the seal portion and a detent portion at a proximal end of the stem portion, the unitary seal hold down being operatively coupled with a recess in the door assembly.

The housing assembly can include a flange portion extending radially from the continuous side portion and having a proximal face that defines the proximal plane of the cover portion. In some embodiments, the flange portion of the cover portion extends radially outward from the continuous side portion. The flange portion of the housing assembly can be configured to restrict flow through the venting structure of the seal when the housing assembly and the door assembly are in the fully engaged configuration. Alternatively, the flange portion of the housing assembly can be configured to block flow through the venting structure of the seal when the housing assembly and the door assembly are in the fully engaged configuration, and enables flow through the venting structure of the seal when the housing assembly and the door assembly are disengaged from the fully engaged configuration. In one embodiment, the venting structure comprises one of a through-passage and a slit formed on the lateral web portion.

In various embodiments of the disclosure, a low energy door seal for a wafer carrier comprises an axial flange portion that includes a proximal portion and a distal portion and defining an inner surface and an outer surface, the proximal portion defining a proximal edge that bridges the inner surface and the outer surface, the inner surface being substantially parallel to a central axis. A lateral web portion can include an inner portion and an outer portion and defining a proximal face and a distal face, the inner portion extending from the distal portion of the axial flange portion and radially outward from the central axis. In various embodiments, a lip portion extends from the outer portion of the lateral web portion, the lip portion defining a peripheral edge and including a thickness that is greater than a thickness of the lateral web portion. The axial flange portion, the lateral web portion, and the lip portion of the low energy seal can be continuous in a tangential direction about the central axis. In some embodiments, the distal face of the lateral web portion defines an acute angle relative to the inner surface of the axial flange portion, and the distal face of the lateral web portion can also define a plane relative to the acute angle. In one embodiment, the lip portion does not extend distal to the plane. The lateral web portion can also be of substantially uniform thickness. In various embodiments, a crown of the lip portion lies substantially on a distal plane when the low energy door seal is not under load. The lip portion can include a venting structure defining a depression relative to the distal plane of the crown. The low energy door seal can comprise, for example, an ethylenepropylenediene monomer.

In one embodiment, the lip portion is characterized as having a tangential length, and the lip portion deflects from 1 mm to 2 mm inclusive in a direction parallel to the central axis when a force of 11 grams per lineal centimeter of the tangential length is applied in the direction parallel to the central axis. In one embodiment, the acute angle is greater than or equal to 60 degrees and less than or equal to 85 degrees. In certain embodiments, the uniform thickness is greater than or equal to 0.4 mm and less than or equal to 0.6 mm. Also, in various embodiments, the distal face of the lateral web portion includes an overall radial dimension defined orthogonal to the central axis, the overall radial dimension being greater than or equal to 5 mm and less than or equal to 10 mm.

In various embodiments, a venting structure is formed in the lateral web portion of the seal member. The venting structure can include, but is not limited to, at least one of a through aperture, a slit, and a depression. The low energy door seal can also include a unitary seal hold down that depends from one of the lateral web portion and the lip portion. The unitary seal hold down can include, for example, a stem portion and a detent portion at a distal end of the stem portion, the detent portion for engagement of a recess formed on a door of a wafer carrier.

For various embodiments of the disclosure, a substrate carrier is disclosed, comprising a housing assembly including a cover portion including a continuous side portion that depends from a top portion, the continuous side portion including a perimeter that defines an opening, the housing assembly having a weight. A door assembly cooperates with the housing assembly to define a chamber for housing a substrate, the door assembly being concentric about a central axis and including a panel portion, a shoulder portion, and a seal member, the shoulder portion surrounding the panel portion, the seal member being disposed between the panel portion and the shoulder portion, the seal member including a lateral web portion that extends in a radial outward direction from the central axis, the lateral web portion including a distal face and a peripheral edge that contacts the perimeter of the housing assembly. For various embodiments, the weight of the housing assembly exerts a sealing force having an axial sealing force component on the seal member with the perimeter of the housing assembly in the axial direction to provide a seal line between the seal member and the perimeter of the housing assembly when a chamber pressure within the chamber is less than or equal to an ambient pressure, the axial sealing force component being parallel to the central axis and being less than the weight of the housing assembly.

The housing assembly optionally includes a plurality of contact members that extend into the chamber for engagement of a substrate and for exertion of a substrate retention force on the substrate, the substrate retention force having an axial retention force component that is parallel to the central axis and being transferred to the door assembly. In one embodiment, a sum of the axial retention force component and the axial sealing force component is less than the weight of the housing assembly. In some embodiments, when the chamber pressure exceeds the ambient pressure, a local separation from the perimeter of the housing assembly. In some embodiments, the chamber pressure is greater than 0.5 Torr and less than 6 Torr to cause an onset of the separation. In some of these embodiments, the chamber pressure is about 2 Torr to cause the onset of the separation.

In various embodiments, the panel portion of the door assembly defines a plane, and the shoulder defines an incline relative to the plane, the incline sloping away from the lateral web portion of the seal member in the radial outward direction. The panel portion can also be substantially planar. In one embodiment, the panel portion and the shoulder portion are integrally formed. Optionally, a stop engages the door assembly to limit axial deflection of the peripheral edge of the lateral web portion of the seal member.

The substrate carrier can further comprise a hold down that depends from and is unitary with one of the lateral web portion and the lip portion. In this embodiment, structure defining a receptacle in the door assembly can receive the hold down to hold a portion of the seal member below a distal plane of the seal member when the seal member is not in contact with the housing assembly, thereby defining a local depression in the seal member. Alternatively, the substrate carrier can comprise an external seal hold down coupled to the door assembly, the external seal hold down being engaged with the seal member to define a local depression of the seal member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a housing assembly and a door assembly in an embodiment of the disclosure;

FIG. 2 is a lower perspective view of the housing assembly of FIG. 1;

FIG. 3 is a perspective view of a seal member of FIG. 1 in an embodiment of the disclosure;

FIG. 3 A is a sectional view of the seal member of FIG. 3;

FIG. 4 is a sectional view of the housing assembly and the door assembly of FIG. 1 in a fully engaged configuration in an embodiment of the disclosure; FIG. 5 is a partial sectional view of a deflection of the seal member of FIG. 4 in an embodiment of the disclosure;

FIG. 6 is a partial sectional view of the seal member of FIG. 4 during pressure release;

FIG. 7 is a perspective view of a vented seal member in an embodiment of the disclosure;

FIG. 7A is a sectional view of the vented seal member of FIG. 7 in an embodiment of the disclosure;

FIGS. 8A through 8D present alternative vent structures for the vented seal member of FIG. 7;

FIGS. 9A and 9B are partial sectional views of the vented seal member of FIG. 7 in operation in an embodiment of the disclosure;

FIGS. 10A and 10B are sectional views of the vented seal member of FIG. 7 in operation in an embodiment of the disclosure;

FIG. 11 is a partial perspective view of a creased seal member in an embodiment of the disclosure;

FIG. 12 is a partial perspective view of a notched seal member in an embodiment of the disclosure;

FIG. 13A is a partial perspective view of a seal member with external seal hold down in an embodiment of the disclosure;

FIGS. 13B and 13C are partial sectional views of the seal member and external seal hold down of FIG. 13A in operation in an embodiment of the disclosure;

FIGS. 14A and 14B are partial sectional views of a seal member with a unitary seal hold down in operation in an embodiment of the disclosure;

FIGS. 15A through 15C are partial sectional views of a seal breaking mechanism in operation in an embodiment of the disclosure; and

FIGS. 16A and 16B are partial sectional views of a seal member mounted to a housing assembly in operation in an embodiment of the disclosure. DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIGS. 1 and 2, a substrate carrier assembly 30 is depicted in a disclosed embodiment. The substrate carrier assembly 30 includes a door assembly 32 and a housing assembly 34 that, in assembly, are aligned along a central axis 36. The door assembly 32 includes a panel portion 38 surrounded by a shoulder portion 42. The panel portion 38 defines a distal face 40 of the door assembly 32 and can include structure(s) for mounting a plurality of fixtures 44 for supporting a substrate mounted on the distal face 40. In one embodiment, a seal member 46 is sealingly mounted within a groove 48 (FIG. 4) formed on the door assembly 32. The seal member 46 can be continuous in a tangential direction. (The "tangential direction" is depicted in FIG. 3 as Θ on a plane that is normal to a z-axis, the z-axis being substantially parallel to the central axis 36 in assembly.) The groove 48 can be formed at the junction of the panel portion 38 and the shoulder portion 42. In one embodiment, the shoulder portion 42 can define an inclined surface 52 that substantially faces the seal member 46. In one embodiment, the inclined surface 52 slopes away from the seal member 46 in a direction that is radially outward from the central axis 36.

The housing assembly 34 can include a cover portion 62 disposed within a frame portion 64, and can include a handle 65 attached to the frame portion 64. In various embodiments, the frame portion 64 includes a plurality of stop portions 66 configured to register against the door assembly 32 and establish the elevation of the housing assembly 34 relative to the door assembly 32.

The stop portions 66 can be appendages that extend downward from the cover portion 62, as depicted, for example, in FIGS. 5 and 6. In other embodiments, the stop portions 66 can comprise rib members that extend radially inward from the frame portion 64, as depicted, for example, in FIGS. 2 and 4. The stop portions 66 can be located at the midspans of the frame portion (as depicted) and/or at the corners. In various embodiments, the door assembly 32 can include slots (not depicted) within which the stop portions 66 of the housing assembly 34 register. In some embodiments, effective stop portions are not discrete appendages or rib portions as depicted herein, but rather a section of the housing assembly 34 that rests on and forms a contact interface with the corners of the door assembly 32 outside the seal member 46. In still other embodiments, stop portions do not depend from the housing assembly 34, but rather extend distally (i.e., upward) from the door assembly 32 to register against the housing assembly 34. The cover portion 62 can include a top portion 68 from which depends a continuous lateral side portion 70. In one embodiment, a flared rim 71 defining a flange portion 72 is located on the lateral side portion 70 of the cover portion 62 to define an opening 74 opposite the top portion 68. The flange portion 72 extends radially outward from the lateral side portion 70, and can be provided by structures other than the flared rim 71 (e.g., a separate frame joined to the continuous side portion 70). In one embodiment, the top portion 68 includes reticle retention members 76 that are coupled to the interior of the cover portion 62. Herein, the cover portion is depicted as being of a polymer material, but can instead be formed of a metallic material.

Referring to FIGS. 3 and 3A, the seal member 46 is depicted in isolation in an embodiment of the disclosure. A cross-section (FIG. 3A) of the seal member 46 can be characterized as having an overall axial dimension 78 that is parallel to the central axis 36 and an overall radial dimension 80 that is orthogonal to the central axis 36. In the depicted embodiment, the seal member 46 includes an axial flange portion 82 that includes a proximal portion 84 and a distal portion 86, and defining an inner surface 88 and an outer surface 92. Herein, "proximal" and "distal" refer to directions or orientations that are parallel to the central axis 36, with proximal being in a direction going from the housing assembly 34 to the door assembly 32 (represented by arrow 93a), and distal being a direction going from the door assembly 32 to the housing assembly 34 (represented by arrow 93b). The proximal portion 84 of the axial flange portion 82 defines a proximal edge 90 that bridges the inner surface 88 and the outer surface 92. In one embodiment, the inner surface 88 is substantially parallel to a central axis 36.

The seal member 46 can also include a lateral flange or lateral web portion 94 that includes an inner portion 96 and an outer portion 98 and further defining a proximal face 100 and a distal face 102 separated by a thickness 104. The thickness 104 can be substantially uniform along the length of the lateral web portion 94. In one embodiment, the inner portion 96 extends from the distal portion 86 of the axial flange portion 82 and radially outward from the central axis 36. The lateral web portion 94 can be canted such that the distal face 102 defines an acute angle φ relative to the inner surface 88 of the axial flange portion 82. In one embodiment, the distal face 102 of the lateral web portion 94 is planar relative to the acute angle φ.

In various embodiments, a lip portion 106 extends from the outer portion 98 of the lateral web portion 94. The lip portion 106 defines a peripheral edge 108 and is of a thickness 112 that is greater than the thickness 104 of the lateral web portion 94. The lip portion 106 can be characterized has having a tangential length 114 from Θ = 0° around to Θ = 360°. The lip portion 106 can be further characterized as having a crown 110 that lies substantially on a plane 111 and represents the uppermost extremity of the seal member 46 when installed in the door assembly 32.

Referring to FIGS. 4 and 5, assembly and operation of the substrate carrier assembly 30 is depicted in an embodiment of the disclosure. In assembly, a substrate is placed 120 on the fixtures 44 of the door assembly 32. The housing assembly 34 is then aligned and oriented over the door assembly 32 and placed onto the door assembly 32. The door assembly 32 and the housing assembly 34 are brought together along the central axis 36 until the stop portions 66 of the housing assembly 34 engage the door assembly 32, thereby defining a fully engaged configuration 118 of the carrier assembly 30. The door assembly 32 and the housing assembly 34 cooperate to define a chamber 121 of the carrier assembly 30 in the fully engaged configuration 118 that contains the substrate 120 and is hermetically sealed from the ambient atmosphere 123.

In one embodiment, the positioning and axial extension of the reticle retention members 76 are such that, when the stop portions 66 engage the door assembly 32, the reticle retention members 76 are in contact with the substrate 120. In other embodiments, the stop portions 66 do not engage the door assembly 32 when the substrate 120 is present, so that the housing assembly 34 is fully supported on the substrate 120 via the reticle retention members 76 when in the fully engaged configuration 118; in such embodiments, the stop portions 66 function to prevent excessive compression of the seal member 46 in the absence of a substrate. In still other embodiments, there are no stop portions, so that the housing assembly 34 is effectively "stopped" by compression of the seal member 46 between the door assembly 32 and the housing assembly 34 when in the fully engaged configuration 118.

Functionally, the lip portion 106 of the seal member 46 provides a tangential rigidity that maintains the planar configuration of the lateral web portion 94. That is, because of the relative thinness of the lateral web portion 94, the distal face 102 of the lateral web portion 94 can become wavy, thereby requiring more actuation force to effect a hermetic seal. The lip portion 106 helps maintain the planar configuration without compromising the low actuation energy aspect provided by the thin lateral web portion 94. The stop portions 66 suspend the housing assembly 34 so that the flange portion 72 of the cover portion 62 contacts but does not compress the lip portion 106. That is, when the housing assembly 34 is seated on the door assembly 32, the flange portion 72 causes a deflection 122 of the lateral web portion 94 and lip portion 106 towards the shoulder portion 42 of the door assembly 32, but does not capture the lateral web portion 94 or lip portion 106 between the flange portion 72 and the shoulder portion 42. For certain embodiments, the inclined surface 52 of the shoulder portion 42 prevents the lateral web portion 94 and lip portion 106 from contacting the door assembly 32 when under full deflection 122. In various embodiments, a clearance 142 is provided between the door assembly 32 and the lateral web portion 94 and/or lip portion 106 of the seal member 46.

The fixtures 44 which suspend the substrate 120 above the panel portion 38 and can also act to limit lateral movement within the substrate carrier assembly 30. The reticle retention members 76 restrain the substrate 120 from moving in the distal direction 93b and can also act to further limit or restrain lateral movement of the substrate 120.

For the depicted embodiment, the housing assembly 34 exerts at least two different forces on the door assembly 32: (1) a sealing force 124 exerted by the flange portion 72 via the seal member 46, and, when substrate retention members 76 are utilized, (2) a substrate retention force 126 exerted by the substrate retention members 76 via the substrate 120 and fixtures 44. The substrate retention force 126 includes an axial retention force component 126a that is parallel to the central axis 36. (NOTE: The substrate retention force 126 and the axial retention force component 126a, despite being depicted as individual to each substrate retention member in FIG. 4, is the sum of all substrate retention forces and axial retention force components exerted on the substrate 120.) The sealing force 124 can also be. characterized as having an axial sealing force component 124a.

In one embodiment, the axial retention force component 126a and the axial sealing force component 124a are derived entirely from the weight of the housing assembly 34. That is, the axial sealing force component 124a causes the flange portion 72 to engage seal member 46 with sufficient force to effect a seal line 128 between the flange portion 72 and the seal member 46. For various embodiments, the seal line 128 is continuous, thereby enabling a hermetic seal between the housing assembly 34 and the door assembly 32. Particularly for embodiments where substrate retention members 76 are utilized, the design of the seal member 46 is such that the force required to effect the seal line 128 is some fraction of the weight of the housing assembly 34.

The force required to effect the seal line 128 between the seal member 46 and the flange portion 72 of the housing assembly 34 can be normalized in units of force per lineal length of the seal member 46. For example, consider a housing assembly 34 that weighs approximately 1500 gm, and has a budget of 800 gmf for the axial sealing force component 124a. (Herein, units of "gmf is equivalent to the weight of a 1 gram mass at standard gravity.) Consider a seal member 46 with a lip portion 106 of approximately 75 cm. Accordingly, the force per lineal length of the seal member 46 would be 800 gmf / 75 cm, or about 1 1 gmf per lineal centimeter (gm/cm) of seal member 76. For some embodiments, the deflection 122 that corresponds to the force per lineal length of the seal member 46 is in the range of 1 mm to 2 mm inclusive.

In the above example, the fraction of the total weight of the housing assembly 34 is allocated at 800/1500 or 0.53. The fraction of the weight allotted for seal actuation can be budgeted at other values. In various embodiments, the fraction of the weight of the housing assembly 34 allocated for establishing the seal line 128 falls within a range of 0.2 to 0.8 inclusive, depending on the requirements of other forces that are derived from the weight of the housing assembly 34, such as the axial retention force component 126a.

It is understood that the above examples are merely representative and non- limiting. The artisan will recognize the requirements can differ while still being achieved utilizing the design principles set forth in this disclosure.

Referring to FIG. 6, a pressure release configuration 140 is depicted in a disclosed embodiment. By virtue of the low energy aspect of the seal member 46, the substrate carrier assembly 30 can also facilitate a release mechanism during purging and/or general pressure relief of the substrate carrier assembly 30 for embodiments where there is the clearance 142 between the door assembly 32 and the lateral web portion 94 and/or lip portion 106 of the seal member 46. For such embodiments, when a pressure Pc within the chamber 121 exceeds an ambient pressure Pa surrounding the substrate carrier assembly 30, the force caused by the pressure differential causes the lateral web portion 94 and/or lip portion 106 to separate locally from the flange portion 72, resulting in an exhaust of gas 144 to exit the chamber 121. In various embodiments, the onset of pressure relief occurs for pressure differences (Pc - Pa) that are greater than 0.5 Torr and less than 6 Torr to cause said separation. In one embodiment, the pressure difference required for the onset of the pressure relief is about 2 Torr.

In a representative and non-limiting example of a seal member 46 having some or all of the operational characteristics describe above, the overall axial dimension 78 falls within a range of 2 mm to 10 mm inclusive, the overall radial dimension 80 falls within a range of 5 mm to 10 mm inclusive, the thickness 104 of the lateral web portion 94 falls within a range of 0.4 mm to 0.6 mm inclusive, the acute angle <j> is within a range of 70° < φ < 85°, the tangential length is on the order of 75 cm, and a normalized force of 11 gmf/cm causes a deflection of the lip portion 106 on the order of 1 mm to 2 mm. An example and non-limiting material for the seal member 46 is VITON, available from Dupont Corporation, or generic ethylenepropylenediene monomer or similar elastomeric materials.

Referring to FIGS. 7 and 7A, a vented seal member 46a is depicted in an embodiment of the disclosure. The vented seal member 46a can include many of the same aspects as the seal member 46, which are indicated in FIGS. 7 and 7A with same- numbered numerical references. In addition, the vented seal member 46a defines a venting structure 151, such as a through-passage 152, that passes through the thickness 104 of the lateral web portion 94. In one embodiment, a plurality (not depicted) of such venting structures 151 are provided at discrete locations on the vented seal member 46a.

Referring to FIGS. 8A through 8D, alternate structures for venting of the seal member 46a are depicted in embodiments of the disclosure. In non-limiting examples, the venting structures 151 can include one or more of a circular through aperture 152a (FIG. 8 A), an elongated through slot 152b (FIG. 8B), a slit 152c (FIG. 8C), or a slit 152c with stress-relief through-apertures 152d (FIG. 8D). The minor dimensions of the various apertures can range, for example, from 0.2 mm to about 3 mm inclusive.

Functionally, the venting structure 151 enables fluid communication between the chamber 121 and the ambient surroundings 123. The fluid communication can equalize the pressure difference between the chamber 121 and the ambient surroundings 123, for example during removal of the cover portion 62 from the seal member 46a that occurs when removing the housing assembly 34 from the door assembly 32. This enables the seal between the door assembly 32 and the housing assembly 34 to "crack" so that the housing assembly 34 can be lifted away from the door assembly 32. The size of the aperture(s) can be sized small enough to not allow a substantial number of particulates to enter the chamber 121 during shipping and handling. Furthermore, slit structures (e.g., 152c) only open when a pressure difference is present, further mitigating particle entry.

Referring to FIGS. 9A and 9B, a double contact arrangement 150 for a seal member 46a is depicted in operation in an embodiment of the disclosure. The seal member 46a includes many of the same components and attributes as seal member 46a, which are indicated with same-numbered numerical references. In the depicted embodiment, the seal member 46a includes an enlarged lip portion 106b that is enlarged relative to lip portions 106 of other embodiments. In the fully engaged configuration 1 18, the flange portion 72 exerts a force against the seal member 46a, deflecting the enlarged lip portion 106b in the proximal direction 93a, such that the enlarged lip portion 106b contacts the shoulder portion 42 of the door assembly 32 (FIG. 9A).

Upon disengagement of the housing assembly 34 from the door assembly 32, the enlarged lip portion 106b of the seal member 46a is drawn in the distal direction 93b (upward in FIGS. 9A and 9B), partly because of the resilience of the seal member 46a and partly because of a momentary suction created due to the effective expansion of the volume of the chamber 121 as the housing assembly 34 and the door portion 32 are drawn away from each other. The distal (upward) motion of enlarged lip portion 106b breaks the contact between the enlarged lip portion 106b and the door assembly 32, providing a direct pathway for gas G (e.g., ambient air) to be drawn through the through-passage 152 (FIG. 9B). The venting enables the seal between the sealing member 46a and the housing assembly 34 to be readily broken.

Functionally, in various embodiments, the contact between the enlarged lip portion 106b and the door assembly 32 provides a second seal line 154 between the sealing member 46a and the door assembly 32 that is continuous, in addition to the seal line 128 between the sealing member 46a and the housing assembly 34. For embodiments where the second seal line 154 is continuous, the double contact arrangement 150 can enable a hermetic seal between the chamber 121 and the ambient surroundings 123, despite presence of the unblocked through-passage 152.

In other embodiments, the second seal 154 is not continuous; for example, the enlarged lip portion 106b may not contact the door assembly 32 at and/or proximate to the corners of the door assembly 32. For embodiments where the second seal 154 is not continuous, gases can circumvent the second seal 154 and access the through-aperture 152; nevertheless, such an arrangement can still inhibit particles or other contaminants from entering the chamber 121 because of the tortuous path from the ambient surroundings 123 to the through-aperture 152.

It is to be understood that contact between the lip portion 106 and the door assembly 32 can be effected without resort to an enlarged lip portion 106b. For example, in one embodiment, the stop portions 66 can be configured so that the seal 46a deflects to contact the shoulder portion 42 of the door assembly 32 before the stop portions 66 are engaged. In another embodiment, the shoulder portion 42 can be configured so that less proximal deflection is required to establish contact between the lip portion 106 and the door assembly 32.

Referring to FIGS. 10A and 10B, a blocking arrangement 156 for selective obstruction of the through-passage 152 defined in the seal member 46a is depicted in an embodiment of the disclosure. The flange portion 72 can extend radially outward and can have a radial dimension 158 so as to engage the lip portion 106 as well as the web portion 94 in the vicinity of the through-passage 152, thereby providing the seal line 128 and obstructing the through-passage 152. By this arrangement, the housing assembly 34 effectively blocks the through-passage 152 when the housing assembly 24 and the door assembly 32 are in the fully engaged configuration 1 18 (FIG. 10A).

Upon disengagement of the housing assembly 34 from the door assembly 32, the lip portion 106 of the seal member 46a is drawn in the distal direction (upward) relative to the through-passage 152, partly because of the resilience of the enlarged lip portion 106b and partly because of a momentary suction created due to the effective expansion of the volume of the chamber 121 as the housing assembly 34 and the door portion 32 are drawn away from each other. The distal motion of lip portion 106 relative to the through-passage 152 causes the through-passage 152 to separate from flange portion 72, thereby enabling gas (e.g., ambient air) to be drawn through the through-passage 152 and into the chamber 121 (FIG. 10B). The venting enables the seal between the sealing member 46a and the housing assembly 34 to be readily broken.

Functionally, the seal line 128 established by the blocking arrangement 156 can be continuous to enable a hermetic seal between the chamber 121 and the ambient surroundings 123. Furthermore, the through-passage 152 can provide relief from excessive pressures that may build up within the chamber 121. That is, a force caused by an excessive pressure differential between the chamber 121 and the ambient surroundings 123 can cause the lateral web portion 94 to separate from the flange portion 72 of the cover portion 62, also separating the through-passage 152 from the flange portion 72 and enabling the high pressure gas within the chamber 121 to be expunged therethrough. The resulting reduction in pressure within the chamber 121 causes the lateral web portion 94 to be drawn back into contact with the flange portion 72, thereby resuming the hermetic seal.

Referring to FIGS. 1 1 and 12, a creased seal member 46c and a notched seal member 46d, respectively, are depicted in an embodiments of the disclosure. The creased seal member 46c and notched seal member 46d include many of the same attributes and components as the seal member 46a, which are indicated with same-numbered numerical references. In addition, the creased seal member 46c and notched seal member 46d includes venting structure 151 that defines a depression 162 in the lip portion 106. In some embodiments, the depression 162 extends into a portion of the lateral web portion 94 that is proximate the lip portion 106. The depression 162 is defined relative to the crown 1 10 of the respective seal member 46c, 46d.

For the creased seal member 46c, the depression 162 is defined by a crease 164. For purposes of this disclosure, the "crease" 164 is a depression that is formed in the seal member 46c where the thickness 1 12 of the lip portion 106 is not substantially reduced at the site of the depression 162 relative to the thickness on either side of the depression 162. The crease 164 can be formed by techniques available to the artisan, including mold shape or post-formation manipulation.

For the notched seal member 46d, the depression 162 is defined by a notch 166. In contrast to the crease 164, the "notch" 166 is a depression 162 that is formed in the seal member 46d where the thickness of at least the lip portion 106 at the depression 162 is reduced relative to the thickness 1 12 of the lip portion 106 on either side of the depression 162. The notch 166 can be formed by techniques available to the artisan, including mold shape or removal of material after formation of the seal member 46d.

In operation, when the flange portion 72 of the housing assembly 34 is seated on the crown 1 10 of the lip portion 106, at least some of the material that defines the depression 162 of either the crease 164 or the notch 166 does not make contact with door assembly 32. Thus, a through-aperture (not depicted) is defined, bounded by the depression 162 and the flange portion 72 of the housing assembly 34. In various embodiments, one or more of such depressions 162 are defined by the seal member 46c, 46d. The size of the through-aperture(s) thus defined can be sized small enough to not allow a substantial number of particulates to enter the chamber 121 during shipping and handling. When the housing assembly 34 is lifted from the door assembly 32, air passes through the through-aperture(s) bounded by the depression 162 and the flange portion 72, thus venting the chamber 121 of the carrier assembly 30 and enabling the seal effected by the seal member 46c, 46d to readily crack.

In one embodiment, the creased seal member 46c or notched seal member 46d can be utilized in a double contact arrangement akin to double contact arrangement 150. That is, the carrier assembly 30 can be configured so that the lip portion 106 of the seal member 46c or 46d contacts both the door assembly 32 and the housing assembly 34 when in the fully engaged configuration 118. In a double contact arrangement, the crease 164 or notch 166 can become further restricted due to compression of the lip portion 106, thereby further mitigating the migration of particles therethrough. For embodiments where enough compression force is available, the crease 164 or notch 166 can be effectively closed by the compression.

In various embodiments, the creased seal member 46c or the notched seal member 46d can be utilized in a blocking arrangement, akin to the blocking arrangement 156 of FIGS. 10A and 10B. That is, the radial dimension 158 of the flange 72 can extend over the entirety of the depression 162 (i.e., over the portion of the lip portion 106 and the web portion 96 on which the depression 162 is formed), thereby effectively blocking gas migration through the depression 162 when the door assembly 62 and the housing assembly 34 are in the fully engaged configuration 1 18. Upon disengagement of the door assembly 62 and the housing assembly 34, the web portion 94 of the seal member 46c or 46d separates from the flange portion 72 of the cover portion 62, causing the passage defined between the depression 162 and the flange portion 72 to open, providing venting to the chamber 121.

Referring to FIGS. 13A through 13C, implementation of an external seal hold down 170 is depicted in an embodiment of the disclosure. The external seal hold down 170 includes a base portion 172 and a stop portion 174. In various embodiments, the stop portion 174 is canted relative to the base portion 172 to define an angle φ2 that is less than the acute angle φ of the distal face 102 of the lateral web portion 94. In assembly, the external seal hold down 170 can be mounted by attaching the base portion 172 to the door assembly 32. The external seal hold down 170 is positioned so that the stop portion 174 engages the. lateral web portion 94 of the seal member 46 and imposes venting structure 151 in the form of a local depression 176 of the seal member 46 when the housing assembly 34 is disengaged from the door assembly 32. That is, the local depression 176 is caused by the stop portion 174 imposing a force against the resiliency of the lateral web portion 94 of the seal member 46. By this arrangement, the lip 106 of the seal member 46 within the local depression 176 is locally depressed at a deflection 178 below the lip 106 immediately adjacent the local depression 176 when the housing assembly 34 and the door assembly 32 are disengaged. This effect is illustrated in FIG. 13B, with the seal member 46 within the local depression 176 being depicted in cross- section, and the seal member 46 adjacent the local depression 176 being depicted in phantom.

In operation, the external seal hold down 170 enables the seal line 128 to be continuous in the fully engaged configuration 118 while providing a way for cracking the seal line 128. Consider the embodiment depicted in FIGS. 13B and 13C. In this embodiment, the angle φ2 is chosen so that the local deflection 178 is less than the deflection 122 (FIG. 5) due to engagement of the seal member 46 with the housing assembly 34. In this way, the lip 106 fully engages the flange portion 72 of the cover portion 34 (even the portion of the lip 106 that is within the local depression 176, as depicted in FIG. 13C) to enable a continuous hermetic seal.

Upon removal of the housing assembly 34, the sequence of FIGS. 13B and 13C are reversed. That is, the lateral web portion 94 and the lip portion 106 will initially be drawn upward as the housing assembly.34 is lifted away from the. door assembly 32 (i.e., from the cross-section position to the phantom position of FIG. 13C). The lifting of the housing assembly 34 effectively expands the volume of the chamber 121, causing a slight suction between the housing assembly 34 and the door assembly 32. However, as the housing assembly 34 is lifted further, the vertical progression of the lateral web portion 94 within the local depression 176 is arrested by engagement with the stop portion 174 of the external seal hold down 170, which also further limits the vertical progression of the lip portion 106 in the vicinity of the external seal hold down 170, thereby re-establishing the local depression 176. The arrested vertical progression of the lip portion 106 causes the seal member 46 to break from the flange portion 72 of the cover portion 34, thereby cracking the seal line 128.

The external seal hold down 170 is depicted and described as being utilized with the seal member 46, which provides the advantage of a continuous seal line 128 that can be readily broken upon removal of the housing assembly 34 from the door assembly 32. However, it is noted that the hold down 170 can be utilized with the other seal members disclosed herein (e.g., seal members 46a through 46d). An advantage of using the hold down 170 with the various vented arrangement of seal members 46a - 46d is that the various venting apertures can be undersized, with assist from the hold down 170 to complete the break. The undersized venting apertures can mitigate particle entry via the vent apertures.

Referring to FIGS. 14A and 14B, a hold down arrangement 180 utilizing seal member 46e with an integral or unitary seal hold down 182 is depicted in assembly and operation in an embodiment of the disclosure. The seal member 46e includes many of the same components and attributes as seal member 46, which are identified with same- numbered numerical references. The unitary seal hold down 182 depends from the web portion 94 and includes a stem portion 184 that extends in the proximal direction 93a to a proximal end 183. (Alternatively or in addition, the unitary seal hold down 182 can depend from lip portion 106 of the seal member 46e.)

In one embodiment, a detent 186 is disposed at the proximal end 183, the detent

186 being characterized as having a larger outer diameter than the stem portion 184. The detent 186 can be disposed in a recess 188, the recess 188 being formed in the door assembly 32 including an access port 185 that enables access to the recess 188 from the distal side of the door assembly 32. The access port can be of an inner diameter that is smaller than the detent 186, but large enough for the detent 186 to be compressed or squeezed through the access port 185 during installation. By this configuration, a shoulder

187 is defined at the confluence of the access port 185 and the recess 188. The detent 186 can have a lead-in structure 188 to augment insertion of the detent through the access port 185.

In assembly, the axial flange portion 82 of the seal member 46e is disposed within the groove 48 of the door assembly 32 to form a seal between the seal member 46e and the door assembly 32, and such that the seal member 46e in an orientation where the unitary seal hold down 182 is in substantial alignment with the access port 185 of the recess 188. The detent 186 at the proximal end 183 of the stem portion 184 is pushed through the access port 185 and into the recess 188. In one embodiment, the detent 186 is of a compliant material, enabling the detent 186 to be constricted or squeezed during passage through the access port 185. Upon entry into the recess 188, the detent 186 substantially resumes its normal shape.

The unitary seal hold down 182 can be dimensioned so that, when the housing assembly 34 is disengaged from the door assembly 32, the resilience of the seal member 46e draws the unitary seal hold down 182 upward so that the detent 186 registers against the shoulder 187 of the recess 188. In some embodiments, the unitary seal hold down 182 is dimensioned so that the engagement of the detent 186 with the shoulder 187 locally inhibits the lip portion 106 of the seal member 46e from resuming a free form or undeflected shape (shown in phantom in FIG. 14A), thereby imposing a venting structure 151 in form of a local depression 176e akin to the local depression 176 created by the external unitary seal hold down 170.

In the fully engaged configuration 118, the housing assembly 34 (e.g., the flange portion 72 of the cover portion 62) engages with the lip portion 106 of the seal member 46e to establish the seal line 128. The engagement exerts a force on the lip portion 106 of the seal member 46e in the proximal (downward) direction 93a. The unitary seal hold down 182 retracts into the recess 188, disengaging from the shoulder 187 and enabling the peripheral edge 108 in the vicinity of the unitary seal hold down 182 to deflect in the proximal direction 93a to the same deflection profile as the portions of the seal member 46e that are not influenced by the unitary seal hold down 182 (FIG.14B). In this way, the depression 176e is obviated when th£ substrate carrier 30 is in the fully engaged configuration 1 18, thereby enabling the seal line 128 to be continuous and further enabling a hermetic seal.

Upon disengagement of the housing assembly 34 from the door assembly 32, the sequence of FIGS. 14A and 14B are reversed. That is, the lateral web portion 94 and the lip portion 106 will initially be drawn upward as the housing assembly 34 is lifted away from the door assembly 32. The lifting of the housing assembly 34 effectively expands the volume of the chamber 121, causing a slight suction between the housing assembly 34 and the door assembly 32. However, as the housing assembly 34 is lifted further, the vertical progression of the lateral web portion 94 within the local depression 176e is arrested by engagement of the unitary seal hold down 182 with the recess 188, further limiting the vertical progression of the lip portion 106 in the vicinity of the unitary seal hold down 182, thereby re-establishing the local depression 176e. The arrested vertical progression of the lip portion 106 causes the seal member 46e to break from the flange portion 72 of the cover portion 34, thereby cracking the seal line 128.

Referring to FIGS. 15A through 15C, a seal breaking mechanism 190 is depicted in an embodiment of the disclosure. The seal breaking mechanism includes a rocker 192 pivotally attached with a pin 194 to the stop portion 66 of the housing assembly 34. The rocker 192 includes a base portion 196 and a claw portion 198, the claw portion 198 being proximate the lip portion 106 of the seal member 46. In one embodiment, a biasing element 197 such as a spring (depicted) is mounted to the stop portion 66 and arranged to exerts a biasing force Fb on the rocker 192, biasing the claw portion 198 toward the lip portion 106 of the seal member 46. It is noted that the stop portion 66, seal breaking mechanism 190, and flange portion 72 are all part of the housing assembly 34, and thus lift away from the door assembly 32 as a single unit.

It is noted that, for embodiments where there is no stop portion in proximity of the seal member 46, a separate post in place of the stop portion 66 that depends from the housing assembly 34 can be utilized for mounting of the rocker 192.

When the housing assembly 34 is fully engaged with the door assembly 32, the base portion 196 of the rocker 192 is engaged with the shoulder portion 42 of the door assembly 32 (FIG. 15 A). This engagement opposes the biasing force Fb exerted on the rocker 192, keeping the claw portion 198 in a retracted position, away from the lip portion 106 of the seal member 46.

As the housing assembly 34 is lifted away from the door assembly 32, the base portion 196 of the rocker is disengaged from the shoulder portion 42 of the door assembly 32 (FIG. 15B). The biasing force Fb exerted by the biasing element 197 causes the rocker 192 to rotate about the pin 194 so that the claw portion 198 engages the lip portion 106 of the seal member 46. The rotational movement of the claw portion 198 about the pin 194 exerts a downward force on the lip portion 106, away from the flange portion 72 of the housing assembly 34. The downward force causes a local separation 199 between the lip portion 106 and the flange portion 72. Vent gas then courses through the separation 94, breaking the seal. As the housing assembly 34 continues to be lifted away, the claw portion 198 disengages from the lip portion 106 of the seal member 46, and the seal member 46 assumes a default, unloaded configuration (FIG. 15C). In one embodiment, the bias force Fb continues to be exerted against the rocker 192, which can cause the base portion 196 of the rocker 1 2 to rotate away from the seal member 46, providing clearance between the base portion 196 and the lip portion 106 of the seal member 46.

When the housing assembly 34 is brought into engagement with the door assembly 32, the progression is as depicted in FIGS. 15A through 15C, but in reverse order. The base portion 196 of the rocker 192, if properly aligned, can move past the lip portion 106 of the seal member 46 (FIG. 15C). As the housing assembly 34 is brought closer to the door assembly 32, the claw portion 198 of the rocker 192 may engage the lip portion 106 of the seal member 46, drawing the lip portion 106 downward locally (FIG. 15B). As the housing assembly 34 is brought into assembly with the door assembly 32, the base portion 196 of the rocker 192 engages with the shoulder portion 42 of the door assembly, causing the claw portion 198 to retract and release the lip portion 106 of the seal member 46. The release enables the seal member 46 to form a continuous seal against the flange portion 72.

Referring to FIGS. 16A and 16B, an inverted seal arrangement 200 is depicted in an embodiment of the disclosure. The inverted seal arrangement 200 includes many of the same components and attributes as embodiments presented above, which are indicated by same-numbered numerical references. In the depicted inverted seal arrangement 200, a proximal portion 202 of the continuous side portion 70 of the cover 62 serves as the stop portion 66, and contacts the distal face 40 of the door assembly 32. In the depicted embodiment, a flange portion 204 extends radially outward from the continuous side portion 70 and over the web portion 94 and lip portion 106 of the seal member 46. The flange portion 204 can also include an outer skirt portion 206 that extends proximally. An annular slot 208 is defined in the housing assembly 34, for example, in the flange portion 204 as depicted.

In assembly, the seal member 46 is inserted into and sealingly engaged with the annular slot 208 in an inverted orientation relative to the other embodiments depicted herein. The outer peripheral edge 108 of the seal member 46 engages the distal face 40 of the door assembly 32 to establish the seal line 128. Functionally, the flange portion 204 acts as a shield that protects the seal member 46 from external elements when the door assembly 32 and the housing assembly 34 are fully engaged. In the depicted inverted seal arrangement 200, the seal member 46 functions substantially the same as in the embodiment of FIGS. 4 through 6 herein, only with the seal line 128 being formed (and relieved) between the distal face 40 of the door assembly 32 and the seal member 46.

Furthermore, the other seal members (i.e., seal members 46a through 46e) can be implemented in the inverted seal arrangement 200 with substantially the same effect. That is, the various venting structures 151 depicted herein can interact with the distal face 40 of the door assembly 32 in the same manner that they interact with the flange portion 72 of other embodiments disclosed herein. For example, the double contact arrangement 150 can be accommodated with the inverted seal arrangement 200 by utilizing the seal 46a with the enlarged lip portion 106b of FIGS. 9A and 9B and/or sizing the stop portion 66 so that the seal 46 or 46a engages a proximal face 212 of the flange portion 204 to form the second seal line. The blocking arrangement 156 of FIGS. 10A and 10B can also be effected by utilizing seal member 46a in the inverted seal arrangement 200, with the distal face 40 of the door assembly 32 covering the through-passage 152 when in the fully engaged configuration 118. Seal members 46c and 46d can also be implemented in the inverted seal arrangement 200 with the same effect as discussed attendant to FIGS. 11 and 12. The depression 176 of FIGS. 13A and 13B can be implemented by mounting an external seal hold down to the proximal portion 202 of the cover 62 that imposes the depression 176. The unitary seal hold down 182 of FIGS. 14A and 14B can be implemented by formation of a recess and/or access port in the flange portion 204. The seal breaking mechanism 190 can also be implemented by mounting the mechanism 190 to the skirt portion 206 in an inverted orientation.

Accordingly, the various embodiments disclosed herein are not limited to a seal member that is mounted to the door assembly 32. Instead, the various seal members can be mounted to the housing assembly 34 as well with equal effect.

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

Various modifications to the embodiments 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 can be suitably combined, un-combined, and re-combined with other features, alone, or in different combinations. Likewise, the various features described above should all be regarded as example embodiments, rather than limitations to the scope or spirit of the disclosure.

Persons of ordinary skill in the relevant arts will recognize that various embodiments can 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 may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the claims can 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)", "disclosure", "present disclosure", "embodiment(s) of the disclosure", "disclosed embodiment(s)", and the like 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. 112(f) 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 substrate carrier, comprising:

a housing assembly including a cover portion having a top portion and a continuous side portion that depends from said top portion, said continuous side portion defining a proximal plane of said cover portion; a door assembly that cooperates with said housing assembly to define a chamber for housing a substrate when in a fully engaged configuration, said door assembly being concentric about a central axis and defining a distal face; and

a seal member disposed between said housing assembly and said door assembly, said seal member defining a seal line between said housing assembly and said door assembly when said housing assembly and said door assembly are in said fully engaged configuration, said seal member defines a venting structure for passage of gas therethrough when said housing assembly and said door assembly are disengaged from said fully engaged configuration.

2. The substrate carrier of claim 1, wherein said housing assembly restricts flow through said venting structure of said seal when said housing assembly and said door assembly are in said fully engaged configuration.

3. The substrate carrier of claim 1, wherein said housing assembly blocks flow, through said venting structure of said seal when said housing assembly and said door assembly are in said fully engaged configuration.

4. The substrate carrier of claim 1, wherein said seal member is sealingly mounted to said door assembly and extends in a distal direction from said distal face.

5. The substrate carrier of claim 4, said housing assembly including a flange portion extending radially from said continuous side portion and having a proximal face that defines said proximal plane of said cover portion.

6. The substrate carrier of claim 5, wherein said flange portion of said cover portion extends radially outward from said continuous side portion.

7. The substrate carrier of claim 5, said seal member including a lateral web portion that extends radially outward to a peripheral edge of said seal member.

8. The substrate carrier of claim 7, wherein said peripheral edge of said seal member is in contact with said housing assembly and said door assembly when said housing assembly and said door assembly are in said fully engaged configuration.

9. The substrate carrier of claim 8, wherein said flange portion of said housing assembly restricts flow through said venting structure of said seal when said housing assembly and said door assembly are in said fully engaged configuration.

10. The substrate carrier of claim 8, wherein said venting structure comprises one of a through-passage and a slit formed on said lateral web portion.

11. The substrate carrier of claim 10, wherein said flange portion of said housing assembly blocks flow through said venting structure of said when said housing assembly and said door assembly are in said fully engaged configuration.

12. The substrate carrier of claim 11, wherein said flange portion of said housing assembly blocks flow through said venting structure of said seal when said housing assembly and said door assembly are in said fully engaged configuration, and enables flow through said venting structure of said seal when said housing assembly and said door assembly are disengaged from said fully engaged configuration.

13. The substrate carrier of any one of claims 6 - 12, said seal member including a lip portion that defines said peripheral edge of said seal member, said lip portion having an axial thickness greater than an axial thickness of said lateral web portion.

14. The substrate carrier of claim 4, wherein said seal member defines a distal plane and said venting structure defines a local depression of said peripheral edge relative to said distal plane.

15. The substrate carrier of claim 14, wherein said local depression is defined when said housing assembly and said door assembly are disengaged and is removed when said housing assembly and said door assembly are in said fully engaged configuration.

16. The substrate carrier of claim 14, wherein said local depression is defined by a hold down.

17. The substrate carrier of claim 16, wherein said hold down is an external seal hold down mounted to said door assembly.

18. The substrate carrier of claim 16, wherein said hold down is a unitary seal hold down that is unitary with said seal member.

19. The substrate carrier of claim 18, wherein said unitary seal hold down includes a stem portion extending proximally from said seal portion and a detent portion at a proximal end of said stem portion, said unitary seal hold down being operatively coupled with a recess in said door assembly.

20. A low energy door seal for a wafer carrier, comprising:

an axial flange portion that includes a proximal portion and a distal portion and defining an inner surface and an outer surface, said proximal portion defining a proximal edge that bridges said inner surface and said outer surface, said inner surface being substantially parallel to a central axis; a lateral web portion that includes an inner portion and an outer portion and defining a proximal face and a distal face, said inner portion extending from said distal portion of said axial flange portion and radially outward from said central axis; and

a lip portion that extends from said outer portion of said lateral web portion, said lip portion defining a peripheral edge and including a thickness that is greater than a thickness of said lateral web portion.

21. The low energy door seal of claim 20, wherein said axial flange portion, said lateral web portion, and said lip portion are continuous in a tangential direction about said central axis.

22. The low energy door seal of claim 20, wherein:

said lip portion is characterized as having a tangential length; and

said lip portion deflects from 1 mm to 2 mm inclusive in a direction parallel to said central axis when a force of 1 1 grams per lineal centimeter of said tangential length is applied in said direction parallel to said central axis.

23. The low energy door seal of claim 20, wherein said distal face of said lateral web portion defines an acute angle relative to said inner surface of said axial flange portion.

24. The low energy door seal of claim 23, wherein said distal face of said lateral web portion defines a plane relative to said acute angle.

25. The low energy seal of claim 24, wherein said lip portion does not extend distal to said plane.

26. The low energy door seal of claim 23, wherein said acute angle is greater than or equal to 60 degrees and less than or equal to 85 degrees.

27. The low energy door seal of claim 20, wherein said lateral web portion is of substantially uniform thickness.

28. The low energy door seal of claim 27, wherein said uniform thickness is greater than or equal to 0.4 mm and less than or equal to 0.6 mm.

29. The low energy door seal of claim 20 wherein said distal face of said lateral web portion includes an overall radial dimension defined orthogonal to said central axis, said overall radial dimension being greater than or equal to 5 mm and less than or equal to 10 mm.

30. The low energy door seal of claim 20, comprising a venting structure formed in the lateral web portion.

31. The low energy door seal of claim 30, wherein said venting structure includes at least one of a through aperture, a slit, and a depression.

32. The low energy door seal of claim 30, comprising a unitary seal hold down that depends from one of said lateral web portion and said lip portion.

33. The low energy door seal of claim 32, wherein said unitary seal hold down includes a stem portion and a detent portion at a distal end of said stem portion, said detent portion for engagement of a recess formed on a door of a wafer carrier.

34. The low energy door seal of claim 20, wherein:

a crown of said lip portion lies substantially on a distal plane when the low energy door seal is not under load; and

said lip portion includes a venting structure defining a depression relative to said distal plane of said crown.

35. The low energy seal of claim 34, wherein said structure defining said depression is one of a crease and a notch.

36. The low energy door seal of any one of claims 20 - 35, wherein said low energy door seal comprises ethylenepropylenediene monomer.

37. A substrate carrier, comprising:

a housing assembly including a cover portion including a continuous side portion that depends from a top portion, the continuous side portion including a perimeter that defines an opening, said housing assembly having a weight; and

a door assembly that cooperates with said housing assembly to define a chamber for housing a substrate, said door assembly being concentric about a central axis and including a panel portion, a shoulder portion, and a seal member, said shoulder portion surrounding said panel portion, said seal member being disposed between said panel portion and said shoulder portion, said seal member including a lateral web portion that extends in a radial outward direction from said central axis, said lateral web portion including a distaj face and a peripheral edge that contacts said perimeter of said housing assembly,

wherein said weight of said housing assembly exerts a sealing force having an axial sealing force component on said seal member with said perimeter of said housing assembly in said axial direction to provide a seal line between said seal member and said perimeter of said housing assembly when a chamber pressure within said chamber is less than or equal to an ambient pressure, said axial sealing force component being parallel to said central axis and being less than said weight of said housing assembly.

38. The substrate carrier of claim 37, wherein said housing assembly includes a plurality of contact members that extend into said chamber for engagement of a substrate and for exertion of a substrate retention force on said substrate, said substrate retention force having an axial retention force component that is parallel to said central axis and being transferred to said door assembly, wherein a sum of said axial retention force component and said axial sealing force component is less than said weight of said housing assembly.

39. The substrate carrier of claim 37 or claim 38, wherein, when said chamber pressure exceeds said ambient pressure, a local separation from said perimeter of said housing assembly.

40. The substrate carrier of claim 39, wherein said chamber pressure is greater than 0.5 Torr and less than 6 Torr to cause an onset of said separation.

41. The substrate carrier of claim 40, wherein said chamber pressure is about 2 Torr to cause said onset of said separation.

42. The substrate carrier of claim 37 or claim 38, wherein said panel portion of said door assembly defines a plane, and said shoulder defines an incline relative to said plane, said incline sloping away from said lateral web portion of said seal member in said radial outward direction.

43. The substrate carrier of claim 37 or claim 38, wherein said housing assembly includes a stop that engages said door assembly to limit axial deflection of said peripheral edge of said lateral web portion of said seal member.

44. The substrate carrier of claim 37, wherein said panel portion is substantially planar.

45. The substrate carrier of claim 37, wherein said panel portion and said shoulder portion are integrally formed.

46. The substrate carrier of claim 37, wherein said seal member includes a venting structure.

47. The substrate carrier of claim 46, wherein said venting structure is formed in the lateral web portion of said seal member.

48. The substrate carrier of claim 37, further comprising:

a hold down that depends from and is unitary with one of said lateral web portion and said lip portion; and

structure defining a receptacle in said door assembly that receives said hold down to hold a portion of said seal member below a distal plane of said seal member when said seal member is not in contact with said housing assembly, thereby defining a local depression in said seal member.

49. The substrate carrier of claim 37, further comprising an external seal hold down coupled to said door assembly, said external seal hold down being engaged with said seal member to define a local depression of said seal member.

50. The substrate carrier of any one of claims 1-19 and 37-49, wherein said substrate carrier is a reticle pod.

51. The substrate carrier of claim 50, in combination with a reticle.

52. The substrate carrier of claim 51, wherein said reticle is a 150 mm reticle.