Insert for spacing in photomask container
By using spacers in the photocoat container, the contact surfaces are separated, and the wear and damage caused by impact and vibration during transportation is solved, thereby achieving higher transportation safety and performance stability.
Patent Information
- Application Number
- CN202380053935.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-06-28
- Filing Date
- 2023-06-20
- Publication Date
- 2025-02-28
AI Technical Summary
The photocoat container is susceptible to impact and vibration during transportation, causing wear, damage or particles to occur on the contact surface, affecting its cleanliness and performance.
A spacer is provided, located within the interior space of the photocoat container, for spaced the contact surfaces apart during transportation, reducing the impact of shock and vibration on the container. The spacer engages through the base with a depression in the cover or base plate of the photocoat box and spaces the cover from the base plate by a contact surface.
Through the use of spacers, the risk of wear and damage of the photocoat container during transportation is reduced, and the possibility of particle generation is reduced, thereby improving the transportation safety and performance stability of the container.
Smart Images
Figure CN119547013A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to inserts for spacing parts of a reticle container apart from one another. Background Art
[0002] A reticle container may include hard contact surfaces. When a reticle container is shipped, it is typically shipped in its fully assembled state. During shipping, the contact surfaces may be subject to shock and / or vibration beyond normal handling and operation of the reticle box, resulting in wear, damage, and particle generation that may affect the cleanliness or other performance of the reticle box. Summary of the invention
[0003] The present disclosure relates to inserts for spacing parts of a reticle container apart from one another.
[0004] By providing a spacer located within the interior space of a reticle container, such as an inner box of a reticle box, a gap can be maintained between contacting surfaces when the reticle box is shipped in an assembled state. The presence of this gap can reduce or eliminate wear or damage caused by shock or vibration experienced during transportation of the reticle container. The gap can be sized so that the reticle container can still be fully assembled, such as by containing the inner box within the outer box of the complete reticle container during this transportation process. This reduces the risk of damage or particle generation when the reticle container is shipped, even when shipped as a complete container.
[0005] In an embodiment, an article includes a spacer for a reticle box. The spacer includes: a base of the spacer configured to engage with a recess formed in one of a lid or a bottom plate of the reticle box; and a contact surface of the spacer configured to contact the other of the lid or the bottom plate. The contact surface is configured to space the lid from the bottom plate so that sealing surfaces included in the lid and the bottom plate are spaced from each other by a gap.
[0006] In an embodiment, the width of the gap is in the range from 20 μm to 1 mm.
[0007] In an embodiment, the spacer comprises a thermoplastic such as polycarbonate (PC), polyetheretherketone (PEEK), perfluoroalkoxy (PFA), and high density polyethylene (HDPE).
[0008] In an embodiment, the recess is a push-pawl pocket formed in the first inner box section.
[0009] In embodiments, the spacer further comprises a disposal feature extending from the body.
[0010] In an embodiment, a reticle box includes: an inner box including a bottom plate and a cover; and one or more spacers. Each spacer includes: a base configured to engage with a recess formed in one of the bottom plate or the cover; and a contact surface configured to contact the other of the bottom plate or the cover. The contact surface is configured to space the bottom plate from the cover so that a bottom plate sealing surface included in the bottom plate and a cover sealing surface included in the cover are spaced from each other by a gap.
[0011] In an embodiment, the width of the gap is in the range from 20 μm to 1 mm.
[0012] In an embodiment, the reticle pod further includes an outer pod configured to accommodate the inner pod and one or more spacers.
[0013] In an embodiment, the recess is a push-pawl pocket formed in the base plate, and the contact surface is configured to contact the cover.
[0014] In embodiments, the spacer further comprises a disposal feature extending from the body.
[0015] In an embodiment, the one or more spacers include a plurality of the spacers. In an embodiment, at least two of the plurality of the spacers are engaged with each other by at least one handling feature.
[0016] In an embodiment, the spacer contacts the cover only outside the cover sealing surface and contacts the base plate only outside the base plate sealing surface.
[0017] A method of preparing a reticle box for shipping includes placing one or more spacers into a recess formed in one of a lid or a bottom plate of a reticle box, and assembling the lid and the bottom plate to form an inner box of the reticle box. The spacers contact the lid and the bottom plate. The lid and the bottom plate are separated by a gap.
[0018] In an embodiment, the width of the gap is in the range from 20 μm to 1 mm.
[0019] In an embodiment, the recess is a push-pawl pocket formed in the base plate, and the contact surface is configured to contact the cover.
[0020] In an embodiment, the cover includes one or more cover sealing surfaces, the base plate includes one or more base plate sealing surfaces, and the spacer contacts the cover only outside the cover sealing surfaces and contacts the base plate only outside the base plate sealing surfaces.
[0021] In an embodiment, the method further includes placing the inner box into an outer box, the outer box including a box dome and a box door, and engaging the box dome to the box door to enclose the inner box of the reticle box within the outer box. In an embodiment, the method further includes transporting the reticle box from a packaging location to a destination location while the box dome is engaged to the box door. In an embodiment, the method further includes removing the spacer from the reticle box at the destination location. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 A reticle container according to an embodiment is shown.
[0023] Figure 2 An internal box of a photomask according to an embodiment is shown.
[0024] Figure 3 A perspective view showing a spacer according to an embodiment.
[0025] Figure 4 A spacer according to an embodiment is shown. DETAILED DESCRIPTION
[0026] The present disclosure relates to inserts for spacing parts of a reticle container apart from one another.
[0027] Figure 1 A reticle container according to an embodiment is shown. The reticle container 100 includes an outer box 102 including a box dome 104 and a box door 106. The reticle container 100 further includes an inner box 108 including a lid 110 and a bottom plate 112. One or more spacers 114 can be placed within the inner box 108.
[0028] The outer box 102 forms the exterior of the reticle container 100. The outer box 102 is configured to accommodate the inner box 108. When the reticle container 100 is transported to a destination, the reticle container may be assembled with the inner box 108 accommodated in the outer box 102. The outer box 102 may be composed of a box dome 104 and a box door 106.
[0029] The inner box 108 is an inner box of the reticle container 100 that is configured to accommodate a reticle. The inner box includes a cover 110 and a bottom plate 112. The cover 110 and the bottom plate 112 may be configured to contact each other during typical use, for example, at corresponding sealing surfaces provided on each of the cover 110 and the bottom plate 112. The cover 110 and the bottom plate 112 may be made of a metal material, and further may have a metal plating, for example, at least at some sealing surfaces. The cover 110 and the bottom plate 112 may be spaced apart from each other at other times, for example, during storage or transportation, for example, using one or more spacers 114.
[0030] A spacer 114 may be included in the reticle container 100 to space the cover 110 and the bottom plate 112 apart from each other when the inner box 108 is assembled. The spacer 114 may include one or more spacing contacts configured to engage with a recess formed in one of the cover 110 or the bottom plate 112 and contact the other of the cover 110 or the bottom plate 112 to space the cover 110 and the bottom plate 112 apart from each other. The recess may be any suitable recess or depression formed in the cover 110 or the bottom plate 112. In an embodiment, the recess may be included specifically for accommodating the spacer 114. In an embodiment, the recess may be an existing feature of the cover 110 or the bottom plate 112, such as a push-pawl pocket, a push-pawl restricted area, a protective film recess, or any other such feature of the cover 110 or the bottom plate 112. The fit between the spacer 114 and the recess allows the spacer 114 to be easily placed into or removed from the recess. In an embodiment, the spacer 114 is not attached to the recess or becomes fixed to the recess. The spacer 114 can rest in the recess so that the spacer 114. The spacer 114 can be configured to be removed from the recess by manual or automatic handling of the spacer 114. The spacer 114 can contact the cover 110 and the bottom plate 112 so that the corresponding sealing surfaces remain separated by the gap. The gap is such that when the spacer 114 is installed in the inner box 108, the cover 110 and the bottom plate 112 do not contact each other. In an embodiment, when the cover 110 and the bottom plate 112 are assembled in place with the spacer 114 and placed in the outer box 102, the gap can be maintained. When the inner box 108 is placed in the outer box 102 and the outer box 102 is closed, the size of the gap can be between 20 microns (μm) and 1 millimeter (mm). In an embodiment, the spacer 114 may include one or more spring members configured to increase the size of the gap when the inner box 108 is not received in the outer box 102 relative to the size of the gap maintained when the inner box 108 is received in the outer box 102 .
[0031] Figure 2 An inner box of a reticle according to an embodiment is shown. The inner box 200 includes a lid 202 having a lid sealing surface 204 and a bottom plate 206 having a recess 208 and a bottom plate sealing surface 210. The spacer 212 includes a base 214 and a contact surface 216.
[0032] The cover 202 is a cover of the inner box 200. The cover 202 is configured to define an inner space capable of accommodating a photomask when coupled with the bottom plate 206. The inner box 200 can be used in a photomask box, for example Figure 1 In one embodiment, the inner box 200 may be contained within an outer box, such as Figure 12 and described above. The lid 202 includes a lid sealing surface 204. The lid sealing surface 204 is a portion of the lid 202 that is configured to contact a corresponding position of the bottom plate sealing surface 210 during normal use of the inner box 200 to accommodate a photomask. The lid sealing surface 204 can be positioned to correspond to the bottom plate contact surface 210.
[0033] Bottom plate 206 is the bottom plate of reticle box 200. Bottom plate 206 is configured to define an interior space capable of accommodating a reticle when engaged with lid 202. Bottom plate 206 includes one or more recesses 208. Recesses 208 are recesses in bottom plate 206. Recesses 208 may have any suitable shape and depth. Recesses 208 may be features included according to reticle box standards, such as a claw pocket configured to allow automatic access to the bottom side of a reticle stored in internal box 200. Bottom plate sealing surface 210 is configured to contact lid sealing surface 204 when reticle box 200 is in normal use, such as to accommodate a reticle. Bottom plate sealing surface is configured to correspond to lid sealing surface 204.
[0034] A spacer 212 may be included in the inner box 200 to space the lid 202 from the bottom plate 206. The spacer 212 may be an item including a base 214 located on one side and a contact surface 216 disposed on a side opposite to the base 214. The base 214 is configured to be received in one of the recesses 208 included in the bottom plate 206. The base may be shaped and sized to fit securely within its corresponding recess 208, such as with very little or no gap within the space. The contact surface 216 is on the side of the spacer 212 opposite to the base 214. The distance from the base 214 to the contact surface 216 is such that when the base is installed into the recess 208 and the contact surface 216 contacts the lid, a gap having a certain width is formed between the lid sealing surface 204 and the bottom plate sealing surface 210. The gap can be maintained even when the inner box 200 is placed into an outer box, such as the outer box 102, and the outer box is closed. The spacer 214 may be any suitable material selected based on the likelihood of generating particles when used with the materials of the cover 202 and the base plate 206. Non-limiting examples of suitable materials include polyolefins. In an embodiment, the spacer 214 may include or be made entirely of high-density polyethylene. In an embodiment, the spacer 214 may include or be made entirely of polycarbonate. In an embodiment, the spacer 214 may include or be made entirely of polyetheretherketone. In an embodiment, the spacer 214 may include or be made entirely of perfluoroalkoxy. In an embodiment, the spacer 214 may be made of a compressible material so that when the cover 202 and the base plate 206 are passed through an outer box containing the inner box 200 (e.g., the outer box 102, described above and as shown in the figure), the spacer 214 may be made of a compressible material. Figure 1In this embodiment, when the inner box 200 is not compressed, such as when the lid 202 rests on the spacer 214 by gravity and the inner box 200 is not compressed by contacting the outer box, the spacer can provide a gap having a second width greater than the first width.
[0035] When the lid 202 needs to be spaced apart from the bottom plate 206, such as when the inner box 200 is transported or stored, the spacers 214 can be included in the inner box 200. In an embodiment, when the lid 202 needs to be spaced apart from the bottom plate 206, at least three spacers 214 are included in the inner box 200.
[0036] Although Figure 2 The recess 208 is shown formed in the base plate 206 and the contact surface 216 contacts the cover 202 , but in embodiments these may be reversed, with the recess 208 instead formed in the cover 202 and the base 214 inserted into this recess 208 and the contact surface 216 contacting the base plate 204 .
[0037] Figure 3A perspective view of a spacer according to an embodiment is shown. The spacer 300 includes a body 302 including a base 304 on one side and a contact surface 306 on a side opposite to the base 304. The body 302 is configured to be inserted into a recess in one of the cover or the bottom plate of the reticle box and contact the other of the cover or the bottom plate so that the cover and the bottom plate are separated from each other by a gap. The body 302 may include any suitable material, such as a polyolefin. Non-limiting examples of the material of the body 302 include high-density polyethylene or polycarbonate. In an embodiment, the body 302 may include an elastic material that is capable of being compressed. The elastic material may be selected so that when the spacer 300 separates the cover and the bottom plate without applying any additional force, a first gap size is maintained, and when the cover and the bottom plate are pressed together by an external box containing the cover and the bottom plate, a second gap size is maintained. The second gap may be smaller than the first gap. In an embodiment, instead of an elastic material, the contact surface 306 can be connected to the body 302 by a deflectable member such as a spring arm 308 to provide the first and second gap sizes. The body 302 includes a base 304, which is configured to be received in a recess formed in the cover or the bottom plate. For example, the base 304 can be accommodated in a push claw pocket formed in the bottom plate of the internal box in which the spacer 300 is installed. The body 302 also includes a contact surface 306 opposite to the base 304. The contact surface is configured to contact the other of the cover or the bottom plate so that the spacer 300 contacts the cover and the bottom plate of the internal box in which the spacer 300 is installed. The distance from the base 304 to the contact surface 306 is selected so that when the base 304 contacts one of the cover or the bottom plate and the contact surface 306 contacts the other of the cover or the bottom plate, the cover and the bottom plate are spaced apart from each other. The cover and the bottom plate are spaced apart by contacting the spacer 300 so that there is a gap between the sealing surfaces of the cover and the bottom plate. In an embodiment, the width of the gap is in the range from 20 μm to 1 mm. The body 302 of the spacer 300 may include handling features 310 configured to allow manipulation of the spacer 300. Figure 3 , the handling feature 310 is a protrusion extending vertically above the contact surface 306. In an embodiment, the handling feature may alternatively include a horizontal protrusion, a flange, and the like. In an embodiment, the handling feature 310 is configured to be engaged by a user, such as a handle for grasping. In an embodiment, the handling feature is configured to be manipulated by automation, such as providing a flange, a tab, a groove, a recess, an opening, and the like, which is configured to interface with an automated handling device, such as a robotic arm.
[0038] Figure 4 A spacer according to an embodiment is shown. The spacer 400 includes a plurality of spacer bodies 402, each spacer body 402 including a base 404 and a contact surface 406. A handling feature 408 connects at least two of the plurality of spacer bodies.
[0039] The spacer 400 includes a plurality of spacer bodies 402. The spacer body 402 is a body configured to be inserted into a recess in one of the cover or the bottom plate of the reticle box and to contact the other of the cover or the bottom plate so that the cover and the bottom plate are separated from each other by a gap. The spacer body 402 may include any suitable material, such as polyolefin. Non-limiting examples of materials for the spacer body 402 include high-density polyethylene, perfluoroalkoxy, polyetheretherketone, or polycarbonate. In an embodiment, the spacer body 402 may include an elastic material that can be compressed. The elastic material may be selected so that when the spacer 400 separates the cover and the bottom plate without applying any additional force, a first gap size is maintained, and when the cover and the bottom plate are pressed together by an external box containing the cover and the bottom plate, a second gap size is maintained. The second gap may be smaller than the first gap. The spacer body 402 includes a base 404, which is configured to be received in a recess formed in one of the cover or the bottom plate. For example, the base 404 can be received in a push claw pocket formed in the bottom plate of the inner box in which the spacer 400 is installed. The spacer body 402 also includes a contact surface 406 opposite the base 404. The contact surface is configured to contact the other of the cover or the bottom plate so that the spacer 400 contacts the cover and the bottom plate of the inner box in which the spacer 400 is installed. The distance from the base 404 to the contact surface 406 is selected so that when the base 404 contacts one of the cover or the bottom plate and the contact surface 406 contacts the other of the cover or the bottom plate, the cover and the bottom plate are spaced apart from each other. The cover and the bottom plate are spaced apart by contacting the spacer 400 so that there is a gap between the sealing surfaces of the cover and the bottom plate. In an embodiment, the width of the gap is in the range of from 20 μm to 1 mm.
[0040] The handling features 408 can engage two or more spacer bodies 402. The handling features 408 can be configured to facilitate handling of the spacer 400, such as by providing a surface that can be grasped by a user or an automated tool (such as a robotic arm) to place the spacer body 402 or remove the spacer body 402 from a corresponding recess that accommodates the spacer body. Figure 4In the embodiment shown in , the disposal feature 408 is a fin 410 protruding from the disposal feature 408. The disposal feature 408 can extend so that it is completely located in the interior space of the inner box in which the spacer 400 is installed. The disposal feature 408 can be configured to avoid contact with the lid and bottom plate of the inner box when the spacer 400 is installed. In an embodiment, when the spacer 400 is installed, at least a portion of the disposal feature 408 can contact one of the lid or bottom plate of the inner box. In an embodiment, the disposal feature 408 can contact the lid or bottom plate of the inner box so that when the inner box includes the spacer 400 and the inner box is not accommodated in the outer box, a gap is formed between the lid and the bottom plate. The gap provided by the contact of the disposal feature 408 with the lid or bottom plate can be larger than the gap maintained by the spacer body 402 when the inner box is accommodated in a larger box. In an embodiment, the base 404 may be sized to be smaller than the recess 412 of the base plate 410 so that there is room in the recess 412 to allow a user or automated tool to reach under the handling feature 408 to lift the spacer 400 out of the base plate 410 .
[0041] aspect:
[0042] It should be understood that any aspect of aspects 1 to 5 may be combined with any aspect of aspects 6 to 13 or any aspect of aspects 14 to 20. It should be understood that any aspect of aspects 6 to 13 may be combined with any aspect of aspects 14 to 20.
[0043] Aspect 1. An article comprising:
[0044] A spacer for a reticle box, the spacer comprising:
[0045] a base of the spacer configured to engage a recess formed in one of the lid or the bottom plate of the reticle pod; and
[0046] a contact surface of the spacer configured to contact the other of the cover or the base,
[0047] in:
[0048] The contact surface is configured to space the cover from the base plate such that sealing surfaces included in the cover and the base plate are spaced apart from each other by a gap.
[0049] Aspect 2. The article according to aspect 1, wherein the width of the gap is in the range from 20 μm to 1 mm.
[0050] Aspect 3. The article according to any one of aspects 1 to 2, wherein the spacer comprises a thermoplastic such as polycarbonate, polyetheretherketone, perfluoroalkoxy and high-density polyethylene.
[0051] Aspect 4. The article according to any one of aspects 1 to 3, wherein the recess is a push claw pocket formed in the first interior box section.
[0052] Aspect 5. An article according to technical solution 1, wherein the spacer further includes a disposal feature extending from the body.
[0053] Aspect 6. A reticle box comprising:
[0054] an inner box comprising a base and a cover; and
[0055] One or more spacers, each spacer comprising:
[0056] a base configured to engage a recess formed in one of the base or the cover; and
[0057] a contact surface configured to contact the other of the base plate or the cover, wherein
[0058] The contact surface is configured to space the base plate from the cover such that a base plate sealing surface included in the base plate and a cover sealing surface included in the cover are spaced apart from each other by a gap.
[0059] Aspect 7. The reticle pod according to aspect 6, wherein a width of the gap is in a range from 20 μm to 1 mm.
[0060] Aspect 8. The reticle pod according to any one of aspects 6 to 7, further comprising an outer pod configured to accommodate the inner pod and the one or more spacers.
[0061] Aspect 9. The reticle pod according to any one of aspects 6 to 8, wherein the recess is a push claw pocket formed in the bottom plate, and the contact surface is configured to contact the cover.
[0062] Aspect 10. The reticle pod of any of aspects 6 to 9, wherein the spacer further comprises a handling feature extending from the body.
[0063] Aspect 11. The reticle pod of any of aspects 6 to 10, wherein the one or more spacers comprises a plurality of spacers.
[0064] Aspect 12. The reticle pod of aspect 11, wherein at least two of the plurality of spacers are engaged with each other by at least one handling feature.
[0065] Aspect 13. The reticle pod according to any one of aspects 6 to 12, wherein the spacer contacts the lid only outside the lid sealing surface and contacts the base plate only outside the base sealing surface.
[0066] Aspect 14. A method of preparing a reticle box for shipping, comprising:
[0067] placing one or more spacers into a recess formed in one of a lid or a bottom plate of a reticle pod; and
[0068] Assembling the cover and the base plate to form an inner box of the reticle box, wherein the spacer contacts the cover and the base plate;
[0069] The cover and the base are separated by a gap.
[0070] Aspect 15. The method according to aspect 14, wherein the width of the gap is in the range from 20 μm to 1 mm.
[0071] Aspect 16. The method of any one of aspects 14 to 15, wherein the recess is a push-pawl pocket formed in the bottom plate, and the contact surface is configured to contact the cover.
[0072] Aspect 17. A method according to any one of aspects 14 to 16, wherein the cover includes one or more cover sealing surfaces, the base plate includes one or more base plate sealing surfaces, and the spacer contacts the cover only on the outside of the cover sealing surfaces and contacts the base plate only on the outside of the base plate sealing surfaces.
[0073] Aspect 18. The method according to any one of aspects 14 to 17, further comprising placing the inner box into the outer box, the outer box comprising a box dome and a box door; and
[0074] The cassette dome is engaged to the cassette door to enclose the inner cassette of the reticle cassette within the outer cassette.
[0075] Aspect 19. The method of aspect 18, further comprising transporting the reticle pod from the packing location to the destination location while the pod dome is engaged to the pod door.
[0076] Aspect 20. The method of aspect 19, further comprising removing the spacer from the reticle pod at the destination location.
[0077] The examples disclosed in this application are to be considered in all respects as illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes within the meaning and range of equivalency of the claims are intended to be embraced therein.
Claims
1. An article comprising: A spacer for a reticle box, the spacer comprising: a base of the spacer configured to engage a recess formed in one of a cover or a bottom plate of the reticle pod; and a contact surface of the spacer configured to contact the other of the cover or the base plate, wherein: The contact surface is configured to space the cover from the base plate such that sealing surfaces included in the cover and the base plate are spaced from each other by a gap. 2 . The article according to claim 1 , wherein the width of the gap is in the range from 20 μm to 1 mm.
3. The article of claim 1, wherein the spacer comprises a thermoplastic.
4. The article of claim 1, wherein the depression is a push-pawl pocket formed in the first interior box section.
5. The article of claim 1, wherein the spacer further comprises a disposal feature extending from the body.
6. A mask box, comprising: an inner box including a base and a cover; and One or more spacers, each spacer comprising: a base configured to engage a recess formed in one of the base plate or the cover; and a contact surface configured to contact the other of the base plate or the cover, wherein The contact surface is configured to space the base plate from the cover such that the base plate sealing surface included in the base plate and the cover sealing surface included in the cover are spaced apart from each other by a gap. 7 . The reticle pod of claim 6 , wherein a width of the gap is in a range from 20 μm to 1 mm.
8. The reticle pod of claim 6, further comprising an outer pod configured to house the inner pod and the one or more spacers.
9. The reticle pod of claim 6, wherein the recess is a push-pawl pocket formed in the bottom plate, and the contact surface is configured to contact the cover.
10. The reticle pod of claim 6 wherein the spacer further comprises a handling feature extending from the body. The reticle pod of claim 6 , wherein the one or more spacers comprises a plurality of the spacers.
12. The reticle pod of claim 11, wherein at least two of the plurality of spacers are engaged with each other by at least one handling feature.
13. The reticle pod of claim 6, wherein the spacer contacts the cover only outside the cover sealing surface and contacts the base plate only outside the base sealing surface.
14. A method of preparing a reticle box for shipping, comprising: placing one or more spacers into a recess formed in one of a lid or a bottom plate of a reticle pod; and assembling the cover and the base plate to form an inner box of the reticle box, wherein the spacer contacts the cover and the base plate; The cover and the base are separated by a gap.
15. The method of claim 14, wherein the width of the gap is in the range from 20 μm to 1 mm.
16. The method of claim 14, wherein the depression is a push-pawl pocket formed in the base plate, and the contact surface is configured to contact the cover.
17. The method of claim 14, wherein the cover comprises one or more cover sealing surfaces, the base plate comprises one or more base plate sealing surfaces, and the spacer contacts the cover only on the outside of the cover sealing surfaces and contacts the base plate only on the outside of the base plate sealing surfaces.
18. The method of claim 14, further comprising placing the inner box into an outer box, the outer box comprising a box dome and a box door; and The cassette dome is engaged to the cassette door to enclose the inner cassette of the reticle pod within the outer cassette.
19. The method of claim 18, further comprising transporting the reticle pod from a packing location to a destination location while the pod dome is engaged to the pod door.
20. The method of claim 19, further comprising removing the spacer from the reticle pod at the destination location.