Reticle pod provided with reticle support for absorbing downward pressure

Abstract

To provide a reticle pod equipped with a reticle support preventing damage and contamination of reticle by absorbing downward pressure during an EUV lithography process.SOLUTION: A reticle pod includes: a base (50); and at least one reticle support (100) which is disposed on the base and carries a reticle (R). The reticle support includes resilient means. When a downward pressure applied to the reticle support is less than or equal to a critical value, a height of the reticle support is maintained at a predetermined height; when the downward pressure applied to the reticle support is greater than the critical value, the reticle support absorbs the downward pressure by deforming, and then the reticle support restores to the predetermined height only when the downward pressure is shared by another reticle support.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] The present invention relates to reticle pods, and more particularly to reticle pods with downward pressure absorbing reticle supports. [Background technology]

[0002] In the current extreme ultraviolet (EUV) lithography process, first and foremost, the reticle needs to be protected by a dual pod (extreme ultraviolet (EUV) reticle transfer pod). The current dual pod includes an outer pod (EOP) and an inner pod (EIP). The reticle is received in the inner pod, and the inner pod is received in the outer pod.

[0003] When the dual pod is located in the working exposure machine, the outer pod and the inner pod are opened to receive the reticle, and then the reticle is taken out by the mechanical arm. While the mechanical arm returns the reticle, if the reticle is not kept horizontal by the mechanical arm for some reason, that is, if the four corners of the reticle are not located substantially on the same horizontal plane, only one of the corners of the reticle will contact one of the support members of the base initially. At this point, if the mechanical arm does not have an adjustment or buffer mechanism so that the opposing force of the support is excessively concentrated on one corner of the reticle, strong collision and friction may be caused between this corner of the reticle and the corresponding support member, resulting in the generation of particles and even damage and contamination of the reticle. Summary of the Invention [Problem to be solved by the invention]

[0004] In consideration of the above problems, the present invention provides a reticle pod with a support member that absorbs downward pressure, which can absorb excessive load when a reticle is picked up or placed, to prevent collision or friction between the reticle and the corresponding support member, thereby preventing wear or contamination of the reticle or the support member.

[0005] It is an object of the present invention to provide a reticle pod having a base and at least one reticle support provided on the base. The reticle support is for carrying a reticle and has elastic means. When the downward pressure applied to the reticle support is less than or equal to a limit value, the height of the reticle support is maintained at a predetermined height, and when the downward pressure applied to the reticle support is greater than the limit value, the reticle support absorbs the downward pressure by deforming, and then the reticle support restores to the predetermined height only when the downward pressure is shared by another reticle support.

[0006] In a particular embodiment, the elastic means is an elastic material, a spring or a hollow structure, and the limit value is determined according to the elastic means.

[0007] In a particular embodiment, the reticle support has protrusions having a resilient material such that the protrusions can be in a resilient contact relationship with the reticle, the resilient material being rubber or a thermoplastic elastomer (TPE).

[0008] In certain embodiments, the reticle support absorbs the downward pressure through compression and deformation of a resilient material.

[0009] In a particular embodiment, the reticle support has a resilient element disposed on a bottom portion thereof, the reticle support being in resilient coupling relationship with the base by the resilient element.

[0010] In certain embodiments, the resilient element is capable of withstanding a downward pressure greater than a threshold value and correspondingly deforms, sags, and absorbs the downward pressure.

[0011] In a particular embodiment, the resilient element is a spring and the reticle support is coupled to the base by the spring.

[0012] In a particular embodiment, the resilient element is a plurality of resilient washers, and the reticle support is coupled to the base by the resilient washers.

[0013] In certain embodiments, a plurality of resilient washers mate with a plurality of fastening elements to secure the reticle support to the base.

[0014] In a particular embodiment, the reticle support has a protrusion and two edge limiters disposed on two sides of the protrusion, and a plurality of elastic washers are provided under the protrusion and the two edge limiters of the reticle support.

[0015] In a specific embodiment, the weight of the reticle is 320g to 330g or more, and the limit value is 3.14N or more.

[0016] In a particular embodiment, the predetermined height is in the range of 0.17 mm to 0.23 mm. [Brief description of the drawings]

[0017] [Figure 1A] 2 is a schematic diagram of a reticle base normally carrying a reticle in accordance with a first embodiment of the present invention. [Figure 1B] 4 is a schematic diagram of a reticle base that is tilted when the reticle is subjected to an external force in accordance with a first embodiment of the present invention. [Figure 2A] 4 is a schematic diagram of a structure of a support member according to a second embodiment of the present invention. [Figure 2B] 5 is a schematic diagram of a variation of the structure of a support member according to a second embodiment of the present invention. [Diagram 3] FIG. 13 is an exploded view of a reticle base and a reticle according to a third embodiment of the present invention. [Figure 4]FIG. 13 is a plan view of a reticle base and a reticle according to a third embodiment of the present invention. [Figure 5A] FIG. 10 is an exploded view of a support member according to a third embodiment of the present invention. [Figure 5B] 5 is a cross-sectional view of the support member taken along line A-A of FIG. 4 according to a third embodiment. [Figure 6A] FIG. 13 is an exploded view of a support member as a first modified example of the third embodiment of the present invention. [Figure 6B] 5 is a cross-sectional view of a support member as a first variant of the third embodiment taken along the line A-A in FIG. 4. [Figure 7A] FIG. 13 is an exploded view of a support member as a second modified example of the third embodiment of the present invention. [Figure 7B] 5 is a cross-sectional view of a support member according to a second variant of the third embodiment taken along the line A-A in FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present invention provides a reticle pod having at least one reticle support for absorbing downward pressure. The reticle support has elastic means for absorbing downward pressure and relieving excessive downward pressure by the elastic means. For clarity of explanation of the present invention, only the reticle and base of the reticle pod of the present invention are shown.

[0019] Referring to FIG. 1A, FIG. 1A is a schematic diagram of a reticle base (e.g., the base of the inner pod of the dual pod described above) that normally carries a reticle R. A reticle support 100 of the present invention is provided on an upper surface 501 of the base 50 of the reticle pod, and the reticle support is for supporting the reticle R. When the reticle R is placed on the reticle support 100, a predetermined height H is maintained between the lower surface R1 of the reticle R and the upper surface 501 of the base 50, the predetermined height H being the height at which the uncompressed reticle support 100 extends upward from the upper surface 501, more specifically, the height at which the reticle support 100 is exposed from the upper surface 501. In one embodiment of the inner pod of the dual pod (or EIP), the predetermined height H is in the range of 0.17 mm to 0.23 mm.

[0020] 1B, the reticle support 100 of the present invention is configured such that when the reticle R is placed or picked up, and the downward pressure caused by the tilt of the reticle R is excessively concentrated on a single or several reticle supports 100, and the normal force of the reticle support 100 applied to the corner of the reticle support 100 is greater than a threshold value, the downward pressure is absorbed by the elastic means of the reticle support 100. Due to the elastic means, the reticle support 100 necessarily generates a height h that is lower than a predetermined height H between the lower surface R1 and the upper surface 501 of the base 50, so that the lower surface R1 and the upper surface 501 form an angle α, and only when the downward pressure is shared by another reticle support 100 after the reticle support 100 first contacts the reticle, the reticle support 100 restores to the predetermined height H. The design of the limit value of the reticle support 100 may be determined according to the weight of the reticle and / or the downward pressure provided by the motion means of the mechanical arm. For example, when the weight of the reticle is greater than or equal to 320g-330g, the limit value may be designed to be 3.14N or more in light of the material or structure of the reticle support 100. In this case, when the downward pressure received by one single reticle support 100 in contact with the reticle is greater than 3.14N, the elastic means of the reticle support 100 will act to intervene and absorb the downward pressure, thus preventing the corresponding corner of the reticle from withstanding an excessively large vertical force.

[0021] In a first embodiment of the present invention, an elastic material that is compressible and elastic, and has heat resistance, wear resistance, or high plasticity, is selected as the material of the elastic means for the reticle support 100. The material includes, but is not limited to, for example, rubber or thermoplastic elastomer (TPE), such as thermoplastic rubber (TPR), thermoplastic vulcanizate (TPV), thermoplastic polyurethane (TPU), or thermoplastic polyester elastomer (TPEE).

[0022] Thus, when the reticle support 100 is made of an elastic material, the top end of the reticle support 100 is in elastic contact with the lower surface R1 of the reticle R, and the reticle support 100 absorbs the downward pressure by self-compression and self-deformation when the downward pressure applied to one single reticle support 100 is greater than a threshold value.

[0023] 2A and 2B, which show a second embodiment of the present invention, reticle supports 200 and 200' each have a protrusion 201, the protrusion 201 of the reticle support 200 is joined with a connecting portion 202, and the protrusion 201 of the reticle support 200' is joined with a connecting portion 203. The connecting portions 202 and 203 are different modifications of elastic elements. In the second embodiment of the present invention, the elastic elements of the reticle supports 200 and 200' are used as elastic means to absorb downward pressure. The protrusion 201 is connected or coupled to the base 50 as shown in FIG. 1A via the connecting portions 202 and 203, so that the protrusion 201 can be compressed or swung against the upper surface 501. The connecting portions 202 and 203 have a structure that is easily deformed compared to the protrusion 201 to absorb downward pressure. Preferably, the connecting part 202 is a spring, the bottom of which can be embedded in the base 50 by a suitable connecting means, and the top of which is connected to the protrusion 201. The connecting part 203 is a hollow structure. As shown, the connecting part 203 mainly consists of four thin posts and a bottom panel. The material forming the thin posts can be appropriately selected to exhibit flexibility, for example the elastic material mentioned above. Thus, it can be seen that the four thin posts of the connecting part 203 can be deformed and bent due to receiving a force, so that the protrusion 201 swings or sinks.

[0024] Thus, when the connecting portions 202, 203 of the reticle supports 200, 200' are elastic elements, in response to a downward pressure applied to the reticle supports 200, 200' that is greater than a threshold value, the protrusions 201 of the reticle supports 200, 200' sink slightly relative to the upper surface 501 to absorb the downward pressure from the corners of the reticle R. In other words, the reticle supports 200, 200' absorb the downward pressure by deforming the elastic elements.

[0025] Preferably, the protrusion 201 or the connecting portion 202, 203 of the reticle support 200, 200' is selectively formed by an elastic material, for example, the first embodiment of the present invention. The protrusion 201 is connected or coupled to the mounting interface (omitted from the drawing) of the base 50 via the connecting portion 202, 203, and when the downward pressure applied to the reticle support 200, 200' is greater than a threshold value, the protrusion 201 or the connecting portion 202, 203 absorbs the downward pressure by compression and deformation.

[0026] Please refer to Figures 3 to 5B, which show a third embodiment of the present invention. Figure 3 is a schematic diagram of the base 50 and the reticle R of the inner pod of the reticle pod, and Figure 4 is a plan view of the base 50 carrying the reticle R, in which mounting holes 51 are provided at the four corners of the base 50, and the support mechanism 30 is provided in the mounting holes 51. As shown in Figures 5A and 5B, the support mechanism 30 includes a reticle support 31, an elastic washer 32, and two fastening members 33. The fastening members 33 are removably fixed and connected to the fixing holes 114 of the base 50 through the two fastening holes 314 of the reticle support 31. In the third embodiment of the present invention, the reticle support 31 uses the elastic washer 32 as an elastic means for absorbing downward pressure.

[0027] The reticle support 31 has a protrusion 311 (contacting the underside of the reticle R) and at least one edge limiter 313 (limiting the side edge of the reticle R). The elastic washer 32 is provided on the top of the protrusion 311 to contact the elastic washer 32 when the reticle R is supported on the reticle support 31, and an elastic contact is formed between the reticle R and the protrusion 311. When the downward pressure applied to the reticle support 31 is greater than the limit value, the elastic washer 32 is sufficient to absorb the downward pressure applied by the corner of the reticle R. In this case, considering the relationship between the predetermined height H and the height h shown in Figures 1A and 1B, the amount of the exposed height of the protrusion 311 plus the compressed thickness of the elastic washer 32 is necessarily smaller than the amount of the exposed height of the protrusion 311 plus the thickness of the elastic washer 32 in the uncompressed state. Preferably, the top of the projection 311 has a suitably formed notch 312 for mating with and coupling to the elastic washer 32. Preferably, the notch 312 is suitably configured for releasably coupling the elastic washer 32 to the projection 311. By providing the elastic washer 32 on the top of the projection 311, a resilient contact is provided instead of a hard (non-resilient) contact between the reticle R and the projection 311, thus reducing contaminant particles and wear of the projection 311. Furthermore, the removable means of the fastener 33 or the notch 312 allows for easy replacement of a different reticle support 31 or elastic washer 32.

[0028] 6A and 6B, which show a first variant of the third embodiment of the present invention, the first variant of the third embodiment of the present invention has two elastic washers 32 and two fastening members 33 that match with each other to fix the reticle support 31 to the base 50. Specifically, the elastic washers 32 are provided between the fixing holes 114 of the base 50 and the reticle support 31, so that a resilient contact is formed between the reticle support 31 and the base 50, but the elastic washers 32 are not substantially compressed by such assembly. The fastening members 33 pass through the fastening holes 314, the elastic washers 32, and the fixing holes 114 of the reticle support 31 in order to attach the reticle support 31 to the mounting holes 51 of the base 50. By providing the elastic washers 32 between the reticle support 31 and the base 50, downward pressure can be absorbed. In a possible variant, the two elastic washers 32 may be replaced by a single elastic washer having a pair of openings, which is similarly provided between the fixing hole 114 of the base 50 and the reticle support 31.

[0029] Preferably, the first variant of the third embodiment has two elastic washers 32 that cooperate with two fastening members 33 respectively, and an elastic contact is formed between the reticle support 31 and the base 50, so that the downward pressure is absorbed by the two elastic washers 32. In this case, considering the relationship between the predetermined height H and height h shown in Figures 1A and 1B, the amount of the exposed height of the protrusion 311 plus the thickness of the elastic washer 32 after compression is necessarily smaller than the amount of the exposed height of the protrusion 311 plus the thickness of the elastic washer 32 in the uncompressed state.

[0030] 7A and 7B, which show a second variant of the third embodiment of the present invention, three elastic washers 32 are provided under the protrusions 311 and two edge limiters 313 of the reticle support 31, so that a resilient contact is formed between the reticle support 31 and the base 50. The mounting holes 51 of the base 50 are provided with fixed protrusions 113 corresponding to the lower parts of the edge limiters 313. During assembly, the elastic washers 32 can be placed in the mounting holes 51 first to surround the fixed protrusions 113, and then the reticle support 31 can be inserted to restrict the elastic washers 32 by the downward pressure of the reticle support 31 (without substantially compressing the elastic washers 32), thereby preventing unnecessary displacement. In another possible variation, the number of elastic washers 32 may be two or less, for example, only two elastic washers 32 correspond to the edge limiter 313, or only one elastic washer 32 corresponds to the protrusion 311.

[0031] Preferably, in the second variant of the third embodiment of the present invention, three elastic washers 32 are disposed below the protrusion 311 and the two edge limiters 313 of the reticle support 31, respectively, and the downward pressure is absorbed by these three elastic washers 32. In this case, taking into consideration the relationship between the predetermined height H and the height h shown in Figures 1A and 1B, the amount of the exposed height of the protrusion 311 plus the thickness of the elastic washer 32 after compression is necessarily smaller than the amount of the exposed height of the protrusion 311 plus the thickness of the elastic washer 32 in the uncompressed state.

[0032] The elastic washer 32 can be a load-absorbing hardware element, such as a rubber washer or a spring washer. If the elastic washer 32 is additionally provided, the mounting position and the mounting number of the elastic washer 32 can be flexibly adjusted to meet the load change during the operation of different machines, thereby preventing excessively large force from being generated between the reticle being picked up and placed and the support member, and thus preventing particle generation or damage.

[0033] The embodiments and modifications of the present invention can be coordinated or implemented according to the requirements of actual applications without departing from the technical spirit or technical principles of the present invention. [Explanation of symbols]

[0034] 30 Support mechanism 32 Elastic washer 33 Fastening members 50 Base 51 Mounting holes 100 Reticle support 201 Protrusion 202,203 Connecting part 311 Protrusion 313 Edge Limiter R Reticle

Claims

1. A reticle pod having a base and at least one reticle support disposed on the base, the reticle support is for carrying the reticle, the reticle support having elastic means; when a downward pressure applied to the reticle support is less than or equal to a threshold value, the height of the reticle support is maintained at a predetermined height; A reticle pod, wherein when a downward pressure applied to the reticle support is greater than a threshold value, the reticle support absorbs the downward pressure by deforming, and then the reticle support returns to the predetermined height only when the downward pressure is shared by another reticle support.

2. 2. The reticle pod of claim 1, wherein the elastic means is an elastic material, a spring, or a hollow structure, and the limit value is determined according to the elastic means.

3. The reticle pod of claim 1 , wherein the reticle support has a protrusion, the protrusion having an elastic material such that the protrusion can be in elastic contact with the reticle, the elastic material being rubber or a thermoplastic elastomer (TPE).

4. The reticle pod of claim 3 , wherein said reticle support absorbs downward pressure by compression and deformation of said elastic material.

5. 2. The reticle pod of claim 1, wherein said reticle support has a resilient element disposed on a bottom portion thereof, said reticle support being in a resilient interlocking relationship with said base by said resilient element.

6. 6. The reticle pod of claim 5, wherein said resilient element is adapted to withstand a downward pressure greater than said threshold value and correspondingly deform, sag, and absorb said downward pressure.

7. 6. The reticle pod of claim 5, wherein said resilient element is a spring, and said reticle support is coupled to said base by said spring.

8. The reticle pod of claim 5 , wherein said resilient elements are a plurality of resilient washers, and said reticle support is coupled to said base by said resilient washers.

9. The reticle pod of claim 8 , wherein the plurality of elastomeric washers mate with a plurality of fastening elements to secure the reticle support to the base.

10. 9. The reticle pod of claim 8, wherein the reticle support has a protrusion and two edge limiters disposed on two sides of the protrusion, and the multiple elastic washers are provided under the protrusion and the two edge limiters of the reticle support.

11. 2. The reticle pod of claim 1, wherein the weight of said reticle is 320 g to 330 g or more, and said limit value is 3.14 N or more.

12. The reticle pod of claim 1 , wherein said predetermined height is in the range of 0.1 mm to 0.23 mm.

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