Reticle compartment and diffusor plate

Abstract

A reticle compartment defining an enclosed interior adapted to store at least two reticles in a resticle storage portion, including an inlet port, through which a purge gas can enter the enclosed enterior, and an outlet port, through which the purge gas can exit the enclosed interior, wherein the reticle compartment further includes a first diffusor plate arranged in the enclosed interior between the inlet port and the reticle storage portion, wherein the first diffusor plate is provided with openings, through which the purge gas can flow, the openings in a central section of the first diffusor plate being provided with a larger individual opening area and/or providing a large total opening area per unit area than openings in a peripheral section of the first diffusor plate.

Claims

1. A reticle compartment defining an enclosed interior adapted to store at least two reticles in a reticle storage portion, comprising: an inlet port, through which a purge gas can enter the enclosed interior; an outlet port, through which the purge gas can exit the enclosed interior; and a first diffusor plate arranged in the enclosed interior between the inlet port and the reticle storage portion, wherein the first diffusor plate is provided with openings, through which the purge gas can flow, the openings in a first section of the first diffusor plate being provided with a larger individual opening area and/or providing a larger total opening area per unit area than openings in a second section of the first diffusor plate, wherein the total opening area per unit area varies from large to small in two orthogonal directions from the first section to the second section.

2. The reticle compartment according to claim 1, further comprising a second diffusor plate arranged between the reticle storage portion and the outlet port.

3. The reticle compartment according to claim 2, wherein the second diffusor plate is provided with openings, through which the purge gas can flow, the openings in a first section of the second diffusor plate being provided with a larger individual opening area and/or providing a larger total opening area per unit area than openings in a second section of the second diffusor plate.

4. The reticle compartment according to claim 3, wherein the openings of the first diffusor plate and/or the openings of the second diffusor plate are provided with at least 2 different individual opening areas, the opening areas decreasing from a largest individual opening area for openings in a first section of the first and/or second diffusor plates, to a smallest opening area in the vicinity of the second section of the first and/or second diffusor plates.

5. The reticle compartment according to claim 2, wherein the reticle storage portion is provided to store the at least two reticles such that each reticle extends essentially perpendicularly to the first diffusor plate and/or the second diffusor plate.

6. The reticle compartment according to claim 1, made at least in part of at least one metal material, the metal material comprising aluminum and/or stainless steel.

7. The reticle compartment according to claim 1, comprising retainer elements on or between which reticles can be positioned.

8. The reticle compartment according to claim 7, wherein the retainer elements are provided with inserts and/or linings made of a polymer material.

9. The reticle compartment according to claim 1, wherein all outermost peripheral openings are smaller in their individual opening area than openings in the first section.

10. The reticle compartment according to claim 1, wherein the individual openings comprise opening areas which are round and/or oval and/or square and/or triangular and/or oblong and/or egg shaped and/or crescent shaped and/or slit shaped and/or polygon shaped.

11. The reticle compartment and diffusor plate according to claim 1 adapted to be used in a storage stocker.

12. A diffusor plate adapted to be used in an interior of a reticle compartment between an inlet port of the reticle compartment and a reticle storage portion of the reticle compartment and/or between the reticle storage portion of the reticle compartment and an outlet port of the reticle compartment, provided with openings, openings in a first section of the diffusor plate being provided with a larger individual opening area and/or providing a larger total opening area per unit area than openings in a second section of the diffusor plate, wherein the total opening area per unit area varies from large to small in two orthogonal directions from the first section to the second section.

13. A method for purge cleaning reticles comprising providing a reticle compartment defining an enclosed interior adapted to store at least two reticles in a reticle storage portion, the reticle compartment having an inlet port, through which a purge gas can enter the enclosed interior, and an outlet port, through which the purge gas can exit the enclosed interior; providing a first diffusor plate arranged in the enclosed interior between the inlet port and the reticle storage portion; and flowing purge gas through openings provided in the first diffusor plate, the openings in a first section of the first diffusor plate being provided with a larger individual opening area and/or providing a larger total opening area per unit area than openings in a second section of the first diffusor plate, wherein the total opening area per unit area varies from large to small in two orthogonal directions from the first section to the second section.

14. The method according to claim 13, further comprising providing a second diffusor plate arranged between the reticle storage portion and the outlet port.

15. The method according to claim 14, wherein the second diffusor plate is provided with openings, through which the purge gas can flow, the openings in a first section of the second diffusor plate being provided with a larger individual opening area and/or providing a larger total opening area per unit area than openings in a second section of the second diffusor plate.

16. The method according to claim 15, wherein the openings of the first diffusor plate and/or the openings of the second diffusor plate are provided with at least 2 different individual opening areas, the opening areas decreasing from a largest individual opening area for openings in a first section of the first and/or second diffusor plates, to a smallest opening area in the vicinity of the second section of the first and/or second diffusor plates.

17. The method according to claim 14, wherein the reticle storage portion is provided to store the at least two reticles such that each reticle extends essentially perpendicularly to the first diffusor plate and/or the second diffusor plate.

18. The method according to claim 13, further comprising retaining, with retainer elements, the reticles within the reticle compartment.

19. The method according to claim 18, wherein the retainer elements are provided with inserts and/or linings made of a polymer material.

20. The method according to claim 13, wherein all outermost peripheral openings are smaller in their individual opening area than openings in the first section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Preferred aspects of the present disclosure will now be further described with reference to the appended figures.

(2) FIG. 1 shows a schematically simplified side sectional view of a first aspect of a reticle compartment according to the present disclosure,

(3) FIG. 2 shows a plan view of a preferred aspect of a diffusor plate according to the present disclosure,

(4) FIG. 3 shows a perspective view of a preferred aspect of body member of a reticle compartment according to the present disclosure,

(5) FIG. 4 shows a preferred aspect of a lid of a reticle compartment according the present disclosure, which, together with the body according to FIG. 3, forms a reticle compartment, and

(6) FIGS. 5a-5i show plan views of various further preferred aspects of diffusor plates according to the present disclosure.

DETAILED DESCRIPTION

(7) FIG. 1 shows, in schematic simplification, a preferred aspect of a reticle compartment according to the present disclosure, generally designated 10.

(8) It defines a closed interior 12, comprising a reticle storage portion 14, in which a multitude of reticles 22 can be stored. The actual interaction between the reticles and the compartment is not shown in FIG. 1. Especially, no retainer elements for holding individual reticles are shown.

(9) The reticle compartment comprises an inlet port 16, through which a purge gas (indicated by arrow 16′) can enter the enclosed interior 12 of the reticle compartment. It further comprises an outlet port 18, through which purge gas can exit the enclosed interior 12, indicated by means of arrow 18′.

(10) To ensure a uniform and essentially turbulence-free flow of purge gas through the whole volume of the reticle storage portion 14, a first diffusor plate 12 is arranged between inlet port 16 and reticle storage portion 14. The first diffusor plate 24 comprises a multitude of openings 25, through which purge gas can enter the reticle storage portion 14. As schematically indicated in FIG. 1, and especially can be seen in FIG. 2, the openings 25a in a central section of first diffusor plate 24 are larger, i.e. are provided with a larger opening area or a larger diameter than openings 25b in peripheral sections.

(11) Between reticle storage portion 14 and outlet port 18, there is provided a second diffusor plate 26, which is also provided with openings 27a and 27b. Advantageously, the pattern of openings 27a and 27b corresponds to that of first diffusor plate 24, i.e. openings 27a in the central section have a larger opening area than openings 27b in peripheral sections.

(12) As can further be seen in FIG. 1, the reticles 22 stored in reticle storage portion 14 are arranged orthogonally relatively to the first and second diffusor plate 24, 26. This arrangement ensures that purge gas flowing through the reticle compartment from inlet port 16 to outlet port 18 provides a uniform flow, so that all reticles 22 are essentially equally exposed to purge gas and thereby purged in an optimal manner. This uniform flow is especially enhanced by the pattern of openings 25a, 25b, 27a, 27b which ensures that the flow of purge gas along more peripherally arranged reticles (for example reticle 22b as indicated in FIG. 1) essentially corresponds to that along a more central reticle (for example reticle 22a as indicated in FIG. 1).

(13) Typically, a reticle compartment comprises a body member provided with retainer elements for holding individual reticles and a lid adapted to close the volume defined by the body member. Preferred aspects of such a body member and a lid are shown in FIGS. 3 and 4 respectively. Be it noted that identical or similar components as already described with reference to FIGS. 1 and 2 have the same reference numerals in FIGS. 3 and 4.

(14) FIG. 3 shows a body member 10a. Body member 10a comprises a plurality of retainer elements 11 on opposing inner walls of body member 10a. The retainer elements are adapted to hold individual reticles. To illustrate this, one reticle 22 is shown in FIG. 3, which, with two opposite sides, rests on corresponding retainer elements 11. As can be immediately seen, the retainer elements 11 are adapted for horizontal storage of reticles 22. The retainer elements 11 according to the embodiment of FIG. 3 are provided as ridges.

(15) The body element 10a is manufactured of a metal material, for example aluminium or stainless steel.

(16) In order to avoid electrostatic effects between the body member 10a or the reticle compartment and reticles 22 stored therein, each retainer element 11 is provided with inserts 13 made of a polymer material. Thus, a reticle stored within the reticle compartment 10 on retainer elements 11 will not contact these retainer elements directly, but will be insulated from them by means of inserts 13. Inserts 13 can also be provided on the inside walls of body member 10a. This electric insulation further reduces the tendency of reticles to attract contamination such as dust particles within the reticle compartment. Inserts 13 also serve to prevent scratching of reticles.

(17) As can be seen in FIG. 3, the rear side of body member 10a is provided with a diffusor plate 26 and an outlet port (not visible in FIG. 3), analogously to the aspect of FIG. 1. The openings 27aa in the central section of diffusor plate 26 are provided with larger opening areas than openings 27b in peripheral sections.

(18) For ease of handling within a compartment stocker, the body member 10a is provided with feet 10b.

(19) A lid 10c as shown in FIG. 4 is adapted to interact with body member 10a, i.e. to tightly close the volume defined by body member 10a to provide an enclosed interior of reticle compartment 10.

(20) Lid 10c is provided with a locking mechanism 17, adapted to interact with grooves 19 provided in the outside walls of body member 10a (see FIG. 3). The inside edges 41 of the lid and/or the edges 31 at the opening of body member 10a are provided with seal members, such that by interaction of the lock mechanism 17 with the groves 19 a gas tight connection between lid and body member is achieved.

(21) The lid is provided with a diffusor plate 24. An inlet port 16 also provided on lid 10c is not visible in FIG. 4.

(22) The openings 25a in the central section of diffusor plate 24 are provided with larger opening areas than those openings 25b in peripheral or edge sections, as explained above. Especially, the openings in the vicinity of at least some of the edges of the diffusor plates are provided with the smallest opening areas. In some aspects, only a top and/or bottom edge section of the diffusor plate is provided with the smallest opening areas. In other aspects, all of the edge sections of the diffusor plate are provided with the smallest opening areas.

(23) The lid 10c is manufactured of a metallic material, for example aluminium and/or stainless steel.

(24) The diffusor plates 24, 26 are preferably made of stainless steel. However, aluminium can also be used.

(25) As explained with reference to FIG. 3, the reticle compartment shown is adapted for horizontal storage of reticles.

(26) Advantageously, the reticles are stored orthogonally in relation to the diffusor plates. A vertical storage within a reticle compartment would also be possible. In this case, the retainer elements are advantageously provided as grooves, to ensure safe positioning and handling.

(27) The reticle container 10 comprising body element 10a and lid 10c is adapted to store reticles within a reticle stocker. In order to insert or extract a reticle, lid 10c is removed from the body member.

(28) Under normal storage conditions within a reticle stocker, the inlet port 16 is connected to a pressurized purge gas source. After flowing through the reticle compartment in the manner described above, purge gas is exhausted into the reticle stocker, from where it is drawn out of the reticle stocker by a vacuum device.

(29) In FIGS. 5a-5i, further designs for preferred aspects of diffusor plates according to the present disclosure are shown. The diffusor plates shown in FIG. 5 can either be used as first and/or second diffusor plate as specified above. It is also possible to utilize different ones of these diffusor plate designs as first and second diffusor plate respectively. The design according to FIG. 5a comprises essentially square openings 50 in a central sections, and slit-shaped openings 52 in peripheral sections. In this aspect, the square shaped openings 50 provide a larger total opening area per unit area than slit-shaped openings 52. An expediently size unit area is, as an example, designated 80 in FIG. 5a. Such unit areas are not shown in the further aspects of FIGS. 5a-5i.

(30) According to the aspect of FIG. 5b, triangular openings 54 are provided. The bases of these triangular openings 54 are located in the central section of the diffusor plate, and the tips towards the upper and lower peripheral sections. Again, comparing the central section to the upper and lower peripheral sections, the total opening area per unit area is larger in the central section.

(31) According to the aspect of FIG. 5c, larger square shaped openings 56 are provided in the central section of the diffusor plate, and smaller square shaped openings 58 in the peripheral section. Again, the total opening area per unit area is larger in the central section.

(32) According to the aspect of FIG. 5d, a number of oblong or rectangular openings 58 are provided. The openings in the central section are larger than those in the left and right peripheral sections, the opening areas thus decreasing from the central section to these peripheral sections.

(33) The aspect of the diffusor plate according to FIG. 5e has similarities to the aspect of FIG. 5c. However, here all square shaped openings 60 have the same opening area. However, the density of openings is larger in the central section than in the peripheral section. Thus, the central section has a larger total opening per unit area as compared to the peripheral section.

(34) According to the aspect of FIG. 5f, oblong or rectangular shaped openings 62 are provided, the opening area of which decreases towards the left and right peripheral sections of the diffusor plate.

(35) According to the aspect of FIG. 5g, a number of oval shaped openings 64 are provided. The oval shaped opening 64 in the central section have larger opening areas as compared to openings in the left and right peripheral sections.

(36) According to the aspect of FIG. 5h, a number of triangular shaped openings 66, 68 are provided. Here again, similarly to FIG. 5b, the bases of the triangular shaped openings are located in the central section, and the tips of the openings in the peripheral sections of the diffusor plate. Thus, the total opening area per unit area is larger in the central section than in the peripheral sections.

(37) According to the aspect of FIG. 5i, a number of rectangular or oblong openings 70 are provided, the opening area of which decreases from a central section towards the left and right as well as top and bottom peripheral sections.

(38) As will be appreciated, and as partly expanded on above, all these diffusor plate designs are provided with openings with larger individual opening areas and/or providing a larger total opening area per unit area in their central sections as compared to peripheral sections.