WO2002080232A2

WO2002080232A2 - Substrate storage pod access device

Info

Publication number: WO2002080232A2
Application number: PCT/US2002/009741
Authority: WO
Inventors: Alex D. Todorov; Mila M. Genov
Original assignee: Genmark Automation, Inc.
Priority date: 2001-03-29
Filing date: 2002-03-28
Publication date: 2002-10-10
Also published as: WO2002080232A3

Abstract

Access to the interior of a substrate storage pod (22) in which substrates such as semiconductor wafers are stored is gained using an access device (20) provided within a micro environment enclosure (26). The access device (20) has a telescoping enclosure door (21) which, in an extended position, serves to close a port (28) of the enclosure (26) and seal the enclosure (26) from the outside. When access is desired, a translational motion assembly (36) grips the pod door (32) and pulls it into a recess (30) in the enclosure door (21). A transverse motion assembly (63) then pulls the enclosure door (21), along with the pod door (32) in the recess (30), to a contracted position such that the port (28) becomes unobstructed, permitting access to the interior of the substrate storage pod (22) from the enclosure (26). The process is reversed when access is to be terminated.

Description

SUBSTRATE STORAGE POD ACCESS DEVICE

BACKGROUND OF THE INVENTION

[0001] The invention relates substrate processing systems, and more particularly, to systems for accessing substrates disposed in a storage pod from within the interior of a substrate processing micro environment enclosure.

DESCRIPTION OF RELATED ART

[0002] Substrates such as semiconductor wafers are processed in micro environment enclosures in which conditions are carefully managed such that temperature and humidity are controlled, and use is made of air filtration systems which remove contaminants that would otherwise corrupt the delicate manufacturing procedures involved. Complex systems are used to effect these controls, and expedients used include establishing laminar flows within the micro environment enclosure to direct air flow towards the filtration devices.

[0003] The substrates, prior to loading into the micro environment enclosure, are conventionally handled in protective containers which seal out contaminants. One type of industry standard container is referred to as a front opening universal pod (FOUP) and is used to store the substrates in a stacked arrangement. The door of the FOUP, from which the interior is accessed, is disposed at the front and is detachable such that when the FOUP is engaged with the enclosure of the micro environment in which the substrates are to be processed, the door is removed to a remote location and access to the substrates is facilitated. The micro environment system has one or more processing stations into and out of which the wafers are transferred from the FOUPs.

[0004] When ready for processing, the pod containing the wafers is docked with an interface portion of the micro environment, which may be referred to as a load lock chamber. The load lock chamber is provided with a port having a door supported therein. The door, normally closed to preserve the micro environment conditions, is opened when the pod is in the docked position. A door of the pod is also opened, thereby permitting transport of the semiconductor wafers between the pod and the micro environment through the load lock chamber. The mating of the pod to the load lock chamber is carefully controlled, and the door opening process coordinated, so that the integrity of the micro environment is undisturbed during the loading and unloading process.

[0005] Opening and closing of the pod and load lock chamber doors is automated. An opening mechanism provided in the load lock chamber simultaneously engages both doors, often sealing them together to sandwich contaminants therebetween, and removes them along a transport path to a remote position to thereby facilitate transfer of the wafers, by a different loading and unloading mechanism, between the pod and the load lock chamber. Prior art devices of this type include U.S. Patents 5,607,276 to Muka, et al., 5,609,459 to Muka, 5,613,821 to Muka, et al., and 5,664,925 to Muka, et al. A typical prior art opening and closing configuration relies on an upright lever which engages both the pod and load lock chamber doors. The lever then swings internally, away from the pod, along a shallow angle, pulling the doors internally with it. When sufficient clearance is thus achieved, the lever, along with the doors, descends downward within the load lock chamber, leaving the pod-load lock chamber interface clear for access to the interior of the pod. The substrates are then withdrawn from the pod, processed, and returned, using suitable robot arms. Once processing is complete and the substrates returned to the pod, the process is reversed and the pod and load lock chamber are again sealed from each other.

[0006] The aforementioned prior art systems suffer from several disadvantages. For instance, the lever described above is relatively massive, and the speed and repetitive motion required to increase throughput are limited by the angular momentum of the arm and the resulting vibrations due to the increased inertia. Additionally, the nature of the motion— that is, the swinging motion itself— is complex when compared with linear motion and generates friction- induced particles which contaminate the controlled micro environment.

Additionally, the rotational components of the swinging motion require greater clearance, imposing larger exclusion zones during translation through the full motion range.

[0007] Another prior art device, the subject of U.S. Patent No. 6, 142,722, is directed to opening and closing pod and load lock chamber doors using the wafer handling robot itself. The arm of the robot, using a specialized, detachable tool, engages both doors and transports these to a dedicated location within the micro environment. The arm then accesses the substrates in the pod, delivers them to the appropriate processing stations, then returns them to the pod and re- seals the pods with the retrieved doors. This prior art device, however, is complex and expensive, and may not be suitable in some situations.

BRIEF SUMMARY OF THE INVENTION

[0008] The present invention overcomes the shortcomings of the prior art by providing a device for controlling access to the interior of a substrate storage pod, wherein a translational motion assembly is used to translate a removable pod door relative to the substrate storage pod in a first, substantially straight path, and wherein a transverse motion assembly is used to translate the removable pod door and an enclosure door in a second, substantially straight path which is transverse to the first path.

[0009] Further in accordance with the invention, a method for accessing the interior of a substrate storage pod from the interior of a semiconductor processing micro environment enclosure involves establishing a seal between the substrate storage pod and an enclosure of the semiconductor processing micro environment, disengaging the pod door from the pod, translating the pod door relative to the substrate storage pod in a first, substantially straight path, and translating the pod door and an enclosure door in a second, substantially straight path which is transverse to the first path.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0010] Many advantages of the present invention will be apparent to those skilled in the art with a reading of this specification in conjunction with the attached drawings, wherein like reference numerals are applied to like elements and wherein:

[0011] FIGS. IA and IB are partial sectional side elevational views of a substrate storage pod in mating engagement with a pod access device in accordance with the invention;

[0012] FIGS. 2A and 2B are cross-sectional views of a translational motion assembly in accordance with the invention; [0013] FIGS. 3 A and 3B are side elevational views showing the operation of a transverse motion assembly in accordance with the invention; and [0014] FIG. 4 is a front elevational view of the a transverse motion assembly in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0015] FIGS. IA and IB show a storage pod access device 20 in accordance with the invention. Storage pod 22 is shown in an engagement position against the exterior wall 24 of a portion of micro environment enclosure 26. Wall 24 has a port 28 through which access to micro environment enclosure 26 is gained. Access device 20 operates enclosure door 21, which, in a first position depicted in FIGS. IA and IB, seals port 28 of wall 24. As described in further detail below, the enclosure door 21 is mounted for translational motion in the direction of double-headed arrow A. Enclosure door 21 has a recess 30 for receiving therein (FIG. IB) removable pod door 32 during operation in which access to the interior of pod 22 is gained from the interior of micro environment enclosure 26.

[0016] Pod access device 20 is shown in greater detail in FIGS. 2A and 2B and includes a frame 34 to which a translational motion assembly 36 is movably mounted. Assembly 36 includes a platform 38 whose motion is actuated by a motor 40 and a linkage consisting of rotatable ball screw 42 threadingly engaging nut 44 rigidly mounted to platform 38. Also rigidly mounted to platform 38 are extensions 46 having alignment pins 48 which mate with corresponding holes 50 provided on pod door 32, and at least one latching mechanism 52 which engages door 32. During engagement of latching mechanism 52 with door 32, motion of platform 38 and latching mechanism 52 induces motion of pod door 32 such that pod door 32 can be translated in a straight path along the axial direction of latching mechanism 52. Engagement and disengagement of latching mechanism 52 from pod door 32 is effected by actuation of a latch motor 54 mechanically linked to a latch 56 which mates with a corresponding hole 58. This mating also serves to engage or disengage pod door 32 from pod 22, via a suitable linkage in pod door 32 (not shown). In this manner the translational motion assembly 36 can grip pod door 32, disengage it from pod 22, and translate the pod door into recess 30 of enclosure door 21. It can also perform the reverse operation, translating pod door 32 out of recess 30 and engaging it with pod 22, then disengaging from the pod door. The integrity of the micro environment enclosure 26 is substantially preserved during these operations by maintaining a seal between storage pod 22 and wall 24 of the enclosure in the vicinity of port 28. Specifically, a seal, indicated generally at 27, is formed at the perimeters of port 28 and the opening in storage pod 22 resulting from removal of door 32 from the storage pod. This seal is maintained using biasing means (not shown) which exerts sufficient pressure to bias the pod 22 against wall 24.

[0017] FIGS. 3 A and 3B show enclosure door 21 in closed and open positions, respectively. Door 21 is slidably mounted and translates in the direction of double-headed arrow A such that when the door is in the open position, access to the interior of pod 22 is gained from micro environment enclosure 26. It will be appreciated that this access is attained after pod 22 is drawn into a sealed mating position against wall 24, and specifically, against port 28, as shown in FIG. 3B. In this manner, substrates (not shown) can be loaded and unloaded into enclosure 26 from pod 22, by a suitably equipped substrate handling robot (not shown). It will further be appreciated that when pod 22 is not in this sealed position— for example, when it is in the position shown in FIG. 3A— door 21 is closed, thereby serving to hermetically seal port 28 and enclosure 26 against the exterior. Pod 22 can be translated to and from the sealed position of FIG. 3B manually or by mechanical means (not shown) disposed in support 59, which mechanical means can further be used to provide the requisite biasing for maintaining the enclosure-pod seal discussed above.

[0018] The mechanism by which enclosure door 21 is translated between the open and closed positions along the path indicated by double-headed arrow A is shown in detail in FIG. 4. Enclosure door 21 is movably mounted in housing 62, which housing is rigidly affixed to wall 24 of enclosure 26 (FIG. 3). Motion of enclosure door 21 is imparted by a transverse motion assembly 63, which comprises a motor 64 mechanically linked to door 21 by way of belt 65, ball screw 66, and nut 68. Actuation of motor 64 causes rotation of ball screw 66, which matingly threads through nut 68 and causes motion of door 21 in the direction of double-headed arrow A such that door 21 effectively telescopes in and out of housing 62. It will be appreciated that transverse motion assembly 63 can comprise components different from those described but still operating to move enclosure door 21 along the path indicated by double-headed arrow A.

[0019] And exemplary mode of operation begins with substrate storage pod

22, containing a plurality of substrates such as semiconductor wafers (not shown), being placed on support 59. A mechanical means in support 59 draws pod 22 against wall 24, and biases the pod so as to ensure a seal between the pod and the door. Translational motion assembly 36 of pod access device 20 then proceeds to engage pod door 32, using latching mechanism 52 and alignment pins 48, and draws the pod door into recess 30 of enclosure door 21. Transverse motion assembly 63 then causes retraction of enclosure door 21, along with pod door 32, such that port 28 is clear and access to the interior of substrate storage pod 22 is gained. A substrate handling robot (not shown) in enclosure 26 then retrieves one or more wafers from within pod 22 and delivers them to various processing stations (not shown) within the enclosure. Then, after processing, these steps are reversed such that the contents of a different pod 22 can then be unloaded for processing in a similar fashion.

[0020] The above are exemplary modes of carrying out the invention and are not intended to be limiting. It will be apparent to those of ordinary skill in the art that modifications thereto can be made without departure from the spirit and scope of the invention as set forth in the following claims.

Claims

Claims:

1. A device for controlling access to the interior of a substrate storage pod from the interior of a semiconductor processing micro environment enclosure, the substrate storage pod having a removable pod door and the semiconductor processing micro environment enclosure having an enclosure door, the device comprising: a translational motion assembly adapted to translate the removable pod door relative to the substrate storage pod in a first, substantially straight path; and a transverse motion assembly adapted to translate the removable pod door and the enclosure door in a second, substantially straight path which is transverse to the first path.

2. The device of Claim 1, wherein the translational motion assembly comprises: a movable platform; a latching mechanism mounted to the movable platform and adapted to engage the pod door; a motor; and a linkage connecting the motor to the movable platform such that actuation of the motor causes translation of the pod door along the first path when the latch mechanism is engaging the pod door.

3. The device of Claim 2, wherein the translational motion assembly further comprises one or more alignment pins rigidly mounted relative to the movable platform and adapted to mate with corresponding alignment holes of the pod door.

4. The device of Claim 2, wherein the linkage comprises a ball screw threadingly mated with a nut.

5. The device of Claim 1, wherein the enclosure door is provided with a recess adapted to receive the pod door during motion in the second path.

6. The device of Claim 1, wherein the transverse motion assembly comprises: a motor; and . a linkage connecting the motor to the movable enclosure door such that actuation of the motor causes translation of the enclosure door along the second path.

7. The device of Claim 6, wherein the linkage comprises a ball screw threadingly mated with a nut.

8. A device for controlling access to the interior of a substrate storage pod from the interior of a semiconductor processing micro environment enclosure, the substrate storage pod having a removable pod door and the semiconductor processing micro environment enclosure having an enclosure door, the device comprising: means for translating the removable pod door relative to the substrate storage pod in a first, substantially straight path; and means for translating the removable pod door and the enclosure door in a second, substantially straight path which is transverse to the first path.

9. The device of Claim 8, wherein the means for translating the removable pod door comprises: means for engaging the pod door; means for moving the means for engaging the pod door such that the pod door is translated along the first path during engagement by the means for engaging the pod door.

10. The device of Claim 8, wherein the enclosure door is provided with a recess adapted to receive the pod door during motion in the second path.

11. A method for accessing the interior of a substrate storage pod from the interior of a semiconductor processing micro environment enclosure, the substrate storage pod having a pod door and the semiconductor processing micro environment enclosure having an enclosure door, the method comprising: establishing a seal between the substrate storage pod and the semiconductor processing micro environment enclosure; disengaging the pod door from the pod; translating the pod door relative to the substrate storage pod in a first, substantially straight path; and translating the pod door and the enclosure door in a second, substantially straight path which is transverse to the first path.

12. The method of Claim 11, wherein translating the pod door in the first path includes disposing the pod door in a recess of the enclosure door.