Vertical Batch Furnace Assembly

Abstract

To provide a vertical batch furnace assembly for processing wafers comprising a cassette handling space with a cassette storage and a cassette handling mechanism.SOLUTION: The cassette handling mechanism comprises a cassette handler which is configured to transfer wafer cassettes between a wafer transfer position and cassette storage positions by supporting and moving the wafer cassettes on a cassette handler arm. The cassette handler arm is provided with a detector to detect a cassette in a detection area. The cassette handler moves the detection area of the detector towards one of the cassette storage positions to detect whether a cassette is present or not.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates generally to a vertical batch furnace assembly for processing wafers, and more particularly to a vertical batch furnace assembly for processing wafers provided with a cassette handling space constructed and arranged to handle wafer cassettes for storing wafers, the space including a cassette storage having a plurality of cassette storage locations and configured to store a plurality of wafer cassettes, and a cassette handler configured to move the wafer cassettes between the cassette storage locations while supporting the wafer cassettes on a cassette handler arm. [Background technology]

[0002] Most vertical batch furnace assemblies are provided with a cassette handling space for receiving and storing wafer cassettes therein. Such cassette handling spaces are typically provided with a cassette handling mechanism for moving wafer cassettes between a cassette entry / exit port, cassette storage, and a wafer transfer position. At the cassette entry / exit port, wafer cassettes can be exchanged between the vertical batch furnace assembly and the clean room environment in which the vertical batch furnace assembly is housed. Received wafer cassettes may be placed in the wafer transfer position, from which wafers are removed from the wafer cassette and loaded into a wafer boat for processing.

[0003] The cassette storage may have multiple cassette storage locations, each of which may store a wafer cassette. The cassette storage locations may be arranged in a storage rack provided with, for example, a storage carousel. A typical cassette handling mechanism may include an elevator mechanism and a robotic arm to reach the input / output ports, wafer transfer locations, and all wafer storage locations. The elevator mechanism may provide vertical movement of the cassette handling mechanism to reach cassette storage locations at different vertical heights. The robotic arm may provide two-dimensional horizontal movement to reach at least some of the storage locations.

[0004] Sensors may be required to detect at least one of the presence and correct orientation of a wafer cassette at at least one of the input / output ports, the cassette storage locations, and the wafer transfer locations in the cassette handling space. Because multiple wafer cassettes may be stored in the cassette storage, multiple cassette storage locations may be required. As a result, multiple sensors may be required to detect the presence and / or correct orientation of a wafer cassette on a storage location, which may result in a bulky structure. Summary of the Invention [Problem to be solved by the invention]

[0005] This Summary is provided to introduce a selection of concepts in a simplified form that are described in more detail below in the Detailed Description of the exemplary embodiments of this disclosure. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0006] It may therefore be an object to provide a vertical batch furnace assembly of improved design for detecting at least one of the presence and correct orientation of a wafer cassette in the assembly. [Means for solving the problem]

[0007] To that end, a vertical batch furnace assembly as recited in claim 1 may be provided. More specifically, the vertical batch furnace assembly may include a cassette handling space constructed and arranged to handle wafer cassettes for storing wafers. The space may include a cassette storage having a plurality of cassette storage positions and configured to store a plurality of wafer cassettes, and a cassette handler configured to move the wafer cassettes between the cassette storage positions. The cassette handler may be provided with a cassette handler arm for supporting the wafer cassettes. The cassette handler arm may be provided with a detector for detecting the cassette in a detection region.

[0008] The cassette handler may be constructed and arranged to move the detector's detection area toward one of a plurality of cassette storage locations and detect whether a cassette is present at the one cassette storage location. Having the detector provided on the cassette handler arm allows for the detector to be used at multiple storage locations. The detector can move along the storage locations with the cassette handler while detecting the presence of a wafer cassette in the detection area. Thus, a separate detector for each storage location may not be necessary.

[0009] For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described hereinabove. It is, of course, to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, those skilled in the art will recognize that the invention may be embodied or performed in a manner that achieves or optimizes, for example, one advantage or group of advantages as taught or suggested herein, without necessarily achieving other objects or advantages that may be taught or suggested herein.

[0010] Various embodiments are claimed in the dependent claims and will be further elucidated with reference to the examples shown in the figures. The embodiments may be combined or applied separately from each other.

[0011] All of these embodiments are intended to be within the scope of the invention disclosed herein. These and other embodiments will be readily apparent to those skilled in the art from the following Detailed Description of Certain Embodiments, which refers to the accompanying drawings, and the invention is not limited to any particular embodiment disclosed.

[0012] While this specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments of the present disclosure, the advantages of embodiments of the present disclosure may be more readily apparent from the following description of certain specific examples of embodiments of the present disclosure when read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0013] [Figure 1] 1 shows a top partial cross-sectional view of an example of an illustrative vertical batch furnace assembly. [Figure 2] 2 shows a cross-sectional top view of the cassette handling space of the embodiment of FIG. 1. [Figure 3] 10 shows a side cross-sectional view of another embodiment of a cassette handling space according to an embodiment; [Figure 4] 1 shows a detailed cross-sectional view of the cassette handler according to the description. DETAILED DESCRIPTION OF THE INVENTION

[0014] In this disclosure, similar or corresponding features are indicated by similar or corresponding reference numerals. The description of various embodiments is not limited to the examples shown in the figures, and the reference numerals used in the detailed description and claims are not intended to limit the description of the embodiments, but are included for a clear understanding of the embodiments by reference to the examples shown in the figures.

[0015] While certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments and / or applications of the invention, as well as obvious modifications and equivalents thereof. Therefore, it is intended that the scope of the disclosed invention should not be limited by the specific disclosed embodiments described below. The figures shown herein are not meant to be actual illustrations of any particular materials, structures or devices, but are merely idealized representations used to describe embodiments of the present disclosure.

[0016] As used herein, the term "wafer" may refer to any underlying material or materials that may be used or upon which a device, circuit, or film may be formed.

[0017] Most generally, the present disclosure may provide a vertical batch furnace assembly 10 for processing wafers, as shown in a top view in Figure 1. The vertical batch furnace assembly 10 may include a cassette handling space 12, a wafer handling space 14, and a first wall 16 separating the cassette handling space 12 from the wafer handling space 14. A wafer handler 56 may be positioned in the wafer handling space. The assembly may further include a process chamber 60 and a wafer boat handling apparatus positioned below the process chamber 60.

[0018] The first wall 16 may have at least one wafer transfer opening 18, and on a side of the first wall 16 facing toward the cassette handling space 12, a wafer transfer position 20 for a wafer cassette 22 may be provided, as shown in the top view of FIG. 2 . The cassette handling space 12 may include cassette storage and cassette handling mechanisms 26, 28. The cassette storage may have a plurality of cassette storage locations 24 and may be configured to store a plurality of wafer cassettes 22, each provided with a plurality of wafers. The cassette handling mechanisms 26, 28 may include a first cassette handler 26 configured to move the wafer cassette 22 between a first set 30 of cassette storage locations 24 and the wafer transfer position 20.

[0019] Optionally, the cassette handling mechanism 26, 28 may be provided with a second cassette handler 28 configured to move wafer cassettes between a second set 32 ​​of cassette storage locations 24 and the wafer transfer location 20. An advantage of an assembly having two cassette handlers 26, 28 may be that each cassette handler 26, 28 can reach at least a portion of the cassette storage locations 24 within the cassette handling space. No single robot arm needs to be able to reach all cassette storage locations. It is sufficient to move the first cassette handler 26 between the first set 30 of cassette storage locations 24 and the second cassette handler 28 between the second set 32 ​​of cassette storage locations 24, as long as the first set 30 and second set 32 ​​together include all cassette storage locations 24 in the cassette storage. By carefully selecting the locations of the first and second cassette handlers 26, 28 within the cassette handling space 12 relative to the cassette storage locations 24, each has a limited reach, while together they can still cover all of the cassette storage locations 24 throughout the cassette handling space 12. The first cassette handler 26 may be located, for example, at or near a first end of the cassette handling space 12, while the second cassette handler 28 may be located at or near a second end of the cassette handling space 12 opposite the first end. Thus, the first set 30 of cassette storage locations 24 would cover approximately half of the cassette handling space 12 near the first end, while the second set 32 ​​of cassette storage locations 24 would cover approximately the other half of the cassette handling space 12 near the second end. Because both the first cassette handler 26 and the second cassette handler 28 only need to cover approximately half the area relative to a given cassette handler, the reach may be much smaller. A smaller reach means that a less sophisticated and therefore cheaper cassette handler can be used.

[0020] Second, by having two cassette handlers 26, 28, both cassette handlers 26, 28 can move wafer cassettes toward the wafer transfer location, and they can do so simultaneously. This means that while the first cassette handler 26 is placing a wafer cassette 22 at the wafer transfer location 20, the second wafer handler 28 may already be retrieving another wafer cassette 22 from a cassette storage location 24 in the cassette storage. By judiciously selecting the locations for storing wafer cassettes 22 and the order in which wafer cassettes 22 are moved from the cassette storage to the wafer transfer location 20, a high overall movement capacity of the cassette handling mechanisms 26, 28 can be achieved. In such a scheme, the total movement capacity of the cassette handling mechanisms can simply be the sum of the movement capacities of the first and second cassette handlers 26, 28. To improve the overall movement capacity of the cassette handling mechanisms 26, 28, the movement speed of both the first and second cassette handlers 26, 28 need only be more than half that of the previously used cassette handler. A lower movement speed means that a less robust, and therefore less expensive, cassette handler can be used. Because of the lower movement speed, the wafer cassette 22 can also move more smoothly, reducing the risk of particle release that could damage the wafers. By using the first and second cassette handlers 26, 28, the reach can be improved and movement capacity can be increased.

[0021] In one embodiment, the first and second cassette handlers 26, 28 may each be provided with a cassette handler arm 34 and an elevator mechanism 36. The elevator mechanism 36 may be configured to reach wafer cassettes 22 located on cassette storage locations 24 at different vertical heights within the cassette handling space 12.

[0022] In one embodiment, the elevator mechanism 36 of the first cassette handler 26 may be located on or adjacent to the second wall 38, and the elevator mechanism 36 of the second cassette handler 28 may be located on or adjacent to the third wall 40. The second and third walls 38, 40 define the boundaries of the cassette-handling space 12 at opposite ends.

[0023] When the elevator mechanisms 36 of the first cassette handler 26 and the second cassette handler 28 are positioned on or adjacent to opposite ends of the cassette handling space 12, the cassette handlers 26, 28 themselves are also positioned on or adjacent to opposite ends of the cassette handling space 12. The first and second sets of cassette storage locations 30, 32 are, in turn, positioned on or adjacent to opposite ends of the cassette handling space 12. The first set 30 of cassette storage locations 24 may be positioned on or adjacent the second wall 38, while the second set 32 ​​of cassette storage locations 24 may be positioned on or adjacent the third wall 40. The first set 30 of cassette storage locations 24 will cover approximately half of the cassette handling space 12 nearest the first end, while the second set 32 ​​of cassette storage locations 24 will cover approximately the other half of the cassette handling space nearest the second end. Because both the first cassette handler 26 and the second cassette handler 28 only need to cover approximately half the area relative to known cassette handlers, their respective reach can be much smaller. The smaller reach means that less complex and robust cassette handlers 26, 28 may be possible, which is beneficial in terms of manufacturing costs.

[0024] In one embodiment, the cassette storage can be configured to store 10 to 50 wafer cassettes 22. The cassette storage may be configured to store, for example, at least 20 wafer cassettes 22. The cassette storage may also be configured to store at least 40 wafer cassettes 22. This means that the cassette storage has at least 20 or 40 cassette storage locations 24. Approximately 50 to 250 wafers are typically required to fill a wafer boat 58. Typically, there are about 25 wafers provided in a wafer cassette 22. This means that typically 2 to 10 wafer cassettes 22 are required to fill one wafer boat 58. By having at least 20 or 40 cassette storage locations 24, enough wafer cassettes 22 can be stored to fill at least two wafer boats 58, and particularly about four wafer boats. Therefore, while the vertical batch furnace assembly 10 is processing wafers from wafer cassettes 22 stored in the cassette handling space 12, the loading and unloading of wafer cassettes 22 into and from the cassette handling space 12 may be postponed for a significant amount of time.

[0025] In one embodiment, wafer cassette 22 may be embodied as a FOUP (Front Opening Unified Pod). FOUPs are industry standard wafer cassettes for wafers. The use of FOUPs is advantageous due to the interchangeability of wafer cassette 22 between vertical batch furnace assembly 10 and other wafer processing machines.

[0026] In one embodiment, the vertical batch furnace assembly 10 may further include at least one cassette entry / exit port 42, 44 provided in a wall 16, 38, 40, 46 bounding the cassette handling space 12. This may be the first, second, or third wall 16, 38, 40 already mentioned, but may also be a separate fourth wall 46. The cassette handling mechanism 26, 28 may be configured to additionally move wafer cassettes 22 to or from the at least one cassette entry / exit port 42, 44. The at least one cassette entry / exit port 42, 44 may provide an entrance to and an exit from the vertical batch furnace assembly 10 for the exchange of wafer cassettes 22 between the vertical batch furnace assembly 10 and the outside world (particularly a clean room environment).

[0027] At least one cassette input / output port 42, 44 may be provided on a fourth wall 46, which may demarcate the cassette handling space 12 at an end opposite the first wall 16, i.e., first and second cassette input / output ports 42, 44. The first cassette input / output port 42 may be reachable by the first cassette handler 26. The second cassette input / output port 44 may be reachable by the second cassette handler 28. The cassette input / output ports 42, 44, and optionally a portion of the cassette storage location 24, may be provided with a rotatable table for rotating the cassettes for proper alignment with the first or second cassette handler 26, 28.

[0028] By associating both the first cassette input / output port 42 and the second cassette input / output port 44 with the first cassette handler 26 and the second cassette handler 28, respectively, and therefore with the first and second sets 30, 32 of cassette storage locations 24, a clear separation is achieved within the cassette handling space 12. Each of the cassette handlers 26, 28 may have its own input / output ports 42, 44 and cassette storage locations 24. This means that they can operate independently of each other without having to wait for or get in each other's way. This may improve the efficiency of handling of wafer cassettes 22 within the cassette handling space 12.

[0029] In one embodiment, as shown in FIG. 3 , which shows a side cross-sectional view of another example of a cassette handling space, the vertical batch furnace assembly 10 can include storage racks 48. The storage racks can include at least some of the cassette storage locations 24. The storage racks 48 can include all of the cassette storage locations 24. The cassette handling space 12 can be accessible through a closable maintenance opening, through which at least one storage rack 48 can be removed from the cassette handling space 12.

[0030] The storage racks 48 are essentially racks of shelves upon which wafer cassettes 22 can be placed. It is a basic design with no moving parts. By placing wafer cassettes 22 on the storage racks 48, sufficient cassette storage locations 24 can be created. When these storage racks 48 are removable from the cassette handling space 12, they can be easily removed, for example, by dolly, when such removal is necessary or desirable. For example, one or more storage racks 48 can be removed to allow service personnel easy access to the first wall 16, where, for example, a cassette door opener device 54 may require maintenance. The cassette handler arm 34 of the second cassette handler 28 can be moved to an upper position, for example, by an elevator mechanism 36, to allow service personnel to pass underneath the cassette handler arm 34. For example, easy access to the cassette door opener device 54 can be obtained by removing three storage racks 48 from the area holding the second set 32 ​​of cassette storage locations 24 (see FIG. 1).

[0031] In one embodiment, the vertical batch furnace assembly 10 may have a substantially rectangular base with two opposing short sides defining a width 50 of the vertical batch furnace assembly 10 and two opposing long sides defining a length 52 of the vertical batch furnace assembly 10. The width 50 of the vertical batch furnace assembly 10 may be 2.2 meters or less, or preferably 1.7 meters or less. The length 52 of the vertical batch furnace assembly 10 may be 5 meters or less, or preferably 4 meters or less.

[0032] By having a substantially rectangular base, multiple vertical batch furnace assemblies 10 can be placed adjacent to one another, thus maximizing the use of available floor space. Adjacent vertical batch furnace assemblies 10 with rectangular bases may have no unused space between them. A width 50 of less than 2.2 meters is beneficial in terms of compatibility with other vertical batch furnace assemblies, for example, from other manufacturers / brands. A length 52 of 5 meters or less, preferably 4 meters or less, is beneficial in reducing the overall floor space.

[0033] In one embodiment, the vertical batch furnace assembly 10 may include a cassette door opener device 54. The cassette door opener device 54 may be located at or near the wafer transfer position 20. The cassette door opener device 54 may be disposed on the first wall 16. The cassette door opener device 54 may be configured to open the cassette door of a wafer cassette 22 located at the wafer transfer position 20. The cassette door opener device 54 may therefore automatically open the cassette door of a wafer cassette 22 located at the wafer transfer position 20.

[0034] In one embodiment, the vertical batch furnace assembly 10 may further include a wafer handler 56, a process chamber 60, and a wafer boat handling apparatus positioned below the process chamber 60. The wafer handler 56 may be positioned within the wafer handling space 14 and may be configured to transfer wafers between the wafer cassettes 22 in the wafer transfer position 20 and a wafer boat 58. The process chamber 60 may be configured to process wafers contained in the wafer boat 58. The wafer boat handling apparatus may be positioned adjacent to the wafer handling space 14. The wafer boat handling apparatus may be provided with a wafer boat 58 at the wafer boat transfer position and may be configured to transfer the wafer boat 58 to and from the process chamber 60.

[0035] When the wafer boat 58 is in the wafer boat transfer position, the wafer handler 56 may transfer unprocessed wafers from the wafer cassettes 22 in the wafer transfer position 20 to the wafer boat 58 and may transfer processed wafers from the wafer boat 58 to the wafer cassettes 22 in the wafer transfer position 20. When the wafer boat 58 is loaded with one or more wafers, the wafer boat handling device may transfer the loaded wafer boat 58 to the process chamber 60, where the wafers may be processed. After processing, the wafer boat handling device can return the processed wafer boat 58 from the process chamber 60 to the wafer boat transfer position, where the wafer handler 56 can transfer the processed wafer(s) from the wafer boat 58 to the wafer cassette 22 in the wafer transfer position 20 and transfer the unprocessed wafers from the wafer cassette 22 in the wafer transfer position 20 to the wafer boat 58, thus completing the batch process of the vertical batch furnace assembly 10.

[0036] In one embodiment, the first set 30 and the second set 32 ​​of cassette storage locations 24 may be different (see FIG. 2). This means that the first set 30 and the second set 32 ​​of cassette storage locations 24 are not equal sets and do not overlap. The first set 30 and the second set 32 ​​may be disjoint sets. Alternatively, they may be overlapping sets. The advantage of disjoint sets is that each cassette storage location 24 is associated with only one cassette handler 26, 28. This minimizes interference between the two cassette handlers 26, 28, which can increase the efficiency and reliability of the cassette handlers 26, 28 and reduce the likelihood of failure.

[0037] A wafer transfer position 20 for a wafer cassette may be provided in front of at least one wafer transfer opening 18 in a side of the first wall 16 facing the cassette handling space 12. The at least one wafer transfer opening 18 may be associated with at least one cassette swapper carousel 21. The at least one cassette swapper carousel 21 may include a plurality of cassette support surfaces, each configured to support a wafer cassette. The swapper carousel 21 may be rotatable by an actuator about a substantially vertical swapper axis 23 to move each cassette support surface 34 to at least one cassette loading / unloading position 25 and to the wafer transfer position 20 in front of the wafer transfer opening 18. The vertical batch furnace assembly, and in particular the cassette handling mechanism, may be configured to load or unload wafer cassettes from the cassette support surface 34 of the swapper carousel 21 in the at least one loading / unloading position 25.

[0038] In one embodiment, the cassette storage may be provided with a rotatable cassette storage carousel having at least a portion of the cassette storage locations 24. The cassette storage carousel may include a central vertical support that may be rotatable about a vertical storage carousel axis. The vertical storage carousel axis may optionally be aligned with the vertical swapper axis 23.

[0039] The cassette storage carousel may also include several platform stages connected to the central vertical support and having cassette storage locations 24. The cassette storage carousel may further include a drive assembly operably connected to the central vertical support for rotating the central vertical support having the several platform stages about the vertical carousel axis. Such a cassette storage carousel is an effective way to store wafer cassettes 22 in a limited space. Because the platform stages are rotatable, the cassette storage carousel may rotate unused or empty cassette storage locations in the general direction of the associated cassette handler 26, 28. Therefore, the cassette handler 26, 28 can always place a wafer cassette in the nearest cassette storage location. Therefore, the cassette handler 26, 28 may only need a smaller reach than would be required for the cassette handler 26, 28 to reach all of the cassette storage locations 24 by itself.

[0040] The cassette handlers 26, 28 may be configured to move the wafer cassettes 22 between the cassette storage locations 24. The wafer cassettes may be supported on a cassette handler arm 34. The cassette handler arm 34 may be provided with a detector 35 for detecting the cassette in a detection area. The cassette handlers 26, 28 may be constructed and arranged to move the detection area of ​​the detector 35 toward one of a plurality of cassette storage locations to detect whether a cassette is present at the one cassette storage location. Having the detector 35 provided on the cassette handler arm 34 allows the detector to be used for multiple storage locations. The detector 35 may be moved along the storage locations with the cassette handler while detecting the presence of a wafer cassette in the detection area.

[0041] As depicted in the top view of FIG. 4 , the cassette handler arm 34 may be provided with a gripper 37 constructed and arranged to be movable in a first direction 39 below a wafer cassette at a cassette storage location to pick up the cassette. The gripper 37 may have a triangular shape, with one of its corners extending in the first direction. A detector 35 may be mounted on the gripper 37. The detector 35 may be mounted at one of the corners of the gripper 37. The detector 35 may be mounted near one of the corners of the gripper 37 extending in the first direction 39. The detector 35 may have its detection area extending in the first direction 39. The detector 35 may be mounted near an edge of the gripper 37. The detector 35 may be constructed and arranged to detect a cassette in the detection area. The detector 35 may be mounted near the edge of the gripper 37, and the detection area may be adjacent to the gripper 37.

[0042] The detector 35 may comprise a laser or laser emitting diode for transmitting a beam of radiation into a detection region, and a receiver that is sufficiently sensitive to the return radiation of the laser beam from the cassette when positioned in the detection region. Such a detector may be relatively simple, fast, inexpensive and accurate.

[0043] The assembly further comprises at least one cassette load / unload position 25 associated with at least one wafer transfer position (20) in front of at least one wafer transfer opening (18) provided in the walls (16, 38, 40, 46) that bound the cassette handling space (12), and at least one cassette entry / exit port (42, 44) provided in the walls (16, 38, 40, 46). The cassette handler may be constructed and arranged to move a detection area of ​​the detector toward the at least one cassette load / unload position 25 and / or the at least one cassette entry / exit port (42, 44) to detect cassettes at the at least one cassette load / unload position 25 and / or the at least one cassette entry / exit port (42, 44). A separate detector at the at least one cassette load / unload position 25 and / or the at least one cassette entry / exit port (42, 44) may then be omitted, or an existing detector may be checked in this way.

[0044] The detector may be an acoustic wave sensor constructed and arranged to transmit acoustic waves into a detection region and to receive reflections of the acoustic waves from the cassette when positioned in the detection region. Such detectors can be relatively simple, fast, inexpensive, and accurate.

[0045] While illustrative embodiments of the invention have been described above, in part with reference to the accompanying drawings, it should be understood that the invention is not limited to these embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0046] Throughout this specification, a reference to "one embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the use of the phrase "in one embodiment" in various places throughout this description does not necessarily refer to the same embodiment.

[0047] Furthermore, it should be noted that one or more specific features, structures, or characteristics of the various embodiments described above may be used or implemented independently of one another and may be combined in any suitable manner to form new embodiments not expressly described. Reference numbers used in the detailed description and claims do not limit the description of the embodiments or the claims. Reference numbers are used for clarity only. [Explanation of symbols]

[0048] 10 Vertical Batch Furnace Assembly 12 Cassette handling space 14 Wafer handling space 16 The First Wall 18 Wafer transfer opening 20 Wafer transfer position 21 Swapper Carousel 22 wafer cassette 23 Vertical Swapper Axis 24 cassette storage locations 26 First Cassette Handler 25 cassette loading / unloading positions 28 Second Cassette Handler 30 First set (of cassette storage locations) 32 Second set (of cassette storage locations) 34 Cassette Handler Arm 35 detectors 36 Elevator mechanism 37 Gripper 38 The Second Wall 39 First Direction 40 The Third Wall 42 First cassette input / output port 44 Second cassette input / output port 46 The Fourth Wall 48 Storage Rack 50 width 52 length 54 Cassette door opener device 56 Wafer Handler 58 Wafer Boat 60 process chambers

Claims

1. A vertical batch furnace assembly (10) for processing wafers provided with a cassette handling space (12) constructed and arranged to handle wafer cassettes for storing wafers, said space comprising: a cassette storage having a plurality of cassette storage locations (24) and configured to store a plurality of wafer cassettes (22); a cassette handler (26) configured to move a wafer cassette (22) between cassette storage locations (24) while supporting the wafer cassette (22) on a cassette handler arm (34); the cassette handler arm (34) is provided with a detector (35) for detecting a cassette in a detection area, the cassette handler constructed and arranged to move the detection area of ​​the detector towards one of the plurality of cassette storage locations to detect whether a cassette is present at the one cassette storage location; at least one cassette loading / unloading position (25) associated with at least one wafer transfer position (20) in front of at least one wafer transfer opening (18) provided in a wall (16, 38, 40, 46) that defines the boundary of said cassette handling space (12); at least one cassette entry / exit port (42, 44) provided in said wall (16, 38, 40, 46); the cassette handler is constructed and arranged to move a detection area of ​​the detector toward the at least one cassette loading / unloading position (25) and the at least one cassette input / output port (42, 44) and to detect whether a cassette is present at the at least one cassette loading / unloading position (25) and the at least one cassette input / output port (42, 44).

2. 2. The vertical batch furnace assembly of claim 1, wherein the cassette handler arm is provided with a gripper constructed and arranged to be movable in a first direction beneath a wafer cassette in a cassette storage location to pick up the cassette.

3. 3. The vertical batch furnace assembly of claim 2, wherein said detector (35) is mounted to said gripper and said detection area extends in said first direction (39).

4. 4. The vertical batch furnace assembly of claim 3, wherein said detector (35) is mounted near a tip of said gripper along said first direction.

5. 3. The vertical batch furnace assembly of claim 2, wherein the detector (35) is mounted near an edge of the gripper.

6. 6. The vertical batch furnace assembly of claim 5, wherein the detector (35) is constructed and arranged to detect the cassette in a detection area, the detector being mounted near an edge of the gripper, and the detection area being adjacent to the gripper.

7. 3. The vertical batch furnace assembly of claim 2, wherein said gripper (37) has a triangular shape, one corner of said triangle extending in said first direction.

8. 2. The vertical batch furnace assembly of claim 1, wherein the cassette handler is provided with an elevator mechanism configured to reach wafer cassettes located at cassette storage locations at different vertical heights within the cassette handling space.

9. 9. The vertical batch furnace assembly of claim 8, wherein the elevator mechanism (36) of the cassette handler (26) is located on or adjacent to a wall (38) of the cassette handling space (12).

10. 2. The vertical batch furnace assembly of claim 1, wherein the cassette storage is configured to store at least 20 wafer cassettes (22).

11. 2. The vertical batch furnace assembly of claim 1, wherein the cassette storage is configured to store at least 40 wafer cassettes (22).

12. 2. The vertical batch furnace assembly of claim 1, wherein the wafer cassette (22) is embodied as a Front Opening Unified Pod (FOUP).

13. 2. The vertical batch furnace assembly of claim 1, further comprising at least one cassette input / output port (42, 44) provided in a wall (16, 38, 40, 46) defining the boundary of the cassette handling space (12), wherein the cassette handler (26, 28) is configured to additionally move wafer cassettes (22) between the at least one cassette input / output port (42, 44).

14. 2. The vertical batch furnace assembly of claim 1, comprising a substantially rectangular bottom surface having two opposing short sides defining a width (50) of the vertical batch furnace assembly (10) and two opposing long sides defining a length (52) of the vertical batch furnace assembly (10), wherein the width (50) of the vertical batch furnace assembly (10) is 2.2 meters or less.

15. 12. The vertical batch furnace assembly of claim 11, wherein the width (50) of the vertical batch furnace assembly (10) is 1.7 meters or less.

16. The vertical batch furnace assembly (10) further comprises at least one wafer transfer position (20) in front of at least one wafer transfer opening (18) provided in a wall (16, 38, 40, 46) defining the boundary of the cassette handling space (12), and the cassette handler (26, 28) is configured to additionally transfer wafer cassettes (22) between at least one cassette loading / unloading position (25) associated with the at least one wafer transfer position (20), and for each wafer transfer opening (18), the vertical batch furnace assembly (10) 16. The vertical batch furnace assembly of claim 1, further comprising a cassette door opener device (54) configured to open a cassette door of a wafer cassette (22) located at the wafer transfer position (20).

17. 17. The vertical batch furnace assembly of claim 1, wherein said cassette storage is provided with a rotatable cassette storage carousel having at least some of said cassette storage locations (24).

18. The detector (35) a laser or laser emitting diode for transmitting a radiation beam in a first direction (39) towards said detection area; 2. The vertical batch furnace assembly of claim 1, further comprising: a receiver surface sensitive to laser beam radiation returned from said wafer cassette (22) when positioned in said detection region.

19. 2. The vertical batch furnace assembly of claim 1, wherein the detector is an acoustic wave sensor constructed and arranged to transmit acoustic waves in a first direction (39) toward the detection region and to receive reflections of the acoustic waves returning from the wafer cassette (22) when positioned in the detection region.

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