FOSB wafer cassette management method and wafer handling system
By establishing a FOSB wafer box model library and using automated systems to manage and handle FOSB wafer boxes, the problems of time-consuming and labor-consuming and copper pollution are solved, and efficient wafer box management and handling are achieved.
Patent Information
- Application Number
- CN202410231318.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-29
- Publication Date
- 2025-08-29
AI Technical Summary
In the prior art, the management and handling process of FOSB wafer boxes are time-consuming and labor-intensive, and are prone to copper pollution problems.
By establishing a FOSB wafer box model library, the control department is used to control AMHS vehicles and sorting machines, and the FOSB wafer box is automatically managed and handled, ensuring that the correct type of wafer box matches the semiconductor process and avoiding copper contamination.
It has achieved the saving of manpower and material resources, reduced the occurrence of copper pollution, and improved management efficiency.
Smart Images
Figure CN120565441A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a management method for a FOSB wafer cassette and a wafer transport system, and in particular to a management method for a FOSB wafer cassette for accommodating test wafers and a test wafer transport system. Background Art
[0002] Test wafers are used to test the performance of equipment and chips during the semiconductor manufacturing process. In chip manufacturing, semiconductor factories often use test wafers to evaluate the performance of manufacturing equipment, verify production processes, and test the functionality and reliability of chips.
[0003] Semiconductor factories often need to use a large number of test wafers for testing. After the test is completed, a FOUP (Front Opening Unified Pod) is used to recover and store the test wafers. The wafers in the FOUP wafer box are transferred to a FOSB (Front Opening Shipping Box) in a sorter (Sorter Tool). Finally, the FOSB wafer box containing the test wafers is shipped to the supplier. Summary of the Invention
[0004] At least one object of the present invention is to provide a FOSB wafer box management method and a wafer handling system that can save time and labor and avoid copper contamination.
[0005] The present invention provides a FOSB wafer box management method, which is used to store test wafers. The FOSB wafer box management method includes: a model library establishment step of establishing multiple FOSB wafer box models represented by parameters to generate a model library (the generated model library includes multiple FOSB wafer box models represented by parameters); an association step of specifying a corresponding model for each FOSB wafer box transported to a semiconductor factory and associating the FOSB wafer box with the model; a first model selection step of selecting a model corresponding to the test of the semiconductor factory from the models associated with the FOSB wafer box in the model library; and a first wafer transfer step of transporting the FOSB wafer box corresponding to the selected model to a sorting machine, and transferring the test wafers in the FOSB wafer box to the FOUP wafer box in the sorting machine.
[0006] In one aspect, the FOSB wafer box management method further includes: after the first wafer transfer step, moving the empty FOSB wafer box to the FOSB wafer box storage station, and moving the FOUP wafer box containing the test wafers to the FOUP wafer box storage station.
[0007] In one aspect, the FOSB wafer box management method further includes: a FOUP wafer box conveying step of recovering the wafers that need to be recovered after testing and storing them in a FOUP wafer box, and conveying the FOUP wafer box to a sorting machine; a second model selection step of selecting a model corresponding to the wafer conveyed in the FOUP wafer box conveying step from the model library; and a second wafer transfer step of conveying the FOSB wafer box corresponding to the model selected in the second model selection step to a sorting machine, and transferring the wafers in the FOUP wafer box to the FOSB wafer box in the sorting machine.
[0008] In one aspect, the FOSB wafer box management method further includes: after the FOSB wafer box containing the wafers in the second wafer transfer step is transported to the FOSB wafer box storage station, an association removal step is performed to remove the association between the FOSB wafer box and the corresponding model in the model library.
[0009] In one aspect of the FOSB wafer box management method, in the second wafer transfer step, before transferring the wafer from the FOUP wafer box to the FOSB wafer box, it is confirmed whether the type of the FOUP wafer box is the same as the type of the FOSB wafer box. If it is confirmed that the type of the FOUP wafer box is the same as the type of the FOSB wafer box, the wafer is transferred from the FOUP wafer box to the FOSB wafer box.
[0010] In one aspect of the FOSB wafer box management method, the parameters include FOSB type, which includes copper and non-copper. A FOSB wafer box with a copper FOSB type is used to accommodate test wafers used in a copper-containing semiconductor production line, and a FOSB wafer box with a non-copper FOSB type is used to accommodate test wafers used in a non-copper semiconductor production line.
[0011] The present invention provides a wafer handling system, which includes: an AMHS carrier for carrying FOUP wafer boxes and FOSB wafer boxes; a sorting machine for transferring wafers between the FOUP wafer boxes and the FOSB wafer boxes; and a control unit for controlling the AMHS carrier and the sorting machine, wherein the control unit executes any of the above FOSB wafer box management methods by controlling the AMHS carrier and the sorting machine. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1FIG. 1 is a flow chart of transferring wafers from a FOSB cassette storage station to a FOUP cassette storage station in one embodiment, where the wafers are used for testing.
[0013] Figure 2 FIG. 1 is a flow chart of recycling tested wafers to a FOSB cassette storage station in one embodiment.
[0014] Figure 3 This is a block diagram showing a wafer transfer system according to another embodiment.
[0015] Figure 4 FIG. 1 is a flow chart of transferring wafers from a FOSB cassette storage station to a FOUP cassette storage station in another embodiment in which the wafers are used for testing.
[0016] Figure 5 The flowchart of another embodiment is to return wafers that have been tested and need to be returned to a storage station of a FOSB wafer box storage station. DETAILED DESCRIPTION
[0017] Below, preferred modes for implementing the present invention are described. Those skilled in the art will appreciate that the following embodiments are merely illustrative and the present invention is not limited thereto. Furthermore, it should be understood that in order not to obscure the technical concepts of the present invention, descriptions of many well-known structures and methods have been omitted.
[0018] In one embodiment of the present invention, test wafers are used to test the performance of devices and / or chips. In this case, to avoid copper contamination, a copper-containing or non-copper FOSB cassette is selected, depending on whether the semiconductor process being tested is copper-containing or copper-free. For example, if the semiconductor process being tested is copper-containing, a copper-containing FOSB cassette is selected; if the semiconductor process being tested is copper-free, a non-copper FOSB cassette is selected. This prevents copper contamination in both the semiconductor process and the FOSB cassette.
[0019] Figure 1 FIG. 1 is a flow chart of transferring wafers from a FOSB cassette storage station to a FOUP cassette storage station in one embodiment, where the wafers are used for testing.
[0020] First, in step S1 , a worker manually transports a FOSB cassette containing wafers corresponding to a semiconductor process to be tested from a FOSB cassette storage station to a sorting machine.
[0021] Next, in step S2, the empty FOUP wafer box is transported to the sorting machine by operating the AMHS (Automated Material Handling System) carrier through the operation interface of the MES (Manufacturing Execution System) (e.g., OpsView UI).
[0022] Next, in step S3 , the sorting machine is caused to transfer the test wafers from the FOSB cassette to the FOUP cassette.
[0023] Then, in step S4, the AMHS carrier is controlled through the operation interface of the MES system to move the FOUP wafer box containing the wafers to the FOUP wafer box storage station so that the wafers can be used for testing.
[0024] Furthermore, in step S5 , a worker manually transports the empty FOSB cassettes from the sorting machine to the FOSB cassette storage station.
[0025] As described above, as the number of test wafers and the FOSB cassettes that house them increases, manual handling of the FOSB cassettes in steps S1 and S5 becomes time-consuming and labor-intensive. Furthermore, in step S1, workers may mistakenly handle a FOSB cassette that is incompatible with semiconductor processes, leading to copper contamination.
[0026] In addition, the above-mentioned "staff manually transporting the FOSB wafer box" means, for example, that after the staff visually confirms the label on the FOSB wafer box to determine the type of FOSB wafer box (for example, whether it contains copper or not), they directly manually transport the required type of FOSB wafer box or use a transport tool.
[0027] Figure 2 FIG. 1 is a flow chart of recycling tested wafers to a storage station of a FOSB cassette in one embodiment.
[0028] First, in step S11 , a worker manually transports an empty FOSB cassette corresponding to the semiconductor process being tested from the FOSB cassette storage station to the sorting machine.
[0029] Next, in step S12, the AMHS carrier is manipulated through the operation interface of the MES system to transport the FOUP wafer box containing the wafers (ie, the wafers that have completed the test) to the sorting machine.
[0030] Next, in step S13 , the test wafers are transferred from the FOUP cassette to the FOSB cassette in the sorting machine.
[0031] Then, in step S14, the empty FOUP wafer box is transported from the sorting machine to the FOUP wafer box storage station using the AMHS carrier.
[0032] Furthermore, in step S15 , a worker manually moves the FOSB cassette containing the wafers from the sorting machine to the FOSB cassette storage station for shipment to a supplier.
[0033] As described above, in steps S11 and S15, workers need to manually operate the FOSB cassette, which is time-consuming and labor-intensive. Furthermore, in step S11, workers may mistakenly handle a FOSB cassette that is not compatible with semiconductor processes, resulting in copper contamination.
[0034] Figure 3 1 is a block diagram showing a wafer transfer system 10 according to another embodiment.
[0035] like Figure 3 As shown, the wafer handling system 10 of this embodiment includes: an AMHS carrier 20 for transporting FOUP wafer boxes and FOSB wafer boxes; a sorting machine 30 for transferring wafers between FOUP wafer boxes and FOSB wafer boxes; and a control unit 40 for controlling the AMHS carrier 20 and the sorting machine 30.
[0036] AMHS carriers are widely used to transport wafer cassettes in semiconductor manufacturing and testing processes. The AMHS carrier 20 of this embodiment uses an OHV (Over Head Vehicle) method. However, other methods can also be used, such as automatic guided vehicles (AGVs), rail guided vehicles (RGVs), conveyor belt systems, and other methods that can transport wafer cassettes.
[0037] The sorting machine 30 of the present embodiment only needs to be configured to be able to transfer wafers between the FOUP cassette and the FOSB cassette, and the structure of the sorting machine 30 is not particularly limited.
[0038] The control unit 40 is, for example, a computer including a processor and a memory, which can realize the functions of the MES system. The processor is composed of one or more combinations of a CPU (central processing unit), a GPU (graphics processing unit), an ASIC (application-specific integrated circuit), an FPGA (field programmable gate array), a circuit composed of multiple discrete semiconductors, etc. The memory is appropriately combined with volatile memory and non-volatile memory (for example, optical disk, hard disk, flash memory, etc.). The memory stores a program that enables the AMHS carrier 20 and the sorting machine 30 to operate. The processor controls the AMHS carrier 20 and the sorting machine 30 by reading and executing the program in the memory. In addition, the control unit 40 can also be composed of multiple computers that communicate information via a network.
[0039] Figure 3 The wafer handling system 10 shown includes the AMHS carrier 20, the sorting machine 30, and the FOUP wafer boxes and FOSB wafer boxes transported by the AMHS carrier 20. Conventional FOUP wafer boxes, FOSB wafer boxes, AMHS carriers and sorting machines can be used. The description of the specific structures of the FOUP wafer boxes, FOSB wafer boxes, AMHS carriers and sorting machines is omitted here.
[0040] Figure 4 FIG. 1 is a flow chart of transferring wafers from a FOSB cassette storage station to a FOUP cassette storage station in another embodiment in which the wafers are used for testing.
[0041] Before transferring wafers from the FOSB cassette storage station to the FOUP cassette, the control unit 40 first establishes multiple FOSB cassette models, and the established multiple FOSB cassette models constitute a model library (step S21).
[0042] The following table is an example of a built model library.
[0043] serial number Storage Station FOSB type supplier owner 990001 F01 Copper Company A Company A 990002 F02 No copper Company B Company B 990003 F03 Copper Company C Company C
[0044] The established model library includes three models, and the model numbers are 990001, 990002, and 990003. It should be understood that this model library is an example, and in practice, the established model library includes a large number of models, not limited to three.
[0045] Each model in the above model library includes four parameters, namely "storage station", "FOSB type", "supplier", and "owner". However, each model is not limited to these four parameters and may also include other parameters.
[0046] In the model library, a storage station refers to a storage station for storing FOSB wafer cassettes. There are usually multiple storage stations. In this embodiment, three are listed, represented by "F01," "F02," and "F03," respectively. However, the number of storage stations is not limited to three and can be any other number, such as one, two, or four or more.
[0047] The table above lists two "FOSB types": "Copper-containing" and "Copper-free." To prevent copper contamination, FOSB cassettes with the "Copper-containing" FOSB type store test wafers for semiconductor processes that contain copper, while FOSB cassettes with the "Copper-free" FOSB type store test wafers for semiconductor processes that do not contain copper. Furthermore, "FOSB types" are not limited to "Copper-containing" and "Copper-free" and may include other types.
[0048] The "supplier" in the above models refers to the company that provides the FOSB wafer cassettes. For example, in model number 990001, the supplier is Company A, which means that the FOSB wafer cassettes in this model were shipped from Company A.
[0049] In addition, the "owner" in the above models refers to the owner of the FOSB wafer box. For example, in model number 990001, the owner is Company A, which means that the owner of the FOSB wafer box in this model is Company A.
[0050] In step S22, a corresponding model is assigned to each FOSB cassette transported to the semiconductor factory, associating the transported FOSB cassette with the previously established model. For example, if a FOSB cassette transported from Company B is destined for storage at the storage station indicated by F02, the wafers contained in the FOSB cassette are used for testing copper-free semiconductor processes, and the owner of the FOSB cassette is Company B, then the model numbered 990002 is assigned to the FOSB cassette, associating the two. Furthermore, until the association between the two is released, the model numbered 990002 is not assigned to any other FOSB cassettes. In other words, a model numbered 990002 is assigned to only one FOSB cassette within the semiconductor factory, and each FOSB cassette within the semiconductor factory is associated (corresponds) with only one model numbered 990002.
[0051] When a semiconductor factory uses test wafers for testing, it selects a model corresponding to the copper-free process from the models associated with the FOSB wafer cassette in the model library (step S23), depending on whether the semiconductor process being tested is a copper-containing process or a copper-free process (in this embodiment, a copper-free process). Because model number 990002 in the model library shown in the table above is associated with the FOSB wafer cassette and corresponds to the copper-free process, model number 990002 is selected from the model library in step S23.
[0052] In addition, in step S23, if there are multiple models in the model library that meet the requirements (for example, if in this embodiment, multiple models are associated with the FOSB wafer box and the FOSB type is a copper-free process), then a model can be randomly selected from the multiple models.
[0053] Next, in step S24 , the control unit 40 controls the AMHS carrier 20 to transport the FOSB cassette corresponding to the selected model (numbered 990002 ) to the sorting machine 30 .
[0054] In step S25 , the control unit 40 controls the AMHS carrier 20 to transport the empty FOUP wafer box to the sorting machine 30 .
[0055] In step S26, the control unit 40 controls the sorting machine 30 to transfer the test wafers from the FOSB cassette to the FOUP cassette within the sorting machine 30. A FOUP cassette typically holds 25 wafers. In step S26, each wafer in the FOUP cassette is assigned a number, associating each wafer with the FOUP cassette and its storage location within the FOUP cassette.
[0056] Then, in step S27 , the control unit 40 controls the AMHS carrier 20 to transport the FOUP cassette containing the wafers to the FOUP cassette storage station so as to perform testing using the test wafers.
[0057] Furthermore, in step S28 , the control unit 40 controls the AMHS carrier 20 to transport the empty FOSB cassette from the sorting machine 30 to the FOSB cassette storage station.
[0058] exist Figure 4 In the process, step S24 of transporting the FOSB wafer box to the sorting machine 30 is performed first, and then step S25 of transporting the FOUP wafer box to the sorting machine 30 is performed, but it is not limited to this. Step S24 and step S25 can also be performed at the same time, or step S25 can be performed first and then step S24.
[0059] In addition, regarding step S27 and step S28, it is not limited to first performing step S27 to transport the FOUP wafer box to the FOUP wafer box storage station and then performing step S28 to transport the FOSB wafer box to the FOSB wafer box storage station. Step S27 and step S28 can be performed at the same time, or step S28 can be performed first and then step S27.
[0060] As described above, in this embodiment, because the AMHS carrier 20 is controlled by the control unit 40 to carry the FOSB wafer cassettes, it is possible to save manpower and reduce the problem of copper contamination caused by mistakenly carrying FOSB wafer cassettes that do not conform to semiconductor processes. These effects are particularly significant when the number of FOSB wafer cassettes is large.
[0061] Figure 5 In yet another embodiment, the present invention is a flow chart of recycling wafers that have undergone testing and need to be recycled to a FOSB wafer box storage station.
[0062] Wafers that have undergone testing and need to be recycled are collected and stored in FOUP cassettes. FOUP cassettes containing test wafers are stored in FOUP cassette storage stations. Information about the FOUP cassettes and the wafers stored therein stored in the FOUP cassette storage station is transmitted to the control unit 40 of the wafer handling system 10 via wired or wireless communication and stored in the storage unit of the control unit 40.
[0063] In step S31, the control unit 40 controls the AMHS carrier 20 to transport the FOUP wafer box containing the wafers to be tested from the FOUP wafer box storage station to the sorting machine 30. Figure 4 The wafers being transported are identical and are used in semiconductor processes that do not contain copper.
[0064] Next, in step S32, the control unit 40 selects a FOSB model from the model library that corresponds to the wafers in the FOUP cassette transported in step S31. Because the wafers in the FOUP cassette transported in step S31 are for use in a copper-free semiconductor process, the FOSB model with the "Copper-Free" FOSB type, i.e., the FOSB model numbered 990002, is selected in step S32. Furthermore, in step S32, if there are multiple models in the model library that correspond to the wafers in the FOUP cassette transported in step S31, a model is randomly selected from these multiple models.
[0065] Next, in step S33 , the control unit 40 controls the AMHS carrier 20 to transport the FOSB cassette associated with the FOSB model numbered 990001 from the FOSB cassette storage station to the sorting machine 30 .
[0066] Next, in step S34, the control unit 40 controls the sorting machine 30 to transfer the recovered test wafers from the FOUP cassettes to the FOSB cassettes within the sorting machine 30. Furthermore, in step S34, before transferring the test wafers from the FOUP cassettes to the FOSB cassettes, it is possible to first confirm whether the types of the FOUP cassettes and the FOSB cassettes are the same, that is, whether both are "copper-containing" or "copper-free." Only if the two types are the same are the wafers transferred from the FOUP cassettes to the FOSB cassettes. This more reliably prevents copper contamination.
[0067] Then, in step S35, the control unit 40 controls the AMHS carrier 20 to transport the FOSB wafer box containing the wafers to the FOSB wafer box storage station for shipment to the supplier, and removes the association between the FOSB model numbered 990001 and the FOSB wafer box from the model library. The FOSB model numbered 990001, which has been removed from the FOSB wafer box, can be assigned (allocated) again to a FOSB wafer box newly transported to the semiconductor factory.
[0068] In step S36 , the control unit 40 controls the AMHS carrier 20 to transfer the empty FOUP cassette from the sorting machine 30 to the FOUP cassette storage station.
[0069] exist Figure 5 In the process, step S31 of transporting the FOUP wafer box to the sorting machine 30 is performed first, and then steps S32 and S33 are performed, but it is not limited to this. Steps S32 and S33 can also be performed first, and then step S31.
[0070] In addition, regarding step S35 and step S36, it is not limited to first performing step S35 to transport the FOSB wafer box to the FOSB wafer box storage station and then performing step S36 to transport the FOUP wafer box to the FOUP wafer box storage station. Step S35 and step S36 can be performed at the same time, or step S36 can be performed first and then step S35.
[0071] As described above, in this embodiment Figure 5 In the illustrated process, the AMHS carrier 20 is controlled by the control unit 40 to transport the FOSB cassettes, saving manpower and reducing the risk of copper contamination caused by incorrectly transporting FOSB cassettes that are not compatible with semiconductor processes. These benefits are particularly significant when a large number of FOSB cassettes are being used.
[0072] In addition, in this embodiment Figure 4 、5 In the flow shown, the FOUP wafer cassette and the FOSB wafer cassette are transported under the control of the control unit 40, and can be configured to be automatically executed. Figure 4 、 5 In this case, the manpower of the workers can be saved and the problem of copper contamination caused by mistakenly transporting FOSB wafer cassettes that do not conform to the semiconductor process is less likely to occur.
[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit the present invention. Those skilled in the art will understand that the technical solutions of the various embodiments can be combined to form new technical solutions, which also fall within the scope of the present invention.
[0074] For example, those skilled in the art can Figure 1 The technical solution shown is Figure 5 The technical solutions shown in the figure are combined to form a new technical solution. Figure 2 The technical solution shown is Figure 4 The technical solutions shown are combined to form a new technical solution. Adopting these new technical solutions can also save manpower of staff and reduce the occurrence of copper pollution.
Claims
1. A method for managing a FOSB wafer cassette, wherein the FOSB wafer cassette is used to store test wafers, the method comprising: A model library building step of building a plurality of FOSB wafer box models represented by parameters to generate a model library; A step of assigning a corresponding model to each FOSB wafer cassette transported to the semiconductor factory and associating the FOSB wafer cassette with the model; A first model selection step of selecting a model corresponding to the test of the semiconductor factory from the models associated with the FOSB cassette in the model library; and The first wafer transfer step is to transport the FOSB cassette corresponding to the selected model to a sorting machine, and transfer the test wafers in the FOSB cassette to a FOUP cassette in the sorting machine.
2. The FOSB cassette management method according to claim 1 , further comprising: After the first wafer transfer step, an empty FOSB wafer box is transported to a FOSB wafer box storage station, and a FOUP wafer box containing the test wafers is transported to a FOUP wafer box storage station.
3. The FOSB cassette management method according to claim 1 , further comprising: The wafers that need to be recycled after testing are collected and stored in a FOUP wafer box, and the FOUP wafer box is transported to a sorting machine, that is, a FOUP wafer box transporting step; A second model selection step of selecting a model corresponding to the wafers transported in the FOUP wafer cassette transport step from the model library; and A second wafer transfer step is to transport the FOSB cassette corresponding to the model selected in the second model selection step to the sorting machine, and transfer the wafers in the FOUP cassette to the FOSB cassette in the sorting machine.
4. The FOSB cassette management method according to claim 3 , further comprising: After the FOSB cassette containing the wafers in the second wafer transfer step is transported to the FOSB cassette storage station, a de-association step is performed to de-associate the FOSB cassette from the corresponding model in the model library.
5. The FOSB wafer box management method according to claim 3, wherein: In the second wafer transfer step, before transferring the wafer from the FOUP wafer box to the FOSB wafer box, confirm whether the type of the FOUP wafer box is the same as the type of the FOSB wafer box. If it is confirmed that the type of the FOUP wafer box is the same as the type of the FOSB wafer box, transfer the wafer from the FOUP wafer box to the FOSB wafer box.
6. The FOSB cassette management method according to any one of claims 1 to 5, wherein: The parameters include FOSB type, which includes copper and non-copper, Use copper FOSB wafer cassettes to store test wafers used in copper-containing semiconductor production lines. A non-copper FOSB cassette is used to store test wafers used in a non-copper semiconductor production line.
7. A wafer handling system comprising: AMHS carrier for handling FOUP wafer cassettes and FOSB wafer cassettes; A sorting machine that transfers wafers between FOUP wafer cassettes and FOSB wafer cassettes; and A control unit that controls the AMHS carrier and the sorting machine, The control unit executes the FOSB wafer cassette management method according to any one of claims 1 to 6 by controlling the AMHS carrier and the sorting machine.