ONO-based dispatching method and dispatching system

Abstract

This invention provides a dispatching method and system based on ONO (On-Organic) equipment. The dispatching method includes: selecting two wafer cassettes; determining a feasible constraint range for the starting slot in the boat based on the number of wafers in the two selected wafer cassettes, the allowable boat slot position range, and the wafer placement orientation; obtaining all candidate values ​​for the starting slot based on the process identifiers of the two wafer cassettes; if one of the candidate values ​​for the starting slot falls within the feasible constraint range, then determining that the two selected wafer cassettes can be batched; grouping the two wafer cassettes that meet the batching conditions into an ONO batch, and dispatching the ONO batch to the target ONO equipment according to preset conditions. This configuration results in high batching efficiency and accuracy, achieving automatic pre-batching and automatic control of shipment, improving equipment capacity, and reducing delivery cycle time.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a dispatching method and system based on an ONO machine. Background Technology

[0002] In advanced semiconductor manufacturing processes, especially for embedded flash memory products, the ONO (Oxide-Nitride-Oxide) stack-up deposition process is highly sensitive to device electrical parameters (such as Vtpi). Studies have shown that Vtpi is easily affected by multiple factors, including performance differences between ONO equipment, process drift before and after preventative maintenance (PM) of the furnace tubes, the aging degree of the individual boat, and the temperature gradient at the boat slot location. To compensate for these variations, the industry commonly employs a "feedforward compensation" strategy—that is, during the ion implantation (IMP) process before the ONO layer, the ion implantation dose is dynamically adjusted according to the final boat slot location where the wafer will be placed.

[0003] The effective implementation of this strategy relies on the pre-construction of ONO batches (ONOBatch) before the wafers enter the ONO site. This involves pairing eligible wafer cassettes together and locking the target boat slot position for each wafer within the cassette. This ensures that process compensation takes effect accurately.

[0004] However, in existing technologies, batching sites cannot wait for extended periods within the Q-Time window, leading to insufficient ONO machine fill rate and lost ONO production capacity. Controlling the fill rate requires manual reassembly, which carries significant risks, potentially resulting in incorrect machine placement or incorrect ordering, causing the Lot to be misplaced in the correct Boat Slot, ultimately leading to yield losses. Summary of the Invention

[0005] The purpose of this invention is to provide a dispatching method and system based on ONO machines to solve the problems of low efficiency and high error rate in existing dispatching methods.

[0006] To solve the above-mentioned technical problems, the present invention provides a dispatching method based on an ONO machine, which includes:

[0007] Select two wafer boxes;

[0008] Based on the number of wafers in the two selected wafer cassettes, the allowable range of the boat slot position, and the wafer placement direction, determine the feasible constraint interval of the starting slot position in the boat slot;

[0009] Based on the process identifiers of the two wafer cells, obtain all candidate values ​​for the starting slot; if there is a candidate value for the starting slot that falls within the feasible constraint range, then determine that the two selected wafer cells can be batched.

[0010] Two wafer cells that meet the batching conditions are grouped into an ONO batch, and the ONO batch is dispatched to the target ONO machine according to preset conditions.

[0011] Optionally, depending on the different placement order of the two wafer cassettes, the feasible constraint interval includes two corresponding sequence constraint sub-intervals;

[0012] If there exists a candidate value for the starting slot that falls within any of the sequence constraint sub-intervals, then it is determined that the two selected wafer cassettes can be batched according to the corresponding placement order.

[0013] Optionally, the process identifier includes the wafer placement orientation corresponding to the initial slot candidate value;

[0014] Based on the two different wafer placement orientations, the feasible constraint interval includes two corresponding orientation constraint sub-intervals;

[0015] If there exists a candidate value for the starting slot corresponding to the wafer placement direction that falls within the corresponding direction constraint sub-interval, then it is determined that the two selected wafer cassettes can be batched according to the corresponding wafer placement direction.

[0016] Optionally, the two different wafer placement orientations are the bottom-to-top (BTM) mode and the top-to-bottom (TOP) mode.

[0017] The direction constraint sub-interval corresponding to the BTM mode is:

[0018] [Max(x1+a-1, x2+a+b-1), Min(y1, y2+a)];

[0019] The direction constraint sub-interval corresponding to the TOP mode is:

[0020] [Max(x1, x2-a), Min(y1-a+1)] , y2-a-b+1)];

[0021] Where a is the number of wafers in the wafer cassette placed first, and [x1, y1] is the allowable boat slot position range of the wafer cassette placed first; b is the number of wafers in the wafer cassette placed later, and [x2, y2] is the allowable boat slot position range of the wafer cassette placed later.

[0022] Optionally, the preset conditions include at least one of the following:

[0023] Obtain the current load status of multiple target ONO machines, and prioritize dispatching the ONO batch to the target ONO machine with the lighter current load status;

[0024] Obtain the number of workable products for multiple target ONO machines, and prioritize assigning the ONO batch to the target ONO machine with a smaller number of workable products;

[0025] Obtain the serial numbers of multiple target ONO machines, and prioritize assigning the ONO batch to the target ONO machine with the smaller serial number.

[0026] Optionally, before batching and dispatching the wafer cassette, the dispatching method further includes:

[0027] For the two wafer cassettes to be batched, determine the target ONO machine to be dispatched after batching.

[0028] The current operating status of the target ONO machine is queried. If the target ONO machine is in operation and the estimated completion time exceeds the allowable waiting time window of the wafer cassette, the wafer cassette is prohibited from being placed and batched from the pre-cleaning site until the target ONO machine is ready to receive it.

[0029] Optionally, when the wafer cassette is at the upstream site of the target ONO machine, the steps of selecting the wafer cassette, determining whether it can be batched, and selecting the target ONO machine are completed.

[0030] When the target ONO machine is ready to receive, the wafer cassette is dropped from the upstream site to complete the batching and dispatching.

[0031] Optionally, the step of selecting two of the wafer cassettes includes:

[0032] Sort all the wafer cassettes to be batched;

[0033] Obtain the process flow formula corresponding to the first wafer cassette in the sorted order;

[0034] From all the wafer cassettes, select the wafer cassettes that have the same process flow formula as the wafer cassette ranked first, and form a subset to be paired.

[0035] Based on the wafer cell ranked first, it is sequentially combined with the wafer cells in the set of wafer cells to be paired to form candidate pairs of two selected wafer cells.

[0036] Optionally, if the wafer cassette that is ranked first cannot be batched with any of the N wafer cassettes in the set to be paired, then the wafer cassette that is ranked next in the order is used as the basis for batching.

[0037] To address the aforementioned technical problems, the present invention also provides a dispatching system based on an ONO machine, comprising: a control module and a wafer cassette; the wafer cassette has a process identifier, the process identifier including a candidate value for the starting slot; the control module is configured to batch and dispatch the wafer cassette according to the dispatching method based on the ONO machine described above.

[0038] In summary, the dispatching method and system based on ONO equipment provided by this invention includes the following steps: selecting two wafer cassettes; determining a feasible constraint range for the starting slot in the boat based on the number of wafers in the two selected wafer cassettes, the allowable boat slot position range, and the wafer placement direction; obtaining all candidate values ​​for the starting slot based on the process identifiers of the two wafer cassettes; if one of the candidate values ​​for the starting slot falls within the feasible constraint range, then determining that the two selected wafer cassettes can be batched; combining the two wafer cassettes that meet the batching conditions into an ONO batch, and dispatching the ONO batch to the target ONO equipment according to preset conditions.

[0039] This configuration, by analyzing the inherent conditions of each wafer cell, determines the feasible constraint range of the starting slot in the boat slot. This range is then compared with the candidate starting slot value in the process identifier of the current wafer cell to determine whether the selected wafer cell can be batched. After batching, the wafer is then assigned to various machines. This method offers high batching efficiency and accuracy, enabling automatic pre-batching and automated control of shipment, thereby increasing machine capacity and reducing delivery cycles. Attached Figure Description

[0040] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention.

[0041] Figure 1 This is a flowchart illustrating the dispatching method based on an ONO machine according to an embodiment of the present invention.

[0042] Figure 2 This is a schematic diagram of the wafer placement orientation in BTM mode according to an embodiment of the present invention.

[0043] Figure 3 This is a schematic diagram of the wafer placement orientation in TOP mode according to an embodiment of the present invention. Detailed Implementation

[0044] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.

[0045] As used in this invention, the singular forms “a,” “an,” “one,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; and the term “at least two” is generally used to mean “two or more”. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature; “one end” and “the other end,” and “proximal end” and “distal end” generally refer to two corresponding parts, which include not only endpoints. Furthermore, the terms "installed," "connected," and "attached," as used in this invention, and the term "set" on one element from another, should be interpreted broadly. They generally only indicate a connection, coupling, cooperation, or transmission relationship between the two elements, which can be direct or indirect through an intermediate element. They should not be construed as indicating or implying a spatial relationship between the two elements, meaning one element can be located inside, outside, above, below, or to one side of another element, unless otherwise explicitly stated. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Additionally, directional terms such as above, below, up, down, upward, downward, left, and right are used relative to exemplary embodiments as shown in the figures, with upward or upper directions pointing towards the top of the corresponding figure, and downward or lower directions pointing towards the bottom of the corresponding figure.

[0046] The purpose of this invention is to provide a dispatching method and system based on ONO machines to solve the problems of low efficiency and high error rate in existing dispatching methods. The following description refers to the accompanying drawings.

[0047] Please refer to Figure 1 This invention provides a dispatching method based on an ONO machine, comprising:

[0048] Step S1: Select two wafer pods (FOUP);

[0049] Step S2: Determine the feasible constraint range of the starting slot position in the boat groove based on the number of wafers in the two selected wafer boxes, the allowable range of the boat groove position, and the wafer placement direction;

[0050] Step S3: Based on the process identifiers of the two wafer cells, obtain all the candidate values ​​for the starting slot; if there is a candidate value for the starting slot that falls within the feasible constraint range, then determine that the two selected wafer cells can be batched.

[0051] Step S4: Combine two wafer cells that meet the batching conditions into an ONO batch, and dispatch the ONO batch to the target ONO machine according to preset conditions.

[0052] According to the ONO process flow, the wafers in the two wafer casks after batching will be placed sequentially into the boat slots of the boat. The boat contains, for example, M boat slots, and the positions of these boat slots are numbered, such as from 1 to M.

[0053] When placing wafers, all wafers in two wafer cassettes must be placed in a series of consecutive boat slots without overlapping (i.e., all wafers in one wafer cassette must be placed before placing wafers in the other wafer cassette). The wafers in both wafer cassettes must be placed in the same orientation (in ascending or descending order based on their serial numbers). Wafers do not need to fill all M boat slots, nor do they need to start placing wafers from the end boat slot numbered 1 or M. Instead, they can start from a starting slot (StartBoatSlot, hereinafter referred to as S) and place them in a specific orientation.

[0054] There are two wafer placement orientations: the bottom-to-top (BTM) orientation (numbers arranged in descending order) and the top-to-bottom (TOP) orientation (numbers arranged in ascending order). Please refer to [link / reference]. Figure 2 It shows an example where the starting slot S is boat slot number 45 and the wafer placement orientation is BTM mode. Figure 2 The example shows wafer placement in the order of boat slot 45 → boat slot 1. For the reverse, please refer to [reference needed]. Figure 3 It shows an example where the starting slot S is boat slot number 1 and the wafer placement orientation is TOP mode. Figure 3 In the example, when placing wafers, they are placed sequentially in the order of 1st boat slot → 45th boat slot.

[0055] Each wafer cassette corresponds to a specific range of boat slot positions. This means that when a wafer from each cassette is placed on the carrier boat, it can only be placed within a certain range, due to the relative positional relationship between the cassette and the carrier boat. The sequence range of boat slot positions that a wafer cassette can correspond to is the allowable boat slot position range for that wafer cassette. Once placed, the wafers in each wafer cassette cannot exceed the allowable boat slot position range of that cassette. (Continuing with...) Figure 2 Taking the carrier boat shown as an example, one wafer cassette is located on the side of the carrier boat with the smaller serial number, and the wafers it carries can be placed in the slots from number 1 to 25. The other wafer cassette is located on the side of the carrier boat with the larger serial number, and the wafers it carries can be placed in the slots from number 26 to 50. The allowable slot position ranges for the two wafer cassettes are [1, 25] and [26, 50], respectively.

[0056] The following description uses a specific embodiment. In step S1, two wafer cassettes are selected. According to the placement order of the two wafer cassettes, the wafer cassette on which the wafers are placed first on the carrier boat is called the first wafer cassette, and the wafer cassette on which the wafers are placed later on the carrier boat is called the second wafer cassette. Let the number of wafers loaded in the first wafer cassette be a, the number of wafers loaded in the second wafer cassette be b, the allowable boat slot position range of the first wafer cassette be [x1, y1], and the allowable boat slot position range of the second wafer cassette be [x2, y2].

[0057] Based on a determined wafer placement orientation, step S2 can determine the feasible constraint interval for the starting slot S in the boat groove. Furthermore, depending on the two different wafer placement orientations, the feasible constraint interval includes two corresponding directional constraint sub-intervals.

[0058] For the top-down placement mode, the a-wafers of the first wafer cassette are placed into the carrier boat in ascending order, starting from slot S. The wafer placement range of the first wafer cassette is [S , S+a-1], which must satisfy [S , S+a-1] ⊆ [x1, y1] to ensure that each wafer does not exceed the allowable slot position range of the first wafer cassette. The b-wafers of the second wafer cassette are placed into the carrier boat in ascending order, starting from slot S+a. The wafer placement range of the second wafer cassette is [S+a , S+a+b-1], which must satisfy [S+a , S+a+b-1] ⊆ [x2, y2].

[0059] By simultaneously solving [S, S+a-1] ⊆ [x1, y1] and [S+a, S+a+b-1] ⊆ [x2, y2], the feasible constraint interval for the initial slot S can be determined.

[0060]

[0061] In other words, the directional constraint sub-interval corresponding to the starting slot S in the TOP mode is:

[0062] [Max(x1, x2-a), Min(y1-a+1)] , y2-a-b+1)]

[0063] For the bottom-up BTM placement mode, the a-wafers of the first wafer cassette are placed into the carrier boat in descending order, starting from slot S. The wafer placement range of the first wafer cassette is [S-a+1, S], which must satisfy [S-a+1, S] ⊆ [x1, y1] to ensure that each wafer does not exceed the allowable slot position range of the first wafer cassette. The b-wafers of the second wafer cassette are placed into the carrier boat in descending order, starting from slot Sa. The wafer placement range of the second wafer cassette is [Sa-b+1, Sa], which must satisfy [Sa-b+1, Sa] ⊆ [x2, y2].

[0064] By simultaneously solving [S-a+1, S] ⊆ [x1, y1] and [Sa-b+1, Sa] ⊆ [x2, y2], the feasible constraint interval for the starting slot S can be determined.

[0065]

[0066] In other words, the starting slot S corresponds to the directional constraint sub-interval of the BTM mode as follows:

[0067] [Max(x1+a-1, x2+a+b-1), Min(y1, y2+a)]

[0068] Optionally, the wafer cassette has a process identifier (PPID) that includes a start boat slot index (SI). Further, the process identifier includes a wafer placement rule corresponding to the start boat slot index SI. Still using... Figure 2 As shown in the example, the process identifier (PPID) of one wafer cassette contains a starting slot candidate value SI=45, corresponding to a BTM (Browser-to-Member) wafer placement orientation. This means that the wafers in this cassette can be placed into the carrier boat in descending order of BTM orientation, starting with slot 45. It should be noted that each wafer cassette's process identifier can contain only one starting slot candidate value SI (and its corresponding wafer placement orientation), or it can contain two or more starting slot candidate values ​​SI (and their respective corresponding wafer placement orientations).

[0069] After determining the feasible constraint range of the starting slot S in step S2, step S3 obtains all candidate starting slot values ​​SI in the process identifiers of the two wafer cassettes, and compares each of these candidate starting slot values ​​SI with the feasible constraint range of the starting slot S. If at least one candidate starting slot value SI falls within the feasible constraint range, it is determined that the two selected wafer cassettes can be batched. Of course, if multiple candidate starting slot values ​​SI fall within the feasible constraint range, it is also determined that the two selected wafer cassettes can be batched.

[0070] In step S3, if it is determined that the two selected wafer cassettes can be batched, step S4 can be executed to combine the two wafer cassettes that meet the batching conditions into an ONO batch (ONOBatch), and the ONO batch is dispatched to the target ONO machine according to preset conditions. Subsequently, the starting slot candidate value SI selected in step S3, falling within the feasible constraint range, is used as the starting slot S, and the wafers are placed according to the wafer placement direction corresponding to the starting slot candidate value SI. Further, in step S3, if no starting slot candidate value falls within the feasible constraint range, it is determined that the two selected wafer cassettes cannot be batched. In this case, it is possible to return to step S1, reselect two wafer cassettes, and re-perform the batching judgment.

[0071] Furthermore, since the feasible constraint interval contains two corresponding directional constraint sub-intervals based on the two different wafer placement orientations, the comparison and judgment of the initial slot candidate value SI in step S3 should also be compared and judged with the directional constraint sub-interval corresponding to the wafer placement orientation. If there exists an initial slot candidate value SI corresponding to the wafer placement orientation that falls within the corresponding directional constraint sub-interval, then it is determined that the two selected wafer cassettes can be batched according to the corresponding wafer placement orientation.

[0072] Specifically, if the wafer placement orientation corresponding to a candidate starting slot value SI in the process identifier is BTM mode, then that candidate starting slot value SI should be compared and judged using the orientation constraint sub-interval corresponding to BTM mode. Similarly, if the wafer placement orientation corresponding to a candidate starting slot value SI in the process identifier is TOP mode, then that candidate starting slot value SI should be compared and judged using the orientation constraint sub-interval corresponding to TOP mode. As long as there exists a candidate starting slot value SI that satisfies the orientation constraint sub-interval of its corresponding wafer placement orientation, it can be determined that the two currently selected wafer cassettes can be batched, and the wafer placement orientation during batching is limited to the wafer placement orientation corresponding to that candidate starting slot value SI.

[0073] Optionally, depending on the different placement order of the two wafer cassettes, the feasible constraint interval includes two corresponding sequence constraint sub-intervals; if there is a candidate value for the starting slot that falls within either of the sequence constraint sub-intervals, then it is determined that the two selected wafer cassettes can be batched according to the corresponding placement order.

[0074] The preceding embodiments specified the placement order as first wafer cassette first, followed by second wafer cassette. In fact, if the placement order were second wafer cassette first, followed by first wafer cassette, with other conditions and parameters remaining unchanged, the feasible constraint interval could be different. That is, depending on the two different placement orders (first wafer cassette before second wafer cassette, or second wafer cassette before first wafer cassette), the feasible constraint interval contains two corresponding sequence constraint sub-intervals. The sequence constraint sub-interval where first wafer cassette precedes second wafer cassette has been specifically described in the preceding embodiments and will not be repeated here. The sequence constraint sub-interval where second wafer cassette precedes first wafer cassette can be obtained by symmetrically transforming a and b, x1 and x2, and y1 and y2 based on the sequence constraint sub-interval where first wafer cassette precedes second wafer cassette.

[0075] Specifically, the sequential constraint sub-interval of the second wafer cell preceding the first wafer cell corresponds to the directional constraint sub-interval of the TOP mode as follows:

[0076] [Max(x2, x1-b), Min(y2-b+1] , y1-b-a+1)]

[0077] The direction constraint sub-interval corresponding to the BTM mode is:

[0078] [Max(x2+b-1, x1+b+a-1), Min(y2, y1+b)]

[0079] For the two wafer cassettes selected in step S1, step S3 should compare the initial slot candidate value SI with the two corresponding sequence constraint sub-intervals according to two different placement orders. As long as there is an initial slot candidate value SI that falls within either sequence constraint sub-interval, it can be determined that the two currently selected wafer cassettes can be batched, and the placement order of the wafer cassettes during batching is limited to the placement order corresponding to the sequence constraint sub-interval.

[0080] The following example further illustrates this point:

[0081] Assume the number of wafers in the first wafer cassette is a=3, the number of wafers in the second wafer cassette is b=2, the allowable slot position range for the first wafer cassette is [1, 5], and the allowable slot position range for the second wafer cassette is [6, 10]. The process identifiers for the first and second wafer cassettes contain two candidate initial slot positions, SI=3 and 7, and the wafer placement orientation corresponding to both candidate initial slot positions SI is BTM mode.

[0082] The order constraint sub-interval of the first wafer cell preceding the second wafer cell corresponds to the direction constraint sub-interval of the BTM mode as follows:

[0083] Max(x1+a-1, x2+a+b-1) ≤ S ≤ Min(y1, y2+a)

[0084] Substituting a, b, x1, x2, y1, y2, we get 10 ≤ S ≤ 5, and S has no solution.

[0085] The sequential constraint sub-interval of the second wafer cell preceding the first wafer cell corresponds to the directional constraint sub-interval of the BTM mode as follows:

[0086] [Max(x2+b-1, x1+b+a-1), Min(y2, y1+b)]

[0087] Substituting a, b, x1, x2, y1, y2, we get 7 ≤ S ≤ 7, and S has a unique solution equal to 7.

[0088] Since the process identifier contains a candidate starting slot value SI=7, corresponding to the BTM mode, which falls within the order constraint sub-interval of the second wafer cassette preceding the first wafer cassette, it can be determined that the currently selected first and second wafer cassettes can be batched. Furthermore, the order of wafer cassette placement during batching is limited to the second wafer cassette being placed before the first. During batching, starting with slot S at 7, following the bottom-up BTM mode (with serial numbers arranged in descending order), the two wafers from the second wafer cassette are placed first (i.e., sequentially placed into slots 7 and 6), followed by the three wafers from the first wafer cassette (i.e., sequentially placed into slots 5, 4, and 3). It can be seen that the boat slot positions of the three wafers in the first wafer box are within the allowable boat slot position range [1, 5], and the boat slot positions of the two wafers in the second wafer box are within the allowable boat slot position range [6, 10]. Both satisfy their respective boat slot position range constraints and meet the rules of continuity and non-intersection.

[0089] Optionally, after grouping two wafer casks that meet the batching conditions into an ONO batch in step S4, it is necessary to dispatch it to the target ONO machine. The preset conditions include at least one of the following:

[0090] Condition C1: Obtain the current load status of multiple target ONO machines, and prioritize assigning the ONO batches to the target ONO machine with the lighter current load status. Among the workable ONO machines, those with fewer assigned batches (i.e., lighter current load status) are given priority. For example, if machine FDONOS01 has been assigned 5 batches and machine FDONOS02 has been assigned 4 batches, then the next assignment will prioritize machine FDONOS02 to ensure that the number of batches on each ONO machine is similar and to prevent polarization.

[0091] Condition C2: Obtain the number of workable products for multiple target ONO machines, and prioritize assigning the ONO batch to the target ONO machine with fewer workable products. Among the workable ONO machines, there may be different numbers of workable products (Lots). For example, machine FDONOS01 has 10 workable products (Lots), while machine FDONOS02 has 5 workable products (Lots). In the next allocation, priority will be given to machine FDONOS02 to prevent machines with fewer workable products from being unable to allocate Lots, thus avoiding capacity loss.

[0092] Condition C3: Obtain the serial numbers of multiple target ONO machines, and prioritize assigning the ONO batch to the target ONO machine with the smaller serial number. Multiple ONO machines can be sorted by machine name or other rules, and allocation can be performed according to the machine's serial number.

[0093] Optionally, one, two, or all three conditions C1, C2, and C3 can be selected. Furthermore, when selecting more than one condition, condition C1 has higher priority than condition C2, and condition C2 has higher priority than condition C3. That is, allocation is first performed based on the number of machine batches. If the number of batches is the same for all machines, the number of workable products for each machine is considered. If conditions C1 and C2 are both the same, allocation is performed using the machine's serial number, for example, by assigning machines in ascending order of name.

[0094] The above preset conditions can be set to distribute the ONO batches evenly after batching, ensuring production capacity.

[0095] Optionally, before batching and dispatching the wafer cassette, the dispatching method further includes:

[0096] Step SA: For the two wafer cassettes to be batched, determine the target ONO machine to be dispatched after batching;

[0097] Step SB: Query the current operating status of the target ONO machine. If the target ONO machine is in operation and the estimated completion time exceeds the allowable waiting time window of the wafer cassette, then prohibit the wafer cassette from being placed and batched from the pre-cleaning site until the target ONO machine is ready to receive it.

[0098] The inventors discovered that before entering the ONO station, wafers need to undergo a pre-cleaning station to remove surface contaminants. After pre-cleaning, wafers must proceed to the next process (such as the ONO process) within the allowed waiting time window (Q-Time); otherwise, surface degradation may affect yield. The ONO station's operation time is approximately 8.5 hours, while the allowed waiting time window (Q-Time) is only 3 hours. Therefore, in existing technology, wafers are held at the pre-cleaning station after pre-cleaning until the ONO station's operation time reaches approximately 7.5 hours before being released. Only then can batching begin, which may result in delayed processing, causing some ONO machines to idle and leading to lost capacity. Furthermore, ONO machines may idle prematurely, and mechanically releasing wafers according to the fixed waiting time (7.5 hours) will also result in lost capacity. ONO machine delays may also occur, potentially causing wafers to exceed the allowed waiting time window (Q-Time).

[0099] Therefore, in this embodiment, instead of controlling the release based on a fixed waiting time, the current operating status of the target ONO machine is actively queried, and the release is dynamically adjusted according to the expected completion time of the target ONO machine, which effectively ensures production capacity and meets the requirement of not exceeding the allowed waiting time window.

[0100] Optionally, when the wafer cassette is at the upstream site of the target ONO machine, the steps of selecting the wafer cassette, determining whether it can be batched, and selecting the target ONO machine are completed; when the target ONO machine has the receiving conditions, the wafer cassette is released from the upstream site, and batching and dispatching are completed.

[0101] Further research by the inventors revealed that in existing technologies, if batching stations only begin searching for wafer cassettes within a waiting time window, they often fail to gather a sufficient number of batches, resulting in insufficient ONO machine fill rates. Therefore, in this embodiment, the upstream station (e.g., the pre-cleaning station) of the target ONO machine needs to begin selecting and batching wafer cassettes. If batching is possible, the next target ONO machine to be dispatched needs to be determined. After these steps are completed, the wafer cassettes remain at the upstream station (e.g., the pre-cleaning station) until the target ONO machine is ready to receive them, at which point they are transferred from the upstream station, completing the batching and dispatching process.

[0102] Based on the preceding batching and dispatching steps, the batching method in this embodiment is highly efficient and accurate, and can achieve the purpose of automatic pre-batching and automatic control of delivery, thereby increasing machine capacity and reducing delivery cycle.

[0103] In some embodiments, although the selection of wafer cassettes in step S1 can be random or exhaustive, to improve the efficiency of selection and batch pairing, preferably, step S1, which selects two wafer cassettes, includes:

[0104] Step S11: Sort all the wafer cassettes to be batched;

[0105] Step S12: Obtain the process flow formula corresponding to the first wafer cell in the sorting;

[0106] Step S13: Select wafer cassettes from all the wafer cassettes that have the same process flow formula as the wafer cassette ranked first, and form a subset to be paired;

[0107] Step S14: Based on the wafer cell ranked first, combine it sequentially with the wafer cells in the set of wafer cells to be paired to form a candidate pair of two selected wafer cells.

[0108] Step S11 can first sort the wafer cassettes according to certain rules, such as sorting by FOUP Sorting. Step S12, after obtaining the wafer cassette ranked first, obtains its corresponding process recipe, because only wafer cassettes with the same process recipe can be batched. Step S13 filters out wafer cassettes with the same process recipe as the wafer cassette ranked first, forming a subset to be paired. Then, step S14 involves pairing the wafer cassettes in the subset to be paired with the wafer cassette ranked first in turn, forming candidate pairs. Subsequently, the batching judgment of these candidate pairs is performed according to steps S2 and S3. If batching is possible, the FOUP Sorting is updated, and step S4 is executed. After the FOUP Sorting is updated, the original wafer cassette ranked first and the wafer cassettes paired with it for batching are deleted. Then, the process returns to step S11 to re-sort all wafer cassettes, and step S12 redefines a new wafer cassette ranked first, and so on.

[0109] Optionally, if the wafer cassette ranked first cannot be batched with any of the N wafer cassettes in the subset to be paired, then the wafer cassette ranked next in the order is used as the basis for batching. In step S14, pairing is performed based on the wafer cassette ranked first. At this time, N wafer cassettes in the subset to be paired can be selected sequentially for pairing and batching. If all attempts fail, it is not necessary to exhaustively search all wafer cassettes in the subset to be paired. Instead, the wafer cassette ranked next in the order (i.e., the second-ranked wafer cassette) can be used as the basis for batching judgment. Further, after selecting the second-ranked wafer cassette, the corresponding process flow formula can be obtained by referring to steps S12 and S13. A subset of wafer cassettes with the same process flow formula as the one to be paired can be constructed, and batching and pairing attempts can be performed N times in sequence. The setting of the value of N here has a certain impact on the efficiency of batching and pairing. The value of N can be set according to the actual situation, for example, it can be selected as 5, or other suitable values.

[0110] Based on the dispatching method described above, this embodiment of the invention also provides a dispatching system based on an ONO machine, comprising: a control module and a wafer cassette; the wafer cassette has a process identifier, the process identifier including a starting slot candidate value SI; the control module is configured to batch and dispatch the wafer cassette according to the dispatching method based on the ONO machine described above. The control module can be integrated into a Manufacturing Execution System (MES), and the structure and principle of other components of the dispatching system can refer to existing technologies, which will not be elaborated here.

[0111] In summary, the dispatching method and system based on ONO equipment provided by this invention includes the following steps: selecting two wafer cassettes; determining a feasible constraint range for the starting slot in the boat based on the number of wafers in the two selected wafer cassettes, the allowable boat slot position range, and the wafer placement orientation; obtaining all candidate values ​​for the starting slot based on the process identifiers of the two wafer cassettes; if one of the candidate values ​​for the starting slot falls within the feasible constraint range, then it is determined that the two selected wafer cassettes can be batched; combining the two wafer cassettes that meet the batching conditions into an ONO batch, and dispatching the ONO batch to the target ONO equipment according to preset conditions. With this configuration, by analyzing the conditions of each wafer cassette, the feasible constraint range for the starting slot in the boat slot is obtained, and then compared with the candidate value for the starting slot in the process identifier of the current wafer cassette, it can be determined whether the currently selected wafer cassette can be batched, and then dispatched to each equipment after batching. It boasts high batching efficiency and accuracy, enabling automatic pre-batching and automatic control of shipment, thereby increasing machine capacity and reducing delivery cycle.

[0112] It should be noted that the above embodiments can be combined with each other. The above description is only a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the present invention.

Claims

1. A dispatching method based on an ONO machine, characterized in that, include: Select two wafer boxes; Based on the number of wafers in the two selected wafer cassettes, the allowable range of the boat slot position, and the wafer placement orientation, determine the feasible constraint range of the starting slot position in the boat slot; Based on the process identifiers of the two wafer cells, obtain all candidate values ​​for the starting slots therein; If there is a candidate value for the starting slot that falls within the feasible constraint range, then it is determined that the two selected wafer cells can be batched. Two wafer cells that meet the batching conditions are grouped into an ONO batch, and the ONO batch is dispatched to the target ONO machine according to preset conditions.

2. The dispatching method based on ONO machines according to claim 1, characterized in that, Depending on the different placement order of the two wafer cassettes, the feasible constraint interval includes two corresponding sequence constraint sub-intervals; If there exists a candidate value for the starting slot that falls within any of the sequence constraint sub-intervals, then it is determined that the two selected wafer cassettes can be batched according to the corresponding placement order.

3. The dispatching method based on ONO machines according to claim 1, characterized in that, The process identifier includes the wafer placement orientation corresponding to the initial slot candidate value; Based on the two different wafer placement orientations, the feasible constraint interval includes two corresponding orientation constraint sub-intervals; If there exists a candidate value for the starting slot corresponding to the wafer placement direction that falls within the corresponding direction constraint sub-interval, then it is determined that the two selected wafer cassettes can be batched according to the corresponding wafer placement direction.

4. The dispatching method based on ONO machines according to claim 3, characterized in that, The two different wafer placement orientations are the bottom-to-top (BTM) mode and the top-to-bottom (TOP) mode. The direction constraint sub-interval corresponding to the BTM mode is: [Max(x1+a-1, x2+a+b-1), Min(y1, y2+a)]; The direction constraint sub-interval corresponding to the TOP mode is: [Max(x1, x2-a), Min(y1-a+1, y2-a-b+1)]; Where a is the number of wafers in the wafer cassette placed first, and [x1, y1] is the allowable boat slot position range of the wafer cassette placed first; b is the number of wafers in the wafer cassette placed later, and [x2, y2] is the allowable boat slot position range of the wafer cassette placed later.

5. The dispatching method based on ONO machines according to claim 1, characterized in that, The preset conditions include at least one of the following: Obtain the current load status of multiple target ONO machines, and prioritize dispatching the ONO batch to the target ONO machine with the lighter current load status; Obtain the number of workable products for multiple target ONO machines, and prioritize assigning the ONO batch to the target ONO machine with a smaller number of workable products; Obtain the serial numbers of multiple target ONO machines, and prioritize assigning the ONO batch to the target ONO machine with the smaller serial number.

6. The dispatching method based on ONO machines according to claim 1, characterized in that, Before batching and dispatching the wafer cassettes, the dispatching method further includes: For the two wafer cassettes to be batched, determine the target ONO machine to be dispatched after batching. The current operating status of the target ONO machine is queried. If the target ONO machine is in operation and the estimated completion time exceeds the allowable waiting time window of the wafer cassette, the wafer cassette is prohibited from being placed and batched from the pre-cleaning site until the target ONO machine is ready to receive it.

7. The dispatching method based on ONO machines according to claim 1, characterized in that, When the wafer cassette is at the upstream site of the target ONO machine, the steps of selecting the wafer cassette, determining whether it can be batched, and selecting the target ONO machine are completed. When the target ONO machine is ready to receive, the wafer cassette is dropped from the upstream site to complete the batching and dispatching.

8. The dispatching method based on ONO machines according to claim 1, characterized in that, The step of selecting two of the wafer cassettes includes: Sort all the wafer cassettes to be batched; Obtain the process flow formula corresponding to the first wafer cassette in the sorted order; From all the wafer cassettes, select the wafer cassettes that have the same process flow formula as the wafer cassette ranked first, and form a subset to be paired. Based on the wafer cassette ranked first, it is sequentially combined with the wafer cassettes in the set of wafer cassettes to be paired, forming candidate pairs of two selected wafer cassettes.

9. The dispatching method based on ONO machines according to claim 8, characterized in that, If the wafer cassette that is ranked first cannot be batched with any of the N wafer cassettes in the set to be paired, then the wafer cassette that is ranked next in order will be used as the basis for batching.

10. A dispatching system based on an ONO machine, characterized in that, include: Control module and wafer box; The wafer cell has a process identifier, which includes a candidate value for the starting slot. The control module is configured to perform batching and dispatching of the wafer cassette according to the dispatching method based on the ONO machine as described in any one of claims 1 to 9.

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