Sampling method for wafer thickness measurement, computer equipment and readable storage medium

Abstract

The invention relates to a sampling method for wafer thickness measurement, computer equipment and a readable storage medium, and the method comprises the steps: determining which process cavity is used for processing each wafer in a target process, and obtaining the corresponding information of the wafers and the process cavities; and according to the corresponding information, wafers measured by the target wafer thickness measurement station in each preset test period cover all process cavities in the target process. According to the method, the wafers extracted by wafer thickness measurement are reasonably distributed according to the recorded corresponding information of the wafers and the process cavities, the extracted wafers are ensured to periodically cover all the process cavities of the target process, the situation that when a certain process cavity is abnormal, the process cavity is not detected due to the fact that the process cavity is not extracted for a long time in wafer thickness measurement is avoided, and the wafer thickness measurement accuracy is improved. Therefore, the product quality can be stabilized.

Description

Technical Field

[0001] The present application relates to semiconductor manufacturing, and particularly to a sampling method for wafer thickness measurement, a computer device, and a readable storage medium. Background Art

[0002] In the semiconductor foundry industry, a wafer goes through hundreds or thousands of processes from offline production to output, involving processes such as film deposition, lithography, etching, and wet cleaning. To ensure the safety and stability of each process, some inspection stations are configured after these processes, such as thickness inspection, line width inspection, alignment inspection, or defect inspection, etc. Among them, the thickness inspection of the wafer is an important inspection index and is an adjacent inspection step for multiple processes (such as film deposition processes like furnace tube and thin film, as well as etching and wet etching). The purpose is to monitor the stability of the thickness control of the hierarchical process machine (process equipment) and ensure that the thickness of the wafers processed by the process machine is within a certain safe range.

[0003] To ensure production efficiency and control production costs, wafer thickness inspection generally adopts a sampling inspection method. The inventor found in actual production that in the wafer thickness inspection using the traditional sampling inspection method, there is a problem that the number of wafers with excessive thickness that are not detected and directly released is relatively large. Summary of the Invention

[0004] Based on this, it is necessary to provide a more reasonable sampling method for wafer thickness measurement, a computer device, and a readable storage medium to reduce the number of wafers with excessive thickness that are not detected.

[0005] A sampling method for wafer thickness measurement includes: determining which process chamber processes each wafer in a target process to obtain the corresponding information between the wafer and the process chamber; according to the corresponding information, enabling the target wafer thickness measurement station to measure wafers covering all the process chambers in the target process within each preset test cycle.

[0006] The above sampling method for wafer thickness measurement reasonably distributes the wafers extracted for wafer thickness measurement through the recorded corresponding information between the wafer and the process chamber, ensuring that the extracted wafers periodically cover all the process chambers in the target process and avoiding the situation where a certain process chamber is not detected for a long time due to not being selected during wafer thickness measurement when it is abnormal. Therefore, the product quality can be stabilized.

[0007] In one embodiment, it further includes: obtaining wafer data waiting to be measured at the target wafer thickness measurement station; when the wafer data meets the first condition, enabling one measurement wafer batch to cover all the process chambers in the target process, and when the wafer data meets the second condition, covering all the process chambers in the target process through a continuous plurality of measurement wafer batches.

[0008] In one embodiment, the step of enabling one measurement wafer lot to cover all process chambers in the target process when the wafer data meets the first condition includes: in the one measurement wafer lot, selecting at least one wafer processed by each of the process chambers for wafer thickness measurement; the step of covering all process chambers in the target process by a plurality of consecutive measurement wafer lots when the wafer data meets the second condition includes: alternately selecting wafers processed by different process chambers for wafer thickness measurement for a plurality of consecutive measurement wafer lots.

[0009] In one embodiment, the step of alternately selecting wafers processed by different process chambers for wafer thickness measurement for different batches of the wafers to be sampled includes: determining the process chamber and measurement time corresponding to each wafer measured at the target wafer thickness measurement station; selecting the wafer processed by the process chamber that has been sampled the longest time ago from each batch of the wafers to be sampled for wafer thickness measurement.

[0010] In one embodiment, the step of selecting at least one wafer processed by each of the process chambers for wafer thickness measurement is to select one wafer processed by each of the process chambers for wafer thickness measurement; the step of alternately selecting wafers processed by different process chambers for wafer thickness measurement for different batches of the wafers to be sampled is to select one wafer processed by one process chamber in each wafer lot for measurement.

[0011] In one embodiment, the wafer data is the number of wafers, and meeting the first condition includes that the number of wafers is less than a preset threshold, and meeting the second condition includes that the number of wafers is greater than the preset threshold.

[0012] In one embodiment, the wafer data is the number of wafer lots, and meeting the first condition includes that the number of wafer lots is less than a preset value, and meeting the second condition includes that the number of wafer lots is greater than the preset value.

[0013] In one embodiment, the step of measuring the thickness of wafers by alternately selecting wafers processed in different ones of the process chambers for a plurality of consecutive measured wafer batches includes: selecting a wafer processed in a first process chamber from a first measured wafer batch for wafer thickness measurement; selecting a wafer processed in a second process chamber from a second measured wafer batch for wafer thickness measurement, where the second measured wafer batch is different from the first measured wafer batch, and the second process chamber is different from the first process chamber; starting from the step of again selecting a wafer processed in the second process chamber from the second measured wafer batch for wafer thickness measurement, and executing until the wafers measured within a preset test cycle cover all the process chambers in the target process.

[0014] In one embodiment, the first process chamber and the second process chamber are process chambers selected in a preset measurement order.

[0015] In one embodiment, the first process chamber is a random one among all the process chambers of the target process, and the second process chamber is a random one among the remaining process chambers of the target process after removing the first process chamber.

[0016] In one embodiment, the second process chamber is a random one among the process chambers that remain after removing the first process chamber from all the process chambers of the target process and that are separated from the last measured one by a first preset time interval.

[0017] In one embodiment, the wafers measured within each preset test cycle do not include the wafers that trigger an alarm during the target process.

[0018] In one embodiment, the target process is a multi-chamber thin film process or a multi-chamber etching process.

[0019] A computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps in the method of any of the above embodiments are implemented.

[0020] A computer device, including a memory and a processor, where a computer program is stored in the memory, and when the processor executes the computer program, the steps in the method described in any of the foregoing embodiments are implemented.

[0021] A computer program product, including a computer program, and when the computer program is executed by a processor, the steps of the method described in any of the foregoing embodiments are implemented. Description of the Drawings

[0022] To better describe and illustrate the embodiments and / or examples of the inventions disclosed herein, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be construed as limiting the scope of any of the disclosed inventions, the presently described embodiments and / or examples, or the presently understood best mode of these inventions.

[0023] Figure 1 is a flowchart of a sampling method for wafer thickness measurement in an embodiment of the present application;

[0024] Figure 2 is a flowchart of a sampling method for wafer thickness measurement in another embodiment of the present application;

[0025] Figure 3 is a schematic diagram of the implementation manner of channel A in an embodiment of the present application;

[0026] Figure 4 is a schematic diagram of the implementation manner of channel B in an embodiment of the present application;

[0027] Figure 5 is a flowchart of measuring the thickness of wafers by alternately selecting wafers processed in different process chambers for a continuous plurality of wafer batches in an embodiment of the present application. Detailed implementation manners

[0028] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0030] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, identify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the related listed items.

[0031] A traditional sampling method for wafer thickness detection is to draw according to the last digits of wafer lots (Lots), that is, several wafers are drawn from wafer lots with certain last digits for wafer thickness detection. Exemplarily, the last digits of wafer lots can be numbers or letters, and the numbers / letters that are prone to confusion are removed, such as the numbers 8, 0, and the letters B, O, I. Thus, the last digits consist of the following 31 letters and numbers:

[0032] 1, 2, 3, 4, 5, 6, 7, 9, A, C, D, E, F, G, H, J, K, L, M, N, P, Q, R, S, T, U, V, W, X, Y, Z.

[0033] For the manufacturing process of multi-chamber operation, there is a certain probability that wafers in a certain abnormal operation chamber will not be drawn for wafer thickness detection for a long time according to this drawing rule, which will in turn lead to the occurrence of a large number of abnormal events when the chamber is abnormal.

[0034] Figure 1 FIG. is a flowchart of a sampling method for wafer thickness measurement in an embodiment of the present application. Taking the application of this method to the main controller of a full-automatic intelligent production line as an example, it includes the following steps:

[0035] S110, determine which process chamber processes each wafer in the target process.

[0036] The target process is the process step that R & D personnel are concerned about and for which wafer thickness measurement is required after the process is completed during the chip production process, such as various types of film deposition processes such as furnace tube, thin film, and deposition, or processes such as etching and wet etching. Wafers are loaded during the production process through wafer carriers (such as BOX, i.e., cassette). Each wafer carrier loads several (such as 25) wafers as a batch (Lot), and each batch of wafers is identified by a wafer lot number. Each wafer in each batch is further identified by a wafer number (1 - 25). The process equipment of the target process can have one or more process chambers. Therefore, a target process step can be to process wafers through multiple process chambers, or to process wafers through one by one process chambers. In an embodiment of the present application, it is recorded which process chamber processes each wafer in the target process, and the corresponding information between the wafer number (including the lot number and the wafer number) and the process chamber is obtained. For example, each process chamber of the target process can be numbered, and the wafer number is correspondingly recorded with the number of the process chamber that processes the wafer to obtain this corresponding information.

[0037] S120, make the wafers measured at the wafer thickness measurement station cover all process chambers within each preset test cycle.

[0038] To ensure that when an abnormality occurs in a certain process chamber in the target process, resulting in abnormal wafer thickness, it can be detected in a timely manner through spot checks. Therefore, we perform sampling allocation based on the corresponding information between the aforementioned wafer numbers and process chambers, ensuring that within a certain period of time (i.e., within a preset test cycle), the wafers measured at the target wafer thickness measurement station cover all the process chambers of the target process. The time required for each process chamber (the wafers processed) to be measured once by the target wafer thickness measurement station is a preset test cycle.

[0039] The above sampling method for wafer thickness measurement reasonably allocates the wafers sampled for wafer thickness measurement through the recorded corresponding information between wafers and process chambers, ensuring that the sampled wafers periodically cover all the process chambers of the target process, avoiding the situation where an abnormality in a certain process chamber is not detected because it has not been sampled for a long time during wafer thickness measurement. Therefore, it can stabilize the product quality.

[0040] Traditional sampling methods for wafer thickness detection set the number of sampled wafers according to the processing capacity of the measurement machine (processing speed, hereinafter simply referred to as production capacity). However, in actual production, there are sometimes situations where the production capacity of the target process fluctuates or the production capacity of the measurement machine fluctuates. This will cause wafers to accumulate at the wafer thickness measurement station. At this time, if the problem of accumulation is solved by skipping products, there will be certain quality risks; or conversely (the number of sampled wafers is less than the production capacity of the measurement machine), the utilization rate of the measurement machine may be relatively low, resulting in waste of resources. To solve this problem, the present application further dynamically switches the sampling method of the wafers waiting to be measured according to the stacking situation at the wafer thickness measurement station, achieving the maximum utilization of wafer thickness measurement resources.

[0041] Specifically, Figure 2 is a flowchart of the sampling method for wafer thickness measurement in another embodiment of the present application, including the following steps:

[0042] S210, determine which process chamber processes each wafer in the target process.

[0043] Same as step S110, which will not be elaborated here.

[0044] S220, obtain the wafer data of the wafers waiting to be measured at the wafer thickness measurement station.

[0045] In an embodiment of the present application, when performing sampling allocation on the wafers waiting to be measured for wafer thickness measurement after the target process is completed, the wafer data of the wafers waiting to be measured at the target wafer thickness measurement station can be obtained first. This wafer data can be the number of wafers waiting to be measured or the number of wafer batches waiting to be measured. In an embodiment of the present application, sampling allocation is performed when each batch of wafers arrives at the target wafer thickness measurement station.

[0046] During the process of the target process, if an abnormality occurs, the process equipment of the target process will give an alarm. In one embodiment of the present application, the wafers that trigger the alarm are recorded, and the wafers that trigger the alarm are not sampled during the sampling distribution. Generally, there are problems with the wafers that trigger the alarm. Therefore, these wafers are excluded during the sampling distribution to make more effective use of the wafer thickness measurement machine.

[0047] S230. When the wafer data meets the first condition, one measurement wafer batch covers all process chambers. When the wafer data meets the second condition, all process chambers are covered by multiple measurement wafer batches.

[0048] In one embodiment of the present application, when each wafer batch arrives at the target wafer thickness measurement station after completing the target process, the wafer data in step S220 is obtained in real time. When the wafer data is small (for example, less than a preset threshold), according to the corresponding information in step S210, at least one wafer processed by each process chamber of the (target process) is selected for wafer thickness measurement. At this time, the time required for the target wafer thickness measurement station to complete the wafer thickness measurement of one wafer batch is a preset test cycle. When the wafer data is large (for example, greater than a preset threshold), wafers processed by different process chambers are alternately selected for wafer thickness measurement for different wafer batches. At this time, the time required for the target wafer thickness measurement station to complete the wafer thickness measurement of k wafer batches is a preset test cycle, where k is the number of process chambers of the target process. Specifically, channel A is started to perform sampling distribution for the wafer batch when the wafer data is small, and channel B is started to perform sampling distribution for the wafer batch when the wafer data is large. The above dynamic switching method of the dual channels for wafer thickness measurement can, on the one hand, maximize the utilization of the wafer thickness measurement capacity of the wafer fab and improve the circulation efficiency; on the other hand, it can ensure that each chamber of multi-chamber modules such as thin film / etching can be effectively monitored and the product quality can be stabilized.

[0049] Assume that the process machine of the target process has three process chambers CH_A, CH_B, and CH_C. By obtaining the wafer data waiting to be measured at the target thickness measurement station in real time and comparing it with the preset threshold set by the system. When the wafer data waiting to be measured is lower than the set preset threshold, channel A is started to select the wafer numbers for thickness measurement. When the wafer data waiting to be measured is higher than the set preset threshold, channel B is started to select the wafer numbers for thickness measurement. The preset threshold is set according to the processing capacity of the measurement machine at the target wafer thickness measurement station.

[0050] See Figure 3, when a batch of wafers (Lot1) arrives at the wafer thickness measurement station, the wafers in Lot1 include wafers processed by CH_A, CH_B, and CH_C. Obtain the wafer data currently waiting for measurement at the station and make a judgment. If it is lower than the preset threshold, trigger Channel A. After excluding the alarm wafer numbers, randomly select one wafer from each of the wafers processed by CH_A / CH_B / CH_C (a total of 3 wafers) for wafer thickness measurement. Channel A measures the wafer thickness by taking one wafer from each of CH_A / CH_B / CH_C for each batch of wafers, which is regarded as a preset test cycle. Since one wafer is selected from each cavity, effective monitoring of multiple cavities can be ensured.

[0051] Table 1

[0052]

[0053] Table 1 is a record form of the sampling distribution of wafer thickness measurement for Channel A. The following uses examples to illustrate the data in the table: After excluding the alarm wafer number (Alarm Wafer ID) 01 in the first row (LOT, CH_A), randomly select one wafer from the wafer numbers (Wafer ID) 04 / 07 / 10 / 13 / 16 / 19 / 22 / 25 for wafer thickness measurement. In the second row (LOT, CH_B), there is no alarm, and randomly select one wafer from the wafer numbers 02 / 05 / 08 / 11 / 14 / 17 / 20 / 23 for wafer thickness measurement. And so on.

[0054] See Figure 4, when a batch of wafers (Lot1) arrives at the wafer thickness measurement station, obtain the wafer data currently waiting for measurement at the station and make a judgment. If it is higher than the preset threshold, trigger Channel B. After excluding the alarm wafer numbers, randomly select 1 wafer processed in CH_A for wafer thickness measurement, and record the process chamber information (number) and the measurement time. When the next batch of wafers Lot2 arrives at the wafer thickness measurement station, after excluding the alarm wafer numbers, randomly select 1 wafer processed in CH_B for thick wafer measurement, and record the process chamber information (number) and the measurement time. When the next batch of products Lot3 arrives at the wafer thickness measurement station, after excluding the alarm wafer numbers, randomly select 1 wafer processed in CH_C for wafer thickness measurement, and record the process chamber information (number) and the measurement time. And so on. When Lot X arrives at the thickness measurement station, select the process chamber that has been the longest time since the last measurement, and randomly select one wafer from the wafers processed by it for measurement, and record the process chamber information (number) and the measurement time. That is, every time a batch of wafers arrives at the thickness measurement station, select the wafer processed by the process chamber that has been the longest time since the last sampled from this batch of wafers for wafer thickness measurement. Channel B performs wafer thickness measurement on the same number of wafer batches as the number of process chambers of the target process (3 in this embodiment), as a preset test cycle. In an embodiment of the present application, even if a preset test cycle of Channel B is not completed, but if the wafer data waiting for measurement is less than the preset threshold, Channel A is immediately started.

[0055] Table 2

[0056]

[0057] Table 2 is a record table of wafer thickness measurement sampling distribution for Channel B. The data in the table is explained by the following example: Randomly select 1 wafer processed in CH_A from LOT1 for wafer thickness measurement, and record the process chamber information (CH_A) and the measurement time (DATETIME1) sampled at the wafer thickness measurement station. The chamber selected for LOT X is obtained according to the previously recorded measurement time.

[0058] See Figure 5 , in an embodiment of the present application, the steps of alternately selecting wafers processed by different process chambers for wafer thickness measurement for a continuous plurality of wafer batches include:

[0059] S332, select the wafer processed by the first process chamber from the first measurement wafer batch for wafer thickness measurement.

[0060] If it is the first preset test cycle after starting Channel B, the first process chamber is any one of all the process chambers of the target process, that is, it can be randomly selected.

[0061] S334, Select wafers processed in the second process chamber from the second measurement wafer lot for wafer thickness measurement.

[0062] The second measurement wafer lot is different from the first measurement wafer lot. In an embodiment of the present application, the second measurement wafer lot is the next lot that arrives at the target wafer thickness measurement site after the first measurement wafer lot arrives at the target wafer thickness measurement site. The second process chamber is different from the first process chamber. If it is the first preset test cycle after starting channel B, the second process chamber is any one of the process chambers in the target process other than the first process chamber.

[0063] S336, Determine whether the measured wafers cover all the process chambers of the target process. If so, proceed to step S338; otherwise, return to step S334.

[0064] Returning to step S334 means repeating the step of selecting wafers processed in the second process chamber from the second measurement wafer lot for wafer thickness measurement until the measured wafers cover all the process chambers in the target process. Each time step S334 is executed, the measurement wafer lot selected is the next lot after the wafer lot selected when step S334 was executed last time.

[0065] S338, The current preset test cycle is completed.

[0066] In an embodiment of the present application, the process chambers selected in step S332 and each time step S334 is executed are the process chambers selected according to a preset measurement order.

[0067] In an embodiment of the present application, the first process chamber is a random one of all the process chambers in the target process, and the second process chamber selected each time step S334 is executed is a random one of the process chambers in the target process that has not been selected in the current preset test cycle.

[0068] In an embodiment of the present application, the second process chamber selected each time step S334 is executed is: a random one of the remaining process chambers in the target process that is separated from the last measurement of this chamber by a first preset time interval after removing the process chambers that have been selected in the current preset test cycle. In an embodiment of the present application, the first preset time interval can be a preset test cycle. In an embodiment of the present application, the first preset time interval involved each time step S334 is executed can also be different.

[0069] In an embodiment of the present application, the following steps are further included:

[0070] Determine the process chamber corresponding to each wafer measured at the target wafer thickness measurement site and the measurement time.

[0071] Based on the measured time and the current time, determine the time interval from the last measurement.

[0072] In one embodiment of the present application, the measured time is constantly refreshed. When a wafer in a current process chamber is measured, the last measured time is replaced by the current time.

[0073] In one embodiment of the present application, each time a wafer processed by a process chamber is selected for thickness measurement, a wafer processed by a process chamber may be randomly selected from the j process chambers with the longest time from the last selection of each process chamber according to the recorded measurement times for thickness measurement. Where j is less than the total number of process chambers of the target process, and may be specifically set based on experience.

[0074] Based on all the above embodiments, this application combines the number of wafers queued at the target thickness measurement site, mines the corresponding information between the cavity and wafer number of the target process equipment, integrates the alarm wafer number in the process, and determines in advance the test wafer number when the batch arrives at the target thickness measurement site. Transform passive measurement into active sampling, and from the perspective of intelligent analysis, ensure that each cavity of the multi-cavity process machine can be effectively monitored to avoid the occurrence of large-area impact caused by sudden abnormalities in a single cavity. At the same time, by combining the cavity rules of historical sampling wafer numbers, it is possible to automatically cycle and search for the cavity with the longest monitoring interval, and dynamically allocate and switch the wafer thickness measurement channel within the limited measurement resources of the factory to maximize the utilization rate of the wafer thickness measurement machine.

[0075] It should be understood that, although the various steps in the flowchart of the present application are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the present application may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0076] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tapes, floppy disks, flash memories, optical memories, high-density embedded non-volatile memories, resistive random access memories (ReRAM), magnetoresistive random access memories (MRAM), ferroelectric random access memories (FRAM), phase change memories (PCM), graphene memories, etc. Volatile memories can include random access memory (RAM) or external cache memories, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logics, data processing logics based on quantum computing, etc., without limitation.

[0077] The present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps in the method described in any one of the above embodiments are implemented.

[0078] The present application also provides a computer device, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, the steps in the method described in any one of the foregoing embodiments are implemented.

[0079] The present application also provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the method described in any one of the foregoing embodiments are implemented.

[0080] In the description of this specification, the descriptions referring to terms such as "some embodiments", "other embodiments", "ideal embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0081] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0082] The above-described embodiments merely represent several implementation manners of the present invention. The descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A sampling method for measuring the thickness of a wafer, characterized in that, Including: Determine which process chamber processes each wafer in the target process to obtain the corresponding information between the wafer and the process chamber; According to the corresponding information, enable the target wafer thickness measurement station to measure wafers covering all process chambers in the target process within each preset test cycle.

2. The sampling method for measuring the thickness of a wafer according to claim 1, wherein It further includes: Obtain wafer data of wafers waiting to be measured at the target wafer thickness measurement station; When the wafer data meets the first condition, enable one measurement wafer batch to cover all process chambers in the target process; when the wafer data meets the second condition, cover all process chambers in the target process through a continuous plurality of measurement wafer batches.

3. The sampling method for measuring the thickness of a wafer according to claim 2, wherein The step of enabling one measurement wafer batch to cover all process chambers in the target process when the wafer data meets the first condition includes: in the one measurement wafer batch, select at least one wafer processed by each of the process chambers for wafer thickness measurement; The step of covering all process chambers in the target process through a continuous plurality of measurement wafer batches when the wafer data meets the second condition includes: alternately select wafers processed by different process chambers for wafer thickness measurement for a continuous plurality of measurement wafer batches.

4. The sampling method for measuring the thickness of a wafer according to claim 3, characterized in that, The step of alternately selecting wafers processed by different process chambers for wafer thickness measurement for a continuous plurality of measurement wafer batches includes: Select a wafer processed by the first process chamber from the first measurement wafer batch for wafer thickness measurement; Select a wafer processed by the second process chamber from the second measurement wafer batch, where the second measurement wafer batch is different from the first measurement wafer batch, and the second process chamber is different from the first process chamber; Start executing the step of again selecting a wafer processed by the second process chamber from the second measurement wafer batch until the wafers measured within one preset test cycle cover all process chambers in the target process.

5. The sampling method for wafer thickness measurement according to claim 4, characterized in that The first process chamber and the second process chamber are process chambers selected according to a preset measurement order.

6. The sampling method for wafer thickness measurement according to claim 4, characterized in that The first process chamber is a random one among all process chambers of the target process, and the second process chamber is a random one among the remaining process chambers of the target process after removing the first process chamber.

7. The sampling method for wafer thickness measurement according to claim 6, characterized in that The second process chamber is a random one among the process chambers that are separated from the last measured one by a first preset time interval among the remaining process chambers of the target process after removing the first process chamber.

8. The sampling method for measuring the thickness of a wafer according to any one of claims 1-7, characterized in that, The wafers measured within each preset test cycle do not include the wafers that trigger an alarm during the target process.

9. A computer device, including a memory and a processor, where a computer program is stored in the memory, and when the processor executes the computer program, it implements the steps in the sampling method for wafer thickness measurement according to any one of claims 1-8.

10. A computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps in the sampling method for measuring the thickness of a wafer as described in any one of claims 1-8 are implemented.

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