Wafer inspection method and device, and storage medium

Abstract

A wafer inspection method and device, and a storage medium. The method is used for inspecting the states of wafers (2) in a wafer boat (1), wherein the states of the wafers (2) comprise a single wafer, a tilted wafer and a stacked wafer; and the wafer boat (1) comprises a plurality of tooth slots (11) arranged in a first direction and used for placing the wafers (2) thereon. The inspection method comprises: sequentially scanning and inspecting all wafers (2) in a wafer boat (1) in a first direction by means of a sensor (31) on a wafer fork; acquiring a first height value when the sensor (31) inspects each wafer (2) and a second height value when the sensor (31) leaves each wafer (2); performing matching to acquire a tooth slot (11) number corresponding to each first height value and second height value; on the basis of the first height value and the second height value, calculating a sensing length of one wafer (2); and on the basis of the range in which the sensing length falls, determining the state of the wafer (2) and whether the tooth slot (11) is abnormal. When inspecting the states of the wafers (2) in the wafer boat (1), the sensor (31) can also check for abnormalities in the tooth slots (11) of the wafer boat (1), and identify an abnormal wafer (2) and tooth slot (11) in a timely manner .

Description

A wafer inspection method, apparatus and storage medium Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a wafer inspection method, apparatus, and storage medium. Background Technology

[0002] Safe wafer handling is a crucial technical indicator in semiconductor production lines. During semiconductor manufacturing, each process involves numerous wafer transfers, placements, and retrievals, thus requiring high levels of safety and reliability in these processes. Wafers are placed within a wafer boat, and forks are used to handle the placement and retrieval. Before gripping a wafer, the fork inspects the wafers within the boat to detect tilting and stacking issues, thereby enhancing retrieval safety.

[0003] Commonly used wafer boats include integrated wafer boats and modular wafer boats. Integrated wafer boats commonly use silicon carbide wafer boats, which offer superior performance in terms of high temperature resistance and lifespan. However, silicon nitride wafer boats are difficult to manufacture and expensive. Modular wafer boats, on the other hand, combine various components into a single unit using snap-fit, threaded, and adhesive-welded methods. Because the components of a modular wafer boat can be pre-fabricated and then assembled, it overcomes the disadvantage of difficult manufacturing. After repeated exposure to high temperatures, modular wafer boats can deform, causing the wafers placed on them to tilt or be misidentified as stacked wafers by sensors on the wafer forks, affecting wafer inspection results. Therefore, how to detect wafer boat anomalies in a timely manner during wafer inspection remains a technical challenge. Summary of the Invention

[0004] To overcome the above-mentioned shortcomings, the present invention aims to provide a wafer inspection method, device and storage medium, in which a sensor can detect the state of the wafer in the wafer boat and at the same time check for abnormalities in the wafer boat grooves, and promptly detect abnormal wafers and grooves.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A wafer inspection method is used for inspecting the state of wafers within a wafer boat, the wafer state including monolithic, oblique, and stacked wafers, the wafer boat including a plurality of slots arranged along a first direction for placing wafers, and the inspection method including:

[0007] The sensors on the fork sequentially scan and detect all wafers in the crystal boat in the first direction.

[0008] Acquire the first height value when the sensor detects each wafer and the second height value when it leaves the wafer;

[0009] The tooth number corresponding to the first height value and the second height value is obtained by matching;

[0010] The inductive length of a wafer is calculated based on the first height value and the second height value;

[0011] Based on the range of the sensing length, the wafer condition and whether there are any abnormalities in the slots are determined, specifically including:

[0012] When the sensing length is greater than the first threshold, the wafer is a slanted wafer;

[0013] The sensing length is compared with the first threshold, the second threshold, and the third threshold, and the comparison results are used to determine whether there are abnormal grooves in the area where the slant is located.

[0014] When there are abnormal grooves in the area where the slant plate is located, the groove number of the abnormal groove is determined according to the degree of deviation between the first height value and the second height value.

[0015] Furthermore, comparing the sensing length with the first, second, and third thresholds, and determining whether there are abnormal grooves in the area where the bevel is located based on the comparison results, specifically includes:

[0016] When the sensing length is greater than the second threshold, or the sensing length is greater than the first threshold but less than the third threshold, there are abnormal grooves in the area where the slant is located.

[0017] Furthermore, determining the tooth number of the abnormal tooth based on the degree of deviation between the first and second height values ​​specifically includes:

[0018] Compare the first height value and the second height value with the third height value and the fourth height value respectively. When the absolute value of the difference between the first height value and the third height value and / or the absolute value of the difference between the second height value and the fourth height value is greater than or equal to the fourth threshold, the tooth groove number corresponding to the first height value and / or the second height value is abnormal.

[0019] The third height value is the height value at which the sensor detects the wafer and causes the sensor signal to jump when the wafer is placed obliquely in the two layers of toothed grooves corresponding to the first and second height values ​​in the standard wafer boat. The fourth height value is the height value at which the sensor leaves the wafer and causes the sensor signal to jump again when the wafer is placed obliquely in the two layers of toothed grooves corresponding to the first and second height values ​​in the standard wafer boat.

[0020] Furthermore, determining the wafer's condition and the presence of anomalies in the slots based on the range of the sensing length also includes:

[0021] When the sensing length is greater than the fifth threshold and less than the sixth threshold, the wafer is a single piece and the slot where the wafer is located causes the wafer to tilt.

[0022] Determine whether the difference between the sensing length and the wafer thickness is greater than the fourth threshold;

[0023] If so, then the groove where the wafer is located is abnormal.

[0024] Furthermore, determining the wafer's condition and the presence of anomalies in the slots based on the range of the sensing length also includes:

[0025] When the sensing length is greater than or equal to the sixth threshold and less than or equal to the seventh threshold, the first height value and the fifth height value are compared. The fifth height value is the height value corresponding to the tooth groove setting wafer of the standard crystal boat and the first height value. When the sensor senses the wafer, the sensor signal jumps.

[0026] If the first height value equals the fifth height value, the wafer is a stacked wafer. If the first height value and the fifth height value are not equal, the groove corresponding to the first height value has an anomaly.

[0027] Furthermore, determining the wafer state and the slot state based on the range of the sensing length also includes:

[0028] When the sensing length is greater than or equal to the wafer thickness and less than or equal to the fifth threshold, the wafer is a single piece, and the corresponding slots of the wafer are normal.

[0029] Furthermore, obtaining the tooth number corresponding to the first height value and the second height value through matching specifically includes:

[0030] Obtain the dataset for each layer of slots in a standard wafer boat when inserting a single wafer. The dataset includes the slot number and the corresponding region height range.

[0031] Traverse the dataset to find the region height range corresponding to the first and second height values ​​to determine the tooth number.

[0032] Furthermore, the sensing length is the absolute value of the difference between the first height value and the second height value.

[0033] The present invention also discloses a wafer inspection device, including a wafer fork, on which a sensor is disposed. The sensor sequentially scans and inspects the wafers in the wafer boat in a first direction. The inspection device adopts the wafer inspection method described above.

[0034] The present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the wafer inspection method described above. Attached Figure Description

[0035] Figure 1 is a flowchart of a detection method according to an embodiment of the present invention;

[0036] Figure 2 is a schematic diagram of a wafer located inside a wafer boat in one embodiment of the present invention;

[0037] Figure 3 is an enlarged view of point A in Figure 2;

[0038] Figure 4 is an enlarged view of point B in Figure 2;

[0039] Figure 5 is an enlarged view of point C in Figure 2;

[0040] Figure 6 is a state diagram of the sensor scanning the wafer in one embodiment of the present invention;

[0041] Figure 7 is a schematic diagram of the structure of a wafer inspection device in one embodiment of the present invention. Detailed Implementation

[0042] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0043] This invention provides a wafer inspection method for detecting the slots in a wafer boat 1 and the wafer state within the wafer boat 1. The wafer state includes single-wafer, angled, and stacked wafers. Referring to Figure 2, the wafer boat 1 includes a plurality of slots 11 uniformly arranged along a first direction for placing wafers 2. The wafer boat 1 includes support portions 12, with adjacent support portions 12 having the same spacing along the first direction, forming a slot 11 between adjacent support portions 12. Normally, only one wafer 2 can be placed in a slot 11, and when a wafer 2 is inserted into a slot 11, it is supported on the corresponding support portion 12 located below that slot 11.

[0044] The wafers used in this embodiment are all standard wafers, meaning that the warpage of the wafers themselves is not considered in this embodiment.

[0045] Referring to Figure 1, the detection method includes:

[0046] S1. The sensor 31 on the fork 3 sequentially scans and detects all the wafers in the crystal boat in the first direction.

[0047] The first direction is the vertical direction. The fork can scan from bottom to top or from top to bottom. In one scan, the fork should be able to cover the entire crystal boat.

[0048] S2. Acquire the first height value when the sensor detects each wafer and the second height value when it leaves the wafer.

[0049] The sensor includes a transmitter and a receiver. A horizontal detection light beam (4) is formed between the transmitter and receiver. The wafer has a certain thickness. When the wafer is detected, the detection light beam is blocked, generating a signal. Therefore, when the sensor detects a wafer, it generates a signal jump both immediately upon detection and upon removal from the wafer. Based on the sensor's signal jump, a first height value and a second height value detected by the sensor can be obtained using a Z-axis encoder. The first height value and the second height value form a data pair, and each data pair corresponds one-to-one with a wafer.

[0050] S3. Obtain the tooth number corresponding to the first height value and the second height value by matching.

[0051] Step S3 specifically includes:

[0052] S31. Obtain the dataset when inserting a single wafer into each slot in the standard wafer boat. The dataset includes the slot number and the corresponding region height range.

[0053] The standard wafer carrier and the wafer carrier are the same type of wafer carrier. The standard wafer carrier must ensure that the slots are free of abnormalities, meaning that there should be no uneven slots where the same wafer is placed. The wafer inserted into the slot is the standard wafer. The standard wafer and the wafer carrier are the same type of wafer, and the standard wafer must ensure that it is free of warping or other abnormalities. The area height range refers to the height range corresponding to each layer of slots in the standard wafer carrier.

[0054] The dataset is acquired and stored in advance before wafer inspection. When wafer inspection is performed on each wafer of the same type, this dataset can be called to look up the slot number.

[0055] S32. Traverse the dataset and find the region height range corresponding to the first height value and the second height value to determine the tooth number.

[0056] For example, the crystal boat has 5 layers of tooth grooves, each with a height of 10, and the support part has a height of 5. The data set for the travel from the 1st to the 5th tooth groove is {(0-10, 1st layer)(15-25, 2nd layer), (30-40, 3rd layer), (45-55, 4th layer), (60-70, 5th layer)}. When the first height value is 35, the corresponding tooth groove number is 3; when the second height value is 45, the corresponding tooth groove number is 4.

[0057] S4. Calculate the induction length of a wafer based on the first height value and the second height value.

[0058] The sensing length is the absolute value of the difference between the first height value and the second height value. For example, when the first height value is 35 and the second height value is 40, the sensing length corresponding to this wafer is 5.

[0059] S5. Based on the range of the sensing length, determine the wafer condition and whether there are any abnormalities in the slots.

[0060] Because the wafer carrier moves up and down with the lifting platform during use, it's inconvenient to inspect the wafer's slots once it's mounted on the platform. Furthermore, the modular wafer carrier may become unstable after repeated exposure to high temperatures, potentially causing uneven slots where wafers are placed. Wafers placed on uneven slots may tilt slightly, increasing the likelihood of them being placed at an angle during the process of transferring them from the wafer cassette to the wafer carrier's slots. Therefore, in this embodiment, a preset algorithm detects both wafer status and slot abnormalities simultaneously, enabling timely identification and replacement or adjustment of the wafer carrier.

[0061] Step S5 specifically includes:

[0062] S511. When the sensing length is greater than the first threshold, the wafer is a skewed wafer.

[0063] The sensing length is L, and the first threshold is (h1+2d)*λ, meaning that when L>(h1+2d)*λ, the detected wafer is a slanted wafer. Here, d is the wafer thickness, h1 is the support thickness, and λ is the sensor position scaling factor. As shown in Figure 6, R is the radius of the wafer, and S is the perpendicular distance from the center o of the wafer to the detection light beam.

[0064] When the wafer is angled, the angled piece spans two adjacent slots in the vertical direction, resulting in a larger detected sensing length. The angled piece has a thickness of at least one *d* within the slots, and at least one *d* is exposed above the surface; therefore, the value *h1+2d* is chosen as a reference. However, *h1+2d* represents the tilt corresponding to a position along one diameter of the wafer. The incident light does not pass through the wafer's center but is offset relative to the center towards the opening of the wafer boat. Therefore, a scaling factor needs to be calculated. When the sensing length is greater than (h1+2d)*λ, the wafer is definitely angled.

[0065] S512. Compare the sensing length with the first threshold, the second threshold and the third threshold, and determine whether there are abnormal grooves in the area where the slant is located based on the comparison results.

[0066] After determining that the wafer is skewed, it may simply be that the wafer is skewed, or it may be skewed along with the abnormality of the grooves. Therefore, further judgment is required.

[0067] The comparison of the sensing length with the first, second, and third thresholds determines the degree of tilt of the bevel relative to the standard bevel, which is inserted into a standard crystal boat. Excessive or insufficient tilt of the bevel indicates the presence of abnormal grooves in the area where it is located.

[0068] S513. When there are abnormal tooth grooves in the area where the slant plate is located, the tooth groove number of the abnormal tooth groove is determined according to the degree of deviation between the first height value and the second height value.

[0069] Step S512 can only determine that there are abnormal grooves in the area where the inclined piece is located, but the inclined piece spans two grooves, so it is necessary to further determine which layer of grooves is abnormal.

[0070] Through steps S511-S513, the abnormality of the tooth groove can be determined simultaneously with the determination of the slanted piece, and the abnormal tooth groove number can be found in a timely manner. This process is completed during a single detection scan by the sensor, without the need for an additional detection mechanism.

[0071] Step S512 specifically includes:

[0072] When the sensing length is greater than the second threshold, or the sensing length is greater than the first threshold but less than the third threshold, there are abnormal grooves in the area where the slant is located.

[0073] The second threshold is (h1+h2+ε+ξ1)*λ, and the third threshold is (h1+h2+ε-ξ2)*λ, as shown in Figure 3. h2 is the height of the groove, ε is the minimum height of the wafer exposed in the groove of the standard wafer when it is placed obliquely, ξ1 is the threshold for the support part in contact with the upper end of the oblique wafer to move upward or the support part in contact with the lower end of the oblique wafer to move downward (the support part in the dotted line in Figure 3 is the offset support part), ξ2 is the threshold for the support part in contact with the upper end of the oblique wafer to move downward or the support part in contact with the lower end of the oblique wafer to move upward. If ξ1 or ξ2 is exceeded, at least one of the two support parts in contact with the oblique wafer is abnormal. The values ​​of ξ1 and ξ2 can be the same, both being ξ, where ξ is the offset distance threshold of the support part relative to the standard position in the first direction. ξ1 and ξ2 can also be different and can be set manually.

[0074] In this embodiment, ε, ξ1, and ξ2 are collected beforehand. By comparing them with the ideal situation, it is determined whether there are abnormal grooves in the area where the beveled wafer is located. When L > (h1 + h2 + ε + ξ1) * λ, it indicates that the tilt of the beveled wafer is greater than the tilt of the standard beveled wafer in the standard wafer boat. In this case, the support portion that abuts the upper part of the wafer moves upward and / or the support portion that abuts the lower part of the wafer moves downward. When (h1 + 2d) * λ < L < (h1 + h2 + ε - ξ2) * λ, it indicates that the tilt of the beveled wafer is less than the tilt of the standard beveled wafer in the standard wafer boat. In this case, the support portion that abuts the upper part of the wafer moves downward and / or the support portion that abuts the lower part of the wafer moves upward. Both of these situations indicate that there are abnormal grooves in the area where the beveled wafer is located.

[0075] When (h1+h2+ε-ξ2)*λ≤L≤(h1+h2+ε+ξ1)*λ, there are no abnormal tooth grooves in the region where the slant plate is located.

[0076] The inclined piece spans two toothed slots. Based on the first and second height values, the toothed slot numbers of the lower and upper halves of the inclined piece can be determined, and these two slot numbers are different at this point. However, after step S512, it is necessary to further determine which of the two toothed slots containing the inclined piece has a problem.

[0077] Step S513 specifically includes:

[0078] The first and second height values ​​are compared with the third and fourth height values, respectively. If the absolute value of the difference between the first and third height values ​​and / or the absolute value of the difference between the second and fourth height values ​​is greater than or equal to the fourth threshold, the slot number corresponding to the first and / or second height values ​​is abnormal. The third height value is the height value at which the sensor detects the wafer and causes a signal jump when the wafer is placed obliquely within the two slots corresponding to the first and second height values ​​in the standard wafer boat. The fourth height value is the height value at which the sensor moves away from the wafer and causes another signal jump when the wafer is placed obliquely within the two slots corresponding to the first and second height values ​​in the standard wafer boat.

[0079] In other words, referring to Figure 4, the placement part with the dashed line in Figure 4 is the abnormal placement part. A standard bevel is placed behind the two slots of the standard crystal boat (the placement part with the solid line) that correspond to the first height value and the second height value. The third height value is the height value when the sensor-sensed standard bevel wafer causes the sensor signal to jump. The fourth height value is the height value when the sensor-sensed standard bevel wafer leaves the sensor and causes the sensor signal to jump. The third height value and the fourth height value are acquired and stored in advance, which are the height values ​​of the ideal bevel state.

[0080] The fourth threshold is nλ*ξ, where n∈(0,1]. For example, n=0.5, and the fourth threshold is 0.5λ*ξ. When the absolute value of the difference between the first height value and the third height value is greater than or equal to the fourth threshold, it indicates that the lower part of the bevel is offset too much in this layer, exceeding the tolerance of the bevel in the corresponding layer of the standard crystal boat. Therefore, the groove corresponding to the first height value must be abnormal. Similarly, when the absolute value of the difference between the second height value and the fourth height value is greater than or equal to the fourth threshold, it indicates that the upper part of the bevel is deviated too much in this layer, exceeding the tolerance of the bevel in the corresponding layer of the standard crystal boat. Therefore, the groove corresponding to the second height must be abnormal.

[0081] For example, the slot number corresponding to the lower half of the bevel is N, and the slot number corresponding to the upper half is N+1. If the absolute value of the difference between the first height value and the third height value of the Nth layer is less than 0.5λ*ξ, then the layer containing the lower half of the bevel is normal, meaning the slots of the Nth layer are normal; otherwise, it is abnormal. If the absolute value of the difference between the second height value and the fourth height value of the N+1th layer is ≥ 0.5λ*ξ, then the slot containing the upper half of the bevel is abnormal, meaning the slots of the N+1th layer are abnormal; otherwise, it is normal.

[0082] In one embodiment, step S5, determining the wafer's state and whether there are any abnormalities in the slots based on the range of the sensing length, further includes:

[0083] S521. When the sensing length is greater than the fifth threshold and less than the sixth threshold, the wafer is a single piece and the slot where the wafer is located causes the wafer to tilt. At this time, the wafer and the slot are shown in Figure 5.

[0084] The fifth threshold is d+δ, and the sixth threshold is 2d, where δ is the sum of the machining error of the slot and the machining error of the wafer. The normal error δ value is relatively small and will not exceed the thickness of one d, for example, 0.5d. When d+δ<L<2d, the sensing length exceeds the sum of the wafer, the wafer error, and the slot error. The wafer does not cross the slot to form a skewed wafer, but there is still a tilting phenomenon within one slot.

[0085] S522. Determine whether the difference between the sensing length and the wafer thickness is greater than the fourth threshold.

[0086] Even if the wafer is tilted at this time, some offset of the slot is acceptable. Therefore, it is necessary to compare the degree of wafer offset at this time with the fourth threshold to determine the degree of offset of the corresponding slot.

[0087] S523. If so, the groove where the wafer is located is abnormal.

[0088] When Ld≥0.5λ*ξ, the offset of the tooth groove is too large, and the tooth groove where the wafer is located is judged to be abnormal; otherwise, the tooth groove where the wafer is located is normal.

[0089] Through steps S521-S523, while identifying the individual wafer, it is possible to check whether there are any abnormalities in the corresponding slots.

[0090] In one embodiment, step S5, determining the wafer's state and whether there are any abnormalities in the slots based on the range of the sensing length, further includes:

[0091] S531. When the sensing length is greater than or equal to the sixth threshold and less than or equal to the seventh threshold, compare the first height value and the fifth height value. The fifth height value is the height value corresponding to the toothed wafer set by the sensor when the wafer is sensed by the sensor, causing the sensor signal to jump.

[0092] The sixth threshold is 2d, and the seventh threshold is 2d+2δ. When 2d≤L≤2d+2δ, the scanned wafer may be a stacked wafer or a wafer skew caused by a groove abnormality. Therefore, it is necessary to compare the first height value and the fifth height value for further judgment.

[0093] S532. If the first height value is equal to the fifth height value, then the wafer is a stacked wafer. If the first height value and the fifth height value are not equal, then there is an anomaly in the groove corresponding to the first height value.

[0094] If the wafers are stacked and there is no tilt, the first and fifth height values ​​are equal. However, if there is an anomaly in the perforation, the wafer will tilt, and the first and fifth height values ​​will not be equal.

[0095] Wafers placed on uneven grooves will tilt slightly. When the wafer is detected by the sensor, it is easy to be identified as a stacked wafer. Through steps S531-S532, the wafer tilt caused by the grooves and the stacked wafer are distinguished. This avoids the situation where the wafer tilt caused by the deformation of the crystal boat is mistakenly identified as a stacked wafer, thus improving the detection accuracy and enabling timely detection of crystal boat problems.

[0096] In one embodiment, step S5, determining the wafer state and the slot state based on the range of the sensing length, further includes:

[0097] S541. When the sensing length is greater than or equal to the thickness of the wafer and less than or equal to the fifth threshold, the wafer is a single piece, and the corresponding slots of the wafer are normal.

[0098] The fifth threshold is d+δ. When d≤L≤d+δ, the wafer is within the allowable error range of the processing. At this time, it can be determined that the wafer is a single piece and the corresponding slot is normal.

[0099] In this embodiment, a sensor, during the vertical scanning process of the crystal boat, determines the single-wafer, stacked, and skewed state of the wafer by acquiring the first and second height values ​​of each wafer. At the same time, it can determine whether there are any abnormalities in the grooves of the crystal boat and accurately locate abnormal grooves.

[0100] Once all wafers in the wafer boat have been inspected, the movement of the wafer forks during transport can be compensated or the wafer positions can be corrected based on the inspection structure, ensuring that the wafer forks can accurately transport the wafers and avoid wafer damage.

[0101] The present invention also discloses a wafer inspection device. As shown in Figure 7, the wafer inspection device includes a wafer fork, on which a sensor is disposed. The sensor sequentially scans and inspects the wafers in the wafer boat in a first direction. The inspection device also includes a controller, which adopts the wafer inspection method described above.

[0102] The fork can be a single fork or a multi-fork with integrated control.

[0103] The present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described wafer inspection method.

[0104] Based on this understanding, the present invention can implement all or part of the processes in the above embodiments by instructing related hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0105] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A wafer inspection method, characterized in that: For detecting the state of a crystal boat and the wafers within the crystal boat, the wafer state including single wafer, oblique wafer, and stacked wafer, the crystal boat including a plurality of slots arranged along a first direction for placing the wafers, the detection method including: The sensors on the fork sequentially scan and detect all the wafers in the crystal boat in a first direction; The sensor acquires a first height value when it detects each wafer and a second height value when it leaves the wafer. The tooth number corresponding to the first height value and the second height value is obtained by matching; The sensing length of one wafer is calculated based on the first height value and the second height value; Based on the range of the sensing length, determine whether the wafer state and the grooves are abnormal, specifically including: When the sensing length is greater than the first threshold, the wafer is a slanted wafer; The sensing length is compared with the first threshold, the second threshold, and the third threshold, and the comparison results are used to determine whether there are abnormal grooves in the area where the oblique plate is located. When there is an abnormal groove in the area where the inclined plate is located, the groove number of the abnormal groove is determined according to the degree of deviation between the first height value and the second height value.

2. The wafer inspection method according to claim 1, characterized in that: The comparison of the sensing length with the first threshold, the second threshold, and the third threshold, and the determination of whether there are abnormal grooves in the area where the inclined plate is located based on the comparison results, specifically includes: When the sensing length is greater than the second threshold, or when the sensing length is greater than the first threshold and less than the third threshold, there is an abnormal groove in the area where the oblique plate is located.

3. The wafer inspection method according to claim 1, characterized in that: Determining the tooth number of the abnormal tooth groove based on the degree of deviation between the first height value and the second height value specifically includes: The first height value and the second height value are compared with the third height value and the fourth height value, respectively. When the absolute value of the difference between the first height value and the third height value and / or the absolute value of the difference between the second height value and the fourth height value is greater than or equal to the fourth threshold, the tooth groove number corresponding to the first height value and / or the second height value is abnormal. The third height value is the height value corresponding to the sensor sensing the wafer and causing the sensor signal to jump when the wafer is placed obliquely in the two layers of the toothed grooves corresponding to the first height value and the second height value in the standard wafer boat. The fourth height value is the height value corresponding to the sensor leaving the wafer and causing the sensor signal to jump again when the wafer is placed obliquely in the two layers of the toothed grooves corresponding to the first height value and the second height value in the standard wafer boat.

4. The wafer inspection method according to claim 1, characterized in that: Determining the state of the wafer and whether there is an abnormality in the tooth groove based on the range of the sensing length also includes: When the sensing length is greater than the fifth threshold and less than the sixth threshold, the wafer is a single piece and the groove where the wafer is located causes the wafer to tilt. Determine whether the difference between the sensing length and the wafer thickness is greater than a fourth threshold. If so, then the groove where the wafer is located is abnormal.

5. The wafer inspection method according to claim 1, characterized in that: Determining the state of the wafer and whether there is an abnormality in the tooth groove based on the range of the sensing length also includes: When the sensing length is greater than or equal to the sixth threshold and less than or equal to the seventh threshold, the first height value and the fifth height value are compared. The fifth height value is the height value corresponding to the sensor sensing the wafer and causing the sensor signal to jump when the wafer is placed in the groove corresponding to the first height value of the standard crystal boat. If the first height value is equal to the fifth height value, then the wafer is a stack; if the first height value and the fifth height value are not equal, then the groove corresponding to the first height value is abnormal.

6. The wafer inspection method according to claim 1, characterized in that: Determining the state of the wafer and the state of the tooth groove based on the range of the sensing length further includes: When the sensing length is greater than or equal to the thickness of the wafer and less than or equal to the fifth threshold, the wafer is a single piece, and the corresponding groove of the wafer is normal.

7. The wafer inspection method according to any one of claims 1-6, characterized in that: Specifically, obtaining the tooth number corresponding to the first height value and the second height value through matching includes: Obtain a dataset when a single wafer is inserted into each of the slots in a standard wafer boat, the dataset including the slot number and the corresponding region height range; Traverse the dataset to find the region height range corresponding to the first height value and the second height value to determine the tooth number.

8. The wafer inspection method according to any one of claims 1-6, characterized in that: The sensing length is the absolute value of the difference between the first height value and the second height value.

9. A wafer inspection device, characterized in that: The device includes a wafer fork, on which a sensor is disposed. The sensor sequentially scans and detects the wafers in the wafer boat in a first direction. The detection device employs the wafer detection method according to any one of claims 1-8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the wafer inspection method according to any one of claims 1-8.

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