Wafer alignment device and wafer alignment method

Abstract

The invention provides a wafer alignment device and a wafer alignment method, relates to the technical field of semiconductor chips, and aims to solve the problems that a wafer to be detected is large in movement error and low in alignment efficiency. The wafer alignment device comprises at least three alignment modules and a moving assembly. The alignment module comprises a light-emitting device used for emitting light and a light-emitting intensity value used for receiving the emitted light and generating the received light in real time. The light-emitting devices and the receivers are in one-to-one correspondence in the first direction and are located on the two sides of the to-be-detected wafer respectively, the alignment position of the to-be-detected wafer can be directly determined according to the light-emitting intensity values of the receivers, the to-be-detected wafer does not need to be repeatedly moved into and out of an alignment area, the alignment efficiency is further improved, and the product yield is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing technology, and in particular to a wafer alignment device and a wafer alignment method. Background Art

[0002] In semiconductor manufacturing technology, bonding technology can bond two wafers together to achieve higher integration. With the development of three-dimensional integrated circuit (3DIC) technology, hybrid bonding technology, as the latest generation of bonding technology, plays an increasingly important role in it.

[0003] The related technology cannot detect the bonding marks of the upper and lower wafers at the same time. Therefore, it is necessary to first determine the alignment position of the upper wafer, then move the upper wafer out, determine the alignment position of the lower wafer, and finally move the upper wafer into the determined alignment position. The wafer is moved in and out multiple times, resulting in large errors in the alignment positions of the upper and lower wafers, reducing the alignment accuracy of the upper and lower wafers, and thus reducing the product yield. Summary of the invention

[0004] The embodiments of the present disclosure provide a wafer alignment device and a wafer alignment method, which aim to solve the problems of large movement error of a wafer to be measured and low alignment efficiency.

[0005] To achieve the above objectives, the embodiments of the present disclosure adopt the following technical solutions:

[0006] On the one hand, a wafer alignment device is provided. The wafer alignment device includes at least three alignment modules and a moving assembly. Among them, the alignment module includes a light emitting device and a receiver. The light emitting device is used to emit light, and the light intensity of all light emitting devices is equal. The receiver is used to receive the light emitted by the light emitting device and generate the light intensity value of the received light in real time. The light emitting device and the receiver correspond one-to-one along a first direction and are respectively located on both sides of the wafer to be tested. The orthographic projection of the light emitting device on the first plane is located on the circumference of the same circle. The first direction is the direction in which the light emitting device emits light, and the first plane is perpendicular to the first direction.

[0007] The wafer alignment device provided by the above-mentioned embodiment of the present disclosure, when the unblocked area of ​​the light-emitting device is larger, the more light emitted falls into the receiver, and the luminous intensity value of the receiver is larger, so the position of the wafer to be tested can be determined in real time according to the luminous intensity value of the receiver. The device is simple to operate, and can adjust the position of the wafer to be tested according to the real-time luminous intensity value. The movement error of the wafer to be tested is small, and the alignment efficiency is high. It can meet the high-precision alignment requirements of the wafer to be tested and improve the product yield.

[0008] In some embodiments, all light emitting devices or all receivers are located on the same side of the wafer to be tested.

[0009] In some embodiments, the light emitting sides of all light emitting devices and / or the receiving sides of all receivers are at the same height from the plane where the wafer to be tested is located.

[0010] In some embodiments, the light emitting devices of the at least three alignment modules are arranged in a circular array as orthographic projections on the first plane.

[0011] In some embodiments, a diameter of an orthographic projection of the light emitting device on the first plane is greater than or equal to 2 mm.

[0012] In some embodiments, the wafer alignment device further comprises a controller. The alignment module and the moving component are coupled to the controller. The controller is configured to: control the moving component to move the wafer to be tested in the extension direction of the first plane according to the luminous intensity value of the receiver.

[0013] In some embodiments, the wafer to be tested includes a first wafer and a second wafer. The moving assembly includes a first moving mechanism and a second moving mechanism. The first moving mechanism includes a first carrier and a first driving unit connected to each other. The first carrier is used to carry the first wafer, and the first driving unit is connected to the alignment module to drive the first carrier to move. The second moving mechanism includes a second carrier and a second driving unit connected to each other. The second carrier is used to carry the second wafer, and the second driving unit is connected to the alignment module to drive the second carrier to move.

[0014] In some embodiments, the first carrier includes a first vacuum chuck connected to a side of the first wafer away from the second wafer. The second carrier includes a second vacuum chuck connected to a side of the second wafer away from the first wafer.

[0015] On the other hand, a wafer alignment method is provided. The wafer alignment method includes: providing a wafer to be tested and a wafer alignment device as described in some embodiments above; the wafer to be tested includes a first wafer and a second wafer. According to the luminous intensity values ​​of the receivers of at least three alignment modules, the position of the first wafer is adjusted, and the first wafer is moved from a first initial position to a first alignment position; at the first alignment position, the difference in the luminous intensity values ​​of any two receivers in at least three alignment modules is less than or equal to a first threshold value, and the orthographic projection of the light-emitting device on the first plane has no overlap or partially overlaps with the orthographic projection of the first wafer on the first plane. According to the luminous intensity values ​​of the receivers of at least three alignment modules, the position of the second wafer is adjusted, and the second wafer is moved from a second initial position to a second alignment position; at the second alignment position, the difference in the luminous intensity values ​​of any two receivers in at least three alignment modules is less than or equal to the second threshold value.

[0016] The wafer alignment method provided by the above-mentioned embodiment of the present disclosure, when it is determined that the first wafer is located at the first alignment position, the light emitted by the light-emitting device can still enter the receiver, and the position of the second wafer can be determined according to the luminous intensity value of the receiver, and the second wafer is moved to the second alignment position without first moving the first wafer out from between the light-emitting device and the receiver. The method is simple to operate, has a small movement error, and has a high alignment efficiency, can meet the high-precision requirements of alignment, and improve product yield.

[0017] In some embodiments, the first threshold is equal to the second threshold.

[0018] It can be understood that the beneficial effects that can be achieved by the wafer alignment method provided by the above embodiments of the present disclosure can be referred to the beneficial effects of the wafer alignment device described above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present disclosure, the following briefly introduces the drawings required to be used in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not limitations on the actual size of the product involved in the embodiments of the present disclosure, the actual process of the method, the actual timing of the signal, etc.

[0020] Figure 1A-Figure 1D It is a flow chart of an alignment method of a wafer to be tested in the related art;

[0021] Figure 2 is a schematic diagram of a three-dimensional structure of a wafer alignment device according to some embodiments;

[0022] Figure 3 is a cross-sectional view of a wafer alignment apparatus according to some embodiments;

[0023] Figure 4 is a top view of a wafer alignment apparatus according to some embodiments;

[0024] Figure 5 is a top view of a wafer to be tested between a light emitting device and a receiver according to some embodiments;

[0025] Figure 6 is another top view of a wafer to be tested between a light emitting device and a receiver according to some embodiments;

[0026] Figure 7 is a top view of a wafer to be tested between a light emitting device and a receiver according to some embodiments;

[0027] Figure 8is a schematic diagram of orthographic overlap of a wafer to be tested and a light-emitting device according to some embodiments;

[0028] Fig. 9 is a flow chart of a wafer alignment method according to some embodiments;

[0029] Figure 10-Figure 17 It is a structural diagram corresponding to each step in the wafer alignment method provided according to some embodiments. DETAILED DESCRIPTION

[0030] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0031] In the description of the present disclosure, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.

[0032] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "exemplarily" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0033] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0034] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0035] “At least one of A, B, and C” has the same meaning as “at least one of A, B, or C” and both include the following combinations of A, B, and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0036] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0037] The use of "adapted to" or "configured to" herein is meant to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0038] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0039] In the context of the present disclosure, the meanings of “on,” “over,” and “over” should be interpreted in the broadest manner, so that “on” means not only “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “over” or “above” means not only “above” or “over” something, but also includes the meaning of “above” or “over” something without intervening features or layers therebetween (i.e., directly on something).

[0040] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0041] Figure 1A-Figure 1D The figure is a flow chart of a method for aligning a wafer to be tested in the related art.

[0042] Related Art In order to improve the alignment accuracy of the wafer to be tested, bonding marks are respectively set on opposite sides of the upper and lower wafers to determine the alignment positions of the upper and lower wafers.

[0043] See also Figure 1A The wafer to be tested includes an upper wafer 301′ and a lower wafer 302′. A first bonding mark M1 is provided on the side of the upper wafer 301′ close to the lower wafer 302′, and a second bonding mark M2 is provided on the side of the lower wafer 302′ close to the upper wafer 301′. The lower wafer 302′ is moved into the alignment area, and the upper lens 101 is aligned with the second bonding mark M2 of the lower wafer 302′, and the position of the lower wafer 302′ at this time is recorded as the first position.

[0044] See also Figure 1B , move the lower wafer 302' out of the alignment area, calibrate the upper lens 101 and the lower lens 102, and read the offset between the upper lens 101 and the lower lens 102. The upper and lower lenses will also form position differences during the calibration process, causing alignment errors, further affecting the alignment accuracy.

[0045] See also Figure 1C , move the upper wafer 301 ′ into the alignment area, align the first bonding mark M1 of the upper wafer 301 ′ through the lower lens 102, and record the position of the upper wafer 301 ′ at this time as the second position.

[0046] See also Figure 1D , move the lower wafer 302 ′ into the first position, complete the error compensation generated in the process through the error compensation function of the alignment system, and align the upper wafer 301 ′ and the lower wafer 302 ′.

[0047] Since the first bonding mark M1 and the second bonding mark M2 are respectively located on the opposite side of the upper wafer 301′ and the lower wafer 302′, when the upper wafer 301′ and the lower wafer 302′ are both located in the alignment area, the bonding marks of the upper and lower wafers are respectively blocked by each other, and the upper lens 101 and the lower lens 102 cannot detect the bonding marks of the upper and lower wafers at the same time. Therefore, it is necessary to first detect the first bonding mark M1 of the upper wafer 301′, and then detect the second bonding mark M2 of the lower wafer 302′ to align the upper and lower wafers. However, this method causes the wafer to be moved in and out multiple times, resulting in a large error in the alignment position of the upper and lower wafers, reduced alignment accuracy, and the position of the upper wafer 301′ and the lower wafer 302′ cannot be determined in real time, resulting in a further reduction in alignment accuracy, thereby reducing the product yield.

[0048] In order to solve the above problems, an embodiment of the present disclosure provides a wafer alignment device, which uses light-emitting devices and receivers instead of upper and lower lenses. There is no need to set bonding marks on the wafer to be tested. During the wafer alignment process, the position of the wafer to be tested is determined in real time according to the light intensity value of the receiver. There is no need to move the wafer to be tested in and out, thereby meeting the high-precision requirements of alignment and improving product yield.

[0049] Figure 2 FIG. 4 is a schematic diagram of a three-dimensional structure of a wafer alignment device according to some embodiments. Figure 3 is a cross-sectional view of a wafer alignment apparatus according to some embodiments. Figure 4 FIG. 4 is a top view of a wafer alignment apparatus according to some embodiments.

[0050] The wafer alignment device is used to align the wafer to be tested 300. The wafer to be tested 300 includes a first wafer 301 and a second wafer 302, and the first wafer 301 and the second wafer 302 are arranged relative to each other. Exemplarily, the first wafer 301 and the second wafer 302 are parallel to each other. The first wafer 301 and the second wafer 302 move in a plane perpendicular to the first direction, and when they move to a certain position, the first wafer 301 and the second wafer 302 are aligned.

[0051] See also Figure 2 , Figure 3 and Figure 4 , the wafer alignment device includes an alignment component and a moving component 200 .

[0052] The alignment assembly is used to determine the position of the wafer to be measured. The alignment assembly includes at least three (eg, three, or more than three) alignment modules 100. The alignment module 100 includes a light emitting device 11 and a receiver 12.

[0053] The light emitting device 11 is used to emit light to the receiver 12. The luminous intensity of each light emitting device 11 is equal. The luminous intensity is used to represent the physical quantity of the luminous flux per unit solid angle in a given direction of the light source, that is, the luminous flux emitted by each light emitting device 11 in the vertical direction is equal. It can be understood that equality includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0054] The receiver 12 is used to receive the light emitted by the light emitting device 11, and to generate a luminous intensity value for characterizing the light received by the receiver 12 in real time. The light emitting device 11 corresponds to the receiver 12 in a first direction (e.g., vertical direction), that is, the light emitted from the light emitting side of a light emitting device 11 can only enter the receiving side of the corresponding receiver 12. The luminous intensity value generated by the receiver 12 is the luminous flux of the light emitted by the light emitting device 11 falling into the receiver 12. The more luminous flux of the light emitted by the light emitting device 11 falling into the receiver 12, the greater the luminous intensity value of the receiver 12. Specifically, the light emitting device 11 emits light to the receiver 12. When there is no obstruction between the light emitting device 11 and the receiver 12, all the light emitted by the light emitting device 11 falls into the receiver 12. At this time, the luminous intensity value of the receiver 12 is the maximum. Because the luminous intensity of each light emitting device 11 is equal, the luminous intensity values ​​of any two receivers are equal. When there is an obstruction between the light emitting device 11 and the receiver 12, part of the light emitting side of the light emitting device 11 is obstructed. The larger the obstructed area, the less luminous flux of the light emitted by the light emitting device 11 falling on the receiver 12, and the smaller the light intensity value of the receiver 12. When the obstructed area of ​​the light emitting device 11 is different, the luminous intensity value of the receiver 12 is also different; when the obstructed area of ​​the light emitting device 11 is equal, the luminous intensity value of the receiver 12 is equal. Therefore, the luminous intensity value of the receiver 12 can represent the obstructed area of ​​the light emitting device 11.

[0055] The light emitting device 11 and the receiver 12 are respectively located on both sides of the wafer 300 to be tested. By way of example, the light emitting device 11 is located on a side of the first wafer 301 away from the second wafer 302, and the receiver 12 is located on a side of the second wafer 302 away from the first wafer 301. By way of another example, the light emitting device 11 may be located on a side of the second wafer 302 away from the first wafer 301, and the receiver 12 may be located on a side of the first wafer 301 away from the second wafer 302. The positions of the light emitting device 11 and the receiver 12 may be interchangeable, and the embodiments of the present disclosure are not limited thereto.

[0056] In order to characterize the position of the wafer 300 to be tested with the luminous intensity value of the receiver 12, the orthographic projection of the light-emitting device 11 on the first plane is located on the circumference of the same circle (for the convenience of the following description, the same circle is defined as the positioning circle 13). It can be understood that the first plane is any virtual plane perpendicular to the vertical direction, which is only used to illustrate the positional relationship between the light-emitting devices 11 and does not actually exist in the wafer alignment device. Exemplarily, the first plane can be parallel to the plane where the wafer 300 to be tested is located, or coincide with the plane where the wafer 300 to be tested is located. Exemplarily, the orthographic projection of the light-emitting device 11 is a circle, and the orthographic projections of the first wafer 301 and the second wafer 302 of the wafer 300 to be tested are also circles. At least three light-emitting devices 11 can determine the size of the positioning circle 13.

[0057] The orthographic projection of the light emitting device 11 on the first plane is located on the circumference of the positioning circle 13. Specifically, the orthographic projection of the light emitting device 11 on the first plane is a circle (for the convenience of the following description, the orthographic projection of the light emitting device 11 on the first plane is defined as a light emitting circle 111), and the distance from the center of the light emitting circle 111 to the center of the positioning circle 13 is equal. In the alignment operation of the wafer 300 to be tested, the first wafer 301 is located between the light emitting device 11 and the receiver 12.

[0058] When the first wafer 301 is located between the light-emitting device 11 and the receiver 12, when the light-emitting intensity values ​​of each receiver 12 are equal, the areas of each light-emitting device 11 blocked by the first wafer 301 are equal, and because the orthographic projections of the first wafer 301 and the light-emitting device 11 on the first plane are both circular, the shapes of the parts of each light-emitting device 11 blocked by the first wafer 301 are the same. At this time, the distances from the edge of the first wafer 301 to the center of the positioning circle 13 are equal, and the center of the first wafer 301 coincides with the center of the positioning circle 13, indicating that the first wafer 301 is moved to the alignment position.

[0059] When the second wafer 302 is located between the light-emitting device 11 and the receiver 12, when the luminous intensity values ​​of each receiver 12 are equal, the areas of each light-emitting device 11 blocked by the second wafer 302 are equal, and because the orthographic projections of the second wafer 302 and the light-emitting device 11 on the first plane are both circular, the shapes of the parts of each light-emitting device 11 blocked by the second wafer 302 are the same. At this time, the distance from the edge of the second wafer 302 to the center of the positioning circle 13 is equal, and the center of the second wafer 302 coincides with the center of the positioning circle 13, indicating that the second wafer 302 is moved to the alignment position.

[0060] Figure 5 FIG. 1 is a top view of a wafer under test between a light emitting device and a receiver according to some embodiments. Figure 6 FIG. 4 is another top view of a wafer to be tested between a light emitting device and a receiver according to some embodiments.

[0061] See also Figure 5 and Figure 6 When the first wafer and the second wafer are aligned, at least a portion of the orthographic projection of the light emitting device 11 on the first plane is not covered by the orthographic projection of the first wafer 301 on the first plane.

[0062] Exemplarily, the orthographic projection of the light emitting device 11 on the first plane (for the convenience of the following description, the orthographic projection is defined as the first circle 3011) partially overlaps with the orthographic projection of the first wafer 301 on the first plane. That is to say, after the alignment position of the first wafer 301 is determined first, the light emitting device 11 is not completely blocked by the first wafer 301, and some light is still emitted through the non-overlapping part and enters the receiver 12. Before determining the position of the second wafer 302, the luminous intensity value of the receiver 12 is still equal. At this time, the alignment position of the second wafer 302 can be determined according to the method for determining the alignment position of the first wafer 301, thereby realizing the alignment of the first wafer 301 and the second wafer 302.

[0063] The radius of the luminous circle 111 is the luminous radius RL, and the radius of the first circle 3011 is the first radius R1. The distance from the center of the luminous circle 111 to the center of the first circle 3011 is the first distance D1, which is less than or equal to the first radius R1 plus the luminous radius RL, and greater than the first radius R1 minus the luminous radius RL.

[0064] When the first distance D1 is equal to the first radius R1 plus the light emitting radius RL, the light emitting circle 111 is circumscribed with the first circle 3011. At this time, the light emitting device 11 is not covered by the first wafer 301, the light emitting intensity value of the receiver 12 is the maximum, and the light emitting intensity values ​​of each receiver 12 are equal. At this time, the alignment position of the second wafer 302 can be determined according to the method for determining the alignment position of the first wafer 301, so as to achieve alignment between the first wafer 301 and the second wafer 302.

[0065] When the first distance D1 is between the first radius R1 plus the luminous radius RL and the first radius R1 minus the luminous radius RL, the luminous circle 111 partially overlaps with the first circle 3011. At this time, a portion of the light-emitting device 11 is covered by the first wafer 301, and the luminous intensity value of the receiver 12 is between the maximum and the minimum, and the luminous intensity values ​​of each receiver 12 are equal. At this time, the alignment position of the second wafer 302 can be determined according to the method for determining the alignment position of the first wafer 301, so as to achieve alignment of the first wafer 301 and the second wafer 302.

[0066] When the first distance D1 is equal to the first radius R1 minus the luminous radius RL, the luminous circle 111 is inscribed in the first circle 3011. At this time, the light-emitting device 11 is completely covered by the first wafer 301, and the luminous intensity value of the receiver 12 is the smallest, for example, 0, and the luminous intensity values ​​of each receiver 12 are equal. Since the first wafer 301 completely covers the light-emitting device 11, the luminous intensity value of the receiver 12 no longer changes, resulting in the inability to determine the alignment position of the second wafer 302 after the alignment position of the first wafer 301 is determined. Therefore, the first distance D1 is less than or equal to the first radius R1 plus the luminous radius RL, and greater than the first radius R1 minus the luminous radius RL.

[0067] The distance between the light emitting devices 11 is determined according to the distance between the radius R1 of the first wafer 301 and the radius RL of the light emitting device 11 , and has nothing to do with the size of the second wafer 302 .

[0068] As another example, at least a portion of the luminous circle 111 is not covered by the orthographic projection of the second wafer 302 on the first plane (for the convenience of the following description, the orthographic projection is defined as the second circle 3021). As another example, at least a portion of the luminous circle 111 is not covered by the orthographic projection of the second circle 3021 on the first plane, that is, after the alignment position of the second wafer 302 is first determined, the light emitting device 11 is not completely blocked by the second wafer 302, and some light is still emitted through the unblocked portion and enters the receiver 12. Before determining the position of the first wafer 301, the luminous intensity value of the receiver 12 is still equal. At this time, the alignment position of the first wafer 301 can be determined according to the method for determining the alignment position of the second wafer 302, so as to achieve alignment of the second wafer 302 and the first wafer 301.

[0069] The radius of the luminous circle 111 is the luminous radius RL, and the radius of the second circle 3021 is the second radius R2. The distance from the center of the luminous circle 111 to the center of the second circle 3021 is the second distance D2, and the second distance D2 is less than or equal to the second radius R2 plus the luminous radius RL, and greater than the second radius R2 minus the luminous radius RL. For specific instructions, please refer to the description of the first distance D1 above, which will not be repeated here. The distance between the light-emitting devices 11 is determined according to the distance between the radius R2 of the second wafer 302 and the radius RL of the light-emitting device 11, and has nothing to do with the size of the first wafer 301.

[0070] As another example, at least a portion of the light emitting circle 111 is not covered by the orthographic projections of the first wafer 301 and the second wafer 302 on the first plane. In other words, the distance between the light emitting devices 11 is determined by the first wafer 301 and the second wafer 302 .

[0071] The disclosed embodiment further includes a moving component 200, which is used to move the wafer 300 to be tested according to the luminous intensity value of the receiver 12. Specifically, the first wafer 301 is moved, and when the difference between the luminous intensity values ​​of each receiver 12 is less than or equal to the first threshold value, the first wafer 301 is stopped from being moved. At this time, the position of the first wafer 301 is the alignment position. The second wafer 302 is moved, and when the difference between the luminous intensity values ​​of each receiver 12 is less than or equal to the second threshold value, the second wafer 302 is stopped from being moved. At this time, the position of the second wafer 302 is the alignment position.

[0072] In some examples, the moving assembly 200 moves the wafer to be tested in a horizontal direction. After the positions of the first wafer 301 and the second wafer 302 are aligned, the moving assembly 200 may also move the wafer to be tested in a vertical direction.

[0073] In the wafer alignment device provided by the above-mentioned embodiment of the present disclosure, the more light emitted by the light-emitting device falls into the receiver, the greater the luminous intensity value of the receiver. The luminous intensity of each light-emitting device is the same, and the larger the unblocked area of ​​the light-emitting device, the more light emitted falls into the receiver, and the greater the luminous intensity value of the receiver. Therefore, the area blocked by the light-emitting device can be obtained according to the luminous intensity value of the receiver, and then the wafer to be tested is moved by the moving component so that the luminous intensity values ​​of the receiver are roughly equal, thereby determining the alignment position of the wafer to be tested. When the alignment position of the first wafer is determined, the first wafer is located between the light-emitting device and the receiver, and because at least a part of the orthographic projection of the light-emitting device on the first plane is not covered by the orthographic projection of the first wafer on the first plane, therefore, when determining the alignment position of the second wafer, it is not necessary to move the first wafer out of between the light-emitting device and the receiver, and the light emitted by the light-emitting device can still be received by the receiver. According to the luminous intensity value of the receiver, the alignment position of the second wafer is determined. When the wafer alignment device provided by the embodiment of the present disclosure determines the alignment position of the first wafer and the second wafer, it is not necessary to move the first wafer and the second wafer in and out between the light emitting device and the receiver multiple times, and the operation is simple, the movement error is small, and the alignment efficiency is high. The alignment position of the wafer to be tested is determined according to the luminous intensity value of the receiver, which can meet the high-precision alignment requirements and improve the product yield.

[0074] In some embodiments, all light emitting devices 11 or all receivers are located on the same side of the wafer 300 to be tested. Specifically, all light emitting devices 11 are located on the side of the first wafer 301 away from the second wafer 302, and because the light emitting devices 11 and the receivers 12 are located on both sides of the wafer 300 to be tested, all receivers 12 are located on the other side of the second wafer 302 away from the first wafer 301. Exemplarily, all light emitting devices 11 are located on the upper side of the plane where the first wafer 301 is located, and all receivers 12 are located on the lower side of the plane where the second wafer 302 is located. The light emitted by the light emitting device 11 is emitted downward into the receiver 12. Again exemplarily, all light emitting devices 11 are located on the lower side of the plane where the second wafer 302 is located, and all receivers 12 are located on the upper side of the plane where the first wafer 301 is located. The light emitted by the light emitting device 11 is emitted upward into the receiver 12. All light emitting devices 11 or all receivers 12 are arranged on the same side of the wafer 300 to be tested, so as to facilitate the simultaneous setting of the positions of all light emitting devices or the receivers and improve the detection efficiency.

[0075] In some embodiments, any two light emitting devices 11 are parallel in a plane perpendicular to the vertical direction. Figure 3, the height from the light-emitting side of all light-emitting devices 11 to the first plane is the same. Exemplarily, the distance h1 from the light-emitting side of the light-emitting device 11 to the upper surface of the first wafer 301 (the side away from the second wafer 302) is equal. In other words, the height of all light-emitting devices 11 is the same, which facilitates setting the installation height of the light-emitting device 11.

[0076] In some embodiments, any two receivers 12 are parallel in a plane perpendicular to the vertical direction. Figure 3 , the height from the receiving side to the first plane of all receivers 12 is the same. Exemplarily, the distance h2 from the light-emitting side of the receiver 12 to the lower surface of the second wafer 302 (the side away from the first wafer 301) is equal. In other words, the height of all receivers 12 is the same, which facilitates setting the installation height of the receiver 12.

[0077] In some embodiments, any two light emitting devices 11 are parallel in a plane perpendicular to the vertical direction. And any two receivers 12 are parallel in a plane perpendicular to the vertical direction. Specifically, the distances between the light emitting sides of all light emitting devices 11 and the receiving sides of the corresponding receivers 12 are equal, which reduces the loss difference of the light emitted by the light emitting device 11 between the light emitting device 11 and the receiver 12, and further improves the accuracy of the luminous intensity value of the receiver 12.

[0078] In some embodiments, the orthographic projection of the light emitting devices 11 on the first plane is arranged in a circular array. Figure 4 The light emitting devices 11 are evenly distributed on the circumference of the positioning circle 13, which is adapted to the shape of the wafer to be tested.

[0079] In some embodiments, see Figure 4 , the diameter h3 of the orthographic projection of the light-emitting device 11 on the first plane is greater than or equal to 2 mm. Specifically, the diameter of the light-emitting circle 111 is greater than or equal to 2 mm. Since there may be a certain error in the diameters of the first wafer 301 and the second wafer 302, the diameter of the light-emitting circle 111 is greater than or equal to 2 mm, which can ensure that at least a part of the orthographic projection of the light-emitting device 11 on the first plane is not covered by the orthographic projection of the first wafer 301 and / or the second wafer 302 on the first plane. After determining the alignment position of the first wafer 301 or the second wafer 302, the receiver 12 can still receive the light emitted by the light-emitting device 11, and then directly determine the alignment position of the other wafer without moving the first wafer 301 or the second wafer 302 to the initial position, which is simple to operate and has high work efficiency.

[0080] Figure 7 FIG. 1 is a top view of a wafer under test between a light emitting device and a receiver according to some embodiments. Figure 8FIG. 4 is a schematic diagram of an orthographic overlap of a wafer to be tested and a light-emitting device according to some embodiments.

[0081] In some embodiments, see Figure 7 and Figure 8 The wafer alignment device further includes a controller, and the alignment module 100 and the moving assembly 200 are coupled to the controller. The controller is configured to: control the moving assembly 200 to move the wafer to be tested in the extension direction of the first plane according to the luminous intensity value of the receiver 12. Specifically, for the first wafer 301, the first wafer 301 is moved between the light-emitting device 11 and the receiver 12, and when the difference between the luminous intensity values ​​of any two receivers 12 is less than or equal to the first threshold, the moving assembly 200 stops moving the first wafer 301 in the extension direction of the first plane. The first threshold can be any set value such as 0, 0.5, 1, etc. When the difference between the luminous intensity values ​​of the receivers 12 does not exceed the first threshold, it can be considered that the luminous intensity values ​​of the receivers 12 are equal. At this time, the light-emitting device 11 is divided into a portion S1 blocked by the first wafer 301 and a portion S2 not blocked by the first wafer 301. In some examples, the portion S1 of the light-emitting device 11 blocked by the first wafer 301 is at least smaller than the entire light-emitting device 11. In some other examples, the portion S2 of the light emitting device 11 not blocked by the first wafer 301 is the entire light emitting device 11, and all the light emitted by the light emitting device 11 falls into the receiver 12. The areas S2 of the portions of the light emitting devices 11 not blocked by the first wafer 301 are equal, the center of the first wafer 301 coincides with the centers of all the light emitting devices 11, and the first wafer 301 is located in an aligned position.

[0082] For the second wafer 302, the second wafer 302 is moved between the light emitting device 11 and the receiver 12. When the difference between the luminous intensity values ​​of any two receivers 12 is less than or equal to the second threshold value, the moving component 200 stops moving the second wafer 302 in the extension direction of the first plane. The second threshold value can be any set value such as 0, 0.5, 1, etc. When the difference between the luminous intensity values ​​of the receivers 12 does not exceed the second threshold value, it can be considered that the luminous intensity values ​​of the receivers 12 are equal. At this time, the areas of the parts of the light emitting device 11 that are not blocked by the second wafer 302 are equal, the center of the second wafer 302 coincides with the centers of all the light emitting devices 11, and the second wafer 302 is located in the alignment position.

[0083] In some examples, the controller may also be configured to: control the moving assembly 200 to move the wafer to be tested in the vertical direction, reduce the vertical distance between the first wafer 301 and the second wafer 302 , and thereby allow the first wafer 301 and the second wafer 302 to fit together.

[0084] In some embodiments, the first threshold is equal to the second threshold. It is only necessary to compare the same value to determine whether the first wafer 301 and the second wafer 302 are in the alignment position, thereby improving the alignment efficiency and further improving the product yield.

[0085] In some embodiments, the moving assembly 200 includes a first moving mechanism 201 and a second moving mechanism 202. The first moving mechanism 201 is used to move the first wafer 301, and the second moving mechanism 202 is used to move the second wafer 302. The first moving mechanism 201 includes a first carrier and a first driving unit connected to each other, the first carrier is used to carry the first wafer 301, and the first driving unit is connected to the alignment module to drive the first carrier to move. The second moving mechanism 202 includes a second carrier and a second driving unit connected to each other, the second carrier is used to carry the second wafer 302, and the second driving unit is connected to the alignment module to drive the second carrier to move.

[0086] In some embodiments, the first carrier includes a first vacuum chuck connected to a side of the first wafer 301 away from the second wafer 302. The second carrier includes a second vacuum chuck connected to a side of the second wafer 302 away from the first wafer 301. In other words, the vacuum chuck is attached to two sides of the wafer 300 to be tested that are away from each other, and the vacuum chuck will not hinder the movement of the wafer 300 to be tested during the movement.

[0087] Some embodiments of the present disclosure also provide a wafer alignment method, which may be based on the wafer alignment device described in any of the above embodiments.

[0088] Fig. 9 is a flow chart of a wafer alignment method according to some embodiments. Figure 10-Figure 17 It is a structural diagram corresponding to each step in the wafer alignment method provided according to some embodiments.

[0089] The wafer alignment method provided by some embodiments of the present disclosure is schematically described below in conjunction with the accompanying drawings.

[0090] See also Fig. 9 , and combined with Figure 10-Figure 17 The above-mentioned wafer alignment method includes: S1-S3.

[0091] S1: Provide a wafer to be tested and a wafer alignment device as described in any of the above embodiments.

[0092] Fig.10 The structure diagram of a wafer to be tested and a wafer alignment device in a wafer alignment method provided according to some embodiments. Fig.11 The diagram is a top view of a wafer to be tested and a wafer alignment device in a wafer alignment method according to some embodiments.

[0093] The wafer 300 to be tested includes a first wafer 301 and a second wafer 302. The shape and structure of the wafer 300 to be tested can be found in the above description and will not be repeated here. The first wafer 301 is located at a first initial position, and the second wafer 302 is located at a second initial position. Among them, the first initial position and the second initial position are not between the light-emitting device 11 and the receiver 12. The first wafer 301 and the second wafer 302 are moved by the moving component 200. The size of the first wafer 301 and the second wafer 302 may be the same or different. Exemplarily, the size of the first wafer 301 is larger than the size of the second wafer 302. Also exemplarily, the size of the first wafer 301 is equal to the size of the second wafer 302. Also exemplarily, the size of the first wafer 301 is smaller than the size of the second wafer 302. The first wafer 301 may be located on the upper side of the second wafer 302 , or may be located on the lower side of the second wafer 302 . Some embodiments of the present disclosure do not limit the upper and lower positions of the first wafer 301 and the second wafer 302 .

[0094] The structure of the wafer alignment device can be found in the above description and will not be described again here.

[0095] S2: adjusting the position of the first wafer 301 according to the luminous intensity values ​​of the receivers 12 of at least three alignment modules, and moving the first wafer 301 from the first initial position to the first alignment position.

[0096] Specifically, the second wafer 302 remains in the second initial position, and the first wafer 301 is moved from the first initial position to the first alignment position according to the real-time luminous intensity values ​​of at least three receivers 12. At the first alignment position, the difference between the luminous intensity values ​​of any two receivers 12 is less than or equal to the first threshold, and at least a part of the orthographic projection of the light-emitting device 11 on the first plane is not covered by the orthographic projection of the first wafer 301 on the first plane. At least three receivers 12 determine the circle where the wafer to be tested is located.

[0097] S21 : moving the first wafer 301 from a first initial position to at least between a light emitting device 11 and a receiver 12 .

[0098] Fig.12 A schematic diagram of movement of a first wafer in a wafer alignment method according to some embodiments is provided. Fig.13 The present invention is another top view of a wafer to be tested and a wafer alignment device in a wafer alignment method according to some embodiments.

[0099] The first wafer 301 is located at least between one light-emitting device 11 and one receiver 12. Exemplarily, the first wafer 301 only blocks one light-emitting device 11 and one receiver 12. The luminous intensity value of the receiver 12 is different from that of other receivers 12, and S22 is continued. Another exemplary embodiment, the first wafer 301 blocks two or more light-emitting devices 11 and receivers 12. There is a difference between the luminous intensity values ​​of any two receivers 12, and S22 is continued. Another exemplary embodiment, the first wafer 301 blocks all light-emitting devices 11 and receivers 12. If the difference between the luminous intensity values ​​of any two receivers 12 is less than or equal to the first threshold value, at this time, the position of the first wafer 301 is in the first alignment position, and S22 is no longer performed. The first threshold value can be referred to the description of the first threshold value above, which will not be repeated here.

[0100] S22: According to the real-time luminous intensity value of each receiver, the position of the first wafer 301 is adjusted to a first alignment position.

[0101] Fig.14 This is a structural diagram of a first wafer located at a first alignment position in a wafer alignment method provided according to some embodiments. Fig.15 The present invention is another top view of a wafer to be tested and a wafer alignment device in a wafer alignment method according to some embodiments.

[0102] The moving component 200 moves the first wafer 301 until the difference in the luminous intensity values ​​of any two receivers 12 is less than or equal to the first threshold, and the moving component 200 stops moving the first wafer 301 in the extension direction of the first plane.

[0103] When the first wafer 301 is located between the light-emitting device 11 and the receiver 12, when the light-emitting intensity values ​​of each receiver 12 are equal, the areas of each light-emitting device 11 blocked by the first wafer 301 are equal, and because the orthographic projections of the first wafer 301 and the light-emitting device 11 on the first plane are both circular, the shapes of the parts of each light-emitting device 11 blocked by the first wafer 301 are the same. At this time, the distances from the edge of the first wafer 301 to the center of the positioning circle 13 are equal, and the center of the first wafer 301 coincides with the center of the positioning circle 13, indicating that the first wafer 301 is moved to the alignment position.

[0104] At this time, at least a part of the orthographic projection of the light emitting device 11 on the first plane is not covered by the orthographic projection of the first wafer 301 on the first plane, and the light emitted by the light emitting device 11 can still enter the corresponding receiver 12 .

[0105] S3: adjusting the position of the second wafer 302 according to the luminous intensity values ​​of the receivers 12 of at least three alignment modules, and moving the second wafer 302 from the second initial position to the second alignment position.

[0106] Fig.16 This is a structural diagram of a second wafer located at a second alignment position in a wafer alignment method provided according to some embodiments. Fig.17 The present invention is another top view of a wafer to be tested and a wafer alignment device in a wafer alignment method according to some embodiments.

[0107] According to the real-time luminous intensity values ​​of at least three receivers 12, the second wafer 302 is moved from the second initial position to the second alignment position; at the second alignment position, the difference in luminous intensity values ​​of any two receivers 12 is less than or equal to the second threshold. The second threshold can be referred to the description of the second threshold above, which will not be repeated here.

[0108] In the embodiment of the present disclosure, after the alignment position of the first wafer 301 is determined, the first wafer 301 is located between the light emitting device 11 and the receiver 12. Since at least a part of the orthographic projection of the light emitting device 11 on the first plane is not covered by the orthographic projection of the first wafer 301 on the first plane, when the alignment position of the second wafer 302 is determined, it is not necessary to move the first wafer 301 out of between the light emitting device 11 and the receiver 12. The light emitted by the light emitting device 11 can still be received by the receiver 12. The alignment position of the second wafer 302 is determined according to the luminous intensity value of the receiver 12. During the movement of the first wafer 301 and the second wafer 302, the moving direction of the wafer to be tested can be fed back to the moving component in real time through the luminous intensity value of the receiver, reducing the number of repeated movements of the wafer to be tested, thereby improving the alignment efficiency of the first wafer 301 and the second wafer 302, reducing the mechanical error of the movement of the wafer to be tested, and thus improving the product yield.

[0109] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A wafer alignment device, characterized in that: include: At least three alignment modules, the alignment modules comprising: Light-emitting devices for emitting light; the light-emitting intensities of all the light-emitting devices are equal; A receiver, used to receive the light emitted by the light emitting device and generate a luminous intensity value of the received light in real time; A moving component, used for moving the wafer to be tested according to the luminous intensity value of the receiver; Among them, the light-emitting device and the receiver correspond one-to-one along the first direction and are respectively located on both sides of the wafer to be tested; the orthographic projection of the light-emitting device on the first plane is located on the circumference of the same circle; the first direction is the direction in which the light-emitting device emits light, and the first plane is perpendicular to the first direction.

2. The wafer alignment device according to claim 1, characterized in that: All of the light emitting devices or all of the receivers are located on the same side of the wafer to be tested.

3. The wafer alignment device according to claim 2, characterized in that: The light emitting sides of all the light emitting devices and / or the receiving sides of all the receivers are at the same height from the plane where the wafer to be tested is located.

4. The wafer alignment device according to claim 1, characterized in that: The orthographic projections of the light emitting devices of the at least three alignment modules on the first plane are arranged in a circular array.

5. The wafer alignment device according to claim 4, characterized in that: A diameter of an orthographic projection of the light emitting device on the first plane is greater than or equal to 2 mm.

6. The wafer alignment device according to claim 1, characterized in that: Also includes: The alignment module and the moving component are coupled to the controller, and the controller is configured to: control the moving component to move the wafer to be tested in the extension direction of the first plane according to the luminous intensity value of the receiver.

7. The wafer alignment device according to any one of claims 1 to 6, characterized in that: The wafer to be tested includes a first wafer and a second wafer; The mobile assembly comprises: The first moving mechanism comprises a first carrying platform and a first driving unit connected to each other; the first carrying platform is used to carry the first wafer, and the first driving unit is connected to the alignment module to drive the first carrying platform to move; The second moving mechanism includes a second carrying platform and a second driving unit connected to each other; the second carrying platform is used to carry the second wafer, and the second driving unit is connected to the alignment module to drive the second carrying platform to move.

8. The wafer alignment device according to claim 7, characterized in that: The first carrying platform comprises a first vacuum chuck, and the first vacuum chuck is connected to a side of the first wafer away from the second wafer; The second carrying platform includes a second vacuum chuck, and the second vacuum chuck is connected to a side of the second wafer away from the first wafer.

9. A wafer alignment method, characterized in that: include: Providing a wafer to be tested and a wafer alignment device as described in any one of claims 1 to 8; the wafer to be tested comprises a first wafer and a second wafer; According to the luminous intensity values ​​of the receivers of the at least three alignment modules, the position of the first wafer is adjusted to move the first wafer from the first initial position to the first alignment position; at the first alignment position, the difference between the luminous intensity values ​​of any two receivers of the at least three alignment modules is less than or equal to a first threshold value, and the orthographic projection of the light emitting device on the first plane has no overlap or partially overlaps with the orthographic projection of the first wafer on the first plane; According to the luminous intensity values ​​of the receivers of the at least three alignment modules, adjusting the position of the second wafer, and moving the second wafer from a second initial position to a second alignment position; At the second alignment position, a difference in luminous intensity values ​​of any two receivers in the at least three alignment modules is less than or equal to a second threshold.

10. The wafer alignment method according to claim 9, characterized in that: The first threshold is equal to the second threshold.

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