Wafer bonding precision measuring device

Abstract

The utility model provides a wafer bonding precision measuring device, relates to the technical field of semiconductors, and aims to improve the measuring precision of the wafer bonding precision measuring device and the stability of a measuring result. The wafer bonding precision measuring device comprises a lens, a wafer bearing table, a light source bearing table and a distance measuring device. Wherein the wafer bearing table is arranged on the image acquisition side of the lens, at least three marks are arranged on the wafer bearing table, and the at least three marks are not collinear; the lens is configured to measure distances from the at least three marks to the lens; the light source bearing table is arranged on the side, away from the lens, of the wafer bearing table. The distance measuring device is arranged on the side, facing the light source bearing table, of the wafer bearing table or the side, facing the wafer bearing table, of the light source bearing table and is configured to measure the distance between the wafer bearing table and the light source bearing table. The wafer bonding precision measuring device is used for measuring the wafer bonding precision.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a device for measuring wafer bonding accuracy. Background Art

[0002] The main function of wafer bonding is to combine two wafers in the vertical direction to achieve signal interconnection between wafers, and the first condition for achieving good signal interconnection is to complete the precise alignment of the two wafers. Therefore, in wafer bonding technology, wafer bonding accuracy is an important parameter to characterize the quality of the wafer bonding process. If there are defects in the bonding accuracy in the wafer bonding process, it will seriously affect the back-end process of the process, which will in turn affect the connection and function of the circuit after wafer bonding, and reduce the yield of the wafer. Therefore, wafer bonding accuracy is particularly critical. After the two wafers are bonded, a wafer bonding accuracy measurement device is needed to measure the bonding accuracy of the bonded wafers, and the measurement results are fed back to the subsequent bonding wafer process for bonding accuracy compensation.

[0003] If the measurement accuracy and stability of the measurement results of the wafer bonding accuracy measurement device are poor, it will lead to errors in the subsequent wafer bonding compensation data, resulting in a decrease in the yield of the product. Utility Model Content

[0004] The embodiments of the present disclosure provide a device for measuring wafer bonding accuracy, aiming to improve the measurement accuracy of the device for measuring wafer bonding accuracy and the stability of the measurement results.

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

[0006] The present disclosure provides a device for measuring wafer bonding accuracy. The semiconductor structure includes a lens, a wafer carrier, a light source carrier and a distance measuring device. The wafer carrier is arranged on the image acquisition side of the lens, and at least three marks are arranged on the wafer carrier, and the at least three marks are not collinear. The lens is configured to measure the distance from the at least three marks to the lens. The light source carrier is arranged on a side of the wafer carrier away from the lens. The distance measuring device is arranged on a side of the wafer carrier facing the light source carrier, or on a side of the light source carrier facing the wafer carrier, and is configured to measure the distance between the wafer carrier and the light source carrier.

[0007] The above-mentioned embodiment of the present disclosure provides a device for measuring the wafer bonding accuracy, wherein the wafer carrier is arranged on the image acquisition side of the lens, and at least three marks are arranged on the wafer carrier, and at least three marks are not collinear, that is, the plane surrounded by the lines connecting at least three marks is the plane where the wafer carrier is located, and the lens is configured to measure the distance from at least three marks to the lens, so based on the plane where the lens is located as the reference plane, and then according to the distance from at least three marks to the lens measured by the lens, the relative horizontal offset between the wafer carrier and the lens is adjusted, which can avoid the error in the relative horizontal offset between the wafer carrier and the lens caused by human judgment, reduce the source of error, and improve the relative level between the wafer carrier and the lens. After the wafer carrier and the lens are kept relatively level, the plane where the wafer carrier is located is used as the reference plane, and the relative horizontal offset between the light source carrier and the wafer carrier is measured using a distance measuring device to ensure the relative level between the lens, the wafer carrier and the light source carrier. Among them, when using the distance measuring device to judge the horizontal offset between the wafer carrier and the light source carrier, it is also possible to avoid the error in the relative horizontal offset between the wafer carrier and the light source carrier caused by human judgment, reduce the source of error, and improve the relative level between the wafer carrier and the light source carrier. Since the lens, the wafer carrier and the light source carrier are kept relatively horizontal, the measurement accuracy of the measuring device that affects the wafer bonding accuracy due to the poor relative level between the lens, the wafer carrier and the light source carrier can be reduced.

[0008] On the other hand, in order to improve the accuracy of the measurement precision, the lens, the wafer carrier and the light source carrier need to maintain relative level and measure the bonding accuracy of the wafer multiple times. During the adjustment process, the horizontal offset of the wafer carrier can be realized in real time using at least three marks on the lens and the wafer carrier. The horizontal offset of the light source carrier can be realized in real time using a ranging device. When the wafer carrier and the light source carrier are not kept relatively level, they can be discovered and adjusted in time. The horizontal offset of the wafer carrier is measured based on the plane where the lens is located as the reference plane, and the horizontal offset of the light source carrier is measured based on the plane where the wafer carrier is located as the reference plane. Therefore, when the plane where the lens is located remains unchanged, the horizontal offset of the wafer carrier and the horizontal offset of the light source carrier have high stability. In summary, the wafer bonding accuracy measurement device has high measurement accuracy and stable measurement results.

[0009] In addition, since the wafer bonding accuracy measurement device provided in the above embodiment has high measurement accuracy and stable measurement results, it is helpful to provide accurate data for subsequent wafer bonding compensation in a timely manner, thereby improving the yield of products.

[0010] In some embodiments, the wafer carrier has a light-transmitting area, and the mark is arranged in the light-transmitting area; and a light source is arranged on a side of the light source carrier facing the wafer carrier.

[0011] In some embodiments, the marking is capable of reflecting light toward the lens.

[0012] In some embodiments, it also includes: at least three first height adjustment components, connected to the wafer carrier platform, and the connection positions of the at least three first height adjustment components and the wafer carrier platform are not collinear; the at least three first height adjustment components are configured to adjust the position of the wafer carrier platform in a first direction, and the first direction is the arrangement direction of the lens, the wafer carrier platform, and the light source carrier platform.

[0013] In some embodiments, the first height adjustment component includes a first motor and a first adjustment rod connected to an output shaft of the first motor, and the first adjustment rod is connected to the wafer supporting platform.

[0014] In some embodiments, it also includes: at least three second height adjustment components, connected to the light source carrier platform, and the connection positions of the at least three second height adjustment components and the light source carrier platform are not collinear; the at least three second height adjustment components are configured to adjust the position of the light source carrier platform in a first direction, and the first direction is the arrangement direction of the lens, the wafer carrier platform, and the light source carrier platform.

[0015] In some embodiments, the second height adjustment component includes a second motor and a second adjustment rod connected to an output shaft of the second motor, and the second adjustment rod is connected to the light source support platform.

[0016] In some embodiments, it also includes: a controller, which is connected to the lens and the ranging device; the controller is configured to obtain first distance data measured by the lens, and determine the horizontal offset of the wafer carrier according to the first distance data, wherein the first distance data includes the distance from the at least three marks to the lens; and obtain second distance data measured by the ranging device, and determine the horizontal offset of the light source carrier according to the second distance data, wherein the second distance data includes the distance between the wafer carrier and the light source carrier.

[0017] In some embodiments, the measuring device also includes at least three first height adjustment components and at least three second height adjustment components, and the controller is also connected to the at least three first height adjustment components and the at least three second height adjustment components; the controller is also configured to adjust at least one of the first height adjustment components according to the horizontal offset of the wafer carrier platform; and adjust at least one of the second height adjustment components according to the horizontal offset of the light source carrier platform.

[0018] In some embodiments, the distance measuring device includes at least one laser distance sensor. 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 1 A structural diagram of a wafer bonding accuracy measurement device provided according to some embodiments;

[0021] Figure 2 A structural diagram of a wafer carrier provided according to some embodiments;

[0022] Figure 3 A schematic diagram of a wafer provided according to some embodiments;

[0023] Figure 4 for Figure 3 A partial enlarged view of the dotted circle S in the middle;

[0024] Figure 5 To adopt Figure 1 A data graph of bonding accuracy obtained by measuring a wafer by a wafer bonding accuracy measuring device;

[0025] Figure 6 A structural diagram of another device for measuring wafer bonding accuracy according to some embodiments;

[0026] Figure 7 A structural diagram of another device for measuring wafer bonding accuracy according to some embodiments;

[0027] Figure 8 A structural diagram of a wafer bonding accuracy measurement device provided according to some embodiments;

[0028] Fig. 9 for Figure 7 A top view of a wafer carrier in FIG.

[0029] Fig.10 for Figure 7 A bottom view of the wafer carrier in FIG.

[0030] Fig.11 for Figure 7 A bottom view of the light source carrier in FIG.

[0031] Fig.12 To adopt Figure 7 A data graph of bonding accuracy obtained by measuring a wafer by a wafer bonding accuracy measuring device;

[0032] Fig.13 The present invention is a schematic flow chart of a working method of a wafer bonding accuracy measuring device provided according to some embodiments. DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] When describing some embodiments, the term "connected" and its derivative expressions 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. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0038] 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.

[0039] 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.

[0040] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of variation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0041] 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.

[0042] like Figure 1 As shown, an embodiment of the present disclosure provides a wafer bonding accuracy measurement device 1000 , including: a lens 100 , a wafer carrier 200 , and a light source carrier 300 .

[0043] The wafer carrier 200 is disposed on the image acquisition side of the lens 100 and is configured to carry a wafer. The wafer carrier 200 may be hollowed out. Figure 2 As shown. Among them, reference Figure 3 The wafer 20 includes a first wafer and a second wafer. The first wafer is provided with a plurality of first bonding marks Mark1, and the second wafer is provided with a plurality of second bonding marks Mark2. The first bonding marks Mark1 and the second bonding marks Mark2 can be metal. During bonding, the first bonding marks Mark1 and the second bonding marks Mark2 can realize the alignment of the first wafer and the second wafer when the first wafer and the second wafer are bonded; when measuring the bonding accuracy of the wafers, the bonding accuracy of the first wafer and the second wafer can be calculated according to the position information of the first bonding marks Mark1 and the second bonding marks Mark2.

[0044] The light source carrier 300 is disposed on the side of the wafer carrier 200 away from the lens 100 and is configured to carry a light source 301. The light source 301 can emit infrared light. When measuring the wafer bonding accuracy, the light emitted by the light source 301 irradiates the wafer carrier 200. Since the wafer carrier 200 is a hollow design, the infrared light emitted by the light source 301 can directly irradiate the wafer 20. Figure 4 , the lens 100 can obtain the position information of the first bonding mark Mark1 and the second bonding mark Mark2 on the wafer 20, and then calculate the offset between the first wafer and the second wafer according to the position information of the first bonding mark Mark1 and the second bonding mark Mark2, that is, the bonding accuracy of the wafer 20.

[0045] like Figure 1 As shown, when measuring the bonding accuracy of the wafer 20, if the wafer carrier 200 and the light source carrier 300 are not kept relatively horizontal, that is, there is an angle between the wafer carrier 200 and the light source carrier 300, in this case, since the light source 301 obliquely illuminates the first wafer and the second wafer, the offset of the first wafer and the second wafer obtained is different from the actual offset of the first wafer and the second wafer. If the wafer carrier 200 and the lens 100 are not kept relatively horizontal, that is, there is an angle between the wafer carrier 200 and the lens 100, in this case, the lens 100 cannot obtain the position information of the first wafer and the second wafer along the normal direction of the wafer carrier 200, so the offset of the first wafer and the second wafer obtained is different from the actual offset of the first wafer and the second wafer. Similarly, if there is an angle between the lens 100 and the light source carrier 300, in this case, the offset of the first wafer and the second wafer obtained is different from the actual offset of the first wafer and the second wafer. Therefore, it is necessary to adjust the relative levels among the lens 100, the wafer carrier 200 and the light source carrier 300. Figure 5 , Figure 5 To adopt Figure 1The data obtained by measuring the bonding accuracy of the wafer 1000 5 times. The horizontal axis represents 12 pairs of first bonding marks Mark1 and second bonding marks Mark2 randomly selected on the wafer, and the vertical axis represents the horizontal offset of the first bonding mark Mark1 and the second bonding mark Mark2 in the same pair of bonding marks, in micrometers (μm). It can be seen that the difference in bonding accuracy of the 5 measurements is large, and the measurement results of the wafer bonding accuracy measurement device 1000 are unstable.

[0046] Therefore, an embodiment of the present disclosure provides a wafer bonding accuracy measurement device 1000, referring to Figure 6 Generally, the staff sets a first level 201 on the side of the wafer carrier 200 away from the light source carrier 300, and sets at least three first height adjustment components 202 connected to the wafer carrier 200, and the positions where the at least three first height adjustment components 202 are connected to the wafer carrier 200 are not collinear; sets a second level 302 on the side of the light source carrier 300 facing the wafer carrier 200, and sets at least three second height adjustment components 303 connected to the light source carrier 300, and the positions where the at least three second height adjustment components 303 are connected to the light source carrier 300 are not collinear.

[0047] Before testing the bonding accuracy, the staff manually adjusts the height of at least three first height adjustment components 202 according to the measurement results of the first level 201. When adjusting the height of at least three first height adjustment components 202, at least three first height adjustment components 202 drive the wafer carrier 200 to move up and down to adjust the wafer carrier 200 to a horizontal state. The staff manually adjusts the height of at least three second height adjustment components 303 according to the measurement results of the second level 302. When adjusting the height of at least three second height adjustment components 303, at least three second height adjustment components 303 drive the light source carrier 300 to move up and down to adjust the light source carrier 300 to a horizontal state.

[0048] Exemplarily, the first height adjustment component 202 includes a first top screw, which includes a first shaft and a first sleeve. When adjusting the horizontal position of the wafer carrier 200, the first sleeve is rotated in the direction of the thread on the first shaft to adjust the extension and retraction of the first height adjustment component 202, thereby driving the horizontal position of the wafer carrier 200 to move.

[0049] Exemplarily, the second height adjustment component 303 includes a second top screw, and the second top screw includes a second shaft and a second sleeve. When adjusting the horizontal position of the light source support platform 300, the second sleeve is rotated in the direction of the thread on the second shaft to adjust the extension and retraction of the second height adjustment component 303, thereby driving the horizontal position of the light source support platform 300 to move.

[0050] First, since the horizontal offsets of the light source platform 300 and the wafer platform 200 in the above-mentioned wafer bonding accuracy measurement device 1000 are manually judged, and the adjustment of the horizontal offsets is also manually adjusted, there may be judgment errors and multiple adjustments are required. Each adjustment of the horizontal offsets of the light source platform 300 and the wafer platform 200 takes about 10 hours. Therefore, this adjustment method is not only time-consuming and labor-intensive, but also prone to errors in the judgment of the horizontal offsets of the wafer platform 200 and the light source platform 300, so that the measurement results of the wafer bonding accuracy also have errors, resulting in errors in the subsequent wafer bonding compensation value, affecting the product yield.

[0051] Secondly, the inventor also found that manual adjustment can only adjust the absolute level of the wafer carrier 200 and the light source carrier 300, and cannot achieve the relative level adjustment between the lens 100, the wafer carrier 200 and the light source carrier 300. Therefore, the wafer bonding accuracy measuring device 1000 has the defects of high adjustment difficulty and low adjustment accuracy, and cannot guarantee the accuracy of the test results. Therefore, the measurement accuracy of the wafer bonding accuracy measuring device 1000 and the stability of the measurement results are poor.

[0052] In order to solve the above technical problems, combined with reference Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 Some embodiments of the present disclosure provide a device 1000 for measuring wafer bonding accuracy, comprising: a lens 100, a wafer carrier 200, a light source carrier 300, and a distance measuring device 400. The wafer carrier 200 is disposed on the image acquisition side of the lens 100, and at least three marks are provided on the wafer carrier 200, and the at least three marks are not collinear. The lens 100 is configured to measure the distance from the at least three marks to the lens 100. The light source carrier 300 is disposed on a side of the wafer carrier 200 away from the lens 100. The distance measuring device 400 is disposed on a side of the wafer carrier 200 facing the light source carrier 300, or on a side of the light source carrier 300 facing the wafer carrier 200, and is configured to measure the distance between the wafer carrier 200 and the light source carrier 300.

[0053] The wafer bonding accuracy measurement device provided in this embodiment is combined with reference Figure 7 and Fig. 9The wafer carrier 200 is arranged on the image acquisition side of the lens 100. At least three mark eyes are arranged on the wafer carrier 200. At least three mark eyes are not collinear, that is, the plane surrounded by the lines connecting at least three mark eyes is the plane where the wafer carrier 200 is located. The lens 100 is configured to measure the distance from at least three mark eyes to the lens 100. Therefore, based on the plane where the lens 100 is located as the reference plane, the distance from at least three mark eyes to the lens 100 is measured according to the lens 100, and the relative level between the wafer carrier 200 and the lens 100 is adjusted. This can avoid the error in the relative level between the wafer carrier 200 and the lens 100 caused by human judgment, reduce the source of error, and improve the relative level between the wafer carrier 200 and the lens 100. After the wafer carrier 200 and the lens 100 are kept relatively level, the plane where the wafer carrier 200 is located is used as the reference plane, and the relative level between the light source carrier 300 and the wafer carrier 200 is measured by the distance measuring device 400 to ensure the relative level between the lens 100, the wafer carrier 200 and the light source carrier 300. Among them, when the distance measuring device 400 is used to judge the level between the wafer carrier 200 and the light source carrier 300, it is also possible to avoid the error in the relative level between the wafer carrier 200 and the light source carrier 300 caused by human judgment, reduce the source of error, and improve the relative level between the wafer carrier 200 and the light source carrier 300. Since the lens 100, the wafer carrier 200 and the light source carrier 300 are kept relatively level, the measurement accuracy of the measuring device 1000 that affects the wafer bonding accuracy due to the poor relative level between the lens 100, the wafer carrier 200 and the light source carrier 300 can be reduced.

[0054] In addition, in order to improve the accuracy of the measurement precision, the lens 100, the wafer carrier 200 and the light source carrier 300 need to be kept relatively level and the bonding accuracy of the wafer needs to be measured multiple times. During the adjustment process, the horizontal offset of the wafer carrier 200 can be fed back in real time using at least three marks on the lens 100 and the wafer carrier 200. The horizontal offset of the light source carrier 300 can be fed back in real time using the distance measuring device 400. When the wafer carrier 200 is not level with respect to the lens 100, and when the wafer carrier 200 is not level with respect to the light source carrier 300, it can be discovered and adjusted in time. Moreover, the horizontal offset of the wafer carrier 200 is based on the plane where the lens 100 is located as the reference plane, and the horizontal offset of the light source carrier 300 is based on the plane where the wafer carrier 200 is located as the reference plane. Therefore, when the plane where the lens 100 is located remains unchanged, the horizontal offset of the wafer carrier 200 and the horizontal offset of the light source carrier 300 are both highly stable. In summary, the wafer bonding accuracy measurement device 1000 has high measurement accuracy and stable measurement results.

[0055] like Fig.12 As shown, Fig.12 To adopt Figure 7 The results of the wafer bonding accuracy measurement device 1000 measuring the bonding accuracy of the wafer 5 times. The horizontal axis represents 12 pairs of first bonding marks Mark1 and second bonding marks Mark2 randomly selected on the wafer, and the vertical axis represents the offset of the first bonding mark Mark1 and the second bonding mark Mark2 in the same pair of bonding marks, in micrometers (μm). It can be seen that the difference in bonding accuracy of the 5 measurements is small, and the wafer bonding accuracy measurement device 1000 has a high and stable measurement result.

[0056] In addition, since the wafer bonding accuracy measurement device 1000 provided in the above embodiment has high measurement accuracy and stable measurement results, it is helpful to provide accurate data for subsequent wafer bonding compensation in a timely manner, thereby improving the yield of products.

[0057] Exemplary, reference Fig. 9 Three mark eyes are provided on the wafer carrier 200 , and the connecting lines of the three mark eyes on the wafer carrier 200 can form an equilateral triangle, which is helpful to improve the relative level between the calibration wafer carrier 200 and the lens 100 .

[0058] In other embodiments, the number of the Mark eyes may be 4, 5 or other integers greater than 3, as long as the multiple Mark eyes are not collinear. The distribution of the multiple Mark eyes may also adopt other distribution modes without limitation.

[0059] In some embodiments, the distance measuring device 400 includes at least one laser distance sensor. The distance measuring device 400 can determine the relative level between the wafer carrier 200 and the light source carrier 300 on the basis of being able to realize automatic distance measurement, and can realize real-time feedback and automatic calibration, thereby improving the relative level between the wafer carrier 200 and the light source carrier 300.

[0060] When the distance measuring device 400 is disposed on the side of the wafer carrier 200 facing the light source carrier 300, the distance measuring device 400 can randomly select at least three test points on the side of the light source carrier 300 facing the wafer carrier 200, and the at least three test points are not collinear, so that the plane surrounded by the lines connecting the at least three test points is the plane where the light source carrier 300 is located. When the distances from the distance measuring device 400 to the at least three test points are equal or approximately equal, the wafer carrier 200 and the light source carrier 300 are kept relatively level.

[0061] When the distance measuring device 400 is arranged on the side of the light source carrier 300 facing the wafer carrier 200, the distance measuring device 400 can randomly select at least 3 test points on the side of the wafer carrier 200 facing the light source carrier 300, and at least 3 test points are not collinear, so that the plane surrounded by the lines connecting at least 3 test points is the plane where the wafer carrier 200 is located. When the distances from the distance measuring device 400 to at least 3 test points are equal or approximately equal, the wafer carrier 200 and the light source carrier 300 are kept relatively level. Among them, when the distance measuring device 400 is measuring the distance, the light source carrier 300 can drive the distance measuring device 400 to move along the plane where the light source carrier 300 is located.

[0062] The horizontal calibration accuracy of the light source carrier 300 can reach 0-10μm, that is, when the difference between the distance between the distance measuring device 400 and any two of the at least three test points is within the range of 0-10μm, such as the difference of 0, 2μm, 5μm, 6μm, 8μm, 10μm, the wafer carrier 200 and the light source carrier 300 are kept relatively level, and there is no need to adjust the horizontal offset of the light source carrier 300. If the difference between the distance between the distance measuring device 400 and any two of the at least three test points is greater than 10μm, the horizontal offset of the light source carrier 300 needs to be adjusted again.

[0063] In some embodiments, continue to refer to Fig. 9, the wafer carrier 200 has a light-transmitting area T, the mark eye is set in the light-transmitting area T, and the mark eye is made of metal material. In this case, a light source 301 is provided on the side of the light source carrier 300 facing the wafer carrier 200. When adjusting the wafer carrier 200 to be relatively horizontal based on the plane where the lens 100 is located, based on the plane where the lens 100 is located as the reference plane, the lens 100 is used to measure the distance from at least 3 mark eyes to the lens 100, and the light source 301 needs to be turned on. The infrared light emitted by the light source 301 can be directly irradiated on at least 3 mark eyes, and the lens can measure the distance from at least 3 mark eyes to the lens 100, and then the position of the wafer carrier 200 is adjusted according to the distance from at least 3 mark eyes to the lens 100, until the distance from at least 3 mark eyes to the lens 100 is equal or approximately equal. In this case, the wafer carrier 200 and the lens 100 remain relatively horizontal.

[0064] In the process of measuring the distances from at least three marks to the lens 100 by using the lens 100 , the light source support platform 300 can drive the light source 301 to move along the plane where the light source support platform 300 is located.

[0065] The horizontal calibration accuracy of the wafer carrier 200 can reach 0-10μm, that is, when the difference between the distance between the lens 100 and any two of the at least three mark eyes is within the range of 0-10μm, such as the difference of 0, 2μm, 5μm, 6μm, 8μm, 10μm, the wafer carrier 200 and the lens 100 are kept relatively level, and there is no need to adjust the horizontal offset of the wafer carrier 200. If the difference between the distance between the lens 100 and any two of the at least three mark eyes is greater than 10μm, the horizontal offset of the wafer carrier 200 needs to be adjusted again.

[0066] In some embodiments, the mark eye can reflect light to the lens 100. In this case, based on the plane where the lens 100 is located as the reference plane, the test result of measuring the distances from at least three mark eyes to the lens 100 by the lens 100 is used to adjust the relative level between the wafer carrier 200 and the lens 100. Since the mark eye can reflect light to the lens 100, the lens 100 can directly obtain the distances from at least three mark eyes to the lens 100. Therefore, it is not necessary to use the light source 301 to illuminate the at least three mark eyes. Since no light source is needed, the measurement cost can be reduced.

[0067] In some embodiments, continue to refer to Figure 7The wafer bonding accuracy measuring device 1000 further includes: at least three first height adjustment components M1 connected to the wafer carrier 200, Fig.10 , at least three first height adjustment components M1 are not collinear with the connection position L1 of the wafer carrier 200; at least three first height adjustment components M1 are configured to adjust the position of the wafer carrier 200 in the first direction z, and the first direction z is the arrangement direction of the lens 100, the wafer carrier 200 and the light source carrier 300. Among them, at least three first height adjustment components M1 are not collinear with the connection position L1 of the wafer carrier 200, so that the position of the horizontal plane where the wafer carrier 200 is located can be adjusted by adjusting at least three first height adjustment components M1. When adjusting the first height adjustment component M1, the first height adjustment component M1 can drive the adjustment of the position of the wafer carrier 200 in the first direction z. Compared with manually adjusting the horizontal offset of the wafer carrier 200.

[0068] The wafer bonding accuracy measuring device 1000 in the present embodiment can use at least three first height adjustment components M1 to adjust the relative level between the lens 100 and the wafer carrier 200, and the relative horizontal offset between the lens 100 and the wafer carrier 200 can be obtained by measuring the distance from at least three marks from the lens 100 to the lens 100, thereby realizing automatic calibration of the relative horizontal offset between the wafer carrier 200 and the lens 100, overcoming the defect of high adjustment difficulty in manual adjustment, and ensuring the accuracy of adjustment, thereby improving the measurement efficiency and measurement accuracy of the wafer bonding accuracy measuring device 1000.

[0069] For example, continue to refer to Figure 7 The wafer bonding accuracy measuring device 1000 includes three first height adjustment components M1. The lines connecting the three first height adjustment components M1 and the three connection positions of the wafer carrier 200 can be an equilateral triangle, which is conducive to improving the horizontal offset of the wafer carrier 200 relative to the lens 100 by the three first height adjustment components M1.

[0070] In other embodiments, the number of the first height adjustment components M1 may also be 4, 5 or other integers greater than 3, as long as the connection positions of the plurality of first height adjustment components M1 and the wafer carrier 200 are not collinear.

[0071] In some embodiments, continue to refer to Figure 7 The first height adjustment component M1 includes a first motor M11 and a first adjustment rod M12 connected to an output shaft of the first motor M11 , and the first adjustment rod M12 is connected to the wafer carrying table 200 .

[0072] In some embodiments, the first adjusting rod M12 is provided with a thread for adjusting the extension of the first adjusting rod M12. When adjusting the position of the wafer carrier 200, the first motor M11 drives the first adjusting rod M12 to rotate in the thread direction to drive the adjustment of the position of the wafer carrier 200.

[0073] Exemplarily, the first height adjustment component M1 includes an electric lead screw.

[0074] In some embodiments, continue to refer to Figure 7 The extension direction of the first adjustment rod M12 in the first height adjustment component M1 may be along the arrangement direction of the lens 100 , the wafer carrying platform 200 , and the light source carrying platform 300 .

[0075] In some embodiments, the first adjusting rod M12 includes a linear motor. When the position of the wafer carrying platform 200 is adjusted, the linear motor drives the wafer carrying platform 200 to move.

[0076] In some embodiments, continue to refer to Figure 7 The wafer bonding accuracy measuring device 1000 further includes: at least three second height adjustment components M2 connected to the light source support platform 300, with reference to Fig.11 , at least three second height adjustment components M2 are not collinear with the connection position L2 of the light source carrier 300; at least three second height adjustment components M2 are configured to adjust the position of the light source carrier 300 in the first direction z, and the first direction z is the arrangement direction of the lens 100, the wafer carrier 200 and the light source carrier 300. Among them, at least three second height adjustment components M2 are not collinear with the connection position L2 of the light source carrier 300, so that the position of the horizontal plane where the light source carrier 300 is located can be adjusted by adjusting at least three second height adjustment components M2. When adjusting the second height adjustment component M2, the second height adjustment component M2 can drive the adjustment of the position of the wafer carrier 200 in the first direction z. Compared with manually adjusting the horizontal offset of the light source carrier 300.

[0077] The wafer bonding accuracy measuring device 1000 in the present embodiment can use at least three second height adjustment components M2 to adjust the relative horizontal offset between the wafer carrier 200 and the light source carrier 300, and the relative horizontal offset between the wafer carrier 200 and the light source carrier 300 can be measured by a distance measuring device 400. The distance measuring device 400 can detect the relative horizontal offset between the light source carrier 300 and the wafer carrier 200 in real time. When the light source carrier 300 is in a tilted state relative to the wafer carrier 200, the light source carrier 300 is horizontally adjusted by at least three second height adjustment components M2, thereby realizing automatic calibration of the relative horizontal offset between the wafer carrier 200 and the light source carrier 300, overcoming the defect of high adjustment difficulty in manual adjustment, ensuring the accuracy of adjustment, and improving the measurement efficiency and measurement accuracy of the wafer bonding accuracy measuring device 1000.

[0078] For example, reference Figure 7 , the wafer bonding accuracy measuring device 1000 includes three second height adjustment components M2. Fig.11 The lines connecting the three connection positions of the three second height adjustment components M2 and the light source supporting platform 300 can be an equilateral triangle, which is conducive to improving the horizontal offset of the three second height adjustment components M2 in adjusting the light source supporting platform 300 relative to the wafer supporting platform 200.

[0079] In other embodiments, the number of the second height adjustment components M2 may also be 4, 5 or other integers greater than 3, as long as the three connection positions of the plurality of second height adjustment components M2 and the light source support platform 300 are not collinear.

[0080] In some embodiments, the second height adjustment component M2 includes a second motor M21 and a second adjustment rod M22 connected to an output shaft of the second motor M21 , and the second adjustment rod M22 is connected to the light source support platform 300 .

[0081] In some embodiments, the second adjusting rod M22 is provided with a thread for adjusting the extension of the second adjusting rod M22. When adjusting the position of the light source support platform 300, the second motor M21 drives the second adjusting rod M22 to rotate in the thread direction to drive the adjustment of the position of the light source support platform 300.

[0082] Exemplarily, the second height adjustment component M2 includes an electric screw.

[0083] In some embodiments, the extension direction of the second adjustment rod M22 in the second height adjustment component M2 may be along the arrangement direction of the lens 100 , the wafer carrying platform 200 , and the light source carrying platform 300 .

[0084] In some embodiments, the second adjusting rod M22 includes a linear motor. When the position of the light source supporting platform 300 is adjusted, the linear motor drives the light source supporting platform 300 to move.

[0085] It should be noted that the first motor M21 and the second motor M22 may be the same motor or different motors. When the first motor M21 and the second motor M22 are the same motor, the cost can be saved and the integration of the wafer bonding accuracy measurement device 1000 can be improved. Figure 7 In the figure, the first motor M21 and the second motor M22 are different motors as an example for schematic description.

[0086] In some embodiments, continue to combine reference Figure 7 and Figure 8 The wafer bonding accuracy measuring device 1000 further includes: a controller 500, which is connected to the lens 100 and the distance measuring device 400; the controller 500 is configured to obtain the first distance data measured by the lens 100, and determine the horizontal offset of the wafer carrier 200 according to the first distance data, wherein the first distance data includes the distance from at least three marks to the lens 100; and obtain the second distance data measured by the distance measuring device 400, and determine the horizontal offset of the light source carrier 300 according to the second distance data, wherein the second distance data includes the distance between the wafer carrier 200 and the light source carrier 300. The position of the lens 100 can be adjusted along the first direction z and on a plane perpendicular to the first direction z.

[0087] In some embodiments, continue to refer to Figure 7 The controller 500 is also connected to the first height adjustment component M1 and the second height adjustment component M2. The controller 500 is also configured to adjust at least one first height adjustment component M1 according to the horizontal offset of the wafer carrier 200; and adjust at least one second height adjustment component according to the horizontal offset of the light source carrier.

[0088] Compared with manually adjusting the horizontal offset of the wafer carrier 200 and the light source carrier 300, the wafer bonding accuracy measuring device 1000 in this embodiment uses the controller 500 to control at least three first height adjustment components M1 to adjust the relative level between the lens 100 and the wafer carrier 200, and controls at least three second height adjustment components M2 to adjust the relative level between the wafer carrier 200 and the light source carrier 300, thereby realizing automatic adjustment. The entire adjustment process takes about 1 minute to 3 minutes, thereby overcoming the defects of high adjustment difficulty and long adjustment time in manual adjustment, and ensuring the accuracy of adjustment, thereby improving the measurement efficiency of the wafer bonding accuracy measuring device 1000.

[0089] The wafer bonding accuracy measuring device 1000 provided in the embodiment of the present disclosure uses the plane where the lens 100 is located as the reference plane for the horizontal offset of the wafer carrier 200. In order to avoid the problem that the wafer 20 may shift on the wafer carrier 200 due to the poor absolute level of the wafer carrier 200 after the horizontal calibration caused by excessive inclination of the lens 100. Therefore, before adjusting the horizontal offset of the wafer carrier 200, the absolute level of the lens 100 needs to be adjusted. In this way, when the absolute level of the lens 100 is relatively good, the absolute level of the wafer carrier 200 will also be maintained in a relatively good state after the horizontal calibration.

[0090] In some embodiments, the absolute level of the lens 100 can be detected using a level meter. If the lens 100 is not absolutely level, the absolute level of the lens 100 can be adjusted manually.

[0091] It is understood that the absolute level of the lens 100 may be adjusted when assembling the wafer bonding accuracy measuring device 1000 .

[0092] refer to Fig.13 This embodiment provides a working method of a wafer bonding accuracy measuring device 1000, including:

[0093] Step S1: obtaining first distance data measured by the lens 100, and determining the horizontal offset of the wafer carrying platform 200 according to the first distance data.

[0094] In the process of determining the horizontal offset of the wafer carrying platform 200 , the plane where the lens 100 is located is used as the reference plane.

[0095] Step S2: determining whether the horizontal offset of the wafer stage 200 is within the horizontal calibration accuracy range.

[0096] If the horizontal offset of the wafer stage 200 is within the horizontal calibration accuracy range, step S3 is executed; if the horizontal offset of the wafer stage 200 is greater than the horizontal calibration accuracy range, step S21 is executed.

[0097] Wherein, step S21 includes: using the controller 500 to control the first height adjustment component M1 to adjust the horizontal offset of the wafer carrying platform 200 until the horizontal offset of the wafer carrying platform 200 is within the horizontal calibration accuracy range.

[0098] Step S3: Obtain the second distance data measured by the distance measuring device 400, and determine the horizontal offset of the light source platform 300 according to the second distance data. In the process of determining the horizontal offset of the light source platform 300, the plane where the wafer platform 200 is located is used as the reference plane.

[0099] Step S4: determining whether the horizontal offset of the light source support platform 300 is within the horizontal calibration accuracy range.

[0100] If the horizontal offset of the light source carrier 300 is within the horizontal calibration accuracy range, the bonding accuracy of the wafer is measured; if the horizontal offset of the light source carrier 300 is greater than the horizontal calibration accuracy range, step S41 is executed.

[0101] Wherein, step S41 includes: using the controller 500 to control the second height adjustment component M2 to adjust the horizontal offset of the light source supporting platform 300 until the horizontal offset of the light source supporting platform 300 is within the horizontal calibration accuracy range.

[0102] The above is only a specific implementation of the utility model, but the protection scope of the utility model 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 utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.

Claims

1. A device for measuring wafer bonding accuracy, characterized in that: include: Lens; A wafer carrier, disposed on the image acquisition side of the lens, wherein at least three marks are disposed on the wafer carrier, and the at least three marks are not collinear; The lens is configured to measure the distances of the at least three marks from the lens; A light source carrier, disposed on a side of the wafer carrier away from the lens; The distance measuring device is arranged on the side of the wafer supporting platform facing the light source supporting platform, or on the side of the light source supporting platform facing the wafer supporting platform, and is configured to measure the distance between the wafer supporting platform and the light source supporting platform.

2. The wafer bonding accuracy measuring device according to claim 1, characterized in that: The wafer carrier has a light-transmitting area, and the mark is arranged in the light-transmitting area; A light source is provided on a side of the light source carrier platform facing the wafer carrier platform.

3. The wafer bonding accuracy measuring device according to claim 1, characterized in that: The marking is capable of reflecting light to the lens.

4. The wafer bonding accuracy measuring device according to claim 1, characterized in that: Also includes: At least three first height adjustment components are connected to the wafer carrying platform, and the connection positions of the at least three first height adjustment components and the wafer carrying platform are not collinear; The at least three first height adjustment components are configured to adjust the position of the wafer carrier in a first direction, where the first direction is an arrangement direction of the lens, the wafer carrier, and the light source carrier.

5. The wafer bonding accuracy measuring device according to claim 4, characterized in that: The first height adjustment component includes a first motor and a first adjustment rod connected to an output shaft of the first motor, and the first adjustment rod is connected to the wafer supporting platform.

6. The wafer bonding accuracy measuring device according to claim 1, characterized in that: Also includes: At least three second height adjustment components are connected to the light source support platform, and the connection positions of the at least three second height adjustment components and the light source support platform are not collinear; The at least three second height adjustment components are configured to adjust the position of the light source supporting platform in the first direction.

7. The wafer bonding accuracy measuring device according to claim 6, characterized in that: The second height adjustment component includes a second motor and a second adjustment rod connected to an output shaft of the second motor, and the second adjustment rod is connected to the light source bearing platform.

8. The wafer bonding accuracy measuring device according to any one of claims 1 to 7, characterized in that: Also includes: A controller connected to the lens and the distance measuring device; The controller is configured to obtain first distance data measured by the lens, and determine the horizontal offset of the wafer carrier according to the first distance data, wherein the first distance data includes the distance from the at least three marks to the lens; And, obtaining second distance data measured by the distance measuring device, and determining the horizontal offset of the light source support platform according to the second distance data, wherein the second distance data includes the distance between the wafer support platform and the light source support platform.

9. The wafer bonding accuracy measuring device according to claim 8, characterized in that: The measuring device further comprises at least three first height adjustment components and at least three second height adjustment components, and the controller is further connected to the at least three first height adjustment components and the at least three second height adjustment components; The controller is further configured to adjust at least one of the first height adjustment components according to a horizontal offset of the wafer carrier platform; and to adjust at least one of the second height adjustment components according to a horizontal offset of the light source carrier platform.

10. The wafer bonding accuracy measuring device according to any one of claims 1 to 7, characterized in that: The distance measuring device includes at least one laser distance sensor.

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