Wafer bonding methods and equipment, wafer deformation adjustment equipment

Abstract

This invention provides a wafer bonding method and apparatus, and a wafer deformation adjustment device. The wafer bonding method includes: providing a first pair of wafers to be bonded; performing a first scaling compensation on the first pair of wafers to be bonded; the first scaling compensation is used to correct a first deformation error caused by each wafer in the first pair undergoing multiple semiconductor processing steps before bonding; performing a second scaling compensation on the bonded wafer pair after the first scaling compensation has been performed; the second scaling compensation is used to correct a second deformation error between the wafers in the first pair of wafers to be bonded after the first scaling compensation has been performed; and bonding the first pair of wafers to be bonded.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a wafer bonding method and apparatus, and a wafer deformation adjustment apparatus. Background Technology

[0002] Wafer bonding is a process that integrates two or more chips with the same or different functions in three dimensions. Using wafer bonding can significantly reduce chip development and manufacturing cycles, shorten the metal interconnects between functional chips, and reduce heat generation, power consumption, and latency. Alignment accuracy is the most critical parameter in the bonding process.

[0003] However, in related technologies, there are problems such as poor compensation effect and low alignment accuracy during wafer bonding. Summary of the Invention

[0004] To address the existing technical problems, this invention provides a wafer bonding method and apparatus, and a wafer deformation adjustment apparatus.

[0005] This invention provides a wafer bonding method, comprising:

[0006] Provide the first pair of wafers to be bonded;

[0007] A first scaling compensation is performed on the first pair of wafers to be bonded; the first scaling compensation is used to correct the first deformation error caused by each wafer in the first pair of wafers to be bonded undergoing multiple semiconductor processing processes before bonding.

[0008] A second scaling compensation is performed on the bonding wafer pair that has undergone the first scaling compensation; the second scaling compensation is used to correct the second deformation error between the wafers in the first wafer pair to be bonded after the first scaling compensation is being performed.

[0009] The first pair of wafers to be bonded are bonded.

[0010] In the above scheme, the first wafer pair to be bonded includes a first wafer and a second wafer; both the first wafer and the second wafer have multiple marking points for bonding alignment;

[0011] The first scaling compensation is performed on the first pair of wafers to be bonded, including:

[0012] A first scaling compensation coefficient is determined based on the vector relationship between the target and actual positions of multiple marker points in the first wafer; and a second scaling compensation coefficient is determined based on the vector relationship between the target and actual positions of multiple marker points in the second wafer.

[0013] Based on the first scaling compensation coefficient and the second scaling compensation coefficient, the deformation of the first wafer and / or the deformation of the second wafer are adjusted to perform the first scaling compensation on the first wafer pair to be bonded.

[0014] The method in the above scheme further includes:

[0015] In the first lithography process performed on the first wafer, the target positions and actual positions of multiple marker points in the first wafer are collected; the first lithography process is the last lithography process performed on the first wafer before bonding; in the second lithography process performed on the second wafer, the target positions and actual positions of multiple marker points in the second wafer are collected; the second lithography process is the last lithography process performed on the second wafer before bonding.

[0016] In the above scheme, adjusting the deformation of the first wafer and / or the deformation of the second wafer based on the first scaling compensation coefficient and the second scaling compensation coefficient to perform the first scaling compensation on the first wafer pair to be bonded includes:

[0017] The deformation of the first wafer or the deformation of the second wafer is adjusted by using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient to perform the first scaling compensation on the first wafer pair to be bonded.

[0018] In the above scheme, the first wafer is disposed on the first chuck, and the second wafer is disposed on the second chuck; the first chuck or the second chuck has a cavity;

[0019] The step of adjusting the deformation of the first wafer or the second wafer by using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient to perform the first scaling compensation on the first wafer pair to be bonded includes:

[0020] Using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient, and in conjunction with the first mapping table, the first inflation pressure in the cavity of the first chuck or the second inflation pressure in the cavity of the second chuck is adjusted.

[0021] Specifically, the deformation of the first wafer is adjusted by the first inflation pressure, or the deformation of the second wafer is adjusted by the second inflation pressure; the first mapping table includes the correspondence between compensation coefficients and inflation pressures.

[0022] In the above scheme, the first wafer pair to be bonded includes a first wafer and a second wafer; both the first wafer and the second wafer have multiple marking points for bonding alignment;

[0023] Performing a second scaling compensation on the bonded wafer pair that has undergone the first scaling compensation includes:

[0024] The third scaling compensation coefficient is determined based on the vector relationship between the actual positions of multiple marker points in the first wafer after the first scaling compensation has been applied and the actual positions of multiple marker points in the second wafer after the first scaling compensation has been applied.

[0025] Based on the third scaling compensation coefficient, the deformation of the first wafer or the deformation of the second wafer is adjusted to perform the second scaling compensation on the first wafer pair to be bonded.

[0026] The method in the above scheme further includes:

[0027] Analyze the bonding results of the first pair of wafers to be bonded;

[0028] When the bonding result does not meet the preset conditions, the third scaling compensation coefficient is adjusted to obtain the fourth scaling compensation coefficient, and the fourth scaling compensation coefficient is used to perform scaling compensation on the second wafer pair to be bonded.

[0029] In the above scheme, each wafer in the first pair of wafers to be bonded is used to form the memory cell array portion of the three-dimensional memory device and the peripheral circuit portion of the three-dimensional memory device, respectively.

[0030] This invention also provides a wafer bonding apparatus, comprising:

[0031] The first wafer deformation adjustment device is used to perform first scaling compensation on the first pair of wafers to be bonded; the first scaling compensation is used to correct the deformation error of each wafer in the first pair of wafers to be bonded before bonding, which is caused by multiple semiconductor processing processes.

[0032] The second wafer deformation adjustment device is used to perform a second scaling compensation on the bonding wafer pair after the first scaling compensation has been performed; the second scaling compensation is used to correct the residual deformation error between wafers in the first wafer pair to be bonded after the first wafer deformation adjustment device performs the first scaling compensation.

[0033] A bonding apparatus for performing bonding on the first pair of wafers to be bonded.

[0034] This invention also provides a wafer deformation adjustment device, comprising: a first chuck, a second chuck, a gas generator, and a controller; wherein,

[0035] The first chuck and the second chuck are stacked and have a gap; the first chuck or the second chuck has a cavity;

[0036] The first wafer in the first wafer pair to be bonded is disposed on the surface of the first chuck in the gap, and the second wafer in the first wafer pair to be bonded is disposed on the surface of the second chuck in the gap;

[0037] The gas generator is connected to the cavity and the controller, and is used to adjust the cavity of the first chuck to a first inflation pressure under the control of the controller, so as to adjust the deformation of the first wafer; or, to adjust the cavity of the second chuck to a second inflation pressure, so as to adjust the deformation of the second wafer.

[0038] This invention provides a wafer bonding method and apparatus, and a wafer deformation adjustment device. The wafer bonding method includes: providing a first pair of wafers to be bonded; performing a first scaling compensation on the first pair of wafers to be bonded; the first scaling compensation corrects a first deformation error caused by multiple semiconductor processing steps performed on each wafer in the first pair of wafers before bonding; performing a second scaling compensation on the bonded wafer pair after the first scaling compensation; the second scaling compensation corrects a second deformation error between wafers in the first pair of wafers to be bonded after the first scaling compensation; and bonding the first pair of wafers to be bonded. In this invention, before bonding, incoming material compensation (first scaling compensation) and process compensation (second scaling compensation) are sequentially performed on the first pair of wafers to be bonded. These two scaling compensations not only compensate for wafer deformation differences caused by previous processes but also compensate for errors in the compensation equipment itself, thus greatly improving the compensation effect and the alignment accuracy during the bonding process. Attached Figure Description

[0039] Figures 1a-1d This is a top view schematic diagram of translational misalignment, rotational misalignment, scaling misalignment, and random error misalignment of the wafer to be bonded, provided in an embodiment of the present invention.

[0040] Figure 2 This is a schematic diagram illustrating the implementation process of a wafer bonding method provided in an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram illustrating how scaling compensation is achieved by adjusting the inflation pressure in the cavity of the chuck, as provided in an embodiment of the present invention.

[0042] Figure 4 This is a schematic diagram of the composition of a wafer bonding device provided in an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the structure of a wafer scaling device provided in an embodiment of the present invention. Detailed Implementation

[0044] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Each wafer in the wafers to be bonded has multiple corresponding bonding alignment marks. In some specific examples, these marks may be conductive contacts. During wafer bonding, the bonding process primarily involves aligning the corresponding bonding alignment marks of the two wafers before proceeding. However, due to various reasons, misalignment may occur among the multiple corresponding bonding alignment marks of each wafer in the wafers to be bonded.

[0046] In some specific examples, the main misalignment methods involved include translation (such as...) Figure 1a As shown), rotate (as shown) Figure 1b As shown), scaling (as shown) Figure 1c (as shown) and random errors (such as) Figure 1d (As shown). Translation is the offset of the relative position of a wafer pair in a two-dimensional plane; rotation is the offset of the relative angle of a wafer pair in a two-dimensional plane; scaling is the spatial offset in a three-dimensional plane when the wafers in a wafer pair undergo deformation such as expansion. In some specific examples, translation, rotation, and scaling can be compensated for by adjusting the process, while random errors cannot be compensated for by adjusting the process and require other methods of compensation.

[0047] In various embodiments of the present invention, before bonding is performed, incoming material compensation (first scaling compensation) and process compensation (second scaling compensation) are sequentially performed on the first pair of wafers to be bonded. These two scaling compensations can not only compensate for the wafer deformation differences caused by the previous process, but also compensate for the errors of the compensation equipment itself. Thus, the compensation effect is greatly improved and the alignment accuracy in the bonding process is improved.

[0048] This invention provides a wafer bonding method. Figure 2 This is a schematic diagram illustrating the implementation process of the wafer bonding method according to an embodiment of the present invention. Figure 2 As shown, the method includes the following steps:

[0049] Step 201: Provide the first pair of wafers to be bonded;

[0050] Step 202: Perform first scaling compensation on the first wafer pair to be bonded; the first scaling compensation is used to correct the first deformation error caused by each wafer in the first wafer pair undergoing multiple semiconductor processing processes before bonding;

[0051] Step 203: Perform second scaling compensation on the bonding wafer pair that has undergone the first scaling compensation; the second scaling compensation is used to correct the second deformation error between wafers in the first wafer pair to be bonded after the first scaling compensation is performed.

[0052] Step 204: Bond the first pair of wafers to be bonded.

[0053] Here, the entity performing the wafer bonding method includes, but is not limited to, wafer bonding equipment.

[0054] In step 201, each wafer in the first wafer pair to be bonded may include silicon, germanium, III-V semiconductor, silicon carbide, silicon on insulating substrate, or a combination thereof.

[0055] The first wafer pair to be bonded may include two wafers to be bonded, namely a first wafer and a second wafer; wherein, the first wafer (also referred to as the upper wafer) and the second wafer (also referred to as the lower wafer).

[0056] In some embodiments, each wafer in the first pair of wafers to be bonded is used to form the memory cell array portion of the three-dimensional memory device and the peripheral circuit portion of the three-dimensional memory device, respectively. In some specific embodiments, the memory can be a three-dimensional NAND type memory device.

[0057] In step 202, the first scaling compensation is used to correct the first deformation error caused by each wafer in the first wafer pair undergoing multiple semiconductor processing steps before bonding.

[0058] For example, for the first wafer used to form the memory cell array portion of a three-dimensional memory device, since the memory cell array is typically a complex structure with multiple functional layers, and these layers also have through-hole structures or interconnect structures, the formation of the memory cell array on the bare wafer involves multiple semiconductor processing techniques, such as epitaxial growth, photolithography, etching, filling, planarization, etc. Similarly, the second wafer used to form the peripheral circuit portion of the three-dimensional memory device also undergoes many semiconductor processing techniques. These processing techniques may cause the design target position of the bonding alignment markers on the wafer to be inconsistent with the actual position. Furthermore, because the first and second wafers undergo different semiconductor processing techniques when aligned, scaling misalignment may occur between the first and second wafers before bonding.

[0059] Here, the first deformation error can be understood as the shape change that occurs when the first wafer and the second wafer undergo semiconductor processing, resulting in bending towards the front or back of the wafer (first wafer and second wafer). The front of the wafer always refers to the surface of the wafer used to form various functional film layers, while the back of the wafer is the surface opposite to the front of the wafer.

[0060] It should be noted that since the first scaling compensation corrects the deformation error of each wafer in the first wafer pair to be bonded before bonding due to the multiple semiconductor processing processes, in some specific examples, the first scaling compensation can be performed on the first wafer and the second wafer respectively, or the compensation amount to be performed on the first wafer and the second wafer can be calculated first, then the difference can be made, and the difference can be used to perform the first scaling compensation on only one of the first wafer or the second wafer.

[0061] Understandably, theoretically, after the first scaling compensation, there should no longer be scaling misalignment between the first and second wafers. However, in some specific examples, the equipment used to perform the first scaling compensation cannot execute the predetermined process control 100%, and scaling misalignment still exists between the first and second wafers after the first scaling compensation is performed.

[0062] Based on this, in step 203, a second scaling compensation is performed; the second scaling compensation is used to correct the second deformation error between the wafers in the first wafer pair to be bonded after the scaling compensation device performs the first scaling compensation.

[0063] Here, the second deformation error can be either the residual deformation error after performing the first scaling compensation, or the deformation error reintroduced after performing the first scaling compensation due to other reasons, such as the first scaling compensation process itself or changes in environmental conditions.

[0064] Since the first scaling compensation has already compensated each wafer in the first wafer pair to be bonded, and the deformation deviation in each wafer has been corrected to a certain extent, the second scaling compensation only needs to supplement the residual expansion error after the first scaling compensation. In other words, the first scaling compensation can be understood as coarse compensation, and the second scaling compensation can be understood as fine compensation.

[0065] After the second scaling compensation, step 204 is executed to bond the first pair of wafers to be bonded.

[0066] In some specific examples, the wafers in the first wafer pair to be bonded can be bonded by any bonding method, such as adhesive bonding, anodic bonding, direct wafer bonding, metal bonding, or hybrid bonding.

[0067] In some embodiments, when the first wafer pair to be bonded is a wafer with a peripheral circuit and a wafer with a memory array, the wafers in the wafer pair to be bonded can be bonded as a hybrid bonding (also known as "metal / dielectric hybrid bonding").

[0068] It is understandable that the alignment of the corresponding marker points of the first pair of wafers to be bonded will be more accurate after two scaling compensations.

[0069] The specific implementation methods for the first and second scaling compensations will be described below. First, the specific implementation method of the first scaling compensation will be explained.

[0070] In some embodiments, the first wafer pair to be bonded includes a first wafer and a second wafer; both the first wafer and the second wafer have a plurality of markers for bonding alignment;

[0071] The first scaling compensation is performed on the first pair of wafers to be bonded, including:

[0072] A first scaling compensation coefficient is determined based on the vector relationship between the target and actual positions of multiple marker points in the first wafer; and a second scaling compensation coefficient is determined based on the vector relationship between the target and actual positions of multiple marker points in the second wafer.

[0073] Based on the first scaling compensation coefficient and the second scaling compensation coefficient, the deformation of the first wafer and / or the deformation of the second wafer are adjusted to perform the first scaling compensation on the first wafer pair to be bonded.

[0074] Here, before semiconductor processing is performed on each wafer, each marker point on the wafer has a target position, i.e., a theoretical position. After semiconductor processing is completed, each marker point on the wafer has an actual position offset from the target position. In some specific examples, the target positions and actual positions of multiple marker points in the first wafer can be collected during the photolithography process.

[0075] In some embodiments, the method further includes:

[0076] In the first lithography process performed on the first wafer, the target positions and actual positions of multiple marker points in the first wafer are collected; the first lithography process is the last lithography process performed on the first wafer before bonding; in the second lithography process performed on the second wafer, the target positions and actual positions of multiple marker points in the second wafer are collected; the second lithography process is the last lithography process performed on the second wafer before bonding.

[0077] It is understandable that when the first photolithography process is the last photolithography process that the first wafer undergoes before bonding, the actual positions of the collected multiple marker points are closer to the final state before bonding.

[0078] In some specific examples, the last major process before bonding the first wafer and the second wafer is to form a bonding layer, that is, to use photolithography to form through holes in the bonding layer for forming conductive contacts. The position corresponding to the pattern in the mask layer of this photolithography process can be used as the target position coordinates of the marker point, and the position of the finally formed marker point can be used as the actual position coordinates of the marker point.

[0079] In some specific examples, the target position coordinates and actual position coordinates of each marker in multiple marker points constitute a vector. The difference between the target position and actual position of each marker point in the first wafer / second wafer is calculated to obtain a first vector set / a second vector set. Each vector in the first vector set represents the vector difference between the target position and actual position of each marker point, and each vector in the second vector set represents the vector difference between the target position and actual position of each marker point. By performing translation, rotation, and scaling on the actual coordinates of all marker points, and through iterative calculation, the optimal values ​​of the coordinate axis transformations that minimize the sum of squares of all vectors can be obtained. The scaling factor calculated in this iterative calculation is the first compensation coefficient / second compensation coefficient.

[0080] It should be noted that different types of compensation can yield corresponding compensation coefficients, and different types of compensation can be implemented using different processes. For example, the translation and rotation compensation can be achieved by adjusting the wafer position, while the scaling compensation can be achieved by adjusting the wafer curvature (bend).

[0081] Next, the deformation of the first wafer can be adjusted using the first compensation coefficient, and the deformation of the second wafer can be adjusted using the second compensation coefficient to achieve the first scaling compensation; alternatively, the difference between the first compensation coefficient and the second compensation coefficient can be used to adjust the deformation of only one of the first or second wafers to achieve the first scaling compensation.

[0082] In some embodiments, adjusting the deformation of the first wafer and / or the deformation of the second wafer based on the first scaling compensation coefficient and the second scaling compensation coefficient to perform the first scaling compensation on the first wafer pair to be bonded includes:

[0083] The deformation of the first wafer or the deformation of the second wafer is adjusted by using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient to perform the first scaling compensation on the first wafer pair to be bonded.

[0084] It is understandable that adjusting the deformation of only one wafer, rather than adjusting the deformation of two wafers separately, can save on the adjustment process and reduce manufacturing costs.

[0085] In some specific examples, for process adjustments, the first scaling compensation can be achieved by adjusting the inflation pressure in the chuck cavity.

[0086] In some embodiments, the first wafer is disposed on a first chuck, and the second wafer is disposed on a second chuck; the first chuck or the second chuck has a cavity;

[0087] The step of adjusting the deformation of the first wafer or the second wafer by using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient to perform the first scaling compensation on the first wafer pair to be bonded includes:

[0088] Using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient, and in conjunction with the first mapping table, the first inflation pressure in the cavity of the first chuck or the second inflation pressure in the cavity of the second chuck is adjusted.

[0089] Specifically, the deformation of the first wafer is adjusted by the first inflation pressure, or the deformation of the second wafer is adjusted by the second inflation pressure; the first mapping table includes the correspondence between compensation coefficients and inflation pressures.

[0090] In some specific examples, the adjustment of the second wafer will be used as an example for illustration, such as... Figure 3 As shown, the second wafer is placed on the surface of the second chuck. Gas is injected into the cavity of the second chuck, causing the surface of the second chuck, carrying the second wafer, to become an arc surface, thereby expanding (deforming) the surface area of ​​the second wafer. By conducting multiple experiments, the relationship between the gas pressure or the chord height of the arc surface and the expansion (deformation) of the wafer surface area is found. Adjusting the gas pressure or chord height during the bonding process can achieve scaling compensation.

[0091] It should be noted that a certain chord height can be defined as the deformation reference, a chord height less than a certain height is considered deformation in one direction, and a chord height greater than a certain height is considered deformation in another direction.

[0092] Since the first scaling compensation corrects the deformation error of each wafer before bonding, the deformation error of both is reduced to a certain extent. It can be understood that the residual deformation error during the second scaling compensation is much smaller than that during the first scaling compensation. The specific implementation of the second scaling compensation will be explained next.

[0093] In some embodiments, the first wafer pair to be bonded includes a first wafer and a second wafer; both the first wafer and the second wafer have a plurality of markers for bonding alignment;

[0094] Performing a second scaling compensation on the bonded wafer pair that has undergone the first scaling compensation includes:

[0095] The third scaling compensation coefficient is determined based on the vector relationship between the actual positions of multiple marker points in the first wafer after the first scaling compensation has been applied and the actual positions of multiple marker points in the second wafer after the first scaling compensation has been applied.

[0096] Based on the third scaling compensation coefficient, the deformation of the first wafer or the deformation of the second wafer is adjusted to perform the second scaling compensation on the first wafer pair to be bonded.

[0097] In some specific examples, a bonding alignment mark measuring device can be used to measure the actual positions of multiple mark points in a first wafer that has undergone first scaling compensation and the actual positions of multiple mark points in a second wafer that has undergone first scaling compensation. In some embodiments, the bonding alignment mark measuring device may include a sensor with camera functionality.

[0098] The actual positions of multiple marker points on the first wafer after the first scaling compensation are subtracted from the actual positions of multiple marker points on the second wafer after the first scaling compensation, resulting in a third vector set. The coordinates of all marker points are then subjected to three coordinate axis transformations: translation, rotation, and scaling. Through iterative calculation, the optimal values ​​of the coordinate axis transformations that minimize the sum of squares of all vectors are obtained. The scaling amount calculated in this iteration is the third compensation coefficient.

[0099] For process adjustments, the second scaling compensation can be implemented in the same or different ways as the first scaling compensation. In some embodiments, the second scaling compensation can be implemented by adjusting the chuck holding time of the wafer.

[0100] In some embodiments, the method further includes:

[0101] Analyze the bonding results of the first pair of wafers to be bonded;

[0102] When the bonding result does not meet the preset conditions, the third scaling compensation coefficient is adjusted to obtain the fourth compensation coefficient, and the fourth scaling compensation coefficient is used to perform scaling compensation on the second wafer pair to be bonded.

[0103] In some specific examples, after bonding is completed, the third scaling compensation coefficient can be corrected based on the bonding result to obtain a fourth compensation coefficient, and the fourth scaling compensation coefficient can be used to perform scaling compensation on the new wafer pair to be bonded, i.e., the second wafer to be bonded.

[0104] In some embodiments, the method further includes:

[0105] When performing the second scaling compensation on the first wafer pair to be bonded, the relative positions between the wafers in the first wafer pair to be bonded are adjusted to perform translation compensation and / or rotation compensation on the first wafer pair to be bonded.

[0106] It is understood that the first scaling compensation largely corrects the expansion error generated by the first wafer and / or the second wafer in the previous semiconductor processing, while the second scaling compensation finely corrects the residual expansion error generated by the first wafer and / or the second wafer in the previous semiconductor processing. The combination of the two improves the alignment accuracy of the first wafer to be bonded.

[0107] This invention also provides a wafer bonding apparatus, which enables the execution of the above-described wafer bonding method. (In conjunction with...) Figure 4 , Figure 4 This is a schematic diagram of the composition of a wafer bonding apparatus 40 provided in an embodiment of the present invention. The wafer bonding apparatus 40 includes:

[0108] The first wafer deformation adjustment device 401 is used to perform first scaling compensation on the first pair of wafers to be bonded; the first scaling compensation is used to correct the first deformation error caused by each wafer in the first pair of wafers to be bonded undergoing multiple semiconductor processing processes before bonding.

[0109] The second wafer deformation adjustment device 402 performs a second scaling compensation on the bonding wafer pair after the first scaling compensation has been performed; the second scaling compensation is used to correct the second deformation error between the wafers in the first wafer pair to be bonded after the first wafer deformation adjustment device performs the first scaling compensation.

[0110] The bonding device 403 is used to perform bonding on the first pair of wafers to be bonded.

[0111] In some embodiments, the first wafer pair to be bonded includes a first wafer and a second wafer; both the first wafer and the second wafer have multiple marker points for bonding alignment.

[0112] The first wafer-level adjustment device 401 is specifically used for:

[0113] A first scaling compensation coefficient is determined based on the vector relationship between the target and actual positions of multiple marker points in the first wafer; and a second scaling compensation coefficient is determined based on the vector relationship between the target and actual positions of multiple marker points in the second wafer.

[0114] Based on the first scaling compensation coefficient and the second scaling compensation coefficient, the deformation of the first wafer and / or the deformation of the second wafer are adjusted to perform the first scaling compensation on the first wafer pair to be bonded.

[0115] In some embodiments, the wafer bonding apparatus 40 further includes: a position recording device for recording the target position and actual position of a plurality of marker points in the first wafer during a first photolithography process; the first photolithography process being the last photolithography process performed on the first wafer before bonding; and the target position and actual position of a plurality of marker points in the second wafer during a second photolithography process; the second photolithography process being the last photolithography process performed on the second wafer before bonding.

[0116] In some embodiments, the first wafer deformation adjustment device 401 is specifically used for:

[0117] The deformation of the first wafer or the deformation of the second wafer is adjusted by using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient to perform the first scaling compensation on the first wafer pair to be bonded.

[0118] In some embodiments, the wafer bonding apparatus 40 further includes: a wafer carrier; the wafer carrier includes a first chuck for carrying a first wafer and a second chuck for carrying a second wafer; the first chuck or the second chuck has a cavity;

[0119] The first wafer-level adjustment device 401 is specifically used for:

[0120] Using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient, and in conjunction with the first mapping table, the first inflation pressure in the cavity of the first chuck or the second inflation pressure in the cavity of the second chuck is adjusted.

[0121] Specifically, the deformation of the first wafer is adjusted by the first inflation pressure, or the deformation of the second wafer is adjusted by the second inflation pressure; the first mapping table includes the correspondence between compensation coefficients and inflation pressures.

[0122] In some embodiments, the first wafer pair to be bonded includes a first wafer and a second wafer; both the first wafer and the second wafer have a plurality of markers for bonding alignment;

[0123] The second wafer size adjustment device 402 is specifically used for:

[0124] The third scaling compensation coefficient is determined based on the vector relationship between the actual positions of multiple marker points in the first wafer after the first scaling compensation has been applied and the actual positions of multiple marker points in the second wafer after the first scaling compensation has been applied.

[0125] Based on the third scaling compensation coefficient, the deformation of the first wafer or the deformation of the second wafer is adjusted to perform the second scaling compensation on the first wafer pair to be bonded.

[0126] In some embodiments, the wafer bonding apparatus 40 further includes: a system correction device, used to analyze the bonding result of the first wafer pair to be bonded; when the bonding result does not meet the preset conditions, the third scaling compensation coefficient is adjusted to obtain a fourth scaling compensation coefficient;

[0127] The second wafer scaling adjustment device 402 is also used to perform scaling compensation on the second wafer pair to be bonded using the fourth scaling compensation coefficient.

[0128] This invention also provides a wafer scaling device, which enables the first wafer scaling device 401 to be adjusted, such as... Figure 5 As shown, the wafer adjustment device 50 includes: a first chuck 501, a second chuck 502, a gas generator 503, and a controller. Figure 5 (not shown in the image); where,

[0129] The first chuck 501 and the second chuck 502 are stacked and have a gap; the first chuck 501 or the second chuck 502 has a cavity 504;

[0130] The first wafer W1 in the first wafer pair to be bonded is disposed on the surface of the first chuck 501 in the gap, and the second wafer W2 in the first wafer pair to be bonded is disposed on the surface of the second chuck 502 in the gap;

[0131] The gas generator 503 is connected to the cavity 504 and the controller, and is used to adjust the cavity of the first chuck 501 to a first inflation pressure under the control of the controller during the execution of the first scaling compensation, so as to adjust the deformation of the first wafer; or, adjust the cavity of the second chuck 502 to a second inflation pressure, so as to adjust the deformation of the second wafer.

[0132] here, Figure 5 The diagram illustrates the case where the second chuck 502 has a cavity. The specific method by which the controller determines the first or second inflation pressure can be found in the description of the aforementioned wafer bonding method, and will not be repeated here. In some specific embodiments, the controller may include a central processing unit, a processor, a programmable array logic, an application-specific integrated circuit, etc.

[0133] In some specific embodiments, the gas generator 503 includes, but is not limited to, an air generator. It should be noted that in the embodiments of the present invention, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0134] The technical solutions described in the embodiments of the present invention can be combined arbitrarily without conflict.

[0135] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A wafer bonding method, characterized by, include: A first wafer pair to be bonded is provided; the first wafer pair to be bonded includes a first wafer and a second wafer; both the first wafer and the second wafer have multiple marker points for bonding alignment; The first scaling compensation coefficient is determined based on the vector relationship between the target position and the actual position of multiple marker points in the first wafer; And based on the vector relationship between the target position and the actual position of multiple marker points in the second wafer, a second scaling compensation coefficient is determined; Based on the first scaling compensation coefficient and the second scaling compensation coefficient, the deformation of the first wafer and / or the deformation of the second wafer are adjusted to perform the first scaling compensation on the first wafer pair to be bonded. The first scaling compensation is used to correct the first deformation error caused by each wafer in the first wafer pair undergoing multiple semiconductor processing processes before bonding. A second scaling compensation is performed on the bonded wafer pair that has undergone the first scaling compensation; The second scaling compensation is used to correct the second deformation error between wafers in the first wafer pair to be bonded after the first scaling compensation is being performed. The first pair of wafers to be bonded are bonded.

2. The method of claim 1, wherein, The method further includes: In the first lithography process performed on the first wafer, the target positions and actual positions of multiple marker points in the first wafer are collected; the first lithography process is the last lithography process performed on the first wafer before bonding; in the second lithography process performed on the second wafer, the target positions and actual positions of multiple marker points in the second wafer are collected; the second lithography process is the last lithography process performed on the second wafer before bonding.

3. The method of claim 1, wherein, The step of adjusting the deformation of the first wafer and / or the deformation of the second wafer based on the first scaling compensation coefficient and the second scaling compensation coefficient to perform first scaling compensation on the first wafer pair to be bonded includes: The deformation of the first wafer or the deformation of the second wafer is adjusted by using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient, so as to perform the first scaling compensation on the first wafer pair to be bonded.

4. The method of claim 3, wherein, The first wafer is disposed on a first chuck, and the second wafer is disposed on a second chuck; the first chuck or the second chuck has a cavity; The step of adjusting the deformation of the first wafer or the second wafer by using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient to perform the first scaling compensation on the first wafer pair to be bonded includes: Using the difference between the first scaling compensation coefficient and the second scaling compensation coefficient, and in conjunction with the first mapping table, the first inflation pressure in the cavity of the first chuck or the second inflation pressure in the cavity of the second chuck is adjusted. Specifically, the deformation of the first wafer is adjusted by the first inflation pressure, or the deformation of the second wafer is adjusted by the second inflation pressure; the first mapping table includes the correspondence between compensation coefficients and inflation pressures.

5. The method according to claim 1, characterized in that, Performing a second scaling compensation on the bonded wafer pair that has undergone the first scaling compensation includes: The third scaling compensation coefficient is determined based on the vector relationship between the actual positions of multiple marker points in the first wafer after the first scaling compensation has been applied and the actual positions of multiple marker points in the second wafer after the first scaling compensation has been applied. Based on the third scaling compensation coefficient, the deformation of the first wafer or the deformation of the second wafer is adjusted to perform the second scaling compensation on the first wafer pair to be bonded.

6. The method of claim 5, wherein, The method further includes: Analyze the bonding results of the first pair of wafers to be bonded; When the bonding result does not meet the preset conditions, the third scaling compensation coefficient is adjusted to obtain the fourth scaling compensation coefficient, and the fourth scaling compensation coefficient is used to perform scaling compensation on the second wafer pair to be bonded.

7. The method of claim 1, wherein, Each wafer in the first pair of wafers to be bonded is used to form the memory cell array portion of the three-dimensional memory device and the peripheral circuit portion of the three-dimensional memory device, respectively.

8. A wafer bonding apparatus, characterized by comprising: include: A first wafer deformation adjustment device is used to perform a first scaling compensation on a first pair of wafers to be bonded; the first pair of wafers to be bonded includes a first wafer and a second wafer; both the first wafer and the second wafer have multiple markers for bonding alignment; the first scaling compensation on the first pair of wafers to be bonded includes: determining a first scaling compensation coefficient based on the vector relationship between the target position and the actual position of the multiple markers in the first wafer; and determining a second scaling compensation coefficient based on the vector relationship between the target position and the actual position of the multiple markers in the second wafer; adjusting the deformation of the first wafer and / or the deformation of the second wafer based on the first scaling compensation coefficient and the second scaling compensation coefficient, so as to perform the first scaling compensation on the first pair of wafers to be bonded; the first scaling compensation is used to correct the first deformation error generated by each wafer in the first pair of wafers to be bonded undergoing multiple semiconductor processing processes before bonding; The second wafer deformation adjustment device is used to perform second scaling compensation on the bonding wafer pair after the first scaling compensation has been performed; the second scaling compensation is used to correct the second deformation error between wafers in the first wafer pair to be bonded after the first wafer deformation adjustment device performs the first scaling compensation. A bonding apparatus for performing bonding on the first pair of wafers to be bonded.

9. A wafer deformation adjustment apparatus characterized by comprising: The wafer scaling device includes a first wafer scaling unit, which performs a first scaling compensation on a first pair of wafers to be bonded. The first pair of wafers to be bonded includes a first wafer and a second wafer. Both the first wafer and the second wafer have multiple markers for bonding alignment. Performing the first scaling compensation on the first pair of wafers to be bonded includes: determining a first scaling compensation coefficient based on the vector relationship between the target and actual positions of the multiple markers in the first wafer; and determining a second scaling compensation coefficient based on the vector relationship between the target and actual positions of the multiple markers in the second wafer; and adjusting the deformation of the first wafer and / or the deformation of the second wafer based on the first and second scaling compensation coefficients to perform the first scaling compensation on the first pair of wafers to be bonded. The first wafer scaling unit includes: a first chuck, a second chuck, a gas generator, and a controller. The first chuck and the second chuck are stacked and have a gap; the first chuck or the second chuck has a cavity; The first wafer in the first wafer pair to be bonded is disposed on the surface of the first chuck in the gap, and the second wafer in the first wafer pair to be bonded is disposed on the surface of the second chuck in the gap; The gas generator is connected to the cavity and the controller, and is used to adjust the cavity of the first chuck to a first inflation pressure under the control of the controller during the execution of the first scaling compensation, so as to adjust the deformation of the first wafer; or, to adjust the cavity of the second chuck to a second inflation pressure, so as to adjust the deformation of the second wafer.

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