Silicon wafer alignment device and silicon wafer alignment method

Abstract

The present invention provides a silicon wafer alignment device and method for aligning and bonding two silicon wafers. The device comprises: two opposing loading modules, each having a loading surface for loading the silicon wafers, the two loading surfaces being arranged opposite each other; at least one alignment contact module, disposed on at least one of the loading modules, for providing a lifting force to the silicon wafers; and at least one vacuum adsorption structure, disposed on the loading surface of the loading module having the alignment contact module, each vacuum adsorption structure having at least two independent, concentric annular vacuum adsorption areas. The adsorption force of at least a portion of the vacuum adsorption areas of any vacuum adsorption structure is adjusted according to the magnification values ​​of the two silicon wafers to reduce the difference in the magnification values ​​of the two silicon wafers. The present invention reduces the magnification difference between the two silicon wafers, thereby improving alignment and bonding accuracy.

Description

Technical Field

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

[0002] With the rapid development of Moore's Law in the semiconductor industry, the cost and difficulty of continued development are increasing. At the same time, 3D ICs are increasingly being used and are proving to be an indispensable complement to Moore's Law in semiconductor development. In 3D ICs, alignment bonding processes offer the advantage of high yield and are increasingly being used. Currently, the highest accuracy of alignment bonding processes is 0.5μm. Its common structure consists of two opposing loading modules, two sets of opposing alignment measurement modules, and an alignment contact module. The two opposing alignment measurement modules are used to measure the position of the corresponding silicon wafers and obtain alignment error information between the two wafers. After compensation via a motion stage, the alignment contact module completes the contact bonding of the two wafers.

[0003] As the industry develops, the precision requirements for alignment and bonding processes are becoming increasingly stringent, potentially requiring alignment and bonding accuracies of 200nm or higher across the entire wafer. However, achieving alignment and bonding accuracies of 200nm is extremely difficult due to two reasons. First, the two incoming silicon wafers often experience a certain rate deviation due to the influence of the upstream process. Second, during alignment and bonding, the two silicon wafers are attached to the upper and lower loading modules, respectively, and their temperature distributions vary. Calculating a 0.1°C deviation, the edges of two 12-inch silicon wafers will experience a deviation of approximately 40nm. Therefore, to achieve higher-precision alignment and bonding, it is crucial to control the rate difference between the two silicon wafers before alignment and bonding, keeping it within an acceptable range. Summary of the Invention

[0004] The object of the present invention is to provide a silicon wafer alignment device and a silicon wafer alignment method to reduce the magnification difference between two silicon wafers and improve the alignment and bonding accuracy.

[0005] In order to achieve the above-mentioned object, the present invention provides a silicon wafer alignment device for aligning and bonding two silicon wafers, comprising:

[0006] Two loading modules are arranged opposite to each other, each having a loading surface for loading the silicon wafer, and the two loading surfaces are arranged opposite to each other;

[0007] at least one alignment contact module, disposed on at least one of the loading modules, for providing a lifting force to the silicon wafer;

[0008] At least one vacuum adsorption structure is provided on the loading surface of the loading module having the alignment contact module, each of the vacuum adsorption structures having at least two independent and concentric annular vacuum adsorption areas;

[0009] The adsorption force of at least part of the vacuum adsorption area of ​​any one of the vacuum adsorption structures is adjusted according to the magnification values ​​of the two silicon wafers to reduce the difference in the magnification values ​​of the two silicon wafers, and the two loading modules move relative to each other to align and bond the two silicon wafers.

[0010] Optionally, the magnification value of the silicon wafer is obtained before the silicon wafer is loaded into the loading module.

[0011] Optionally, the two loading modules are respectively a first loading module and a second loading module, the alignment and contact module is arranged on the first loading module, and the first loading module is used for loading silicon wafers with a smaller magnification value.

[0012] Optionally, at least two alignment measurement modules are further included, which are arranged on the two loading modules and are used to obtain the magnification value of the silicon wafer.

[0013] Optionally, the alignment contact module is provided on both of the loading modules.

[0014] Optionally, the alignment contact module is provided on any one of the loading modules; the silicon wafer alignment device further comprises a temperature control module, provided on any one of the loading modules, for adjusting the temperature of the carrying surface of the loading module.

[0015] Optionally, a motion platform is further included for driving at least one of the loading modules to move.

[0016] Optionally, the vacuum adsorption area includes a first vacuum adsorption area and at least one second vacuum adsorption area, and the second vacuum adsorption area sequentially surrounds the first vacuum adsorption area to form a concentric ring.

[0017] A silicon wafer alignment method using the silicon wafer alignment device as described above comprises:

[0018] Providing two silicon wafers, loading the two silicon wafers onto two carrying surfaces respectively, and obtaining magnification values ​​of the two silicon wafers;

[0019] adjusting the adsorption force of at least a portion of the vacuum adsorption area of ​​any one of the vacuum adsorption structures according to the magnification values ​​of the two silicon wafers, so as to reduce the difference between the magnification values ​​of the two silicon wafers;

[0020] The two loading modules move relative to each other to align and bond the two silicon wafers.

[0021] Optionally, the two loading modules are respectively a first loading module and a second loading module, the alignment and contact module is arranged on the first loading module, and the first loading module is used to load silicon wafers with a smaller magnification value, and the magnification value of the silicon wafer is obtained before the silicon wafer is loaded into the loading module; and

[0022] Adjust the vacuum adsorption structure on the loading surface of the first loading module.

[0023] Optionally, it further comprises at least two alignment measurement modules, which are provided on the two loading modules and are used to obtain the magnification value of the silicon wafer, and the alignment contact module is provided on both loading modules; and

[0024] The vacuum adsorption structure on the loading surface of the silicon wafer with a smaller loading magnification value is adjusted.

[0025] Optionally, it further comprises at least two alignment measurement modules, which are arranged on the two loading modules and are used to obtain the magnification value of the silicon wafer, and the alignment contact module is arranged on any one of the loading modules; and

[0026] When the loading module set by the alignment contact module is loaded with silicon wafers with a smaller magnification value, the vacuum adsorption structure on the loading surface of the loading module is adjusted; when the loading module set by the alignment contact module is loaded with silicon wafers with a larger magnification value, the temperature of any of the silicon wafers and the vacuum adsorption structure on the loading surface of the loading module are adjusted.

[0027] Optionally, adjusting the temperature of any of the silicon wafers includes lowering the temperature of the silicon wafer with a larger magnification value or raising the temperature of the silicon wafer with a smaller magnification value.

[0028] In the silicon wafer alignment device and silicon wafer alignment method provided by the present invention, an alignment contact module is arranged on at least one loading module, and a vacuum adsorption structure is provided on the loading surface of the loading module having the alignment contact module. The vacuum adsorption structure has at least two independent and concentric ring-shaped vacuum adsorption areas. The adsorption force of at least part of the vacuum adsorption area of ​​any vacuum adsorption structure is adjusted according to the magnification value of the two silicon wafers. In combination with the alignment contact module, a pushing force is provided to the silicon wafer to adjust the magnification value of the silicon wafer, thereby reducing the difference in the magnification value between the two silicon wafers, that is, reducing the magnification difference between the two silicon wafers, and improving the alignment bonding accuracy when performing alignment bonding. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic structural diagram of a silicon wafer alignment device provided in one embodiment of the present invention;

[0030] Figure 2 A schematic diagram of a vacuum adsorption structure in a silicon wafer alignment device provided in one embodiment of the present invention;

[0031] Figure 3 and Figure 4 A schematic diagram of the position of a silicon wafer alignment device provided by one embodiment of the present invention when measuring a silicon wafer magnification value;

[0032] Figure 5 A flow chart of a silicon wafer alignment method provided in one embodiment of the present invention;

[0033] Figure 6 A schematic diagram of adjusting the silicon wafer magnification value by the silicon wafer alignment method provided by one embodiment of the present invention;

[0034] Wherein, the accompanying drawings are marked as follows:

[0035] 101, 201 - silicon wafer; 111, 112, 211, 212 - alignment marks; 102, 202 - loading module; 103, 203 - alignment measurement module; 104 - alignment contact module; 204 - motion stage. DETAILED DESCRIPTION

[0036] The following is a more detailed description of the specific embodiments of the present invention with reference to schematic diagrams. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are greatly simplified and not to exact scale, and are only used for the purpose of conveniently and clearly illustrating the embodiments of the present invention.

[0037] Figure 1 This is a schematic diagram of the structure of the silicon wafer alignment device provided in this embodiment. Figure 2 This is a schematic diagram of the vacuum adsorption structure in the silicon wafer alignment device provided in this embodiment. Figure 1 and Figure 2 This embodiment provides a silicon wafer alignment device for aligning and bonding two silicon wafers 101 and 201, including two oppositely arranged loading modules 102 and 202, at least one alignment contact module 104 and at least one vacuum adsorption structure.

[0038] The two loading modules 102 and 202 are arranged vertically relative to each other and each has a loading surface for loading silicon wafers. The two loading surfaces are arranged opposite to each other. At least two alignment marks are provided on each of the two silicon wafers 101 and 201. The positions of all alignment marks on the two silicon wafers 101 and 201 are the same. Figure 1Each silicon wafer in the figure shows only two alignment marks, that is, two alignment marks 111 and 112 are provided on silicon wafer 101, and two alignment marks 211 and 212 are provided on silicon wafer 201. The positions of the two alignment marks 111 and 112 on silicon wafer 101 are the same as the positions of the two alignment marks 211 and 212 on silicon wafer 201, that is, the distance between the two alignment marks 111 and 112 on silicon wafer 101 is the same as the distance between the two alignment marks 211 and 212 on silicon wafer 201.

[0039] At least one loading module is provided with an alignment contact module for providing a lifting force to the silicon wafer placed on the loading module. Figure 1 2 shows that the loading module 102 is provided with an alignment contact module 104 for providing a downward push force to the silicon wafer 101 . The loading module 202 may also be provided with an alignment contact module.

[0040] The loading surface of the loading module with the alignment contact module is provided with a vacuum adsorption structure, which has at least two independent and concentric ring-shaped vacuum adsorption areas. Any silicon wafer is loaded onto the loading surface of the loading module with the alignment contact module through the vacuum adsorption structure. The loading surface of the loading module without the alignment contact module is not provided with a vacuum adsorption structure, and another silicon wafer is loaded onto the loading surface of another loading module through conventional adsorption. Figure 1 A vacuum adsorption structure is provided on the loading surface of the loading module 102 of the center alignment contact module 104 , and the silicon wafer 101 is loaded onto the loading module 102 through the vacuum adsorption structure.

[0041] In this embodiment, the vacuum adsorption area includes a first vacuum adsorption area and at least one second vacuum adsorption area. The second vacuum adsorption area surrounds the first vacuum adsorption area in sequence to form concentric rings. At least two independent vacuum adsorption areas are concentric rings, which can evenly adjust the magnification for different areas of the silicon wafer. Figure 2 The figure shows that the vacuum adsorption structure on the loading surface of the loading module 102 has three independent vacuum adsorption areas 102a, 102b, and 102c. The vacuum degrees of the three vacuum adsorption areas 102a, 102b, and 102c can be set to be the same or different according to actual conditions. The vacuum adsorption area 102a is the first vacuum adsorption area, and the two vacuum adsorption areas 102b and 102c are both second vacuum adsorption areas. The vacuum adsorption area 102a is circular, and the two vacuum adsorption areas 102b and 102c are annular and surround the vacuum adsorption area 102a in sequence to form concentric rings.

[0042] In this embodiment, the first example can obtain the magnification values ​​of the two silicon wafers 101 and 201 before loading them into the two loading modules 102 and 202 respectively. The two loading modules 102 and 202 are respectively the first loading module and the second loading module. The alignment contact module is set on the first loading module, and the first loading module is used to load silicon wafers with smaller magnification values. Figure 1 The middle loading module 101 is the first loading module, the loading module 102 is the second loading module, the alignment contact module 104 is set on the loading module 101, and the loading module 101 is used to load the silicon wafer 101 with a smaller magnification value. The vacuum adsorption structure on the loading surface of the loaded silicon wafer 101 is adjusted according to the difference in the magnification values ​​of the two silicon wafers 101 and 201. Specifically, the adsorption force of at least part of the vacuum adsorption area in the vacuum adsorption structure is adjusted. Adjusting the adsorption force is to adjust the vacuum degree of the vacuum adsorption area. Since the vacuum adsorption areas in the vacuum adsorption structure are independent of each other, the vacuum degree of a certain vacuum adsorption area can be adjusted individually or the vacuum degrees of multiple vacuum adsorption areas can be adjusted in combination to achieve the adjustment of the adsorption force of at least part of the vacuum adsorption area of ​​the vacuum adsorption structure. Adjust the adsorption force of at least part of the vacuum adsorption area of ​​the vacuum adsorption structure corresponding to the silicon wafer 101 and combine with the alignment contact module 104 to provide a pushing force to the silicon wafer 101. The directions of the adsorption force and the pushing force are opposite, and the silicon wafer 101 is stretched to increase the magnification value of the silicon wafer 101, thereby reducing the difference in the magnification value between the two silicon wafers 101 and 201, that is, reducing the magnification difference between the two silicon wafers 101 and 201, and improving the alignment and bonding accuracy.

[0043] In this embodiment, the second example may include at least two alignment measurement modules 103, 203, which are respectively arranged on the two loading modules 102, 202, for obtaining the magnification values ​​of the two silicon wafers 101, 201. That is, each loading module is connected to at least one alignment measurement module. When each loading module is connected to multiple alignment measurement modules, the multiple alignment measurement modules can simultaneously perform partitioned measurements on the silicon wafer. Figure 1 It is only shown that each loading module is connected to one alignment and measurement module, that is, the loading module 102 is connected to the alignment and measurement module 103 , and the loading module 202 is connected to the alignment and measurement module 203 .

[0044] Furthermore, both loading modules 102 and 202 are provided with an alignment contact module ( Figure 1Only one alignment contact module 104 is shown in the figure. The magnification values ​​of the two silicon wafers 101 and 201 can be measured by two alignment measurement modules 103 and 203. The vacuum adsorption structure on the loading surface of the silicon wafer with a smaller magnification value is adjusted according to the difference in the magnification values ​​of the two silicon wafers 101 and 201. Specifically, the adsorption force of at least part of the vacuum adsorption area in the vacuum adsorption structure is adjusted. Adjusting the adsorption force is to adjust the vacuum degree of the vacuum adsorption area. Since the vacuum adsorption areas in the vacuum adsorption structure are independent of each other, the vacuum degree of a certain vacuum adsorption area can be adjusted individually or the vacuum degrees of multiple vacuum adsorption areas can be adjusted in combination to achieve adjustment of the adsorption force of at least part of the vacuum adsorption area of ​​the vacuum adsorption structure. Adjust the adsorption force of at least part of the vacuum adsorption area of ​​the vacuum adsorption structure corresponding to the silicon wafer with a small magnification value and combine it with the alignment contact module corresponding to the silicon wafer with a small magnification value to provide a pushing force thereto. The directions of the adsorption force and the pushing force are opposite, and the silicon wafer with a small magnification value is stretched to increase the magnification value of the silicon wafer with a small magnification value, thereby reducing the difference in the magnification value between the two silicon wafers 101 and 201, that is, reducing the magnification difference between the two silicon wafers 101 and 201, and improving the alignment and bonding accuracy.

[0045] In this embodiment, the third example may include at least two alignment measurement modules 103, 203, which are respectively arranged on the two loading modules 102, 202, for obtaining the magnification values ​​of the two silicon wafers 101, 201. That is, each loading module is connected to at least one alignment measurement module. When each loading module is connected to multiple alignment measurement modules, the multiple alignment measurement modules can simultaneously perform partitioned measurements on the silicon wafer. Figure 1 It is only shown that each loading module is connected to one alignment and measurement module, that is, the loading module 102 is connected to the alignment and measurement module 103 , and the loading module 202 is connected to the alignment and measurement module 203 .

[0046] Furthermore, the alignment contact module is disposed on any loading module. Furthermore, the silicon wafer alignment apparatus further includes a temperature control module, disposed on any loading module, for adjusting the temperature of the loading module's support surface. In this embodiment, the temperature control module is disposed on any loading module. Of course, the temperature control module can also be disposed on each loading module, depending on actual circumstances.

[0047] Specifically, the two loading modules 102 and 202 are respectively the first loading module and the second loading module. When the alignment contact module is set on the first loading module, a temperature control module can be set on the second loading module to adjust the temperature of the carrying surface of the second loading module so as to increase the temperature of the silicon wafers on the carrying surface of the second loading module. Increasing the temperature can increase the magnification value of the silicon wafers on the carrying surface of the second loading module. For example Figure 1When only the loading module 102 is provided with the alignment contact module 104, a temperature control module is provided on the loading module 202, and the magnification values ​​of the two silicon wafers 101 and 201 can be measured by the two alignment measurement modules 103 and 203. When the magnification value of the silicon wafer 101 is greater than the magnification value of the silicon wafer 201, the temperature control module is used to control the temperature of the silicon wafer 201 on the carrying surface of the loading module 202, so that the temperature of the silicon wafer 201 increases, and the thermal expansion and contraction increase the magnification value of the silicon wafer 201, so that the magnification value of the silicon wafer 101 is less than the magnification value of the silicon wafer 201.

[0048] Alternatively, when the alignment contact module is disposed on the first loading module, a temperature control module may be disposed on the first loading module to adjust the temperature of the carrying surface of the first loading module so as to reduce the temperature of the silicon wafers on the carrying surface of the first loading module. Lowering the temperature may reduce the magnification value of the silicon wafers on the carrying surface of the first loading module. For example Figure 1 When only the alignment contact module 104 is provided on the loading module 102, a temperature control module is provided on the loading module 102, and the magnification values ​​of the two silicon wafers 101 and 201 can be measured by the two alignment measurement modules 103 and 203. When the magnification value of the silicon wafer 101 is greater than the magnification value of the silicon wafer 201, the temperature control module is used to control the temperature of the silicon wafer 101 on the carrying surface of the loading module 102 to reduce the temperature of the silicon wafer 101. Thermal expansion and contraction reduce the magnification value of the silicon wafer 101, so that the magnification value of the silicon wafer 101 is less than the magnification value of the silicon wafer 201.

[0049] Furthermore, when the magnification value of silicon wafer 101 is less than that of silicon wafer 201, the vacuum adsorption structure on the loading surface of silicon wafer 101 is adjusted based on the difference in the magnification values ​​of the two silicon wafers 101 and 201. Specifically, the adsorption force of at least a portion of the vacuum adsorption area of ​​the vacuum adsorption structure is adjusted. Adjusting the adsorption force means adjusting the vacuum level of the vacuum adsorption area. Since the vacuum adsorption areas in the vacuum adsorption structure are independent of each other, the vacuum level of a vacuum adsorption area can be adjusted individually or in combination to adjust the vacuum level of at least a portion of the vacuum adsorption area of ​​the vacuum adsorption structure. The adsorption force of at least a portion of the vacuum adsorption area of ​​the vacuum adsorption structure corresponding to silicon wafer 101 is adjusted in conjunction with the alignment contact module 104 corresponding to silicon wafer 101 providing a pushing force thereto. The adsorption force and the pushing force are in opposite directions, stretching silicon wafer 101 to increase the magnification value of silicon wafer 101, thereby reducing the difference in the magnification values ​​between the two silicon wafers 101 and 201. In other words, reducing the magnification difference between the two silicon wafers 101 and 201, thereby improving alignment and bonding accuracy. The combination of the vacuum adsorption area and the alignment contact module can more accurately reduce the rate difference between the two silicon wafers 101 and 201 than the temperature control module alone.

[0050] Furthermore, the silicon wafer alignment device also includes a moving platform for driving at least one of the loading modules to move. Under the drive of the moving platform and the alignment contact module, the two loading modules move relative to each other to align and bond the two silicon wafers. When the alignment contact module is provided on the moving platform, the alignment contact module is located between the moving platform and the loading module. Figure 1 The alignment contact module 104 is used to drive the silicon wafer 101 toward the silicon wafer 201 to align and bond the two wafers 101 and 201. The motion stage 204 is used to drive the loading module 202 and the alignment measurement module 203 to move, so that the alignment measurement modules 103 and 203 can obtain the position information of all alignment marks and align and bond the two wafers 101 and 201.

[0051] Figure 3 and Figure 4 This is a schematic diagram of the position of the silicon wafer alignment device provided in this embodiment when measuring the silicon wafer magnification value. Please refer to Figure 3 The motion stage 204 drives the loading module 202 and the alignment measurement module 203 to move, so that the alignment measurement module 103 is aligned with the two alignment marks 211 and 212 respectively, and obtains the position information of the two alignment marks 211 and 212; please refer to Figure 4 The moving stage 204 drives the loading module 202 and the alignment measurement module 203 to move, so that the alignment measurement module 203 is aligned with the two alignment marks 111 and 112 respectively, and obtains the position information of the two alignment marks 111 and 112, wherein the distance value of the two alignment marks 211 and 212 is the magnification value of the silicon wafer 201, and the distance value of the two alignment marks 111 and 112 is the magnification value of the silicon wafer 101.

[0052] Figure 5 This is a flow chart of the silicon wafer alignment method provided in this embodiment. Please refer to Figure 5 This embodiment further provides a silicon wafer alignment method using the silicon wafer alignment device as described above, the silicon wafer alignment method comprising:

[0053] Step S1: providing two silicon wafers, loading the two silicon wafers onto two carrying surfaces respectively, and obtaining the magnification values ​​of the two silicon wafers;

[0054] Step S2: adjusting the adsorption force of at least a portion of the vacuum adsorption area of ​​any vacuum adsorption structure according to the magnification values ​​of the two silicon wafers, so as to reduce the difference in the magnification values ​​of the two silicon wafers;

[0055] Step S3: The two loading modules move relative to each other to align and bond the two silicon wafers.

[0056] The silicon wafer alignment method provided in this embodiment is described in detail below.

[0057] Execute step S1: Provide two silicon wafers, each of which is provided with at least two alignment marks. The positions of all alignment marks on the two silicon wafers are identical, so that the distance between every two alignment marks on the two silicon wafers is the same. The distance between any two alignment marks on the silicon wafer is the magnification value of the silicon wafer. If the distance between any two alignment marks on the silicon wafer deviates in practice, it indicates that there is a magnification difference between the two silicon wafers. The magnification difference may be caused by the influence of the front-end process or the temperature difference between the two loading modules. Therefore, it is necessary to compensate for this magnification difference to reduce the magnification difference between the two silicon wafers.

[0058] In this embodiment, the first example can obtain the magnification values ​​of two silicon wafers before loading them into two loading modules. The user can specify the magnification values ​​of the two silicon wafers based on previous process requirements. For example, if the magnification values ​​of two silicon wafers have been previously tested, the magnification values ​​can be specified based on the saved magnification values. The two loading modules are respectively a first loading module and a second loading module. The alignment and contact module is located on the first loading module, and the first loading module is used to load silicon wafers with smaller magnification values.

[0059] In this embodiment, the second example may further include at least two alignment measurement modules, disposed on the two loading modules, for obtaining magnification values ​​for the two silicon wafers. Specifically, the alignment measurement modules are used to obtain positional information of all alignment marks on the two silicon wafers and calculate the distance between any two alignment marks on the silicon wafers as the magnification value for the silicon wafers. Furthermore, both loading modules are provided with alignment contact modules, and the two silicon wafers are loaded onto the two loading modules, respectively.

[0060] In this embodiment, the third example may further include at least two alignment measurement modules, disposed on the two loading modules, for obtaining magnification values ​​for the two silicon wafers. Specifically, the alignment measurement modules are used to obtain positional information of all alignment marks on the two silicon wafers and calculate the distance between any two alignment marks on the silicon wafers as the magnification value for the silicon wafers. Furthermore, an alignment contact module is disposed on either loading module, and the two silicon wafers are loaded onto the two loading modules, respectively.

[0061] Executing step S2: adjusting the suction force of at least a portion of the vacuum suction area of ​​the vacuum suction structure on the loading surface of the silicon wafer with the smaller suction value based on the difference in the suction values ​​of the two silicon wafers, thereby reducing the difference in the suction values ​​of the two silicon wafers. Because it is difficult to adjust the suction values ​​of the two silicon wafers to be exactly the same, a threshold value can be set. If the difference in the suction values ​​of the two silicon wafers is greater than the threshold value, the suction force of at least a portion of the vacuum suction area of ​​the vacuum suction structure on the loading surface of the silicon wafer with the smaller suction value needs to be adjusted based on the difference in the suction values ​​of the two silicon wafers.

[0062] In this embodiment, the first example adjusts the suction force of at least a portion of the vacuum adsorption area of ​​the vacuum adsorption structure on the loading surface of the first loading module based on the difference in magnification values ​​between the two silicon wafers. An alignment contact module applies a lifting force to the silicon wafer on the loading surface of the first loading module, while the loading surface of the first loading module has a suction force that adsorbs the silicon wafer, the suction force being in the opposite direction of the lifting force. The position of the alignment mark on the silicon wafer indicates which vacuum adsorption area the alignment mark corresponds to. The vacuum level of at least a portion of the vacuum adsorption area of ​​the vacuum adsorption structure on the loading surface of the first loading module is adjusted based on the difference in magnification values ​​between the two silicon wafers. The vacuum level of the vacuum adsorption area corresponding to the position of the alignment mark can be adjusted to change the suction force of at least a portion of the vacuum adsorption area, thereby reducing the difference in magnification values ​​between the two silicon wafers.

[0063] In this embodiment, a second example adjusts the suction force of at least a portion of the vacuum suction area of ​​the vacuum suction structure on the loading surface of the silicon wafer with the smaller magnification value based on the difference in magnification values ​​between the two silicon wafers. An alignment contact module applies a lifting force to the silicon wafer on the loading surface of the silicon wafer with the smaller magnification value, while the loading surface of the silicon wafer with the smaller magnification value has a suction force that holds the silicon wafer in place, the suction force being in the opposite direction of the lifting force. The position of the alignment mark on the silicon wafer indicates which vacuum suction area the alignment mark corresponds to. Based on the difference in magnification values ​​between the two silicon wafers, the vacuum level of at least a portion of the vacuum suction area of ​​the vacuum suction structure on the loading surface of the silicon wafer with the smaller magnification value is adjusted. The vacuum level of the vacuum suction area corresponding to the position of the alignment mark can be adjusted to change the suction force of at least a portion of the vacuum suction area, thereby reducing the difference in magnification values ​​between the two silicon wafers.

[0064] In this embodiment, a third example adjusts the suction force of at least a portion of the vacuum suction area of ​​the vacuum suction structure on the loading surface of the silicon wafer with the smaller magnification value based on the difference in magnification values ​​between the two silicon wafers. When the loading module provided by the alignment contact module is loaded with the silicon wafer with the smaller magnification value, the alignment contact module applies a lifting force to the silicon wafer on the loading surface of the silicon wafer with the smaller magnification value. The loading surface of the silicon wafer with the smaller magnification value has a suction force that holds the silicon wafer in place, and the suction force is in the opposite direction of the lifting force. The position of the alignment mark on the silicon wafer indicates which vacuum suction area the alignment mark corresponds to. Based on the difference in magnification values ​​between the two silicon wafers, the vacuum level of at least a portion of the vacuum suction area of ​​the vacuum suction structure on the loading surface of the silicon wafer with the smaller magnification value is adjusted. The vacuum level of the vacuum suction area corresponding to the position of the alignment mark can be adjusted to change the suction force of at least a portion of the vacuum suction area, thereby reducing the difference in magnification values ​​between the two silicon wafers.

[0065] When the loading module set by the alignment contact module is loaded with a silicon wafer with a larger magnification value, the temperature of the silicon wafer with a larger magnification value can be lowered, resulting in thermal expansion and contraction, so that the magnification value of this silicon wafer is reduced, so that the magnification value of the silicon wafer loaded by the loading module set by the alignment contact module is smaller than the magnification value of the silicon wafer loaded by the loading module not set with the alignment contact module. Furthermore, an alignment contact module is used to apply a pushing force to the silicon wafer on the loading surface of the silicon wafer with a smaller magnification value, and the loading surface of the silicon wafer with a smaller magnification value has an adsorption force to adsorb the silicon wafer, and the adsorption force is opposite to the direction of the pushing force; since the vacuum adsorption area on the loading surface of the silicon wafer with a smaller magnification value has at least two vacuum adsorption areas, and these vacuum adsorption areas are used to adsorb the silicon wafer, it can be seen that the silicon wafer is adsorbed and controlled by different vacuum adsorption areas, and the position of the alignment mark on the silicon wafer can be used to know which vacuum adsorption area the alignment mark corresponds to, and the vacuum degree of at least part of the vacuum adsorption area on the loading surface of the silicon wafer with a smaller magnification value is adjusted according to the difference in the magnification values ​​of the two silicon wafers. The vacuum degree of the vacuum adsorption area corresponding to the position of the alignment mark can be adjusted to change the adsorption force of at least part of the vacuum adsorption area, so as to reduce the difference in the magnification values ​​of the two silicon wafers.

[0066] Alternatively, when the loading module set up for the alignment contact module is loaded with a silicon wafer with a larger magnification value, the temperature of the silicon wafer loaded by the loading module not set up for the alignment contact module can be increased to produce thermal expansion and contraction, and the magnification value of this silicon wafer is increased, so that the magnification value of the silicon wafer loaded by the loading module set up for the alignment contact module is smaller than the magnification value of the silicon wafer loaded by the loading module not set up for the alignment contact module. Furthermore, an alignment contact module is used to apply a pushing force to the silicon wafer on the loading surface of the silicon wafer with a smaller magnification value, and the loading surface of the silicon wafer with a smaller magnification value has an adsorption force to adsorb the silicon wafer, and the adsorption force is opposite to the direction of the pushing force; since the vacuum adsorption area on the loading surface of the silicon wafer with a smaller magnification value has at least two vacuum adsorption areas, and these vacuum adsorption areas are used to adsorb the silicon wafer, it can be seen that the silicon wafer is adsorbed and controlled by different vacuum adsorption areas, and the position of the alignment mark on the silicon wafer can be used to know which vacuum adsorption area the alignment mark corresponds to, and the vacuum degree of at least part of the vacuum adsorption area on the loading surface of the silicon wafer with a smaller magnification value is adjusted according to the difference in the magnification values ​​of the two silicon wafers. The vacuum degree of the vacuum adsorption area corresponding to the position of the alignment mark can be adjusted to change the adsorption force of at least part of the vacuum adsorption area, so as to reduce the difference in the magnification values ​​of the two silicon wafers. In this embodiment, it is preferred to adjust the temperature of any one silicon wafer first, and then adjust the vacuum adsorption structure to reduce the difference in the magnification values ​​of the two silicon wafers, but it is not limited to this adjustment order. The vacuum adsorption structure can also be adjusted first, and then the temperature of any one silicon wafer is adjusted, and finally the vacuum adsorption structure is adjusted to finally reduce the difference in the magnification values ​​of the two silicon wafers. The specific adjustment order depends on the actual situation.

[0067] In this embodiment, in order to increase the magnification value of the silicon wafer with a smaller magnification value, the difference in the magnification values ​​of the two silicon wafers is reduced. Therefore, it is necessary to stretch the silicon wafer with a smaller magnification value to increase the magnification value, and reduce the vacuum degree of any vacuum adsorption area according to the difference in the magnification values ​​of the two silicon wafers. Any vacuum adsorption area is the vacuum adsorption area corresponding to the alignment mark position. Reducing the vacuum degree of any vacuum adsorption area reduces the adsorption force of the vacuum adsorption area, and the adsorption force at the position corresponding to the vacuum adsorption area on the silicon wafer is reduced, while the adsorption force of other vacuum adsorption areas is greater than the adsorption force of the adjusted vacuum adsorption area. The adsorption force at the position corresponding to the other vacuum adsorption areas on the silicon wafer is also greater than the adsorption force of the adjusted vacuum adsorption area on the silicon wafer. The position of the area is subjected to the adsorption force, the position of the corresponding adjusted vacuum adsorption area on the silicon wafer is subjected to the pushing force given by the alignment contact module, and the edge of the position of the corresponding adjusted vacuum adsorption area on the silicon wafer will be subjected to the adsorption force of the position of other vacuum adsorption areas on the silicon wafer. This pushing force is opposite to the adsorption force of the edge of the position of the corresponding adjusted vacuum adsorption area on the silicon wafer, so that the position of the corresponding adjusted vacuum adsorption area on the silicon wafer is stretched to increase the magnification value of the silicon wafer with a small magnification value and reduce the difference in the magnification values ​​of the two silicon wafers. During alignment bonding, the alignment and bonding accuracy can be improved.

[0068] In this embodiment, the vacuum degree of any vacuum adsorption area is reduced according to the difference in the magnification values ​​of the two silicon wafers. Any vacuum adsorption area is the vacuum adsorption area corresponding to the alignment mark position. The vacuum degree of the vacuum adsorption area corresponding to the alignment mark position can also be reduced while the vacuum degree of other vacuum adsorption areas is increased to increase the adsorption force of the edge of the position corresponding to the adjusted vacuum adsorption area on the silicon wafer, thereby improving the stretching effect of the silicon wafer. How to specifically adjust the adsorption force of at least part of the vacuum adsorption area depends on actual conditions.

[0069] Figure 6 This is a schematic diagram of the silicon wafer alignment method provided in this embodiment for adjusting the silicon wafer magnification value. Figure 6 The vacuum adsorption structure of the loading module for adsorbing the silicon wafer 101 has three vacuum adsorption areas. The three vacuum adsorption areas adsorb the silicon wafer 101, and the silicon wafer 101 can be divided into three corresponding adsorption areas 101a, 101b, and 101c (similar to the Figure 2corresponding to the three vacuum adsorption areas 102a, 102b, and 102c). If the magnification value of the silicon wafer 101 needs to be increased, for example, the adsorption force at the adsorption area 101a can be reduced, that is, the vacuum degree of the vacuum adsorption area corresponding to the adsorption area 101a can be reduced. The alignment contact module will apply a downward push force F1 to the adsorption area 101a, and the adsorption force at the adsorption area 101b is greater than the adsorption force at the adsorption area 101a. The edge of the adsorption area 101a will also be subjected to the upward adsorption force F2 of the adsorption area 101b. The downward push force F1 and the upward adsorption force F2 determine the stretching degree of the adsorption area 101a. The stretching degree can be determined by adjusting the vacuum degree of the vacuum adsorption area corresponding to the adsorption area 101a. The relationship between the stretching degree and the vacuum degree of different vacuum adsorption areas can be obtained through offline calibration. The size of the adjusted vacuum degree can be directly determined according to the required stretching degree. The stretching degree determines the magnification difference between the two silicon wafers 101 and 201. Therefore, increasing the magnification value of the silicon wafer 101 reduces the magnification difference between the two silicon wafers 101 and 201.

[0070] Execute step S3: The silicon wafer alignment device also includes a moving stage for driving at least one of the loading modules to move. Driven by the moving stage and the alignment contact module, the two loading modules move relative to each other to align and bond the two silicon wafers.

[0071] In summary, in the silicon wafer alignment device and silicon wafer alignment method provided by the present invention, an alignment contact module is arranged on at least one loading module, and a vacuum adsorption structure is provided on the loading surface of the loading module having the alignment contact module. The vacuum adsorption structure has at least two independent and concentric ring-shaped vacuum adsorption areas. The adsorption force of at least part of the vacuum adsorption area of ​​any vacuum adsorption structure is adjusted according to the magnification value of the two silicon wafers. In combination with the alignment contact module, a pushing force is provided to the silicon wafer to adjust the magnification value of the silicon wafer, thereby reducing the difference in the magnification value between the two silicon wafers, that is, reducing the magnification difference between the two silicon wafers, and improving the alignment bonding accuracy when performing alignment bonding.

[0072] The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any way. Any person skilled in the art who, without departing from the scope of the present invention, makes any equivalent substitution, modification, or other changes to the technical solution and technical content disclosed in the present invention shall be deemed to be within the scope of the present invention and still fall within the scope of protection of the present invention.

Claims

1. A silicon wafer alignment device for aligning and bonding two silicon wafers, characterized in that: include: Two loading modules are arranged opposite to each other, each having a loading surface for loading the silicon wafer, and the two loading surfaces are arranged opposite to each other; at least one alignment contact module, disposed on at least one of the loading modules, for providing a lifting force to the silicon wafer; At least one vacuum adsorption structure is provided on the loading surface of the loading module having the alignment contact module, each of the vacuum adsorption structures having at least two independent and concentric annular vacuum adsorption areas; The adsorption force of at least part of the vacuum adsorption area of ​​any one of the vacuum adsorption structures is adjusted according to the magnification values ​​of the two silicon wafers to reduce the difference in the magnification values ​​of the two silicon wafers. The two loading modules move relative to each other to align and bond the two silicon wafers, wherein at least two alignment marks are provided on each of the two silicon wafers, and the distance value between the two alignment marks at the same position in the two silicon wafers is measured as the magnification value of the two silicon wafers.

2. The silicon wafer alignment device according to claim 1, wherein: The magnification value of the silicon wafer is obtained before the silicon wafer is loaded into the loading module.

3. The silicon wafer alignment device according to claim 2, wherein: The two loading modules are respectively a first loading module and a second loading module. The alignment and contact module is arranged on the first loading module, and the first loading module is used for loading silicon wafers with a smaller magnification value.

4. The silicon wafer alignment device according to claim 1, wherein: It also includes at least two alignment measurement modules, which are arranged on the two loading modules and are used to obtain the magnification value of the silicon wafer.

5. The silicon wafer alignment device according to claim 4, wherein: The alignment contact module is provided on each of the two loading modules.

6. The silicon wafer alignment device according to claim 4, wherein: The alignment contact module is arranged on any one of the loading modules; the silicon wafer alignment device further comprises a temperature control module, which is arranged on any one of the loading modules and is used to adjust the temperature of the carrying surface of the loading module.

7. The silicon wafer alignment device according to claim 1, wherein: It also includes a motion platform for driving at least one of the loading modules to move.

8. The silicon wafer alignment device according to claim 1, wherein: The vacuum adsorption area includes a first vacuum adsorption area and at least one second vacuum adsorption area, and the second vacuum adsorption area sequentially surrounds the first vacuum adsorption area to form a concentric ring shape.

9. A silicon wafer alignment method using the silicon wafer alignment device according to any one of claims 1 to 8, characterized in that: include: Providing two silicon wafers, loading the two silicon wafers onto two carrying surfaces respectively, and obtaining magnification values ​​of the two silicon wafers; adjusting the adsorption force of at least a portion of the vacuum adsorption area of ​​any one of the vacuum adsorption structures according to the magnification values ​​of the two silicon wafers, so as to reduce the difference between the magnification values ​​of the two silicon wafers; The two loading modules move relative to each other to align and bond the two silicon wafers.

10. The silicon wafer alignment method according to claim 9, wherein: The two loading modules are respectively a first loading module and a second loading module, the alignment and contact module is arranged on the first loading module, and the first loading module is used to load silicon wafers with a smaller magnification value, and the magnification value of the silicon wafer is obtained before the silicon wafer is loaded into the loading module; and Adjust the vacuum adsorption structure on the loading surface of the first loading module.

11. The silicon wafer alignment method according to claim 9, wherein: It also includes at least two alignment measurement modules, which are arranged on the two loading modules and are used to obtain the magnification value of the silicon wafer, and the alignment contact module is arranged on both loading modules; and The vacuum adsorption structure on the loading surface of the silicon wafer with a smaller loading magnification value is adjusted.

12. The silicon wafer alignment method according to claim 9, wherein: It also includes at least two alignment measurement modules, which are arranged on the two loading modules and are used to obtain the magnification value of the silicon wafer, and the alignment contact module is arranged on any one of the loading modules; and When the loading module set by the alignment contact module is loaded with silicon wafers with a smaller magnification value, the vacuum adsorption structure on the loading surface of the loading module is adjusted; when the loading module set by the alignment contact module is loaded with silicon wafers with a larger magnification value, the temperature of any of the silicon wafers and the vacuum adsorption structure on the loading surface of the loading module are adjusted.

13. The silicon wafer alignment method according to claim 12, wherein: Adjusting the temperature of any of the silicon wafers includes lowering the temperature of the silicon wafer with a larger magnification value or raising the temperature of the silicon wafer with a smaller magnification value.

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