Alignment device and bonding method for three-layer wafer bonding

Abstract

The present invention provides a three-layer wafer bonding alignment device and a method for bonding three layers of wafers using the alignment device. The alignment device includes a body, a spacer mechanism and a fixing mechanism arranged on the body. The spacer mechanism includes two layers of spacers, and there is a gap between the two layers of spacers. A plurality of spacer mechanisms can clamp the wafer using the closed end of the gap. The spacer mechanism has a limiting and fixing effect on the wafer located between the double-layer spacers. The structure is simple, the operation is convenient, and the bonding steps are simplified, so that the alignment device can complete the alignment and fixing of three layers of wafers at one time. Without increasing too much cost, the bonding of three layers of wafers can be directly completed at one time, thereby improving efficiency and reducing production costs.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor integrated circuit manufacturing, and in particular relates to an alignment device and a bonding method for three-layer wafer bonding. Background Art

[0002] In the manufacturing process of semiconductor devices, in order to achieve miniaturization, multi-functionality and high performance of the devices, it is often necessary to bond multiple wafers together. According to different application fields, the process equipment and parameters of wafer bonding are different, but the basic principles are similar, mainly including vacuuming, heating, applying pressure, releasing pressure and cooling to break vacuum. Usually, a complete set of wafer bonding equipment is mainly composed of two types of equipment: alignment equipment and bonding equipment. The alignment equipment can align the two wafers according to the alignment marks, insert the isolation sheet, and fix the two wafers. Generally, it takes 10 minutes to align and fix a pair of wafers using the alignment equipment; the bonding equipment can combine wafers of different materials together by vacuuming, pulling the isolation sheet, heating, applying pressure, cooling and breaking the true hole. It takes 4 hours for the bonding equipment to bond a pair of wafers.

[0003] At present, conventional wafer bonding equipment can only bond two wafers at a time, and cannot directly complete the precise alignment and bonding of three layers of wafers. For example, using a 3-layer stacked structure fiber template silicon-silicon bonding, it is necessary to complete the bonding of three wafers in two times, first completing the bonding of two wafers, and then bonding with the third layer of wafer. Because the bonding surface contact equipment is contaminated, it is necessary to clean the bonded two layers of wafers before bonding with the third layer of wafer, which increases the cleaning cost. This process has a high bonding cost, a long completion time, and will also introduce some additional defects.

[0004] Recently, a three-layer wafer bonding alignment device has appeared, which can align three layers of wafers at the same time, so as to complete the bonding of three layers of wafers at one time. However, the isolation plate mechanism of this alignment device is composed of multiple single-layer isolation plate mechanisms, which has a complex structure and is inconvenient to operate. Summary of the invention

[0005] In view of the above problems, the present invention provides a three-layer wafer bonding alignment device and a method for three-layer wafer bonding using the alignment device, which has a simple structure and is easy to operate, simplifies the bonding steps, improves the bonding efficiency, and saves cost and time.

[0006] In order to achieve the above-mentioned purpose and other related purposes, the present invention provides a wafer bonding alignment device, including a body and a plurality of spacer mechanisms and fixing mechanisms arranged on the body, the spacer mechanism including a linear drive component and a double-layer spacer component arranged on the linear drive component, the double-layer spacer component including two layers of spacers, a gap between the two layers of spacers, and the plurality of spacer mechanisms can clamp the wafer using the closed end of the gap. The linear drive component drives the two layers of spacers of the double-layer spacer component to synchronously complete the action of inserting and withdrawing the multi-layer wafer, the two layers of spacers can be driven by the same drive structure to complete the action of inserting and withdrawing the spacers, when inserting, the closed end of the gap between the two layers of spacers presses against the side wall of the wafer to clamp and fix the wafer, so that the whole device has a simple structure and is easy to operate, the spacer mechanism has a limiting and fixing effect on the wafer located between the double-layer spacers, so that the alignment device can complete the alignment and fixation of three layers of wafers at one time, so that the bonding of three layers of wafers can be directly completed at one time.

[0007] In some preferred embodiments, the number of the isolation sheet mechanisms is equal to the number of the fixing mechanisms, and the plurality of isolation sheet mechanisms and the plurality of fixing mechanisms are evenly spaced and distributed on the body, with one isolation sheet mechanism being located between two adjacent fixing mechanisms. Preferably, each isolation sheet mechanism is disposed adjacent to a corresponding fixing mechanism, so that the operation of withdrawing the isolation sheet mechanism can be completed more conveniently. Furthermore, the number of the isolation sheet mechanisms and the fixing mechanisms is more than three, because at least three points can determine a plane, which can avoid the problem of wafer bending caused by clamping the wafer at both ends of the wafer diameter at the same time.

[0008] In some preferred embodiments, the double-layer spacer component includes two layers of spacers and a mounting handle, the two layers of spacers are fixed on the mounting handle, and are in a U-shape or a V-shape, and a plurality of double-layer spacer components evenly spaced can clamp and fix the wafer between the plurality of double-layer spacer components using the closed ends of the U-shape or the V-shape. Preferably, the double-layer spacer component is a metal elastic sheet, which has a certain elasticity, and can prevent the double-layer spacer component from crushing the wafer.

[0009] In some preferred embodiments, the body is in a circular shape, with a plurality of vacuum suction heads protruding inwardly from the circular ring, and vacuum suction holes are provided on the vacuum suction heads for adsorbing wafers on the surface of the vacuum suction heads. Preferably, the vacuum suction heads also cooperate with the fixing mechanism to clamp the multi-layer wafers therebetween. Preferably, the number of the vacuum suction heads is equal to the number of the isolation plate mechanisms or the fixing mechanisms, and the position of each vacuum suction head corresponds to the position of a isolation plate mechanism or the fixing mechanism.

[0010] In some preferred embodiments, the linear drive component includes a mounting seat, a waist-shaped hole seat and a lever 1, the double-layer isolation plate component is fixedly arranged on the mounting seat, the mounting seat can be linearly slidably arranged on the body of the alignment device, the waist-shaped hole seat is fixedly arranged on the mounting seat, the support shaft 1 of the lever 1 is arranged on the body, the lever 1 can rotate around the support shaft 1, and a rotating shaft 1 is arranged at one end of the resistance arm of the lever 1, and the rotating shaft 1 is passed through the waist-shaped hole of the waist-shaped hole seat. Preferably, the lever 1 is in a curved shape, which can reduce the volume of the lever, thereby reducing the volume of the entire linear drive component, and further preferably, the angle between the power arm and the resistance arm of the lever is an obtuse angle. Preferably, an elastic element is connected between the power arm of the lever 1 and the body, and the elastic element can assist in completing the action of inserting and withdrawing the isolation sheet, and can also fasten the isolation sheet in the withdrawal position and the insertion position. When the double-layer isolation sheet component is in the insertion position, the elastic element can apply a certain tensioning force to the power arm of the lever 1, so that the closed end of the gap between the two layers of isolation sheets is pressed against the side wall of the wafer to keep the wafer clamped and fixed. Preferably, a through hole is provided on the body, a bracket is provided in the through hole, and the isolation sheet mechanism is provided on the bracket.

[0011] In some preferred embodiments, the fixing mechanism includes a clamp and an opening and closing driving component, the opening and closing driving component drives the clamp to clamp or release the wafer, the middle part of the clamp is rotatably arranged on the body through a second rotating shaft, the opening and closing driving mechanism includes a second lever and a connecting rod, one end of the second lever is rotatably connected to the body through a second supporting shaft, one end of the connecting rod is rotatably connected to one end of the clamp, and the other end is rotatably connected to the middle part of the second lever, the clamp is driven to rotate around the second rotating shaft by the second lever and the connecting rod, thereby driving the clamp to clamp or release the wafer. Preferably, an elastic element is connected between the middle part of the second lever and the body, the elastic element can assist in completing the clamping or releasing action, and can also fasten the clamp in the clamping or releasing position. Preferably, the fixing mechanism is also arranged on the bracket in the through hole of the body.

[0012] The present invention also provides a spacer mechanism for a wafer bonding alignment device, comprising a bracket, a linear drive component and a double-layer spacer component, wherein the bracket is arranged on the alignment device, the linear drive component is arranged on the bracket, the double-layer spacer component is arranged on the linear drive component, and the double-layer spacer component comprises two layers of spacers. The linear drive component drives the two layers of spacers of the double-layer spacer component to synchronously reciprocate in the horizontal direction to complete the action of inserting and withdrawing a multi-layer wafer. Preferably, a through hole is arranged on the alignment device, and the bracket is arranged in the through hole.

[0013] In some preferred embodiments, the linear drive component includes a mounting seat, a waist-shaped hole seat and a lever 1, the two-layer isolation sheet is fixedly arranged on the top of the mounting seat, the mounting seat can be linearly slidably arranged on the bracket, and the waist-shaped hole seat is fixedly arranged on the bottom of the mounting seat. Preferably, the waist-shaped hole in the waist-shaped hole seat extends in the vertical direction. The support shaft 1 of the lever 1 is arranged on the bracket, and the free end of the resistance arm of the lever 1 is provided with a rotating shaft 1, and the rotating shaft 1 is passed through the waist-shaped hole of the waist-shaped hole seat. Preferably, the lever 1 is in a curved shape, which can reduce the volume of the lever 1, thereby reducing the volume of the entire linear drive component. More preferably, the angle between the power arm and the resistance arm of the lever is an obtuse angle. Preferably, the power arm of lever one is connected to the bracket through an elastic element. The elastic element can assist in completing the action of inserting and withdrawing the isolation plate, and can also fix the isolation plate in the withdrawal position and the insertion position. When the double-layer isolation plate component is in the insertion position, the elastic element can apply a certain tensioning force to the power arm of lever one, so that the closed end of the gap between the two layers of isolation plates is pressed against the side wall of the wafer to keep the wafer clamped.

[0014] The present invention also provides a fixing mechanism for a wafer bonding alignment device, comprising a bracket, a clamping claw arranged on the bracket, and an opening and closing driving component, wherein the bracket is arranged on the alignment device, and the clamping claw is rotatably arranged on the bracket through a second rotating shaft, and the opening and closing driving mechanism comprises a second lever and a connecting rod, wherein one end of the second lever is rotatably connected to the bracket through a second supporting shaft, one end of the connecting rod is rotatably connected to one end of the clamping claw, and the other end is rotatably connected to the second lever, and the clamping claw is driven to rotate around the second rotating shaft through the second lever and the connecting rod, thereby driving the clamping claw to clamp or release the wafer. Preferably, the middle part of the second lever is connected to the bracket through an elastic element, and the elastic element can assist in completing the clamping or releasing action, and can also fix the clamping claw in a clamping or releasing position.

[0015] The present invention also provides a three-layer wafer bonding method, which utilizes the above-mentioned wafer bonding alignment device for alignment and fixation, comprising the following steps:

[0016] Step 1: placing the first layer of wafer on the alignment device and fixing it;

[0017] Step 2: placing the middle second layer wafer into the alignment device and aligning it with the first layer wafer, inserting a plurality of isolation plate mechanisms, and clamping the second layer wafer between two isolation plates of the plurality of isolation plate mechanisms;

[0018] Step 3: placing the third layer of wafer into the alignment device and aligning it with the second layer of wafer, and using the fixing mechanism on the alignment device to fix and clamp the three layers of wafer;

[0019] Step 4: Place the aligned three-layer wafer into the bonding machine for bonding.

[0020] Wherein, in the step 1, vacuum adsorption can be used to adsorb and fix the first layer of wafers on the main body of the alignment device.

[0021] In the above steps, tools such as a suction pen or a chuck can be used to place the wafer on the alignment device and move the wafer to complete the alignment.

[0022] The bonding in the above step 4 includes processes such as vacuuming, heating, applying pressure, releasing pressure, cooling and breaking vacuum, etc. After vacuuming, the isolation sheet mechanism is removed.

[0023] The isolation plate mechanism is withdrawn in a step-by-step manner, first opening a fixing mechanism, withdrawing the isolation plate mechanism corresponding to the fixing mechanism, allowing the fixing mechanism to re-clamp the wafer, and repeating the above steps until all isolation plate mechanisms are withdrawn.

[0024] The beneficial effects of the present application are: as described above, the present invention provides a three-layer wafer bonding alignment device and a method for three-layer wafer bonding using the alignment device, the isolation plate mechanism has a limiting and fixing function for the wafer located between the double-layer isolation plates, the structure is simple, the operation is convenient, and the bonding steps are simplified, so that the alignment device can complete the alignment and fixation of the three-layer wafer at one time, and can directly complete the bonding of the three-layer wafer at one time without increasing too much cost, thereby improving efficiency and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the wafer bonding alignment device of Example 1 of the present invention.

[0026] Figure 2 It is a schematic structural diagram of a double-layer isolation film component of a wafer bonding alignment device according to Example 1 of the present invention.

[0027] Figure 3 It is a schematic diagram of the structure of the wafer bonding alignment equipment of embodiments 2 and 3 of the present invention.

[0028] Figure 4 It is a schematic structural diagram of the isolation plate mechanism and the fixing mechanism of Examples 2 and 3 of the present invention.

[0029] Figure 5 It is a schematic structural diagram of the isolation plate mechanism (the bracket is not shown) of Example 2 of the present invention.

[0030] Figure 6 It is a schematic diagram of the structure of the fixing mechanism (the bracket is not shown) of Example 3 of the present invention. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0032] See also Figure 1 to Figure 6 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0033] Example 1

[0034] like Figure 1-2 As shown, a wafer bonding alignment device 1 can align and fix three layers of wafers thereon, so as to achieve bonding of three layers of wafers at one time. The alignment device 1 includes a body 2, an isolation sheet mechanism 3 and a fixing mechanism 4 arranged on the body 2, the body 2 is in a circular shape, and three vacuum suction heads 5 protrude inwardly from the circular ring, and the three vacuum suction heads 5 are symmetrically arranged on the inner side of the circular ring at intervals of 120°, and vacuum suction holes are arranged on the vacuum suction heads 5 for adsorbing and fixing the first layer of wafers on the surface of the vacuum suction heads 5, and the vacuum suction heads 5 also cooperate with the fixing mechanism 4 to fix and clamp the three layers of wafers therebetween.

[0035] The alignment device 1 includes three spacer mechanisms 3 and three fixing mechanisms 4, which are symmetrically arranged on the annular body 2 at intervals of 120°, and one spacer mechanism 3 is located between two adjacent fixing mechanisms 4. Each spacer mechanism 3 is arranged adjacent to a corresponding fixing mechanism 4, so that the operation of removing the spacer mechanism can be completed more conveniently. Each vacuum suction head 5 is adjacent to a spacer mechanism 3 and a fixing mechanism 4, and the spacer mechanism 3 and the fixing mechanism 4 are located radially outside the vacuum suction head 5.

[0036] The spacer mechanism 3 includes a double-layer spacer component 6 and a linear drive component. The linear drive component is mounted on the body 2 and can be a conventional power device, such as a cylinder. The double-layer spacer component 6 includes two layers of spacers 6A, 6B and a mounting handle 6C. One end of the two layers of spacers 6A, 6B is fixed on the mounting handle 6C. There is a gap between the two layers of spacers 6A, 6B. The mounting handle 6C is detachably arranged on the power output end of the linear drive component. In another embodiment, the double-layer spacer component 6 does not include the mounting handle 6C, and one end of the two layers of spacers 6A, 6B is fixed to the power output end of the linear drive component 7 by a fixing component such as a bolt. The linear drive component drives the double-layer spacer component 6 to perform linear reciprocating motion along the radial direction of the ring of the body 2, thereby completing the action of inserting and withdrawing the two layers of spacers from the three layers of wafers. When the double-layer spacer component 6 is in the insertion position, the closed end 6D of the gap between the two layers of spacers is pressed against the side of the wafer, and the wafer is clamped and fixed between the three spacer mechanisms 3.

[0037] The fixing mechanism 4 includes a clamping jaw 20 and an opening and closing driving component, and the opening and closing driving component drives the clamping jaw 20 to be pressed downward or tilted upward. When pressed downward, the free end of the clamping jaw 20 is pressed on the third layer of wafer, and cooperates with the upper surface of the vacuum suction head 5 to clamp the three layers of wafer between the clamping jaw 20 and the vacuum suction head 5. When tilted upward, the free end of the clamping jaw 20 moves upward away from the third layer of wafer.

[0038] The two-layer spacers 6A, 6B and the mounting handle 6C can be metal elastic thin sheets. The two-layer spacers 6A, 6B are arranged in parallel and spaced apart above the upper surface of the body 2 in a U shape. The distance between the two is greater than the thickness of the second layer of wafers. The distance between the lower layer of spacers 6B and the upper surface of the body 2 is slightly greater than the thickness of the first layer of wafers. Since the spacers are elastic, when the fixing mechanism 4 presses the three layers of wafers, the spacers 6B are pressed between the first layer of wafers and the second layer of wafers, and the spacers 6A are pressed between the third layer of wafers and the second layer of wafers. The two-layer spacers 6A, 6B can be an integrated structure or fixed on the mounting handle 6C respectively. In another embodiment, the two-layer spacers 6A and 6B may also be in a V-shaped structure, and the distance between the two gradually increases from the fixed end to the free end. The opening gap of the V-shaped structure is large, and the double-layer spacer component 6 can be conveniently inserted into the second-layer wafer. Even if the second-layer wafer is not on the same plane as the closed end 6D of the two-layer spacers 6A and 6B due to machine error, it can still slide into the closed end 6D due to the elastic deformation between the two-layer spacers 6A and 6B and the wafer, so as to avoid the two-layer spacers 6A and 6B from being inserted into the wrong position. The two-layer spacers 6A and 6B in the spacer mechanism 3 are driven by the same linear drive component to complete the action of inserting and withdrawing the spacers, so that the entire device structure is simple and easy to operate. The spacer mechanism 3 has a limiting and fixing function for the second-layer wafer located between the two-layer spacers 6A and 6B, so that the alignment device 1 can complete the alignment and fixing of the three-layer wafer at one time. Subsequently, the alignment device 1 and the three-layer wafer fixed thereon are sent to a conventional bonding device to realize the one-time direct completion of the bonding of the three-layer wafer.

[0039] Example 2

[0040] like Figure 3-5As shown, a spacer mechanism 3 for a wafer bonding alignment device 1 includes a linear drive component 7 and a double-layer spacer component 6. The linear drive component 7 drives the double-layer spacer component 6 to perform linear reciprocating motion along the radial direction of the ring of the body 2, thereby completing the action of inserting and withdrawing the two-layer spacer into and from the three-layer wafer. The linear drive component 7 includes a mounting seat 8, a waist-shaped hole seat 9, a lever 10 and a tension spring 11. The double-layer spacer component 6 is fixedly arranged on the mounting seat 8 and is located above the upper surface of the body 2. The mounting seat 8 is slidably arranged in the through hole 12 of the body 2. Specifically, a bracket 16 is arranged in the through hole 12. The bracket 16 is detachably fixed on the body 2. A guide rail 13 extending along the radial direction of the body ring is arranged on the bracket 16. A slider 14 sliding with the guide rail 13 is arranged on one side of the mounting seat 8. Under the guidance of the guide rail 13 and the slider 14, the mounting seat 8 can slide along the extension direction of the guide rail 13, that is, the radial direction of the body ring. The waist-shaped hole seat 9 is fixedly arranged on the lower surface of the mounting seat 8, and a waist-shaped through hole 15 extending along the axial direction of the main body ring is provided on the waist-shaped hole seat 9. The lower end of the bracket 16 extends a through hole 12 downward, which is located below the lower surface of the main body 2. The fulcrum shaft 17 of the lever 10 is rotatably arranged on the lower end of the bracket 16. The free end of the resistance arm 10B of the lever 10 is provided with a rotating shaft 18, and the rotating shaft 18 is rotatably penetrated in the waist-shaped through hole 15 of the waist-shaped hole seat 9. The lever 10 is in a curved shape, and the power arm 10A is located below the main body 2. The angle between the power arm 10A and the resistance arm 10B is an obtuse angle, which can reduce the volume of the lever 1, and further reduce the volume of the entire linear drive component 7. The entire isolation plate mechanism 3 is installed on the main body 1 through the bracket 16, and different types of isolation plate mechanisms 3 can be easily replaced or the position of the isolation plate mechanism 3 can be adjusted.

[0041] When an external force (such as the thrust of a cylinder) pushes the power arm 10A upward, the power arm 10A drives the resistance arm 10B to rotate, and the rotating shaft 18 at the free end of the resistance arm 10B moves downward in the waist-shaped through hole 15, and pushes the waist-shaped hole seat 9, the mounting seat 8 and the double-layer isolation film component 6 to move radially inward of the main body ring, inserting the isolation film between the three layers of wafers, so that the closed end of the gap between the two layers of isolation films is pressed against the side of the middle layer wafer; when an external force (such as the thrust of a cylinder) pushes the power arm 10A downward, the power arm 10A drives the resistance arm 10B to rotate, and the rotating shaft 18 at the free end of the resistance arm 10B moves upward in the waist-shaped through hole 15, and pushes the waist-shaped hole seat 9, the mounting seat 8 and the double-layer isolation film component 6 to move radially outward of the main body ring, and pulls the isolation film out from between the three layers of wafers. The power arm 10A of lever one is connected to the bracket 16 through a tension spring 19, one end of the tension spring 19 is connected to the power arm 10A, and the other end is connected to the bracket 16. The tension spring 19 can assist in completing the insertion and withdrawal of the isolation plate, and can also fix the isolation plate in the withdrawal position and the insertion position. When the double-layer isolation plate component 6 is in the insertion position, the tension spring 19 can apply a certain tensioning force to the power arm 10A of lever one, so that the closed end of the gap between the two layers of isolation plates is pressed against the side wall of the middle layer wafer, so that the three isolation plate mechanisms 3 keep the middle wafer clamped and fixed.

[0042] The double-layer isolation film component 6 includes two layers of isolation films 6A, 6B and a mounting handle 6C. One end of the two layers of isolation films 6A, 6B are fixed to one end of the mounting handle 6C. A position adjustment groove is provided on the other end of the mounting handle 6C. A fastening bolt 22 is provided in the adjustment groove 21. The adjustment groove 21 extends along the length direction of the double-layer isolation film component 6. By changing the relative positions of the adjustment groove 21 and the fastening bolt 22, the position of the double-layer isolation film component 6 in the radial direction of the main body 2 can be adjusted.

[0043] Example 3

[0044] like Figure 3 , 4 As shown in Figure 6, a fixing mechanism 4 for a wafer bonding alignment device 1 includes a clamp 20 and an opening and closing driving component 21. The opening and closing driving component 21 drives the clamp 20 to press downward or tilt upward. When pressing downward, the free end 20A of the clamp 20 presses on the third layer of wafer, and cooperates with the upper surface of the vacuum suction head 5 to clamp the three layers of wafers between the two. When tilting upward, the free end 20A of the clamp 20 leaves the third layer of wafer upward to release the three layers of wafer. In this embodiment, the free end 20A of the clamp 20 is provided with a pressure roller 23, and the pressure roller 23 presses on the surface of the third layer of wafer when pressing downward.

[0045] The middle part of the clamping jaw 20 is rotatably arranged on the bracket 16 through the second rotating shaft 24, and the bracket 16 is detachably fixed in the through hole 12 of the body 2. The opening and closing driving component 21 includes a second lever 25 and a connecting rod 26. The second lever 25 is rotatably arranged on the bracket 16 through a fulcrum shaft 27, and the fulcrum shaft 27 is located at one end of the second lever 25. One end of the connecting rod 26 is rotatably connected to one end of the clamping jaw 20, and the other end is rotatably connected to the middle part of the second lever 25. The clamping jaw 20 is driven to rotate around the second rotating shaft 24 through the second lever 25 and the connecting rod 26, thereby driving the clamping jaw 20 to clamp or release the multi-layer wafer.

[0046] The free end of the lever 25 is located below the body 2. When the free end of the lever 25 is pushed upward by an external force, the lever 25 drives the clamp 20 to rotate around the rotating shaft 24 through the connecting rod 26, so that the pressure roller 23 of the free end 20A of the clamp is pressed downward on the third layer of wafers; when the free end of the lever 25 is pushed downward by an external force, the lever 25 drives the clamp 20 to rotate around the rotating shaft 24 through the connecting rod 26, so that the pressure roller 23 of the free end 20A of the clamp is tilted upward, and the multi-layer wafers are applied. The middle part of the lever 25 is connected to the bracket 16 through the tension spring 27. One end of the tension spring 27 is connected to the middle part of the lever 25, and the other end is connected to the bracket 16. The tension spring 27 can assist in completing the clamping or loosening action, and can also fix the clamp in the clamping or loosening position.

[0047] Example 4

[0048] This embodiment provides a three-layer wafer bonding method, which uses the wafer bonding alignment device 1 in the above embodiment to align and clamp the three-layer wafer, and specifically includes the following steps:

[0049] Step 1: Provide 3 wafers to be bonded. The wafers can be silicon wafers, silicon germanium wafers, germanium wafers, gallium nitride wafers or SiC wafers, etc. There is no restriction on the type of wafers. The 3 wafers can be wafers of the same type or different types. Pre-treat the surface of the wafers, such as hydrophilic treatment or plasma treatment, to improve the bonding strength of the wafers after bonding. Set the placement order of the wafers during bonding, which are the first layer wafer, the middle second layer wafer and the third layer wafer, and set alignment marks on the three layers of wafers.

[0050] Place the side of the alignment device 1 with the isolation plate mechanism 3 and the fixing mechanism 4 downward, use a suction pen or a chuck to place the first layer of wafers on a predetermined position of the main body 2, use three vacuum suction heads 5 to adsorb and fix the first layer of wafers on the surface of the vacuum suction heads 5, use a microscope to move and find the alignment mark of the first layer of wafers, and the first layer of wafers will become the reference for subsequent wafer alignment.

[0051] Step 2: Use a suction pen or chuck to place the middle second layer wafer into the alignment device 1 and align it with the first layer wafer. The specific alignment method is: use a microscope to find the alignment mark of the first layer wafer, and move the second layer wafer until its alignment mark overlaps with the alignment mark of the first layer wafer.

[0052] Three isolation film mechanisms 3 are inserted at the same time, with the upper isolation film 6A stuck on the second layer wafer, and the lower isolation film 6B stuck under the second layer wafer. The second layer wafer is located in the gap between the two isolation films 6A and 6B, so that the closed end 6D of the gap between the two isolation films 6A and 6B is pressed against the side wall of the middle second layer wafer, so that the three isolation film mechanisms 3 keep the middle second layer wafer clamped and fixed.

[0053] Step 3: Use a suction pen or chuck to place the third layer of wafer into the alignment device 1 and align it with the second layer of wafer. The specific alignment method is: use a microscope to find the alignment mark of the third layer of wafer, and move the third layer of wafer until its alignment mark overlaps with the alignment mark of the second layer of wafer. Use the fixing mechanism 4 of the alignment device 1 to clamp the three layers of wafers on the body 2.

[0054] Step 4: Place a graphite sheet on the third wafer, reverse the alignment device so that the third wafer is on the top, send the entire alignment device 1 to the bonding chamber of the bonding machine, evacuate the chamber, remove the isolation sheet mechanism 3, increase the temperature, move the bonding plate downward to apply pressure to bond multiple wafers, release the pressure after bonding is completed, cool down and break the vacuum before taking out the wafer.

[0055] The separation plate mechanism 3 is withdrawn in a step-by-step manner, first opening a fixing mechanism 4, withdrawing the separation plate mechanism 3 adjacent to the fixing mechanism 4, and allowing the fixing mechanism 4 to clamp the wafer again. Open another fixing mechanism 4, and repeat the above steps until all separation plate mechanisms 3 are withdrawn.

[0056] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A wafer bonding alignment device, comprising a main body and a plurality of isolation sheet mechanisms and fixing mechanisms arranged on the main body, characterized in that: The isolation plate mechanism includes a linear driving component and a double-layer isolation plate component arranged on the linear driving component, the double-layer isolation plate component includes two layers of isolation plates, and there is a gap between the two layers of isolation plates. The multiple isolation plate mechanisms can use the closed end of the gap to clamp the wafer; the two layers of isolation plates in the same isolation plate mechanism are driven by the same linear driving component; the linear driving component includes a mounting seat, a waist-shaped hole seat and a lever 1, the double-layer isolation plate component is fixedly arranged on the mounting seat, the mounting seat can be linearly slidably arranged on the main body, the waist-shaped hole seat is fixedly arranged on the mounting seat, the lever 1 is rotatably arranged on the main body through a support shaft 1, and the free end of the resistance arm of the lever 1 is provided with a rotating shaft 1, and the rotating shaft 1 is penetrated into the waist-shaped hole of the waist-shaped hole seat.

2. The device according to claim 1, characterized in that: The number of the isolation sheet mechanisms is equal to the number of the fixing mechanisms. The multiple isolation sheet mechanisms and the multiple fixing mechanisms are evenly distributed on the main body, and each isolation sheet mechanism is arranged adjacent to a corresponding fixing mechanism.

3. The device according to claim 1, characterized in that: The main body is a circular ring, and a plurality of vacuum suction heads protrude inwardly from the circular ring, and vacuum suction holes are arranged on the vacuum suction heads.

4. The device according to claim 1, characterized in that: The double-layer spacer component also includes a mounting handle, and the two-layer spacer is fixed on the mounting handle.

5. The device according to claim 4, characterized in that: The two layers of isolation sheets are connected in a U-shape or a V-shape.

6. The device according to claim 4, characterized in that: The double-layer isolation sheet component is a metal elastic sheet.

7. The device according to claim 4, characterized in that: The mounting handle is provided with a position adjustment groove, and the position adjustment groove extends along the length direction of the double-layer isolation piece component.

8. The device according to claim 1, characterized in that: The lever 1 is in a curved shape.

9. The device according to claim 8, characterized in that: The angle between the power arm and the resistance arm of the lever 1 is an obtuse angle.

10. The device according to claim 9, characterized in that: An elastic element is connected between the power arm of the lever 1 and the body.

11. The device according to claim 1, characterized in that: The fixing mechanism includes a clamping jaw and an opening and closing driving component, the middle part of the clamping jaw is rotatably arranged on the main body through a second rotating shaft, and the opening and closing driving component includes a second lever and a connecting rod, one end of the second lever is rotatably connected to the main body through a second supporting shaft, one end of the connecting rod is rotatably connected to one end of the clamping jaw, and the other end is rotatably connected to the middle part of the second lever.

12. The device according to claim 11, characterized in that: An elastic element is connected between the middle portion of the lever 2 and the body.

13. A bonding method for three-layer wafers, which uses the wafer bonding alignment device according to any one of claims 1 to 12 for alignment and fixation, comprising the following steps: Step 1: placing the first layer of wafer on the alignment device and fixing it; Step 2: placing the middle second layer wafer into the alignment device and aligning it with the first layer wafer, inserting the isolation plate mechanism, and clamping the second layer wafer between two isolation plates of the multiple isolation plate mechanisms; Step 3: placing the third layer of wafer into the alignment device and aligning it with the second layer of wafer, and using the fixing mechanism on the alignment device to fix and clamp the three layers of wafer; Step 4: Place the aligned three-layer wafer into the bonding machine for bonding.

14. The method according to claim 13, characterized in that: In the step 1, the first layer of wafers is adsorbed and fixed on the main body of the alignment device by using vacuum adsorption.

15. The method according to claim 13, characterized in that: The wafer is placed on the alignment device using a suction pen or a chuck and the wafer is moved to complete the alignment.

16. The method according to claim 13, characterized in that: The bonding in step 4 includes vacuuming, removing the isolation plate mechanism, heating, applying pressure, releasing pressure, cooling and breaking the vacuum process.

17. The method according to claim 16, characterized in that: The isolation plate mechanism is withdrawn in a step-by-step manner. First, one of the fixing mechanisms is opened, and the isolation plate mechanism corresponding to the fixing mechanism is withdrawn, so that the fixing mechanism re-clamps the wafer, and the above steps are repeated until all the isolation plate mechanisms are withdrawn.

Images