Wafer alignment apparatus and alignment method

Abstract

The application belongs to the technical field of semiconductor material bonding, and discloses a wafer alignment device and an alignment method. The wafer alignment device comprises a base, a stage assembly, a first vision mechanism, a second vision mechanism and a control system. The stage assembly is installed on the base, and comprises a support seat, an upper stage and a lower stage installed on the support seat. The upper stage is used for supporting an upper wafer, and the lower stage is used for supporting a lower wafer. The first vision mechanism is installed on the base and is arranged correspondingly with the stage assembly. The second vision mechanism is installed on the base and is arranged correspondingly with the stage assembly. The first vision mechanism and the second vision mechanism are both in communication connection with the control system. The control system is used for acquiring the near-infrared light transmittance of the upper wafer and / or the lower wafer and making the first vision mechanism or the second vision mechanism align the upper wafer and the lower wafer. The alignment method is applied to the above-mentioned wafer alignment device. The wafer alignment device satisfies the wafer alignment requirement of different light transmittance materials, and has high alignment efficiency.

Description

Technical Field

[0001] This invention relates to the field of semiconductor material bonding technology, and more particularly to a wafer alignment device and alignment method. Background Technology

[0002] In the rapid development of the information technology industry, semiconductor chips, as core supporting components, have always had performance improvement and cost optimization as core industry goals. Heterogeneous integration and advanced packaging technologies are key paths to continue the chip performance improvement curve. Heterogeneous integration technology integrates chips or devices with different processes, functions, and material systems into the same package, achieving a high degree of functional integration and synergistic performance optimization, effectively improving the overall chip performance, reducing power consumption, and shrinking package size. Advanced packaging, as the core technology supporting heterogeneous integration, directly determines the implementation effect of heterogeneous integration, and bonding technology, with its ultra-high bonding precision, low contact resistance, and excellent heat dissipation performance, has become one of the core supporting technologies in the field of advanced packaging.

[0003] In the entire bonding process, alignment is a critical step that determines bonding quality and yield, and its accuracy directly affects the reliability and electrical performance of inter-chip interconnects. However, in heterogeneous integration applications, the materials to be bonded often employ heterogeneous material systems, with some materials exhibiting high transmittance while others exhibit low transmittance or are opaque. Most existing alignment platforms are designed based on a single optical alignment principle, making it impossible to simultaneously accommodate the alignment requirements of materials with different transmittances. When facing heterogeneous integration scenarios, it is often necessary to change alignment equipment or adjust process parameters, which not only reduces production efficiency but may also introduce alignment errors due to multiple adjustments, affecting bonding yield.

[0004] Therefore, there is an urgent need for a wafer alignment device and alignment method to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a wafer alignment device and method, which aims to solve the problem that existing alignment devices cannot meet the wafer alignment requirements of materials with different light transmittance and have low alignment efficiency. The wafer alignment device and method can select the corresponding vision mechanism according to the near-infrared light transmittance of the wafer to perform alignment operations on the upper and lower wafers, thereby meeting the wafer alignment requirements of materials with different light transmittance and achieving high alignment efficiency.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] The wafer alignment apparatus includes:

[0008] Base;

[0009] A stage assembly is mounted on the base. The stage assembly includes a support base and an upper stage and a lower stage mounted on the support base. The upper stage is used to support an upper wafer, and the lower stage is used to support a lower wafer.

[0010] The first vision mechanism is installed on the base and is configured correspondingly to the platform assembly;

[0011] The second vision mechanism is installed on the base and is correspondingly arranged with the platform assembly. The second vision mechanism is spaced apart on one side of the first vision mechanism.

[0012] The control system is configured to communicate with both the first vision mechanism and the second vision mechanism. The control system is used to acquire the near-infrared light transmittance of the upper wafer and / or the lower wafer and to align the upper wafer and the lower wafer with the first vision mechanism or the second vision mechanism.

[0013] In some possible implementations, the first vision mechanism includes two first vision systems, which are symmetrically arranged on both sides of the platform assembly. Each first vision system includes two cameras, one of which is located above the upper platform and the other is located below the download platform, with the two cameras facing each other.

[0014] The second vision mechanism includes two second vision systems, which are symmetrically arranged on both sides of the stage assembly. The second vision system is a near-infrared vision system.

[0015] In some possible implementations, the wafer alignment device further includes two C-shaped supports, which are symmetrically arranged on both sides of the stage assembly. The two C-shaped supports correspond one-to-one with the two first vision systems. One camera of the first vision system is connected to a support plate on one side of the C-shaped support, and the other camera of the first vision system is connected to a support plate on the other side of the C-shaped support.

[0016] In some possible implementations, the wafer alignment apparatus further includes a first drive mechanism for driving the C-shaped frame to move relative to the download stage in the X or Y direction.

[0017] In some possible implementations, the wafer alignment device further includes a support beam in the form of a C-shape, with the two side beams of the C-shape detachably connected to the base, and the second vision system mounted on the top beam of the C-shape.

[0018] In some possible implementations, a passive damper is provided between the support and the base.

[0019] In some possible implementations, the wafer alignment device further includes a second drive mechanism and a third drive mechanism. The loading stage includes an upper table and an upper platform rotatably mounted on the upper table. The upper platform is used to support the upper wafer. The second drive mechanism can drive the upper table to move along the X and Y directions and can drive the upper platform to rotate about the Z direction.

[0020] The download stage includes a lower platform and a lower table that is slidably mounted on the lower platform. The lower table is used to support the lower wafer, and the third driving mechanism can drive the lower table to move relative to the lower platform in the Y direction.

[0021] In some possible implementations, the wafer alignment apparatus further includes a leveling mechanism comprising three leveling elements that pass through the support base, one end of each leveling element being connected to the base and the other end being connected to the download stage, and the three leveling elements being evenly distributed at the bottom of the download stage.

[0022] A wafer alignment method, applied to a wafer alignment apparatus as described in any of the above embodiments, the wafer alignment method comprising the steps of:

[0023] The control system acquires the near-infrared light transmittance of the upper wafer and the lower wafer;

[0024] If the near-infrared light transmittance is zero, the first vision mechanism is controlled to align the upper wafer and the lower wafer; if the near-infrared light transmittance is one, the second vision mechanism is controlled to align the upper wafer and the lower wafer.

[0025] In some possible implementations, aligning the upper wafer and the lower wafer includes the steps of:

[0026] The wafer is mounted on the download stage, and the vision mechanism identifies the markings on the wafer.

[0027] The wafer is mounted on the loading stage, and the vision mechanism identifies the markings on the wafer.

[0028] The beneficial effects of this invention are:

[0029] The wafer alignment device provided by this invention, by setting a first vision mechanism and a second vision mechanism, can select the corresponding vision mechanism according to the near-infrared light transmittance of the upper and lower wafers, and perform alignment operations on the upper and lower wafers. It is applicable to the alignment of wafers of different materials, improves versatility, and expands the application range. At the same time, the two vision mechanisms are integrated into the same device, reducing the footprint and reducing processing costs. Attached Figure Description

[0030] Figure 1This is a three-dimensional view of the wafer alignment apparatus provided in an embodiment of the present invention;

[0031] Figure 2 This is a front view of the wafer alignment apparatus (second vision system not shown) provided in an embodiment of the present invention;

[0032] Figure 3 This is a front view of the wafer alignment device (first vision system not shown) provided in an embodiment of the present invention.

[0033] In the picture:

[0034] 100. Base; 210. Support base; 220. Loading platform; 221. Upper desktop; 222. Upper platform base; 230. Download platform; 231. Lower platform base; 232. Lower desktop; 311. Camera; 410. Second vision system; 500. C-frame; 600. First drive mechanism; 700. Support beam; 800. Passive shock absorber; 901. Leveling component; 1000. Roller. Detailed Implementation

[0035] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0036] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0039] like Figures 1 to 3 As shown, the present invention provides a wafer alignment apparatus, including a base 100, a stage assembly, a first vision mechanism, a second vision mechanism, and a control system. The stage assembly is mounted on the base 100 and includes a support 210 and an upper stage 220 and a lower stage 230 mounted on the support 210. The upper stage 220 supports an upper wafer, and the lower stage 230 supports a lower wafer. The first vision mechanism is mounted on the base 100 and correspondingly arranged with respect to the stage assembly. The second vision mechanism is mounted on the base 100 and correspondingly arranged with respect to the stage assembly, and is spaced apart from one side of the first vision mechanism. Both the first and second vision mechanisms are communicatively connected to the control system. The control system is used to acquire the near-infrared light transmittance of the upper wafer and / or the lower wafer and to align the upper and lower wafers using the first or second vision mechanism. In this embodiment, the near-infrared light transmittance of the wafer includes zero and one. The near-infrared transmittance of the wafer is one when near-infrared light can penetrate the wafer and the second vision mechanism can form a clear image; the near-infrared transmittance of the wafer is zero when near-infrared light cannot penetrate the wafer or does not meet the image clarity requirements of the second vision mechanism after penetration. For example, the wavelength of the near-infrared light is 1200 nanometers.

[0040] The wafer alignment apparatus provided in this embodiment, by setting up a first vision mechanism and a second vision mechanism, can select the corresponding vision mechanism based on the near-infrared light transmittance of the upper and lower wafers to perform alignment operations on the upper and lower wafers. This is applicable to the alignment of wafers of different materials, improving versatility and expanding the application range. Simultaneously, integrating the two vision mechanisms within the same device reduces the footprint and lowers processing costs. For example, when near-infrared light cannot penetrate the wafer, the first vision mechanism is selected to align the upper and lower wafers; when near-infrared light can penetrate the wafer and meets the imaging clarity requirements of the second vision mechanism, the second vision mechanism is selected to align the upper and lower wafers.

[0041] In this embodiment, the first vision mechanism includes two first vision systems symmetrically arranged on both sides of the stage assembly. Each first vision system includes two cameras 311, one positioned above the upper stage 220 and the other below the lower stage 230, with the two cameras facing each other. The second vision mechanism includes two second vision systems 410 symmetrically arranged on both sides of the stage assembly. Each second vision system 410 is a near-infrared vision system. The camera 311 of the first vision system positioned above the upper stage 220 is used to identify the markings on the lower wafer, and the camera 311 of the first vision system positioned below the lower stage 230 is used to identify the markings on the upper wafer. The use of two first vision systems and two second vision systems 410 improves alignment efficiency and accuracy.

[0042] Optionally, the wafer alignment apparatus further includes two C-frames 500, symmetrically arranged on both sides of the stage assembly. Each C-frame 500 corresponds to one of the two first vision systems. One camera 311 of each first vision system is connected to a support plate on one side of the C-frame 500, and the other camera 311 of the first vision system is connected to the other support plate on the other side of the C-frame 500. The two cameras 311 are respectively mounted on the two support plates of the C-frame 500, which support the cameras 311 and improve the coaxiality of the two cameras 311.

[0043] Preferably, the wafer alignment apparatus further includes a first drive mechanism 600, which drives the C-shaped frame 500 to move relative to the download stage 230 in the X or Y direction. This configuration facilitates adjustment of the position of the C-shaped frame 500 and the first vision system mounted on the C-shaped frame 500, thereby adjusting the position of the first vision system relative to the marking portion on the wafer. This solves the problem of inconsistent marking portion positions on wafers from different manufacturers and batches, improving system compatibility. For example, the first drive mechanism 600 may include a motor structure or a cylinder structure.

[0044] Optionally, the wafer alignment device also includes a support beam 700, which has a C-shaped structure. The two side beams of the C-shaped structure are detachably connected to the base 100, and the second vision system 410 is mounted on the top beam of the C-shaped structure. During installation, the top beam of the C-shaped structure is located above the stage assembly. Mounting the second vision system 410 on the top beam of the C-shaped structure provides the second vision system 410 with an unobstructed top-down view. The detachable connection between the two side beams of the C-shaped structure and the base 100 improves the ease of assembly and disassembly. For example, the side beams can be connected to the base 100 via threaded fittings.

[0045] Preferably, a passive vibration damper 800 is provided between the support 210 and the base 100. The passive vibration damper 800 can absorb the vibration of the base 100, while blocking the internal vibration of the equipment generated during the operation of the stage assembly and the drive mechanism, preventing the vibration from being transmitted to the first vision mechanism and the second vision mechanism, preventing the vision mechanism from shaking, and ensuring the alignment accuracy of the upper and lower wafers.

[0046] In this embodiment, the wafer alignment device further includes a second driving mechanism and a third driving mechanism. The loading stage 220 includes an upper tabletop 221 and an upper platform 222 rotatably mounted on the upper tabletop 221. The upper platform 222 is used to support the upper wafer. The second driving mechanism can drive the upper tabletop 221 to move along the X and Y directions and can drive the upper platform 222 to rotate around the Z direction. The download stage includes a lower platform 231 and a lower tabletop 232 slidably mounted on the lower platform 231. The lower tabletop 232 is used to support the lower wafer. The third driving mechanism can drive the lower tabletop 232 to move relative to the lower platform 231 along the Y direction. The second drive mechanism drives the upper tabletop 221 to move along the X and Y directions and can drive the upper stage 222 to rotate around the Z direction, performing dual adjustment of the position and angle of the upper wafer to compensate for the initial placement deviation of the upper wafer and ensure alignment accuracy. The third drive mechanism drives the lower tabletop 232 to move along the Y direction, enabling the lower wafer to translate horizontally, and simultaneously cooperating with the alignment action of the upper stage 220 to improve alignment accuracy. For example, the second drive mechanism may include a cylinder structure for the movement of the upper tabletop 221 along the X and Y directions and a motor structure for driving the upper stage 222 to rotate around the Z direction; the third drive mechanism may include a cylinder structure for driving the lower tabletop 232 to move relative to the lower stage 231 along the Y direction.

[0047] Preferably, the wafer alignment apparatus further includes a leveling mechanism comprising three leveling components 901. Each leveling component 901 passes through the support base 210, with one end connected to the base 100 and the other end connected to the lower platform 231. The three leveling components 901 are evenly distributed on the bottom of the lower platform 231. By adjusting the height of each of the three leveling components 901, the lower platform 231 can be horizontally calibrated, thereby horizontally calibrating the lower wafer mounted on the lower tabletop 232 of the lower platform 231 and eliminating tabletop tilt caused by processing or assembly errors. Exemplarily, the leveling component 901 may include a leveling cylinder or a leveling bolt.

[0048] In this embodiment, a roller 1000 is provided at the bottom of the base 100 to facilitate the rapid transfer of the wafer alignment device.

[0049] This embodiment also provides a wafer alignment method applied to the above-mentioned wafer alignment apparatus. The wafer alignment method includes the following steps:

[0050] S1. The control system acquires the near-infrared light transmittance of the upper and lower wafers;

[0051] S2. If the near-infrared light transmittance is zero, control the first vision mechanism to align the upper and lower wafers; if the near-infrared light transmittance is one, control the second vision mechanism to align the upper and lower wafers.

[0052] The wafer alignment method provided in this embodiment can select the corresponding vision mechanism according to the near-infrared light transmittance of the upper and lower wafers, and perform alignment operations on the upper and lower wafers. It is applicable to the alignment of wafers of different materials and improves alignment efficiency.

[0053] Optionally, aligning the upper and lower wafers includes the following steps:

[0054] S21. The lower wafer is mounted on the download stage 230, and the vision mechanism identifies the markings on the lower wafer;

[0055] S22. The upper wafer is mounted on the loading stage 220, and the vision mechanism identifies the markings on the upper wafer.

[0056] Specifically, when using the first vision mechanism for alignment, the lower wafer is first placed on the download stage 230, and the camera 311 of the first vision system, located above the upload stage 220, is used to identify the markings on the lower wafer; then the upper wafer is placed on the upload stage 220, and at the same time, the lower wafer on the download stage 230 is moved out of the identification area, and the upper wafer on the upload stage 220 is moved into the identification area, and the camera 311 of the first vision system, located below the download stage 230, is used to identify the markings on the upper wafer.

[0057] When aligning using the second vision mechanism, the lower wafer is placed on the download stage 230 and the upper wafer is placed on the loading stage 220. The lower wafer on the download stage 230 and the upper wafer on the loading stage 220 are simultaneously moved into the recognition area. The overlap of the upper and lower wafer markings is identified by the near-infrared vision system. The download stage 230 and / or the loading stage 220 are adjusted until the upper and lower wafer markings overlap.

[0058] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A wafer alignment apparatus, characterized in that, include: Base (100); A stage assembly is mounted on the base (100). The stage assembly includes a support base (210) and an upper stage (220) and a lower stage (230) mounted on the support base (210). The upper stage (220) is used to support the upper wafer, and the lower stage (230) is used to support the lower wafer. The first vision mechanism is installed on the base (100) and is correspondingly arranged with the platform assembly; The second vision mechanism is installed on the base (100) and is correspondingly arranged with respect to the platform assembly. The second vision mechanism is spaced apart on one side of the first vision mechanism. The control system includes a first vision mechanism and a second vision mechanism communicatively connected to the control system. The control system is used to acquire the near-infrared light transmittance of the upper wafer and / or the lower wafer and to align the upper wafer and the lower wafer using either the first vision mechanism or the second vision mechanism. The first vision mechanism includes two first vision systems, which are symmetrically arranged on both sides of the stage assembly. Each first vision system includes two cameras (311). The second vision mechanism includes two second vision systems (410), which are symmetrically arranged on both sides of the stage assembly. Each second vision system (410) is a near-infrared vision system. When the near-infrared light transmittance is zero, the control system causes the first vision mechanism to align the upper wafer and the lower wafer. When the near-infrared light transmittance is one, the control system causes the second vision mechanism to align the upper wafer and the lower wafer.

2. The wafer alignment apparatus according to claim 1, characterized in that, One of the cameras (311) is positioned above the loading platform (220), and the other camera (311) is positioned below the download platform (230), with the two cameras (311) facing each other.

3. The wafer alignment apparatus according to claim 2, characterized in that, The wafer alignment device further includes two C-shaped supports (500), which are symmetrically arranged on both sides of the stage assembly. The two C-shaped supports (500) correspond one-to-one with the two first vision systems. One camera (311) of the first vision system is connected to one side support plate of the C-shaped support (500), and the other camera (311) of the first vision system is connected to the other side support plate of the C-shaped support (500).

4. The wafer alignment apparatus according to claim 3, characterized in that, The wafer alignment device further includes a first driving mechanism (600) for driving the C-shaped frame (500) to move relative to the download stage (230) in the X or Y direction.

5. The wafer alignment apparatus according to claim 2, characterized in that, The wafer alignment device also includes a support beam (700), which has a C-shaped structure. The two side beams of the C-shaped structure are detachably connected to the base (100), and the second vision system (410) is mounted on the top beam of the C-shaped structure.

6. The wafer alignment apparatus according to claim 1, characterized in that, A passive shock absorber (800) is provided between the support (210) and the base (100).

7. The wafer alignment apparatus according to claim 1, characterized in that, The wafer alignment device further includes a second driving mechanism and a third driving mechanism. The upper stage (220) includes an upper table (221) and an upper platform (222) rotatably mounted on the upper table (221). The upper platform (222) is used to support the upper wafer. The second driving mechanism can drive the upper table (221) to move along the X and Y directions, and can drive the upper platform (222) to rotate around the Z direction. The download stage (230) includes a lower platform (231) and a lower tabletop (232) slidably mounted on the lower platform (231). The lower tabletop (232) is used to support the lower wafer. The third driving mechanism can drive the lower tabletop (232) to move relative to the lower platform (231) in the Y direction.

8. The wafer alignment apparatus according to claim 1, characterized in that, The wafer alignment device further includes a leveling mechanism, which includes three leveling components (901). The leveling components (901) are inserted through the support base (210). One end of the leveling component (901) is connected to the base (100), and the other end is connected to the download stage (230). The three leveling components (901) are evenly distributed on the bottom of the download stage (230).

9. A wafer alignment method, characterized in that, Applied to the wafer alignment apparatus as described in any one of claims 1-8, the wafer alignment method includes the steps of: The control system acquires the near-infrared light transmittance of the upper wafer and the lower wafer; If the near-infrared light transmittance is zero, the first vision mechanism is controlled to align the upper wafer and the lower wafer; if the near-infrared light transmittance is one, the second vision mechanism is controlled to align the upper wafer and the lower wafer.

10. The wafer alignment method according to claim 9, characterized in that, When aligning the upper wafer and the lower wafer, the steps include: The lower wafer is mounted on the download stage (230), and the vision mechanism identifies the markings on the lower wafer; The upper wafer is mounted on the upper stage (220), and the vision mechanism identifies the markings on the upper wafer.

Images