Chip wafer bonding alignment system and bonding alignment method

Abstract

The invention provides a chip wafer bonding alignment system and a bonding alignment method, and relates to the technical field of semiconductor processing, and the system comprises near-infrared light sources which comprise a first near-infrared light source and a second near-infrared light source, and the light outlets of the near-infrared light sources are respectively provided with an optical filter; light outlets of the first near-infrared light source and the second near-infrared light source are connected to the lighting system; the reflector is arranged at a light outlet of the lighting system; the large-view-field near-infrared dispersion microscope objective is arranged below the spectroscope, the wafer and the chip are located on the object side of the large-view-field near-infrared dispersion microscope objective, the large-view-field tube lens and the two infrared cameras are sequentially arranged above the spectroscope, and after four focusing points on a wafer alignment mark and a chip alignment mark form four reflection images, the four reflection images are reflected by the two infrared cameras. The light sequentially passes through the spectroscope and the large-field-of-view tube lens and is clearly imaged in the field of view of the two infrared cameras. The positions of the four mark points can be observed at the same time in the bonding process, and high-precision bonding of the chip and the wafer is achieved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing technology, and more specifically to a chip wafer bonding alignment system and bonding alignment method. Background Technology

[0002] Alignment accuracy is the most critical factor in ensuring wafer bonding quality in wafer bonding equipment, and the vision system plays a decisive role. The latest high-precision bonding equipment uses near-infrared optical systems, which can penetrate the semiconductor wafer to directly observe the marking points. A major application of bonding is wafer-to-wafer bonding (W2W). In wafer-to-wafer bonding, marking points are made on the edges of each wafer, and then two vision systems are used to bond these marking points separately. During the bonding process, the infrared system first observes the marking points on the lower surface of the upper wafer. Then, a piezoelectric ceramic actuator moves the entire optical system downwards to observe the marking points on the upper surface of the lower wafer. The positions of the marking points on both wafers are recorded. Finally, a high-precision displacement platform adjusts the position of the lower wafer to move the lower wafer marking points to the upper wafer marking points. In this process, the infrared system's ability to observe the marking point positions improves bonding accuracy.

[0003] Another important application of bonding is die-to-wafer bonding (D2W), which involves bonding a chip to a wafer. D2W typically requires the simultaneous alignment of two marker points—two marker points on the wafer and two marker points on the chip. Unlike W2W, chips are usually very small, and depending on the product and process, the distance between the two marker points on the chip is typically around 6–11 mm. Conventional high-magnification microscope systems (with a very small object-side field of view, only 0.8 mm with a 10X infrared camera objective) cannot cover both marker points within this range, but the spacing between the two marker points also makes it impossible to deploy two separate systems. Therefore, it is impossible to simultaneously align two marker points spaced only a few millimeters apart. Summary of the Invention

[0004] In view of this, embodiments of this application provide a chip wafer bonding alignment system and bonding alignment method for a new D2W dual-marker bonding system, which uses a vision system to simultaneously capture four marker points (two for the die and two for the wafer) on both the die and the wafer. During the bonding process, the positions of the four marker points can be observed in real time, thereby achieving high-precision bonding between the chip and the wafer.

[0005] This application provides the following technical solution: a chip wafer bonding alignment system, comprising:

[0006] A near-infrared light source, comprising a first near-infrared light source and a second near-infrared light source, wherein filters are respectively provided at the light outlets of the first near-infrared light source and the second near-infrared light source;

[0007] The lighting system has the light output ports of the first near-infrared light source and the second near-infrared light source connected to the lighting system via optical fibers, so that the two beams of narrow-band monochromatic light with different center wavelengths obtained after being filtered by the filter are connected to the lighting system after passing through the optical fibers.

[0008] A reflector and a beam splitter are provided, the reflector and the beam splitter being arranged in parallel. The reflector is located at the light outlet of the illumination system and is used to reflect two beams of monochromatic illumination light with different center wavelengths to the beam splitter.

[0009] A large field-of-view near-infrared dispersive microscope objective is provided below the beam splitter, allowing illumination light and monochromatic light of different wavelengths after passing through the beam splitter to enter the large field-of-view near-infrared dispersive microscope objective.

[0010] A wafer and a chip are positioned on the object side of a large field-of-view near-infrared dispersive microscope objective, with the wafer and chip placed face-to-face. Two wafer alignment marks are provided on the lower surface of the wafer, and two chip alignment marks are provided on the upper surface of the chip. When two monochromatic illumination beams with different center wavelengths enter the large field-of-view near-infrared dispersive microscope objective, they simultaneously form focal points on the two wafer alignment marks and the two chip alignment marks, respectively.

[0011] A wide-field telescope and an imaging device are arranged sequentially above the beam splitter. The imaging device includes a first infrared camera and a second infrared camera arranged side by side. After the four focal points on the wafer alignment mark and the chip alignment mark form four reflected images, the reflected waves pass through the beam splitter and the wide-field telescope in sequence, and finally form clear images in the fields of view of the first infrared camera and the second infrared camera, respectively.

[0012] According to one embodiment of this application, the lens parameters of the large field-of-view near-infrared dispersive microscope objective are as follows: and satisfy the following relationship: 0.001≤Δλ / ΔWD≤0.002;

[0013] 20nm≤Δλ;

[0014] 20μm≤ΔWD,WD(λ min ≥35mm;

[0015] 8≤2y≤11mm;

[0016] NA ≥ 0.3;

[0017] Where, λ min λ is the shortest operating wavelength of the large field-of-view near-infrared dispersive microscope objective. max Δλ = λ, where λ is the longest operating wavelength of the large field-of-view near-infrared dispersive microscope objective. max -λ min WD(λ) max ) represents the back intercept corresponding to the longest operating wavelength, WD(λ) min ) represents the back intercept corresponding to the shortest operating wavelength, ΔWD = WD(λ) max )-WD(λ min ), where y is the half field of view and NA is the numerical aperture of the large field of view near-infrared dispersive microscope objective.

[0018] According to one embodiment of this application, the shortest operating wavelength λ of the large field-of-view near-infrared dispersive microscope objective is... min The longest operating wavelength λ of the large field-of-view near-infrared dispersive microscope objective is 1100 nm. max The value is 1300nm; 100μm≤ΔWD≤200μm.

[0019] According to one embodiment of this application, the large field-of-view tube lens has a focal length f = 400 mm, a numerical aperture NA of 0.035, a field of view of 110 mm, and a working wavelength λ of 1.1 to 1.3 μm; the CRA angle of the large field-of-view tube lens is ≤10°, wherein the CRA angle is the maximum angle between the light rays emitted from the object side of the tube lens and the optical axis.

[0020] According to one embodiment of this application, the filter is a narrowband filter with a bandwidth of ±1 to 2 nm.

[0021] According to one embodiment of this application, the first near-infrared light source and the second near-infrared light source are respectively a first near-infrared lamp box and a second near-infrared lamp box, used to emit near-infrared bands.

[0022] According to one embodiment of this application, the optical fiber is a two-in-one optical fiber, through which two monochromatic lights of different wavelengths are coupled and connected to the lighting system.

[0023] This application also provides a bonding alignment method for the chip wafer bonding alignment system as described above, including:

[0024] Turn on the first and second near-infrared light sources so that they emit near-infrared wavelengths respectively; after being filtered by the filters at the light outlets of the first and second near-infrared light sources, two beams of narrow-band monochromatic light with different center wavelengths are obtained, and the two beams of narrow-band monochromatic light with different center wavelengths are connected to the lighting system.

[0025] The two monochromatic illumination beams with different center wavelengths of the illumination system are reflected by a mirror to a beam splitter, so that the two monochromatic illumination beams with different center wavelengths after passing through the beam splitter enter the large field of view near-infrared dispersive microscope objective and simultaneously form focal points on two wafer alignment marks and two chip alignment marks, respectively; after the four focal points form four reflected images, the reflected waves pass through the beam splitter and the large field of view tube lens in sequence, and finally form clear images in the fields of view of the first infrared camera and the second infrared camera, respectively.

[0026] The position coordinates of the four marker points imaged in the first infrared camera and the second infrared camera are read respectively. Based on the position coordinates, the compensation value of the wafer and the chip is calculated. The position of the chip is adjusted according to the compensation value, and the chip and the wafer are aligned and corrected.

[0027] According to one embodiment of this application, the light emission ports of the first near-infrared light source and the second near-infrared light source are respectively provided with a plurality of filters, and the plurality of filters are narrowband filters with adjacent center wavelengths.

[0028] Compared with the prior art, the beneficial effects achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least the following: using the chip-wafer bonding alignment system and bonding alignment method of the embodiments of this invention, the adjacent mark points of the chip and the wafer to be bonded can be observed simultaneously during the bonding process. Combined with a large NA (numerical aperture) and large field-of-view near-infrared dispersive microscope objective, a single system can simultaneously and very clearly observe the adjacent mark points on the same layer of the chip and the wafer. Using this system significantly improves the bonding accuracy of adjacent mark points on two layers, ensuring high-precision bonding quality between the chip and the wafer. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the overall structure of the chip wafer bonding alignment system according to an embodiment of the present invention;

[0031] Figure 2 This is a detailed structural schematic diagram of the chip wafer bonding alignment system according to an embodiment of the present invention;

[0032] Figure 3 This is an alignment diagram of adjacent marker points during chip and wafer bonding in an embodiment of the present invention;

[0033] Among them, 100-alignment system, 1-first near-infrared light box, 2-second near-infrared light box, 3-first narrowband filter, 4-second narrowband filter, 5-two-in-one optical fiber, 6-illumination system, 7-reflector, 8-beam splitter, 9-large field-of-view near-infrared dispersive microscope objective, 10-stage, 11-wafer, 12-chip, 13-first wafer alignment mark, 14-second wafer alignment mark, 15-first chip alignment mark, 16-second chip alignment mark, 17-large field-of-view telescope, 18-first infrared camera, 19-second infrared camera, 20-chip holder. Detailed Implementation

[0034] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0035] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] like Figures 1-2 As shown, this embodiment of the invention provides a chip wafer bonding alignment system, comprising:

[0037] A near-infrared light source, comprising a first near-infrared light source and a second near-infrared light source, wherein filters are respectively provided at the light outlets of the first near-infrared light source and the second near-infrared light source;

[0038] The lighting system 6 has its light-emitting ports of the first and second near-infrared light sources connected to it via optical fibers, so that the two beams of narrow-band monochromatic light with different center wavelengths obtained after being filtered by the filter are connected to the lighting system 6 after passing through the optical fibers.

[0039] A reflector 7 and a beam splitter 8 are arranged in parallel. The reflector 7 is located at the light outlet of the illumination system 6 and is used to reflect two beams of monochromatic illumination light with different center wavelengths to the beam splitter 8.

[0040] A large field-of-view near-infrared dispersive microscope objective 9 is disposed below the beam splitter 8, so that two monochromatic illumination lights with different center wavelengths after passing through the beam splitter 8 enter the large field-of-view near-infrared dispersive microscope objective 9.

[0041] A wafer 11 and a chip 12 are located on the object side of the large field-of-view near-infrared dispersive microscope objective 9, and are placed face-to-face. Two wafer alignment marks are respectively provided on the lower surface of the wafer 11, and two chip alignment marks are respectively provided on the upper surface of the chip 12. When two monochromatic illumination lights with different center wavelengths enter the large field-of-view near-infrared dispersive microscope objective 9, they simultaneously form focal points on the two wafer alignment marks and the two chip alignment marks, respectively.

[0042] A wide-field telescope 17 and an imaging device are sequentially arranged above the beam splitter 8. The imaging device includes a first infrared camera 18 and a second infrared camera 19 arranged side by side. After the four focal points on the wafer alignment mark and the chip alignment mark form four reflected images, the reflected waves pass through the beam splitter 8 and the wide-field telescope 17 in sequence, and finally form clear images in the fields of view of the first infrared camera 18 and the second infrared camera 19 respectively.

[0043] In specific implementation, the lower surface of the wafer 11 is respectively provided with a first wafer alignment mark 13 and a second wafer alignment mark 14, and the upper surface of the chip is respectively provided with a first chip alignment mark 15 and a second chip alignment mark 16 corresponding to the first wafer alignment mark 13 and the second wafer alignment mark 14. The wafer 11 is placed on a stage 10, and the chip 12 is picked up by the gripping head of the chip holder 20. The stage 10 is a transparent stage, and the alignment system 100 is located below the stage 10, simultaneously observing two adjacent markers on the chip 12 and the wafer 11 through the stage 10. The gripping head adjusts its position according to the feedback from the vision system, aligning the two markers on the chip 12 with the two markers on the wafer 11 before bonding. Figure 3 As shown.

[0044] In this embodiment, the filter is a narrowband filter with a bandwidth of ±1 to 2 nm. Specifically, the first near-infrared light source and the second near-infrared light source are respectively a first near-infrared light box 1 and a second near-infrared light box 2, used to emit near-infrared wavelengths; the light output port of the first near-infrared light box 1 is equipped with a first narrowband filter 3, and the light output port of the second near-infrared light box 2 is equipped with a second narrowband filter 4. The optical fiber is a two-in-one optical fiber 5, through which two beams of monochromatic light of different wavelengths are coupled and connected to the lighting system 6.

[0045] To ensure clear imaging of the markers on chip 12 and wafer 11 simultaneously and to eliminate crosstalk from other wavelengths, two near-infrared lamp boxes are used. Narrowband filters are placed at the lamp box interfaces. These narrowband filters can achieve ±1nm bandwidth. To further improve monochromaticity, multiple narrowband filters can be placed, such as those with adjacent center wavelengths (e.g., 1199.5nm / 1200nm / 1201.5nm; since they all have ±1nm bandwidth, their superposition can produce a relatively pure 1200nm band). Different filters are placed in each lamp box, allowing for the emission of two different wavelengths. A two-in-one fiber optic cable 5 couples the light emitted from both lamp boxes to a single fiber.

[0046] In practice, the first near-infrared light box 1 and the second near-infrared light box 2 emit near-infrared wavelengths. These wavelengths are filtered by a narrow-band filter in front of the light boxes to obtain two wavelengths with very good monochromaticity (different wavelengths of monochromatic light can be obtained through the filter). The two light boxes enter the illumination system 6 through the two-in-one optical fiber 5, and then enter the large field-of-view near-infrared dispersive microscope objective 9 through the reflector 7 and the beam splitter 8. The dispersive microscope objective focuses the light onto the mark on the lower surface of the chip and the mark on the upper surface of the wafer, forming four focal points. These four reflected images return to the vision system. The reflected waves pass through the beam splitter 8 and the large field-of-view tube lens 17, and finally, two infrared cameras receive the alignment images of the adjacent marks on the wafer and the chip, respectively.

[0047] Therefore, using the chip-wafer bonding alignment system of this invention, adjacent mark points of the chip and wafer to be bonded can be observed simultaneously during the bonding process. Combined with a large NA (numerical aperture) and wide field-of-view near-infrared dispersive microscope objective, a single system can simultaneously and very clearly observe adjacent mark points on the same layer. Using this system significantly improves the bonding accuracy of adjacent mark points on two layers, ensuring high-precision bonding quality between the chip and the wafer.

[0048] In practical implementation, conventional microscope objectives require achromatic or apochromatic designs, meaning that the focusing positions of all wavelengths are designed together. This embodiment uses a large field-of-view near-infrared dispersive microscope objective 9, which takes the opposite approach. Its principle is to utilize the dispersive characteristics of the lens to design different wavelengths at different focusing positions, similar to a spectral confocal dispersive lens, but significantly different. The goal of a dispersive lens is to measure position, not to image; therefore, it only considers on-axis point design, has a small numerical aperture (NA), and requires a large range of dispersive distances. However, the dispersive microscope objective used in this embodiment requires imaging, thus needing to consider the camera's field of view, i.e., the performance of each wavelength within a certain field of view. The distance between the bonded chip and the wafer is relatively close (on the order of tens of micrometers), and to prevent crosstalk between upper and lower images, the depth of field range for each wavelength is small, requiring a certain numerical aperture. Therefore, the dispersive microscope objective needs parameters similar to a microscope objective and characteristics of a dispersive lens. However, high-magnification microscope objectives have a very small field of view. Furthermore, because the bonding vision system uses an infrared camera with a very small field of view (1 / 2-inch sensor, 8.2mm diagonal), for example, a 10X objective has an object-side field of view of only 0.82mm. The spacing between the two markers on the same layer of the chip or wafer to be bonded ranges from 6 to 11mm. Therefore, dispersive microscope objectives must not only have a high numerical aperture (a large numerical aperture corresponds to a small field of view) but also a large field of view.

[0049] In one embodiment, the large field-of-view near-infrared dispersive microscope objective 9 comprises, from the emission side to the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens; wherein the first lens and the second lens are cemented together to form a cemented doublet lens.

[0050] And it satisfies the following relationship: 0.001≤Δλ / ΔWD≤0.002;

[0051] 20nm≤Δλ;

[0052] 20μm≤ΔWD,WD(λ min ≥35mm;

[0053] 8≤2y≤11mm;

[0054] NA ≥ 0.3;

[0055] Where, λ min λ is the shortest operating wavelength of the large field-of-view near-infrared dispersive microscope objective. max Δλ = λ, where λ is the longest operating wavelength of the large field-of-view near-infrared dispersive microscope objective. max -λ min WD(λ) max) represents the back intercept corresponding to the longest operating wavelength, WD(λ) min ) represents the back intercept corresponding to the shortest operating wavelength, ΔWD = WD(λ) max )-WD(λ min ), where y is the half field of view and NA is the numerical aperture of the large field of view near-infrared dispersive microscope objective.

[0056] The positions of the chip and wafer vary depending on the bonding process, typically ranging from 30 to 200 μm. Therefore, the dispersive objective is designed with a focal length of 1.1–1.3 μm. The focusing distance at 1.1 μm and 1.3 μm differs by 200 μm. Within this wavelength range, the focusing distance is essentially linear; that is, the difference between 1.1 μm and 1.2 μm is approximately 100 μm, and so on. Therefore, for bonding processes of different durations, only the filter in front of the lamp box needs to be changed to obtain clear images of the chip and wafer at different distances. This allows for rapid adaptation to various high-precision bonding requirements. Furthermore, due to its good wavelength monochromaticity, it improves the contrast of the wafer and chip mark images (multiple wavelengths affect the low frequencies of the image, i.e., contrast; single-wavelength images have better contrast), which is beneficial for algorithm processing. Therefore, in this embodiment, the shortest operating wavelength λ of the large field-of-view near-infrared dispersive microscope objective is... min The longest operating wavelength λ of the large field-of-view near-infrared dispersive microscope objective is 1100 nm. max The value is 1300nm; 100μm≤ΔWD≤200μm.

[0057] In practical implementation, the lens parameters of this large field-of-view near-infrared dispersive microscope objective 9 are as follows:

[0058] 1) f = 40mm (focal length f is 40mm, matched with a 400mm tube lens, magnification is -10X, the objective lens in this embodiment is a 10X objective lens);

[0059] 2) Numerical aperture NA: 0.35;

[0060] 3) Field of view: 8.8mm (large field of view);

[0061] 4) Back offset WD: ≥35mm (large working distance);

[0062] 5) Wavelength: 1.1~1.3μm;

[0063] 6) The focusing positions of the two limiting wavelengths differ by 200 μm (i.e., the focusing positions of 1.1 μm and 1.3 μm differ by 200 μm);

[0064] 7) Distortion: ≤0.7%;

[0065] 8) Infinite conjugate telecentric design;

[0066] 9) Thickness compensation design (30mm fused quartz chuck stage + 0.8mm glass or Si substrate).

[0067] In one embodiment, the large field-of-view telescope 17 comprises, from the exit side to the object side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens; wherein the first lens and the second lens are cemented together to form a cemented doublet lens, the third lens and the fourth lens are cemented together to form a cemented doublet lens, and the fifth lens and the sixth lens are cemented together to form a cemented doublet lens.

[0068] Since the infrared camera's field of view cannot cover the large field of view of the object side (11mm), while the 10X system's image side corresponds to 110mm, and the infrared camera's diagonal field of view is only 8mm, the large field of view tube lens 17 in this embodiment adopts a beam-splitting design. That is, two cameras are used to receive two marker images through the tube lens respectively. In addition, different interval marker imaging observations can be achieved by adjusting the interval between the two cameras (adjusting the interval between the two infrared cameras corresponds to different field of view of the object side), which is compatible with the alignment requirements of different types of D2W bonded markers with intervals of 6-11mm.

[0069] In practical implementation, the lens parameters of the wide field-of-view telescope 17 are as follows:

[0070] 1) f = 400mm (focal length f is 400mm, matched with a 40mm objective lens, the magnification is -10X)

[0071] 2) Numerical aperture NA: 0.035;

[0072] 3) Field of view: 110mm (large field of view)

[0073] 4) Wavelength: 1.1~1.3μm

[0074] 5) Distortion: ≤0.05%

[0075] 6) CRA angle ≤ 10° (When the field of view is large, the angle at which the off-axis field of view is incident on the camera is also larger. If this angle is too large, it will reduce the camera's ability to receive light. That is, the center position of the camera with a smaller CRA (Chief Ray Angle) angle has much higher gray level than the edge position with a larger CRA angle. Therefore, it is necessary to control the CRA angle. The CRA angle is the maximum angle between the light ray emitted from the object side of the tube lens and the optical axis.)

[0076] This invention also provides a bonding alignment method for the chip wafer bonding alignment system as described above, comprising:

[0077] Turn on the first and second near-infrared light sources to emit near-infrared wavelengths; after being filtered by the filters at the light outlets of the first and second near-infrared light sources, two narrowband monochromatic lights with different center wavelengths are obtained, and the two monochromatic lights with different wavelengths are connected to the lighting system.

[0078] The two monochromatic illumination beams with different center wavelengths of the illumination system are reflected by a mirror to a beam splitter, so that the two monochromatic illumination beams with different center wavelengths after passing through the beam splitter enter the large field of view near-infrared dispersive microscope objective and simultaneously form focal points on two wafer alignment marks and two chip alignment marks, respectively; after the four focal points form four reflected images, the reflected waves pass through the beam splitter and the large field of view tube lens in sequence, and finally form clear images in the fields of view of the first infrared camera and the second infrared camera, respectively.

[0079] The position coordinates of the four marked points as imaged in the first infrared camera and the second infrared camera are read respectively. Based on the position coordinates, the compensation value of the wafer and the chip is calculated. The position of the chip is adjusted according to the compensation value, and the chip and the wafer are aligned and corrected.

[0080] In a specific implementation, the light outlets of the first near-infrared light source and the second near-infrared light source are respectively provided with multiple filters, and the multiple filters are narrowband filters with adjacent center wavelengths.

[0081] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A chip wafer bonding alignment system, characterized in that, include: A near-infrared light source, comprising a first near-infrared light source and a second near-infrared light source, wherein filters are respectively provided at the light outlets of the first near-infrared light source and the second near-infrared light source; The lighting system has the light output ports of the first near-infrared light source and the second near-infrared light source connected to the lighting system via optical fibers, so that the two beams of narrow-band monochromatic light with different center wavelengths obtained after being filtered by the filter are connected to the lighting system after passing through the optical fibers. A reflector and a beam splitter are provided, the reflector and the beam splitter being arranged in parallel. The reflector is located at the light outlet of the illumination system and is used to reflect two beams of monochromatic illumination light with different center wavelengths to the beam splitter. A large field-of-view near-infrared dispersive microscope objective is provided, which is positioned below the beam splitter so that two beams of monochromatic illumination light with different center wavelengths after passing through the beam splitter enter the large field-of-view near-infrared dispersive microscope objective. A wafer and a chip are positioned on the object side of a large field-of-view near-infrared dispersive microscope objective, with the wafer and chip placed face-to-face. Two wafer alignment marks are provided on the lower surface of the wafer, and two chip alignment marks are provided on the upper surface of the chip. When two monochromatic illumination beams with different center wavelengths enter the large field-of-view near-infrared dispersive microscope objective, they simultaneously form focal points on the two wafer alignment marks and the two chip alignment marks, respectively. A wide-field telescope and an imaging device are arranged sequentially above the beam splitter. The imaging device includes a first infrared camera and a second infrared camera arranged side by side. After the four focal points on the wafer alignment mark and the chip alignment mark form four reflected images, the reflected waves pass through the beam splitter and the wide-field telescope in sequence, and finally form clear images in the fields of view of the first infrared camera and the second infrared camera, respectively.

2. The chip wafer bonding alignment system according to claim 1, characterized in that, The lens parameters of the large field-of-view near-infrared dispersive microscope objective are as follows: 0.001≤Δλ / ΔWD≤0.002; 20nm≤Δλ; 20μm≤ΔWD,WD(λ min )≥35mm; 8≤2y≤11mm; NA ≥ 0.3; Where, λ min λ is the shortest operating wavelength of the large field-of-view near-infrared dispersive microscope objective. max Δλ = λ, where λ is the longest operating wavelength of the large field-of-view near-infrared dispersive microscope objective. max -λ min WD(λ) max ) represents the back intercept corresponding to the longest operating wavelength, WD(λ) min ) represents the back intercept corresponding to the shortest operating wavelength, ΔWD = WD(λ) max )-WD(λ min ), where y is the half field of view and NA is the numerical aperture of the large field of view near-infrared dispersive microscope objective.

3. The chip wafer bonding alignment system according to claim 2, characterized in that, The shortest operating wavelength λ of the large field-of-view near-infrared dispersive microscope objective min The longest operating wavelength λ of the large field-of-view near-infrared dispersive microscope objective is 1100 nm. max The value is 1300nm; 100μm≤ΔWD≤200μm.

4. The chip wafer bonding alignment system according to claim 1, characterized in that, The large field-of-view tube lens has a focal length f = 400 mm, a numerical aperture NA of 0.035, a field of view of 110 mm, and a working wavelength λ of 1.1–1.3 μm. The CRA angle of the large field-of-view tube lens is ≤10°, where the CRA angle is the maximum angle between the light rays emitted from the object side of the tube lens and the optical axis.

5. The chip wafer bonding alignment system according to claim 1, characterized in that, The filter is a narrowband filter with a bandwidth of ±1 to 2 nm.

6. The chip wafer bonding alignment system according to claim 1, characterized in that, The first near-infrared light source and the second near-infrared light source are respectively the first near-infrared light box and the second near-infrared light box, used to emit near-infrared bands.

7. The chip wafer bonding alignment system according to claim 1, characterized in that, The optical fiber is a two-in-one optical fiber, through which two monochromatic beams of different wavelengths are coupled and connected to the lighting system.

8. A bonding alignment method for a chip wafer bonding alignment system as described in any one of claims 1 to 7, characterized in that, include: Turn on the first and second near-infrared light sources so that they emit near-infrared wavelengths respectively; after being filtered by the filters at the light outlets of the first and second near-infrared light sources, two beams of narrow-band monochromatic light with different center wavelengths are obtained, and the two beams of narrow-band monochromatic light with different center wavelengths are connected to the lighting system. The two monochromatic illumination beams with different center wavelengths of the illumination system are reflected by a mirror to a beam splitter, so that the two monochromatic illumination beams with different center wavelengths after passing through the beam splitter enter the large field of view near-infrared dispersive microscope objective and simultaneously form focal points on two wafer alignment marks and two chip alignment marks, respectively; after the four focal points form four reflected images, the reflected waves pass through the beam splitter and the large field of view tube lens in sequence, and finally form clear images in the fields of view of the first infrared camera and the second infrared camera, respectively. The position coordinates of the four markers imaged in the first infrared camera and the second infrared camera are read respectively. Based on the position coordinates, the compensation value of the wafer and the chip is calculated. The position of the chip is adjusted according to the compensation value, and the chip and the wafer are aligned and corrected.

9. The bonding alignment method according to claim 8, characterized in that, The light outlets of the first near-infrared light source and the second near-infrared light source are respectively provided with a plurality of filters, and the plurality of filters are narrowband filters with adjacent center wavelengths.

Images