CN218169060U - Wafer laser bonding-breaking system based on two-dimensional acousto-optic deflector - Google Patents

Abstract

The embodiment of the application discloses a wafer laser de-bonding system based on a two-dimensional acousto-optic deflector. Wherein, this system includes: a shaping module configured to shape the emitted laser beam of a gaussian intensity distribution such that the laser beam, when focused, is capable of producing a square flat-topped focal spot; the beam adjusting module is configured to modulate the shaped laser beam to generate 1 st-order diffracted light, and perform two-dimensional adjustment on the diffraction angle of the 1 st-order diffracted light at a frequency higher than a preset frequency threshold value, so that the 1 st-order diffracted light scans in a two-dimensional plane at a speed higher than a first preset speed threshold value; a field lens configured to focus the 1 st order diffracted light to generate the square flat-topped focal spot for de-bonding the wafer to be de-bonded. The embodiment of the application solves the technical problem of low bonding understanding efficiency.

Description

Wafer laser bonding-breaking system based on two-dimensional acousto-optic deflector

Technical Field

The embodiment of the application relates to the field of chips, in particular to a wafer laser de-bonding system based on a two-dimensional acousto-optic deflector.

Background

With the development requirements of various electronic products on multifunction, low power consumption and long endurance, the wafer-level chip packaging size gradually develops towards the direction of higher density, higher speed, smaller size and lower cost. In order to meet the demand of ultra-thin wafer level packaging chips, wafer temporary bonding and debonding technologies are developed. The traditional thermal slip bonding, chemical bonding, mechanical bonding, infrared laser bonding and other bonding technologies are gradually eliminated due to the defects of low efficiency, high fragment rate, thermal damage and the like, and the traditional thermal slip bonding, chemical bonding, mechanical bonding, infrared laser bonding and other bonding technologies are replaced by ultraviolet laser bonding technologies capable of performing high-speed wafer bonding at room temperature.

Currently, commonly used ultraviolet lasers are excimer lasers and diode-pumped all-solid-state lasers. The output laser is a laser beam with Gaussian intensity distribution, and after being focused, the intensity distribution of transverse focus spots is still Gaussian. When the device is used for wafer laser de-bonding, the central area of a focus light spot is excessively damaged due to overhigh energy; the focal edge region is difficult to use for debonding due to the low energy, resulting in wasted laser energy.

In order to solve the above problems, a method of debonding by using a flat-top nanosecond ultraviolet laser is proposed in the prior art. Compared with Gaussian light under the same condition, the transverse size of the flat-top light spot is 369.5 percent of the original Gaussian light spot (1/e of the normalized intensity of the original Gaussian light beam) ² And e is a natural constant), therefore, the method for wafer laser de-bonding by using the flat-top light can improve the de-bonding efficiency by 269.5 percent. In the prior art, the laser bonding of the wafer is realized by controlling the flat-top light spots to scan point by point in a quick manner through a vibrating mirror. However, the scanning speed must match the focal spot size and the repetition frequency of the laser pulse in this process, and therefore, the lower scanning speed of the galvanometer greatly limits the improvement of the debonding efficiency.

An optical device for laser-photolytic bonding of semiconductor wafers has also been proposed in the prior art. The flat-top light generating module, the shaping module and the imaging module are used for shaping the Gaussian beam into a rectangular beam with the size of 50 mu m multiplied by 1000 mu m to carry out line scanning processing. The method can effectively reduce the cost and improve the flexibility of bonding resolution, however, the bonding resolution efficiency is low because the processing platform is used for scanning relative to the laser spot movement mode.

In view of the above problems, no effective solution has been proposed.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a wafer laser bonding removal system based on a two-dimensional acousto-optic deflector, which at least solves the technical problem of low bonding removal efficiency.

According to an aspect of an embodiment of the present application, there is provided a wafer-laser optical-decomposition-bonding optical system based on a two-dimensional acousto-optic deflector, including: a shaping module configured to shape the emitted laser beam of a gaussian intensity distribution such that the laser beam, when focused, is capable of producing a square flat-topped focal spot; the beam adjusting module is configured to modulate the shaped laser beam to generate 1 st-order diffracted light, and perform two-dimensional adjustment on the diffraction angle of the 1 st-order diffracted light at a frequency higher than a preset frequency threshold value, so that the 1 st-order diffracted light scans in a two-dimensional plane at a speed higher than a first preset speed threshold value; and the field lens is configured to focus the 1 st order diffracted light to generate the square flat-top focal spot, wherein the square flat-top focal spot scans the wafer to be debonded, which is placed on the processing surface, in the processing surface of the wafer at a speed higher than a second preset speed threshold under the action of the two-dimensional adjustment so as to debond the wafer to be debonded.

In one exemplary embodiment, the beam adjustment module includes: a two-dimensional acousto-optic deflector configured to modulate the shaped laser beam to generate the 1 st order diffracted light, the zero order light without modulation, and other unnecessary diffracted lights, and to two-dimensionally adjust a diffraction angle of the 1 st order diffracted light at a frequency higher than a preset frequency threshold; a mirror configured to change a propagation direction of the 1 st order diffracted light generated by the two-dimensional acousto-optic deflector such that the 1 st order diffracted light is reflected into a galvanometer; the galvanometer is configured to adjust the position of the 1 st order diffracted light, so that the square flat-topped focus light spot can be positioned and irradiated on the position of the wafer to be unbonded.

In one exemplary embodiment, the two-dimensional acousto-optic deflector includes: a first acousto-optic deflector provided orthogonally to a direction in which the laser beam is incident, configured to modulate the shaped laser beam to generate the 1 st order diffracted light, and to control the 1 st order diffracted light to scan in a horizontal direction of the processing surface; a half-wave plate configured to adjust the polarization direction of the 1 st order diffracted light output from the first acousto-optic deflector 31; and a second acoustic-optical deflector disposed orthogonal to the first acoustic-optical deflector and configured to control the 1 st order diffracted light whose polarization direction is adjusted to scan in a direction perpendicular to the processing surface.

In an exemplary embodiment, the acousto-optic crystals of the first acousto-optic deflector and the second acousto-optic deflector are fused silica glass, the operating wavelength is in a range from 343nm to 355nm, the bandwidth is in a range from 100MHz to 240MHz, the frequency resolution is greater than or equal to 1kHz, the frequency refresh interval is less than 1 mus, and the window size is greater than 1mm.

In an exemplary embodiment, the system further comprises a beam stop configured to block the unmodulated zero-order light and the other unwanted diffracted light, wherein the beam stop is a water-cooled light barrier.

In an exemplary embodiment, the maximum light-entering aperture of the field lens is greater than or equal to 10mm, the focal length is less than 300mm, the processing breadth is less than 200mm x 200mm, and the maximum light-entering aperture of the galvanometer is greater than or equal to 10mm.

In one exemplary embodiment, the system further comprises: a processing platform configured to hold the wafer to be debonded; and the motion control mechanism is configured to drive the processing platform to move along a preset path relative to the square flat-topped focus light spot, drive the galvanometer to deflect angularly, and drive the acousto-optic deflector to deflect so as to adjust the deflection angle of the 1-order diffracted light beam.

In one exemplary embodiment, the system further comprises a laser configured to emit the laser beam with a gaussian intensity distribution, wherein the gaussian beam has a wavelength in a range of 200nm to 1000nm, a diameter of less than 5mm, a pulse width of less than 50ns, a power of greater than 5W, a pulse repetition frequency in a range of 1Hz to 3.5MHz, a maximum single pulse energy of greater than 0.4mJ, a beam quality factor M ² Less than 1.5.

In an exemplary embodiment, the shaping module is a diffractive optical element configured to change a phase at each point of the laser beam to shape the laser beam.

In an exemplary embodiment, the processing platform has a width of more than 300mm by 300mm.

According to another aspect of the embodiments of the present application, there is also provided a method for wafer-laser optical de-bonding based on a two-dimensional acousto-optic deflector, including: shaping the emitted laser beam with Gaussian intensity distribution so that the laser beam can generate a square flat-top focus spot under the condition of focusing; modulating the shaped laser beam to generate 1 st-order diffracted light, and performing two-dimensional adjustment on the diffraction angle of the 1 st-order diffracted light at a frequency higher than a preset frequency threshold value, so that the 1 st-order diffracted light is scanned in a two-dimensional plane at a speed higher than a first preset speed threshold value; and focusing the 1 st-order diffracted light to generate the square flat-top focal spot, wherein the square flat-top focal spot scans the wafer to be debonded on the processing surface in the processing surface of the wafer at a speed higher than a second preset speed threshold value under the action of the two-dimensional adjustment so as to debond the wafer to be debonded.

In the embodiment of the application, the two-dimensional acousto-optic deflector is used for carrying out two-dimensional adjustment on the diffraction angle of the 1 st order diffraction light at the frequency higher than the preset frequency threshold, so that the 1 st order diffraction light is scanned in a two-dimensional plane at the speed higher than the first preset speed threshold, the technical effect of greatly improving the flexibility of bonding resolution is achieved, and the technical problem of low bonding resolution efficiency is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the embodiments of the application and not to limit the embodiments of the application unduly. In the drawings:

fig. 1 is a schematic structural diagram of a wafer to be debonded according to an embodiment of the present application;

FIG. 2 is a schematic diagram of an optical system for wafer-laser photolytic bonding based on a two-dimensional acousto-optic deflector in accordance with an embodiment of the present application;

FIG. 3 is a schematic diagram of a laser spot sequential scan and a random scan trajectory partial magnification according to an embodiment of the present application;

FIG. 4 is a schematic beam deflection diagram of an acousto-optic deflector according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a two-dimensional acousto-optic deflector regulating and controlling two-dimensional scanning of a square flat-topped light spot under input of ultrasonic waves of different frequencies according to an embodiment of the application;

FIG. 6 is a schematic diagram illustrating an alternative wafer-laser optical de-bonding optical system based on a two-dimensional acousto-optic deflector in accordance with an embodiment of the present application;

FIG. 7 is a circular profile of laser trace composition according to an embodiment of the present application;

fig. 8 is a flowchart of a method for wafer-laser optical de-bonding based on a two-dimensional acousto-optic deflector according to an embodiment of the present application.

In the drawings:

1. a laser; 2. a shaping module; 3. a two-dimensional acousto-optic deflector; 4. a beam termination device; 5. a first reflector; 6. a second reflector; 7. a galvanometer; 8. a field lens; 11. a focusing unit; 10. a processing platform; 9. a wafer to be debonded; 91. a carrier wafer; 92. a release layer; 93. a protective layer; 94. a device wafer; 31. a first acousto-optic deflector; 32. a half-wave plate; 33. and a second acoustic light deflector.

Detailed Description

In order to make the embodiments of the present application better understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments, not all embodiments, of the embodiments of the present application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without any creative effort shall fall within the protection scope of the embodiments in the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of the embodiments of the present application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or otherwise described herein. Moreover, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Example 1

According to the embodiment of the application, an optical system for wafer laser photolysis bonding based on a two-dimensional acousto-optic deflector is provided. The optical system is mainly used for bonding and debonding the wafer to be debonded.

Fig. 1 is a schematic structural diagram of a wafer to be unbonded according to an embodiment of the present application, and as shown in fig. 1, the wafer to be unbonded 9 includes a carrier wafer 91, a release layer 92 applied on the carrier wafer, a protective layer 93 applied on a device wafer, and a device wafer 94.

The carrier wafer 91 is used as a temporary carrier, so that the device wafer 94 is convenient to thin and transport and is transparent to ultraviolet laser; the release layer 92 serves to bond the carrier wafer 91 to the device wafer 94 and has strong absorption properties for the processing laser wavelength, with the thickness being selected to be more than 2 times the penetration depth of the processing laser; the protective layer 93 is used to protect the device wafer 94 from damage to the wafer 94 caused by the laser transmissive release layer 92.

Fig. 2 is a schematic structural diagram of a wafer laser optical de-bonding optical system based on a two-dimensional acousto-optic deflector according to an embodiment of the present application, and as shown in fig. 2, the system includes a laser 1, a shaping module 2, a beam conditioning module, a beam stop device 4, a field lens 8, and a processing platform 10, which are sequentially arranged along an optical path. The beam conditioning module comprises a two-dimensional acousto-optic deflector 3, mirrors, and a galvanometer 7, wherein the mirrors comprise a first mirror 5 and a second mirror 6.

1. Laser device

The laser 1 is used to emit a laser beam with an initial gaussian intensity distribution. In one example, laser 1 is a diode-pumped all-solid-state laser that emits an initial gaussian beam having a wavelength of 355nm and a power greater than 5W. The ultraviolet laser wavelength comprises: 343 nm-355 nm, 308nm, 266nm and 248nm. The uv laser breaks the chemical bonds of the release layer 92 and causes it to lose its adhesion, while the carrier wafer 91 is typically quartz glass, which has a high transmittance for the uv laser and a transmittance that decreases with decreasing laser wavelength, so that a 355nm laser is suitable for debonding.

In one example, the beam quality factor M of the initial Gaussian beam emitted by the laser 1 ² Less than 1.5, so as to ensure that the square flat-topped focus light spot close to the designed value can be generated after passing through the shaping module 2 and being focused by the field lens 8.

In one example, laser 1 is a nanosecond laser with a pulse width of less than 50ns. The nanosecond laser adopts a Q-switching technology, and has the advantages of simple structure and low cost compared with mode-locked lasers such as picoseconds and femtoseconds. The nanosecond laser has the advantage of high peak power compared with microsecond long pulse laser, and the repetition frequency of the nanosecond laser can reach several megahertz, so the nanosecond laser is more suitable for laser de-bonding.

In one example, the power of the laser 1 is greater than 5W, the pulse repetition rate is 1 Hz-3.5 MHz, and the maximum single pulse energy is greater than 0.4mJ. Using a lower single pulse energy can prevent laser energy from damaging device wafer 94 through protective layer 93 during the de-bonding process. The repetition frequency of the laser pulse is in positive correlation with the processing speed, so that the de-bonding efficiency of the laser with high repetition frequency and low single pulse energy is higher.

In one example, the laser 1 emits laser pulses with a polarization direction of horizontal polarization and a beam diameter greater than 1mm to meet the polarization and size requirements of the first acousto-optic deflector 31 for the incident light.

2. Shaping module

The shaping module 2 shapes the laser beam with gaussian intensity distribution emitted by the laser 1, so that the laser beam can generate a square flat-top focus spot under the condition of focusing. For example, the shaping module 2 may cause it to produce a square flat-topped focal spot in the focused case by changing the phase at each point of the laser beam.

In one example, the shaping module 2 is a diffractive optical element that is directed at an ideal gaussian beam, i.e., M ² Designed for =1, therefore M ² The smaller the actual spot result is, the closer to the design value.

The shaping module 2 is used for changing the phase of each point of the laser beam, so that a square flat-top focus spot is formed at the focus plane of the field lens 8 after the laser beam is focused by the field lens 8. Compared with the Gaussian beam with the same single pulse energy, the normalized intensity of the square flat-topped focus spot is reduced to 1/e of the light intensity on the original Gaussian optical axis ² When the size of the square flat-top focus light spot is 369.5% of that of the Gaussian light. During the laser bonding process, the larger the light spot is, the time required for scanning the whole waferThe shorter the time, and therefore, the efficiency of laser debonding using a square flat-topped focal spot was 269.5% higher than gaussian under the same conditions. In the actual bonding process, if circular flat-top light spots are adopted, dead zones inevitably occur, or device wafers are damaged due to excessive laser irradiation because of light spot overlapping, and square flat-top focus light spots can be better used for splicing and avoiding the dead zones, so that the square flat-top light beams are more suitable for laser bonding removal.

3. Light beam adjusting module

The beam adjusting module is used for modulating the 1 st-order diffracted light generated by the shaped laser beam and adjusting the diffraction angle of the 1 st-order diffracted light in two dimensions at a frequency higher than a preset frequency threshold value, so that the 1 st-order diffracted light scans in a two-dimensional plane at a speed higher than a first preset speed threshold value.

The beam conditioning module comprises a two-dimensional acousto-optic deflector 3, a mirror and a galvanometer 7.

The two-dimensional acousto-optic deflector 3 is composed of a first acousto-optic deflector 31 arranged horizontally, a half-wave plate 32 and a second acousto-optic deflector 33 arranged vertically, and is used for ultrafast two-dimensional adjustment of high-speed scanning of 1-order diffracted light in a two-dimensional plane. The first acousto-optic deflector 31 and the second acousto-optic deflector 33 are disposed orthogonally, and the half-wave plate 32 is disposed between the first acousto-optic deflector 31 and the second acousto-optic deflector 33.

The first acousto-optic deflector 31 is used to adjust the 1 st order diffraction light to scan in the horizontal direction, the half-wave plate 32 is used to adjust the polarization direction of the 1 st order diffraction light, and the second acousto-optic deflector 33 is used to adjust the 1 st order diffraction light to scan in the vertical direction.

In one example, the acousto-optic crystals of the first optical deflector 31 and the second optical deflector 33 are fused silica glass, the window size is larger than 1mm, the operating wavelength is 343nm to 355nm, the bandwidth is 100MHz to 240MHz, the frequency resolution is 1kHz, and the frequency refresh interval is less than 1 μ s. With such a structure, the two-dimensional acousto-optic deflector 3 can control the light beam to scan at a frequency exceeding 1MHz, and the scanning frequency of the galvanometer is usually only tens of kilohertz, so in this embodiment, the efficiency of laser de-bonding by using the two-dimensional acousto-optic deflector 3 is much higher than the de-bonding efficiency of the galvanometer.

In the two-dimensional acousto-optic deflector 3, the first acousto-optic deflector 31 and the second acousto-optic deflector 33 are scanned in such a manner as to sequentially scan and randomly scan in one-dimensional direction. The scanning mode of the two-dimensional acousto-optic deflector 3 is sequential scanning and random scanning in a two-dimensional plane, as shown in fig. 3, wherein the solid line of the black bar arrow indicates the scanning track of the laser spot. Fig. 3 (a) is a schematic diagram of laser spot sequential scanning according to an embodiment of the present application, and (b) is a schematic diagram of partial enlargement of a random scanning track. By the mode, the two-dimensional acousto-optic deflector 3 can support the laser facula to carry out random bonding solving operation on any point on the wafer to be subjected to bonding solving, so that the isolated dead zone generated in the bonding solving process on the wafer can be repaired without damage, and the flexibility of laser bonding solving is greatly improved.

Fig. 4 is a schematic diagram illustrating an operation of the acousto-optic deflector according to an embodiment of the present application. An acousto-optic deflector is a beam scanning device based on the acousto-optic effect. The ultrasonic waves are generated in the acousto-optic crystal by inputting an ultrasonic drive signal into the acousto-optic transducer to generate vibrations. Under the action of ultrasonic wave, the periodic distribution phenomenon of refractive index is generated in the acousto-optic crystal, so that a Bragg diffraction grating is formed.

In this embodiment, when laser light is incident at a specific angle, bragg diffraction occurs, and the included angle between the 1 st order diffracted light and the zero order light is θ. Then, the change of the diffraction angle of the 1 st order diffraction light is realized by changing the ultrasonic frequency to change the grating constant, thereby realizing the one-dimensional scanning of the light beam, and the angle scanning range is delta theta.

It is noted that the acousto-optic deflector 3 frequency refresh interval is extremely short, typically less than 1 mus, which means that it can be used for ultra-high frequency beam scanning. In addition, since the ultrasonic drive signal of the acousto-optic deflector can be switched randomly within the bandwidth range thereof, this means that the 1 st order diffracted light of the acousto-optic deflector can realize sequential scanning and random scanning of angles within the scanning angle range thereof.

In the embodiment, two sets of acousto-optic deflectors are orthogonally arranged in series and are controlled in a linkage manner, so that high-speed sequential scanning or random scanning of 1-order diffracted light beams in a two-dimensional plane perpendicular to an optical axis can be realized, wherein the optical axis is defined as the optical axis of 1-order diffracted light of the two-dimensional acousto-optic deflector at a central working frequency.

FIG. 5 shows a schematic diagram of a two-dimensional acousto-optic deflector controlling two-dimensional scanning of a square flat-topped focal spot in a plane, where f _L 、f _C 、f _H Corresponding to the low frequency, center frequency and high frequency ultrasonic signals of the driver of the acousto-optic deflector, respectively. Two-dimensional ultrafast scanning of the light beam can be realized by inputting different driving frequency combinations to two sets of one-dimensional acousto-optic deflectors which are orthogonally arranged, namely the first acousto-optic deflector 31 and the second acousto-optic deflector 33.

The positions of the first acousto-optic deflector 31 and the second acousto-optic deflector 33 can be interchanged, and the two-dimensional adjusting effect of the two-dimensional acousto-optic deflector 3 on the 1 st order diffracted light is not affected by the interchange of the positions of the first acousto-optic deflector 31 and the second acousto-optic deflector 33, however, a half-wave plate needs to be added before the two-dimensional acousto-optic deflector 3, and the half-wave plate is used for adjusting the polarization direction of the laser light shaped by the shaping module 2 so as to meet the polarization requirement of the two-dimensional acousto-optic deflector 3 on the incident light.

The light generated by the laser beam after being modulated and shaped by the two-dimensional acousto-optic deflector 3 comprises non-modulated zero-order light and other unnecessary diffracted light besides the 1 st-order diffracted light, and the zero-order light and other unnecessary diffracted light are shielded by the light beam termination device 4 so as to avoid damaging devices and accidentally injuring operators.

The mirrors include a first mirror 5 and a second mirror 6 for changing the propagation direction of the 1 st order diffracted light output from the two-dimensional acousto-optic deflector 3 so that the 1 st order diffracted light is reflected into the galvanometer 7.

The galvanometer 7 adjusts the position of the 1 st order diffracted light, so that the square flat-topped focus light spot can be positioned and irradiated at the position of the wafer 9 to be unbonded. Thus, the position of the square flat-top focus spot irradiated on the wafer 9 to be debonded can be positioned through the galvanometer 7, and the position adjustment is carried out.

In laser processing using the galvanometer 7, a lower scanning speed (less than 3 m/s) and a higher jump speed (less than 10 m/s) are generally used to shorten the processing time while ensuring the processing accuracy. In the embodiment of the application, the galvanometer 7 does not participate in regulating and controlling laser spot scanning, and is only used for controlling the square flat-top focus spot position, so that the square flat-top focus spot position jumps to different processing breadth units, and the speed and the precision of knowing bonding are improved.

In the embodiment of the application, the acousto-optic deflector is introduced, so that not only can the light beam be scanned at a very high speed, but also the mechanical vibration and acceleration and deceleration are avoided, and the optical path system is more stable, therefore, the bonding resolution system can greatly improve the bonding resolution efficiency and flexibility, and can effectively ensure the bonding resolution quality.

4. Scene lens

The field lens 8 is used to focus the shaped laser beam to produce a square flat-topped focal spot at its focal plane. Specifically, the field lens 8 focuses the 1 st order diffracted light to generate the square flat-top focal spot, wherein the square flat-top focal spot scans the wafer 9 to be unbonded, placed on the processing surface, in the processing surface of the wafer at a speed higher than a second preset speed threshold under the two-dimensional adjustment effect of the two-dimensional acousto-optic deflector 3, so as to debond the wafer 9 to be unbonded. Wherein, the wafer 9 to be debonded is fixed on the processing surface of the processing platform 10.

In one example, the maximum light entrance aperture of the field lens 8 is greater than or equal to 10mm, the focal length is less than 300mm, and the processing width is less than 200mm × 200mm, when the size of the wafer 9 to be debonded is greater than the processing width of the field lens 8, the processing platform 10 needs to be moved for splicing, so the processing platform 10 width should be greater than 300mm × 300mm.

In particular, during application, the laser irradiates the release layer 92 through the carrier wafer 91, and breaks the chemical bond of the release layer 92, so that the adhesive property of the release layer is lost, thereby separating the device wafer 94 from the carrier wafer 91. In the process, the output laser power of the laser needs to be adjusted to ensure that the square flat-top focus spot irradiation area can be rapidly de-bonded, and the energy of the spot is not enough to penetrate through the protective layer 93 and damage the device wafer 94.

The operation flow of the system will be described below.

The wafer 9 to be debonded is placed on the processing side of the processing platform 10 of the optical system. Laser beams with initial Gaussian intensity distribution emitted by a laser 1 are subjected to beam shaping through a shaping module 2, the shaped laser beams are modulated by a two-dimensional acousto-optic deflector 3 to generate 1-level diffraction light capable of scanning at a high speed in a two-dimensional plane, the 1-level diffraction light is guided to enter a vibrating mirror 7 and a field lens 8 by utilizing a first reflecting mirror 5 and a second reflecting mirror 6, square flat-top focus light spots with uniform energy distribution are generated at a focal plane of the field lens 8, the square flat-top focus light spots are irradiated on a wafer 9 to be debonded and break chemical bonds of a release layer 92 of the wafer 9 to be debonded, and the device wafer 94 in an irradiation area is separated from a carrier wafer 91.

In the bonding process, the galvanometer 7 positions the position of the optical spot irradiated on the wafer 9 to be bonded; the two-dimensional acousto-optic deflector 3 carries out ultrafast adjustment on the 1 st order diffracted light, so that the square flat-topped focus light spot is scanned on the wafer 9 to be debonded at a high speed. Due to the limitation of the working bandwidth of the two-dimensional acousto-optic deflector 3, the scanning angle is small, so that the focus spot can only scan in a small square area. If the maximum scanning area is defined as a processing breadth unit, after the processing breadth unit is de-bonded, the galvanometer 7 moves the square flat-top focus light spot to the central position of the next processing breadth unit, and the operations are repeated until the focus light spot traverses the whole wafer 9, so that the separation of the device wafer 94 and the carrier wafer 91 is realized.

The system for high-efficiency wafer laser de-bonding based on the two-dimensional acousto-optic deflector has the following beneficial effects:

1) The square flat-top focus light spot is utilized to avoid the damage of laser to the wafer, and the advantages of no mechanical vibration and no mechanical inertia in the light beam scanning process are regulated and controlled by the two-dimensional acousto-optic deflector, so that the bonding resolution quality is effectively ensured;

2) By utilizing the advantages of sequential scanning and random scanning of the two-dimensional acousto-optic deflector, dead zones can be effectively avoided and repaired, so that the flexibility of bonding understanding is greatly improved;

3) The method can improve the bonding resolution efficiency by about 1 order of magnitude while ensuring the high-quality wafer laser bonding resolution. The wafer de-bonding cost is greatly reduced, the wafer packaging requirement can be better met, and the wafer de-bonding method has very important application value and wide market prospect.

Example 2

According to the embodiment of the present application, a system for wafer laser de-bonding based on a two-dimensional acousto-optic deflector is provided, and the embodiment takes 8-inch wafer laser de-bonding as an example.

As shown in fig. 6, the system includes a laser 1, a shaping module 2, a two-dimensional acousto-optic deflector 3, a beam stop device 4, a galvanometer 7, a focusing unit 11, a processing platform 10 and a motion control mechanism (not shown) arranged in sequence along an optical path.

The laser 1 is used to emit a laser beam with an initial gaussian intensity distribution. In one example, the laser 1 may be a Quasar UV80 laser with a wavelength of 355nm, a laser pulse width of 10ns, a pulse repetition frequency set to 1MHz, and a beam quality factor M ² < 1.3, beam diameter D =3.7mm; the focal length of the field lens 8 is 160mm. Thus, the full width at half maximum diameter of the generated Gaussian spot is about 67.5 μm, so that the Gaussian spot can be shaped into a square flat-top focus spot after shaping, and the side length of the square flat-top focus spot is about 115 μm.

In another example, the laser 1 emits an initial Gaussian beam with a wavelength of 200nm to 1000nm, a pulse width of less than 50ns, a power of greater than 5W, a pulse repetition frequency of 1Hz to 3.5MHz, a maximum single pulse energy of greater than 0.4mJ, and a beam quality factor M ² Less than 1.5, the polarization direction of the beam is perpendicular to the direction of propagation of the beam in the horizontal plane, here the plane perpendicular to the direction of gravity of the earth.

The shaping module 2 is used for changing the phase of each point of the laser beam, so that the laser beam can generate a square flat-top focal spot under the condition of focusing. In one example, the shaping module 2 is a diffractive optical element.

The two-dimensional acousto-optic deflector 3 is a beam scanning device based on the acousto-optic effect. The ultrasonic waves are generated in the acousto-optic crystal by inputting an ultrasonic drive signal into the acousto-optic transducer to generate vibrations. Under the action of ultrasonic wave, the periodic distribution phenomenon of refractive index is generated in the acousto-optic crystal, so that a Bragg diffraction grating is formed. When laser light is incident at a specific angle, bragg diffraction occurs. The grating constant can be changed by changing the ultrasonic frequency, and the diffraction angle of the 1 st order diffraction light can be further changed, so that the light beam scanning is realized. It should be noted that the frequency refresh interval of the two-dimensional acousto-optic deflector 3 is very short, typically less than 1 μ s, so that the two-dimensional acousto-optic deflector 3 can be used for ultra-high frequency beam scanning. Further, since the ultrasonic drive signal of the two-dimensional acousto-optic deflector 3 can be switched randomly within its bandwidth range, the 1 st order diffracted light of the two-dimensional acousto-optic deflector 3 can realize sequential scanning of angles and random scanning within its scanning angle range.

In the present embodiment, the two-dimensional acousto-optic deflector 3 is used for ultrafast two-dimensional adjustment of the 1 st order diffracted light thereof to scan the 1 st order diffracted light in a two-dimensional plane at high speed. In one example, the two-dimensional acousto-optic deflector 3 has a 7mm clear aperture, an operating wavelength of 355nm, an operating frequency of 130MHz to 210MHz, and a frequency resolution of 1kHz. At a center frequency of 170MHz, the deflection angle of 1 st order diffracted light is 10.5mrad, and the maximum scan angle is 4.9mrad. The maximum single breadth of the focus spot scanning regulated by the two-dimensional acousto-optic deflector 3 is about 5.8mm multiplied by 5.8mm.

According to the size of the square flat-top focus light spot, under the condition that the square flat-top focus light spots are not overlapped and are tightly spliced, the single processing breadth of the two-dimensional acousto-optic deflector 3 is divided into 50 multiplied by 50 areas, the line spacing is 115 mu m, namely the single processing breadth unit is 5.75mm multiplied by 5.75mm. In the embodiment, the two-dimensional acousto-optic deflector 3 controls the square flat-top focus light spot to perform uniform scanning at the point spacing of 115 μm and the line spacing of 115 μm and traverse one processing format unit, the total time consumption is 2.5ms, and the corresponding line scanning speed is 115m/s. The scanning speed is much higher than that of any current galvanometer, so that the efficiency of wafer laser de-bonding is greatly improved by using the acousto-optic deflector in the embodiment.

In addition, because the diffraction angle of the two-dimensional acousto-optic deflector 3 is small, the 1 st order diffraction light needs to be completely separated from the zero order light and other unwanted diffraction order light by the light beam termination device 4 after being transmitted for 360 mm. The beam stop means 4 blocks unwanted laser light and thus avoids damaging the device and accidentally injuring the operator.

In the present embodiment, the two-dimensional acousto-optic deflector 3 performs two-dimensional adjustment of the diffraction angle of the 1 st order diffracted light at an ultrahigh frequency, so that the square flat-topped light spot generated by the focusing unit 11 scans in the processing plane at a high speed. Therefore, the whole wafer to be debonded is traversed in a mode of controlling light spot positioning through the galvanometer 7 and controlling light spot scanning through the two-dimensional acousto-optic deflector 3, so that efficient separation of the device wafer and the carrier wafer is achieved, namely wafer laser debonding.

In one example, the two-dimensional acousto-optic deflector 3 includes: a first acousto-optic deflector 31, a half-wave plate 32 and a second acousto-optic deflector 33. The first acousto-optic deflector 31 is placed perpendicular to the laser beam in the horizontal plane; the second acousto-optic deflector 33 is placed perpendicular to the laser beam and the first acousto-optic deflector 31 in the vertical plane; the half-wave plate 32 is used for adjusting the polarization direction of the 1 st order diffracted light modulated by the first acousto-optic deflector; the half-wave plate 32 is arranged on a three-dimensional adjusting frame which can be rotationally adjusted with high precision in a vertical plane; the first acousto-optic deflector 31 and the second acousto-optic deflector 33 are both disposed on a six-dimensional adjustable frame.

In one example, the acousto-optic crystals of the first optical deflector 31 and the second optical deflector 33 are fused silica glass, the operating wavelength is 343nm to 355nm, the bandwidth is 100MHz to 240MHz, the frequency resolution is 1kHz, the frequency refresh interval is less than 1 μ s, and the window size is greater than 1mm; the scanning mode of the 1 st order diffraction light of the first optical deflector and the second optical deflector is sequential scanning and random scanning in the one-dimensional direction; the scanning mode of the 1 st order diffraction light of the two-dimensional acousto-optic deflector is sequential scanning and random scanning in a two-dimensional plane.

The galvanometer 7 is used for positioning the position of the square flat-topped focus light spot acting on the wafer to be debonded. Specifically, the galvanometer 7 positions the position of the square flat-top focus spot irradiated on the wafer to be debonded and performs position adjustment. The laser spot must have a track that covers the entire wafer and therefore can be controlled by the galvanometer 7 to scan the spot along a "zigzag" track, as shown in figure 7. In the bonding process, the galvanometer 7 is only used for regulating and controlling focus spots to different processing format units without participating in scanning, and after the spots traverse one processing format unit at a very high speed under the two-dimensional regulation and control of the two-dimensional acousto-optic deflector, the galvanometer 7 quickly regulates the spots to the next processing format unit. In one example, the maximum entrance aperture of the galvanometer 7 is greater than or equal to 10mm. In one example, the galvanometer 7 is set to a jump speed of 10m/s.

In order to avoid missing edges, the size of the spot scanning pattern is slightly larger than the size of the wafer, for example, for an 8-inch wafer with a diameter of 200mm, the diameter of the scanning pattern is set to 210mm, and the pattern is divided into processing frame units with the size of 5.75mm × 5.75mm, wherein the total number of the processing frame units is 1020. The two-dimensional acousto-optic deflector controls square flat-top focus spots to scan by taking 115 mu m as a spot distance and taking 115 mu m as a line distance, and after the spots traverse the unit, the galvanometer 7 adjusts the spots to jump to the next processing breadth unit area. And repeating the operation until the wafer bonding-releasing operation is stopped after the light spots traverse all the areas on the wafer to be bonded.

The focusing unit 11 serves to focus the incident laser beam. In one example, the focusing unit 11 is a field lens, the maximum light entrance aperture of the field lens is greater than or equal to 10mm, the focal length is less than 300mm, and the processing format is less than 200mm × 200mm.

Through the focusing unit 11, the initial gaussian beam emitted by the laser 1 passes through the shaping module 2 and then is focused by the field lens, and a square flat-top light spot with uniform energy distribution is generated at the focal plane of the field lens, wherein the side length of the square flat-top light spot is 50 micrometers-1 mm.

In one example, the system may further include a motion control mechanism for driving the processing stage 10 to move along a predetermined path with respect to the spot, driving the galvanometer 7 to perform angular deflection, driving the acousto-optic deflector to perform angular deflection to adjust a deflection angle of the 1 st order diffracted light, and the like.

The specific operation flow of the system of the embodiment is as follows: the initial Gaussian beam emitted by the laser 1 is subjected to beam shaping through the shaping module 2, the shaped beam is modulated by the two-dimensional acousto-optic deflector to generate 1-order diffraction light, unmodulated zero-order light and other unnecessary diffraction light, the zero-order light and the other unnecessary diffraction light are collected by the beam termination device 4, the 1-order diffraction light is reflected by the reflector and enters the vibrating mirror 7 and the field lens 8, the 1-order diffraction light is focused by the field lens to generate square flat-top light spots with uniform energy distribution on a focal plane of the field lens, and the square flat-top light spots act on a wafer to be debonded and arranged on a processing plane.

In the present embodiment, during the wafer debonding process, the galvanometer 7 controls the beam jump distance to be about 6.1m, which takes 0.61s, and the two-dimensional acousto-optic deflector controls the square flat-top focal spot to scan 1020 square grid areas, which takes about 2.55s. That is, the debonding time for the entire 8 inch wafer is about 3.2s. Compared with other bonding solving methods under the same condition, the wafer laser bonding solving system utilizing the two-dimensional acousto-optic deflector can improve the bonding solving efficiency by about one order of magnitude, so that the time cost of bonding solving is reduced undoubtedly, and the wafer laser bonding solving system has very important application value. In addition, it should be noted that, in the embodiment, under the condition of a higher laser power, the number of scanning times required by the focal spot to traverse the wafer to be debonded may be reduced by designing and replacing the combination of the shaping module 2 and the field lens 8, which is capable of generating a larger-size square flat-topped focal spot, so as to further improve the debonding efficiency of the wafer.

Example 3

According to an embodiment of the present application, there is provided a wafer laser debonding method based on a two-dimensional acousto-optic deflector, as shown in fig. 8, the method includes:

step S802, shaping the emitted laser beam with Gaussian intensity distribution, so that the laser beam can generate a square flat-top focus spot under the condition of focusing.

Step S804, modulating the shaped laser beam to generate 1 st-order diffracted light, and performing two-dimensional adjustment on the diffraction angle of the 1 st-order diffracted light at a frequency higher than a preset frequency threshold, so that the 1 st-order diffracted light is scanned in a two-dimensional plane at a speed higher than a first preset speed threshold.

Step S806, focusing the 1 st order diffracted light to generate the square flat-top focal spot, wherein the square flat-top focal spot scans the wafer to be debonded, placed on the processing surface, in the processing surface of the wafer at a speed higher than a second preset speed threshold under the action of the two-dimensional adjustment, so as to debond the wafer to be debonded.

The method in this embodiment can implement all the functions of the systems in embodiments 1 and 2, and therefore, the description thereof is omitted here.

The embodiment of the present application may also be configured as shown in fig. 2:

1. a wafer laser photolysis bonding optical system based on a two-dimensional acousto-optic deflector comprises the following components which are sequentially arranged along an optical path: a shaping module 2 configured to shape the emitted laser beam of gaussian intensity distribution such that the laser beam, when focused, is capable of producing a square flat-topped focal spot; the beam adjusting module is configured to modulate the shaped laser beam to generate 1 st-order diffraction light and perform two-dimensional adjustment on the diffraction angle of the 1 st-order diffraction light at a frequency higher than a preset frequency threshold value, so that the 1 st-order diffraction light scans in a two-dimensional plane at a speed higher than a first preset speed threshold value; and the field lens 8 is configured to focus the 1 st order diffracted light to generate the square flat-top focal spot, wherein the square flat-top focal spot scans the wafer to be debonded 9 placed on the processing surface of the wafer in the processing surface of the wafer at a speed higher than a second preset speed threshold under the action of the two-dimensional adjustment so as to debond the wafer to be debonded 9.

2. The system of item 1, wherein the beam adjustment module comprises: a two-dimensional acousto-optic deflector 3 configured to modulate the shaped laser beam to generate the 1 st order diffracted light, the non-modulated zero order light and other unnecessary diffracted lights, and two-dimensionally adjust a diffraction angle of the 1 st order diffracted light at a frequency higher than a preset frequency threshold; a mirror configured to change a propagation direction of the 1 st order diffracted light generated by the two-dimensional acousto-optic deflector 3 such that the 1 st order diffracted light is reflected into a galvanometer 7; the galvanometer 7 is configured to adjust the position of the 1 st order diffracted light, so that the square flat-topped focus light spot can be positioned and irradiated on the position of the wafer 9 to be debonded.

3. The system according to item 2, wherein the two-dimensional acousto-optic deflector 3 comprises: a first acousto-optic deflector 31 provided orthogonally to a direction in which the laser beam is incident, configured to modulate the shaped laser beam to generate the 1 st order diffracted light, and to control the 1 st order diffracted light to scan in a horizontal direction of the processing surface; a half-wave plate 32 configured to adjust the polarization direction of the 1 st order diffracted light output from the first acousto-optic deflector 31; and a second acousto-optic deflector 33 disposed orthogonal to the first acousto-optic deflector 31 and configured to control the 1 st order diffracted light whose polarization direction is adjusted to scan in a direction perpendicular to the processing surface.

4. The system according to item 3, wherein the acousto-optic crystals of the first and second acousto- optic deflectors 31 and 33 are both fused silica glass, the operating wavelength is in the range of 343nm to 355nm, the bandwidth is in the range of 100MHz to 240MHz, the frequency resolution is greater than or equal to 1kHz, the frequency refresh interval is less than 1 μ s, and the window size is greater than 1mm.

5. The system according to item 2, wherein the system further comprises a beam stop 4 configured to block the unmodulated zero-order light and the other unwanted diffracted light, wherein the beam stop 4 is a light barrier with water cooling.

6. The system according to item 2, wherein the galvanometer 7 is further configured to adjust and control the square flat-top focal spot to different processing format units by adjusting the position of the 1 st order diffracted light, so that the square flat-top focal spot is irradiated to a next processing format unit after traversing one processing format unit at a preset speed under the two-dimensional adjustment and control of the two-dimensional acousto-optic deflector 3, wherein the processing format unit is a unit obtained by dividing the surface of the wafer 9 to be debonded, which is to be irradiated by the square flat-top focal spot.

7. The system of item 6, wherein the galvanometer 7 is further configured to control a square flat-topped focal spot to scan the wafer 9 to be debonded along a "zigzag" trajectory.

8. The system of item 7, wherein a maximum entrance aperture of the galvanometer is greater than or equal to 10mm.

9. The system according to item 2, wherein the maximum light entrance aperture of the field lens is greater than or equal to 10mm, the focal length is less than 300mm, the processing breadth is less than 200mm x 200mm, and the maximum light entrance aperture of the galvanometer 7 is greater than or equal to 10mm.

10. The system of item 2, wherein the system further comprises: a processing platform configured to hold the wafer 9 to be debonded; and the motion control mechanism is configured to drive the processing platform to move along a preset path relative to the square flat-topped focus spot, drive the galvanometer 7 to deflect angularly, and drive the acousto-optic deflector 3 to deflect so as to adjust the deflection angle of the 1-order diffracted beam.

11. The system of any of items 1 to 10, wherein the system further comprises a laser configured to emit the laser beam with a gaussian-shaped intensity distribution, wherein the gaussian beam has a wavelength in the range of 200nm to 1000nm, a diameter of less than 5mm, a pulse width of less than 50ns, a power of greater than 5W, a pulse repetition frequency in the range of 1Hz to 3.5MHz, a maximum single pulse energy of greater than 0.4mJ, a beam quality factor M ² Less than 1.5.

12. The system according to any one of items 1 to 10, wherein the shaping module 2 is a diffractive optical element configured to change the phase at the laser beam point to shape the laser beam.

13. The system of any of claims 1 to 10, wherein the processing platform has a width greater than 300mm x 300mm.

14. The system according to any one of items 2 to 10, wherein the scanning mode of the 1 st order diffracted light of the two-dimensional acousto-optic deflector is sequential scanning or random scanning in a two-dimensional plane.

15. A wafer laser photolysis bonding method based on a two-dimensional acousto-optic deflector comprises the following steps: shaping the emitted laser beam with Gaussian intensity distribution so that the laser beam can generate a square flat-top focus spot under the condition of focusing; modulating the shaped laser beam to generate 1 st-order diffraction light, and performing two-dimensional adjustment on the diffraction angle of the 1 st-order diffraction light at a frequency higher than a preset frequency threshold value, so that the 1 st-order diffraction light scans in a two-dimensional plane at a speed higher than a first preset speed threshold value; and focusing the 1 st-order diffracted light to generate the square flat-top focal spot, wherein the square flat-top focal spot scans the wafer to be debonded on the processing surface in the processing surface of the wafer at a speed higher than a second preset speed threshold value under the action of the two-dimensional adjustment so as to debond the wafer to be debonded.

It should be noted that, for simplicity of description, the foregoing method embodiments are described as a series of acts or combination of acts, but those skilled in the art will recognize that the present embodiment is not limited by the described order of acts, as some steps may occur in other orders or concurrently depending on the embodiment. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and modules referred to are not necessarily required for the embodiments of the application.

Through the above description of the embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but the former is a better implementation mode in many cases. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially or partially embodied in the form of a software product, where the computer software product is stored in a storage medium (e.g., ROM/RAM, magnetic disk, optical disk), and includes several instructions for enabling a terminal device (which may be a mobile phone, a computer, a server, or a network device) to execute the methods described in the embodiments of the present application.

The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.

The integrated unit in the above embodiments, if implemented in the form of a software functional unit and sold or used as a separate product, may be stored in the above computer-readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially implemented or make a contribution to the prior art, or all or part of the technical solutions may be implemented in the form of a software product stored in a storage medium, and including several instructions for causing one or more computer devices (which may be personal computers, servers, or network devices, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application.

In the foregoing embodiments of the present application, descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

In the several embodiments provided in the present application, it should be understood that the disclosed client may be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units is only one type of division of logical functions, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, units or modules, and may be in an electrical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit may be implemented in the form of hardware, or may also be implemented in the form of a software functional unit.

The foregoing is merely a preferred embodiment of the embodiments of the present application, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the embodiments of the present application, and such improvements and modifications should also be considered as the protection scope of the embodiments of the present application.

Claims (10)

1. A wafer laser bonding-removing system based on a two-dimensional acousto-optic deflector is characterized by comprising the following components which are sequentially arranged along an optical path:

a shaping module (2) configured to shape the emitted laser beam of a gaussian intensity distribution such that the laser beam, when focused, is capable of producing a square flat-topped focal spot;

the beam adjusting module is configured to modulate the shaped laser beam to generate 1 st-order diffracted light, and perform two-dimensional adjustment on the diffraction angle of the 1 st-order diffracted light at a frequency higher than a preset frequency threshold value, so that the 1 st-order diffracted light scans in a two-dimensional plane at a speed higher than a first preset speed threshold value;

a field lens (8) configured to focus the 1 st order diffracted light to generate the square flat-top focal spot, wherein the square flat-top focal spot scans the wafer (9) to be debonded, which is placed on the processing surface, in the processing surface of the wafer at a speed higher than a second preset speed threshold under the two-dimensional adjustment, so as to debond the wafer (9) to be debonded.

2. The system of claim 1, wherein the beam conditioning module comprises:

a two-dimensional acousto-optic deflector (3) configured to modulate the shaped laser beam to generate the 1 st order diffracted light and the non-modulated zero order light and other unnecessary diffracted light, and to two-dimensionally adjust the diffraction angle of the 1 st order diffracted light at a frequency higher than a preset frequency threshold;

a mirror configured to change a propagation direction of the 1 st order diffracted light generated by the two-dimensional acousto-optic deflector (3) such that the 1 st order diffracted light is reflected into a galvanometer (7);

the galvanometer (7) is configured to adjust the position of the 1 st order diffracted light, so that the square flat-topped focus light spot can be positioned and irradiated on the position of the wafer (9) to be unbonded.

3. The system according to claim 2, wherein the two-dimensional acousto-optic deflector (3) comprises:

a first acousto-optic deflector (31) disposed orthogonally to the direction in which the laser beam is incident, configured to modulate the shaped laser beam to generate the 1 st order diffracted light, and to control the 1 st order diffracted light to scan in the horizontal direction of the processing surface;

a half-wave plate (32) configured to adjust the polarization direction of the 1 st order diffracted light output from the first acousto-optic deflector 31;

and a second acousto-optic deflector (33) disposed orthogonal to the first acousto-optic deflector (31) and configured to control the 1 st order diffracted light whose polarization direction is adjusted to scan in a direction perpendicular to the machining surface.

4. The system according to claim 3, wherein the acousto-optic crystals of the first acousto-optic deflector (31) and the second acousto-optic deflector (33) are fused silica glass, the operating wavelength is in the range of 343nm to 355nm, the bandwidth is in the range of 100MHz to 240MHz, the frequency resolution is greater than or equal to 1kHz, the frequency refresh interval is less than 1 μ s, and the window size is greater than 1mm.

5. The system according to claim 2, further comprising a beam stop (4) configured to block the unmodulated zero-order light and the other unwanted diffracted light, wherein the beam stop (4) is a water-cooled light barrier.

6. The system according to claim 2, wherein the galvanometer (7) is further configured to adjust the position of the 1 st order diffracted light to adjust the square flat-top focal spot to different processing format units, so that the square flat-top focal spot is irradiated to a next processing format unit after traversing one processing format unit at a preset speed under the two-dimensional adjustment of the two-dimensional acousto-optic deflector (3), wherein the processing format unit is a unit obtained after dividing the surface of the wafer (9) to be debonded, which is irradiated by the square flat-top focal spot.

7. The system according to claim 6, wherein the galvanometer (7) is further configured to control a square flat-topped focal spot to scan the wafer (9) to be debonded along a "zigzag" trajectory.

8. The system of claim 2, further comprising:

a processing platform configured to hold the wafer (9) to be debonded;

and the motion control mechanism is configured to drive the processing platform to move along a preset path relative to the square flat-topped focus spot, drive the galvanometer (7) to deflect angularly, and drive the acousto-optic deflector (3) to deflect so as to adjust the deflection angle of the 1-order diffracted beam.

9. The system of any one of claims 1 to 8, further comprising a laser configured to emit the laser beam with a gaussian intensity distribution, wherein the laser beam has a wavelength in a range of 200nm to 1000nm, a diameter of less than 5mm, a pulse width of less than 50ns, a power of greater than 5W, a pulse repetition frequency in a range of 1Hz to 3.5MHz, a maximum single pulse energy of greater than 0.4mJ, a beam quality factor M ² Less than 1.5.

10. The system according to any one of claims 2 to 8, wherein the two-dimensional acousto-optic deflector scans the 1 st order diffracted light in a two-dimensional plane sequentially or randomly.

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