Wafer Laser Modification Structure, Method and System

Abstract

This invention discloses a wafer laser modification structure, method, and system. Multi-layer modification is performed inside the wafer sample, forming a repeating structure of multiple wafer modification layers and multiple first blank layers. The range of the laser heat-affected zone (HAZ) of the wafer modification layers is controlled, reducing the overlap of HAZ regions between adjacent wafer modification layers. This ensures that thermal cracks generated by the wafer modification layers are locally confined within the first blank layer, reducing the potential for hidden damage areas within the material and the uncontrolled propagation of cracks due to nearby heat sources. It avoids problems such as reduced bending strength and edge chipping caused by longitudinal-lateral thermal crack propagation. This approach ensures both the hidden modification properties and the appearance and physicochemical properties, significantly improving sample strength and thus enhancing sample appearance quality and processing accuracy.

Description

Technical Field

[0001] This invention relates to the field of laser processing imaging, and more particularly to a wafer laser modification structure, method, and system. Background Technology

[0002] As technology advances, the microstructures on wafers become more precise and complex, the size of individual chips becomes smaller and smaller, and the requirements for dimensional accuracy become higher. Consequently, the requirements for processing methods and processing quality also become more stringent.

[0003] In traditional wafer dicing processes, dicing wheels are typically used for cutting. However, due to the high hardness of wafer materials and the need to consider product appearance, relatively expensive diamond materials are required for the dicing wheels. Furthermore, the dicing blades directly act on the wafer samples, significantly reducing the lifespan of the dicing wheel consumables. Because wafer materials have high mechanical strength, the cost of dicing wheel consumables is even higher, and the cutting efficiency is extremely low. At the same time, dicing wheel cutting generates a large amount of dust and heat during the production process, requiring a large amount of deionized water, which increases production costs.

[0004] Due to its excellent directionality, collimation, focusing, ultra-short pulses, and ultra-high frequencies, laser processing has become the mainstream of ultra-precision machining technology and advanced manufacturing. However, the expansion of the resolidified layer and heat-affected zone causes problems such as cracks and edge chipping, affecting the final processing quality. Laser refining involves focusing a laser beam, which has a transparent effect on the material, into the material through optical elements such as lenses. Through the relative movement between the sample and the laser, an internal refining layer is generated. This refining layer consists of a high-density dislocation layer, cracks, and pulse holes. Ultimately, under external force, stress propagation leads to sample separation. Crack formation is essential for laser refining, but uncertain and uncontrolled crack propagation significantly affects processing quality and accuracy. Under applied external force, the formed thermal cracks will further propagate uncontrollably, affecting the bending strength of the sample. Summary of the Invention

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a wafer laser modification structure, method, and system. By controlling the laser parameters, multi-layer modification is performed inside the material to form a multi-layered repeating structure of multiple modified layers and multiple blank layers. This reduces the possibility of crack elongation caused by the influence of nearby heat sources, which could lead to uncontrolled propagation, thereby improving the appearance quality and processing accuracy of the sample.

[0006] This invention provides a wafer laser-modified structure, comprising a wafer sample, wherein the upper surface of the wafer sample is covered with an imaging adhesive layer, the imaging adhesive layer serving as a carrier for optical imaging, and the wafer laser-modified structure further comprising:

[0007] Multiple wafer modification layers are arranged in parallel along the vertical direction of the wafer sample, and a first blank layer is provided between two adjacent wafer modification layers;

[0008] An imaging resist modifier layer is disposed within the imaging resist layer, parallel to the wafer modifier layer;

[0009] The thickness of the wafer modification layer is greater than the thickness of the first blank layer.

[0010] The above-mentioned technical solutions also include:

[0011] Two third blanking layers are respectively disposed on the upper and lower sides of the imaging adhesive modifier layer.

[0012] The above-mentioned technical solutions also include:

[0013] The second blank layer is disposed between the wafer modification layer and the imaging adhesive layer;

[0014] A fourth blank layer is disposed between the lower surface of the wafer sample and the wafer modification layer.

[0015] In any of the above technical solutions, the wafer modification layer includes high-density dislocation regions, pulse holes, and thermal cracks.

[0016] In any of the above technical solutions, the longitudinal length of the hot crack is 0 to 15 μm.

[0017] In any of the above technical solutions, the wafer sample has a size of 4 to 12 inches and a thickness of 0.2 to 2.4 mm.

[0018] In any of the above technical solutions, any two of the wafer modification layers are of equal size, the thickness of the wafer modification layer is 40-100μm, and the thickness of the first blank layer is 20-30μm.

[0019] According to one aspect of the present invention, a wafer laser enhancement method is provided, comprising:

[0020] Step S10: Load the wafer sample onto a tape with an expansion ring and place it on a vacuum adsorption stage;

[0021] Step S20: When forming each wafer modification layer, control the relative movement between the vacuum adsorption stage and the laser, and adjust the position of the laser focus in the vertical direction multiple times through the optical lens to form multiple wafer modification layers and imaging adhesive modification layers.

[0022] Step S30: Adjust the horizontal position of the laser focus according to the required wafer size, and repeat step S20.

[0023] Step S40: After rotating the vacuum adsorption stage by 90°, repeat steps S20 and S30.

[0024] Step S50: Apply mechanical force to the wafer sample to separate and obtain the wafer.

[0025] In any of the above technical solutions, before step S20, a vision camera is used to align the sample along a predetermined modification position and a predetermined direction, and the laser focus position is adjusted to focus on the upper surface of the wafer sample.

[0026] In any of the above technical solutions, in step S20, the thickness of the multilayer wafer modification layer, the thickness of the imaging adhesive modification layer, the thickness of the first blanking layer between adjacent wafer modification layers, the thickness of the third blanking layer on the upper and lower sides of the imaging adhesive modification layer, and the thickness of the fourth blanking layer between the lower surface of the wafer sample and the wafer modification layer are controlled by controlling the moving speed of the vacuum adsorption stage, the laser power, and the focusing depth.

[0027] In any of the above technical solutions, the vacuum adsorption stage moving speed of the laser-treated wafer sample is 400-600 mm / s;

[0028] The laser-assisted imaging adhesive layer is mounted on a vacuum adsorption stage at a speed of 100-200 mm / s.

[0029] In any of the above technical solutions, the laser focusing depth is -500 to 30 μm, and the laser repetition frequency is 50 to 150 kHz.

[0030] In any of the above technical solutions, the power of the laser applied to the wafer sample is 1.5-4W;

[0031] The laser-assisted imaging adhesive layer has a power of 0.8-1.5W.

[0032] In any of the above technical solutions, the laser is an ultrashort pulse laser beam, using an infrared laser with a pulse width of 15ps to 500fs and a wavelength of 1064nm.

[0033] According to one aspect of the present invention, a wafer laser refining system is provided, comprising:

[0034] A multi-axis work platform, wherein the work platform is equipped with a vacuum adsorption stage on which a wafer sample with a steel ring is loaded;

[0035] A laser system outputs laser light and adjusts the position of its laser focus in the longitudinal direction of the Z-axis through an optical lens, and finally transmits it to the wafer sample and incident from the upper surface of the wafer sample.

[0036] A wafer dicing apparatus, mainly consisting of a backing plate and an external mechanical force, is used to apply mechanical force to the wafer sample along the wafer processing trajectory, causing the brittle material to fracture with high quality and separating it into wafers.

[0037] The main control unit stores a computer program that can be executed to implement the steps of the method as described in any of the above technical solutions, in order to control one or more of the working platform, laser, and dicing device to operate.

[0038] This invention discloses a wafer laser modification structure, method, and system. It involves multi-layer modification within a wafer sample, forming a repeating structure of multiple wafer modification layers and multiple first blank layers. By controlling the laser heat-affected zone (HAZ) of the wafer modification layers, the superposition of HAZ regions between adjacent wafer modification layers is reduced. This ensures that thermal cracks generated by the wafer modification layers are locally confined within the first blank layer, reducing the potential for hidden damage areas within the material and the uncontrolled propagation of cracks due to nearby heat sources. It also avoids problems such as reduced bending strength and edge chipping caused by longitudinal-lateral thermal crack propagation. This approach ensures both the hidden modification properties and the appearance and physicochemical properties, significantly improving sample strength and thus enhancing sample appearance quality and processing accuracy.

[0039] The use of cutting wheels, which eliminates the need for traditional cutting processes, reduces the consumption of cutting wheels and eliminates the need for large amounts of deionized water, thereby lowering production costs. It also avoids dust generated during the production process, ensuring product cleanliness and improving the working environment for operators. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic cross-sectional view of a wafer laser-modified structure according to one embodiment of the present invention;

[0042] Figure 2 A schematic cross-sectional view of a wafer laser-modified structure illustrating another embodiment of the present invention;

[0043] Figure 3 This schematic diagram illustrates the connection structure of a wafer laser-modified structure processing fixture according to one embodiment of the present invention.

[0044] Figure 4 A schematic diagram of a conventional laser-modified cross-section;

[0045] Figure 5 This schematic diagram illustrates the composition of a single-layer wafer laser modification structure according to one embodiment of the present invention.

[0046] Figure 6 A flowchart illustrating a wafer laser enhancement method according to one embodiment of the present invention;

[0047] Figure 7 This schematic diagram illustrates the structure of a wafer laser refining system according to one embodiment of the present invention.

[0048] Figure 8 This diagram illustrates the operation of a wafer laser refining system wafer stacking device according to one embodiment of the present invention.

[0049] Figure label:

[0050] 10. Wafer sample; 11. Wafer modification layer; 12. First blanking layer; 13. Second blanking layer; 14. Fourth blanking layer; 20. Imaging adhesive layer; 21. Imaging adhesive modification layer; 22. Third blanking layer; 30. Die-expanding ring; 40. Adhesive tape; 50. Wafer; 60. Focal point; 61. Laser system; 62. Optical lens; 63. Wafer sample to be processed; 64. Vacuum adsorption device; 65. Multi-axis processing platform; 70. Backing plate; 111. High-density dislocation region; 112. Pulse hole; 113. Hot crack. Detailed Implementation

[0051] The description of the embodiments in this specification should be taken in conjunction with the accompanying drawings, which should form part of the complete specification. In the drawings, the shape or thickness of the embodiments may be exaggerated and may be indicated in a simplified or convenient manner. Furthermore, parts of the various structures in the drawings will be described separately; it is worth noting that elements not shown in the figures or not described in words are in a form known to those skilled in the art.

[0052] The descriptions of the embodiments herein, including any references to directions and orientations, are for ease of description only and should not be construed as limiting the scope of the invention. The following description of preferred embodiments involves combinations of features, which may exist independently or in combination; the invention is not particularly limited to the preferred embodiments. The scope of the invention is defined by the claims.

[0053] like Figures 1 to 5 As shown, a wafer laser-modified structure of the present invention includes a wafer sample 10, the upper surface of which is covered with an imaging adhesive layer 20, and further includes:

[0054] Multiple wafer modification layers 11 are arranged in parallel along the vertical direction of the wafer sample 10, and a first blank layer 12 is provided between two adjacent wafer modification layers 11;

[0055] The imaging adhesive modifier layer 21 is disposed parallel to the wafer modifier layer 11 within the imaging adhesive layer 20;

[0056] The thickness of the wafer modification layer 11 is greater than the thickness of the first blank layer 12.

[0057] In this embodiment, multi-layer modification is performed inside the wafer sample 10 to form a repeating structure of multiple wafer modification layers 11 and multiple first blank layers 12. The range of the laser heat-affected zone of the wafer modification layer 11 is controlled, and the mutual superposition of heat-affected zones between adjacent wafer modification layers 11 is reduced. This ensures that the thermal cracks 113 generated by the wafer modification layer 11 are locally confined within the first blank layer 12, reducing the possibility of hidden damage areas inside the material and uncontrolled expansion of cracks caused by nearby heat sources. It also avoids problems such as reduced bending strength and edge chipping caused by the longitudinal-lateral expansion of thermal cracks 113. This ensures both the modification properties of the hidden layer and the appearance and physicochemical properties, significantly improving the sample strength and thus enhancing the sample's appearance quality and processing accuracy.

[0058] Secondly, the elimination of traditional cutting wheel technology reduces the need for cutting wheel consumables and large amounts of deionized water, thereby lowering production costs. It also avoids dust generated during production, ensuring product cleanliness and improving the working environment for operators.

[0059] Specifically, the ultrashort pulse laser beam is focused into a high-energy laser focal spot using a focusing lens 62 and incident on a specific location within the wafer sample 10 to be processed. When the energy density of the ultrashort pulse laser focal spot is greater than the threshold modification energy value of the material, melting, evaporation, and plasma impact occur in a specific region of the material, causing the processed material to form a modified layer along a specific direction inside and subsequently generating thermal cracks 113.

[0060] Furthermore, based on ensuring the number and vertical width of the wafer modification layer 11 and the first blank layer 12, by adjusting control parameters such as laser focusing depth, pulse output power, and stage moving speed, the thermal cracks 113 generated by the wafer modification layer 11 are controlled to terminate within the first blank layer 12 between adjacent wafer modification layers 11. This restricts the thermal cracks 113 from crossing the corresponding first blank layer 12 and overlapping with the heat-affected zone of the next modification layer, thereby controlling the vertical propagation length of the thermal cracks 113; and controlling the spacing between modification channels of different depths and the crack propagation length.

[0061] The imaging adhesive layer 20 is a polymer material that serves as a carrier for optical imaging and is an integral part of the micro / nano device. This imaging adhesive layer is often composed of thermosetting or photosetting polymers such as organosilicon hybrids or fluoropolymers. Using nanoimprint lithography, the pattern on the photomask can be transferred onto this photoresist, creating various high-resolution gratings and microlens arrays with micro / nano scales and structures. Through relevant processes, a carrier that meets the designed imaging effect can be prepared, such as epoxy acrylic or polyurethane.

[0062] Typically, the maximum thickness of the imaging adhesive layer is 0.15 mm. It is nearly transparent to visible light in the wavelength range of 400-760 nm. When coupled to the wafer substrate, the overall transmittance is >90%, and the imaging adhesive layer has no yellowing (yellowing refers to the yellowing of the surface appearance caused by the aging of polymer materials), with a yellowing index of less than 0.5. At the same time, the overall thickness fluctuation (TVV) of the imaging adhesive layer is less than 20 μm, the roughness fluctuation (Ra) is less than 5 nm, the Young's modulus is greater than 1000 MPa, the tensile strength is less than 50 MPa, and the Shore hardness is 60-100.

[0063] In addition, after the modification is completed, the wafer sample 10 is subjected to external mechanical force at a predetermined position and in a predetermined direction, causing the material to fracture brittlely and separate into single samples.

[0064] In one embodiment of the present invention, preferably, it further includes:

[0065] Two third blanking layers 22 are respectively set on the upper and lower sides of the imaging adhesive modification layer 21.

[0066] In one embodiment of the present invention, preferably, it further includes:

[0067] The wafer sample 10 is also provided with a second blank layer 13, which is disposed between the wafer modification layer 11 and the imaging adhesive layer 20;

[0068] The fourth blank layer 14 is disposed between the lower surface of the wafer sample 10 and the wafer modification layer 11.

[0069] In this embodiment, when the wafer sample 10 is modified, the wafer sample 10 is placed on a stage. The surface of the wafer sample 10 that contacts the stage is the lower surface of the wafer sample 10. Conversely, the surface of the wafer sample 10 that contacts the imaging adhesive layer 20 is the upper surface of the wafer sample 10. The multilayer wafer modification layer 11 is arranged parallel to the wafer sample 10 in the vertical direction. A fourth blanking layer 14 is provided between the lower surface of the wafer sample 10 and the wafer modification layer 11, that is, the wafer modification layer 11 is not on the lower surface of the wafer sample 10.

[0070] In one embodiment of the present invention, preferably, the wafer modification layer 11 includes a high-density dislocation region 111, a pulse hole 112, and a thermal crack 113.

[0071] In one embodiment of the present invention, preferably, the longitudinal length of the hot crack 113 is 0 to 15 μm.

[0072] In one embodiment of the present invention, preferably, the wafer sample 10 has a size of 4 to 12 inches and a thickness of 0.2 to 2.4 mm.

[0073] In one embodiment of the present invention, preferably, any two wafer modification layers 11 are of equal size, the thickness of the wafer modification layer 11 is 40-100μm, and the thickness of the first blank layer 12 is 20-30μm.

[0074] like Figure 6 As shown, according to one aspect of the present invention, a wafer laser refining method is provided, comprising:

[0075] Step S10: Load the wafer sample 10 onto the tape 40 with the die expansion ring 30 and place it on the vacuum adsorption stage.

[0076] Step S20: When forming each wafer modification layer, control the relative movement between the vacuum adsorption stage and the laser, and adjust the position of the laser focus in the vertical direction multiple times through the optical lens 62 to form a multilayer wafer modification layer 11 and an imaging adhesive modification layer 21.

[0077] Step S30: Adjust the horizontal position of the laser focus according to the required wafer size 50, and repeat step S20.

[0078] Step S40: After rotating the vacuum adsorption stage by 90°, repeat steps S20 and S30.

[0079] Step S50: Apply mechanical force to the wafer sample 10 to separate and obtain wafer 50.

[0080] In this embodiment, the wafer sample 10 is fixed to the vacuum adsorption stage by the expansion ring 30 and the adhesive tape 40. During the formation of each wafer modification layer, the vacuum adsorption stage 64 is controlled to have relative movement with the laser, and the laser focus is adjusted vertically multiple times using the optical lens 62 to form multiple wafer modification layers 11 within the wafer sample 10 and an imaging adhesive modification layer 21 within the imaging adhesive layer 20. A first blanking layer 12 is formed between two adjacent wafer modification layers 11 to control the laser heat-affected zone range of the wafer modification layer 11 and reduce... The overlapping of heat-affected zones between adjacent wafer modification layers 11 confines the thermal cracks 113 generated by the wafer modification layer 11 to the first blank layer 12. This reduces the potential for uncontrolled expansion of the hidden damage area within the material caused by the hidden modification and the influence of nearby heat sources on the cracks. It also avoids problems such as reduced bending strength and edge chipping caused by the longitudinal and transverse expansion of the thermal cracks 113. This ensures both the hidden modification properties and the appearance and physicochemical properties, significantly improving the sample strength and thus enhancing the sample's appearance quality and processing accuracy.

[0081] For example, a glass wafer sample 10 with a thickness of 0.8 mm, a diameter of 6 inches, and an imaging adhesive layer 20 thickness of 100 μm is fixed to the vacuum adsorption stage of the laser refining equipment through wafer frames 30 and the imaging adhesive layer 20. When refining the wafer sample 10, the longitudinal spacing between adjacent wafer refining layers 11 is about 50 μm. By adjusting the focal depth of each refining channel, seven wafer refining layers 11 are designed from bottom to top, six alternating first blanking layers 12, and a wider unrefined area in the longitudinal direction for the second blanking layer 13 and the fourth blanking layer 14. Similarly, the wafer sample 10 is separated into a wafer 50, which requires multiple modification processes. Therefore, after completing the seven wafer modification layers 11 and the imaging adhesive modification layer 21, the lateral distance is adjusted according to the required wafer 50 size, and the modification of the seven wafer modification layers 11 and the imaging adhesive modification layer 21 is repeated multiple times. After rotating 90°, the process is repeated multiple times to fabricate the wafer sample 10 into a wafer 50.

[0082] The wafer modification layer 11 has a longitudinal thickness of approximately 70 μm, the first blank layer 12 has a longitudinal thickness of approximately 20 μm, the second blank layer 13 has a longitudinal thickness of 60 μm, the fourth blank layer 14 has a longitudinal thickness of 30 μm, the imaging adhesive modification layer 21 has a longitudinal thickness of 50 μm, and the third blank layer 22 on the upper and lower sides of the imaging adhesive modification layer 21 has a longitudinal thickness of 25 μm.

[0083] More specifically, the horizontal direction is the X-axis, the vertical direction is the Z-axis, and the direction perpendicular to the X and Z directions is the Y-axis. Figure 1The direction is the Y direction. The remodeling movement is expressed using coordinates (X, Y, Z). First, starting from the coordinates (X1, 0, Z1), it moves laterally to (XN, 0, Z1), completing one wafer remodeling layer 11. Then, changing the vertical coordinates, the starting point (X1, 0, Z2) moves laterally to (XN, 0, Z2) to form multiple wafer remodeling layers 11, until it moves from the starting point (X1, 0, ZN) to (XN, 0, ZN). Multiple movements in the X direction are performed according to the required wafer size. The vacuum adsorption stage is rotated... Rotating 90° is equivalent to swapping the X-axis and Y-axis. At this point, the horizontal movement is still performed, but the Y-axis coordinates are changed. First, the starting point coordinates (0, Y1, Z1) are moved horizontally to (0, YN, Z1), completing one layer of wafer modification layer 11. The vertical coordinates are changed, starting from (0, Y1, Z2) and moving horizontally to (0, YN, Z2) to form multiple layers of wafer modification layer 11, until the starting point (0, Y1, ZN) is moved to (0, YN, ZN). Multiple movements in the Y-axis are performed according to the required wafer size 50.

[0084] Alternatively, this application can also perform laser refining in the following manner: starting from the coordinates (X1, 0, Z1), move laterally to (XN, 0, Z1) to complete one wafer refining layer 11; change the vertical coordinates, starting from the coordinates (XN, 0, Z2), move laterally to (X1, 0, Z2) to form multiple wafer refining layers 11 until the starting point (X1, 0, ZN) moves to (XN, 0, ZN) or (XN, 0, ZN) moves to (X1, 0, ZN), and multiple moves in the X direction can be made according to the required wafer size 50; rotating 90° has the same principle.

[0085] In one embodiment of the present invention, preferably, before step S20, a vision camera is used to align the sample along a predetermined modification position and a predetermined direction, and the laser focus position 60 is adjusted to focus on the upper surface of the wafer sample 10.

[0086] In this embodiment, before laser refining, initial positioning is required. The sample is aligned along the predetermined refining position and direction using a vision camera. This improves the accuracy of the laser refining position, avoids the waste of wafer sample 10 due to deviation of the refining position and direction, and reduces production costs.

[0087] In one embodiment of the present invention, preferably, in step S20, the thickness of the multilayer wafer modification layer 11, the thickness of the imaging adhesive modification layer 21, the thickness of the first blanking layer 12 between adjacent wafer modification layers 11, the thickness of the third blanking layer 22 on the upper and lower sides of the imaging adhesive modification layer 21, and the thickness of the fourth blanking layer 14 between the lower surface of the wafer sample 10 and the wafer modification layer 11 are controlled by controlling the moving speed of the vacuum adsorption stage, the laser power, and the focusing depth.

[0088] In one embodiment of the present invention, preferably, the laser-actuated wafer sample 10 is subjected to a vacuum adsorption stage moving at a speed of 400-600 mm / s.

[0089] The laser-assisted imaging adhesive layer 20 is used, and the vacuum adsorption stage moves at a speed of 100-200 mm / s.

[0090] In one embodiment of the present invention, preferably, the laser focusing depth is -500 to 30 μm and the laser repetition frequency is 50 to 150 kHz.

[0091] In one embodiment of the present invention, preferably, the laser is used to treat the wafer sample 10 with a power of 1.5-4W;

[0092] Laser imaging layer 20, with a power of 0.8-1.5W.

[0093] In this embodiment, the wafer sample 10 is typically made of glass, which requires a higher threshold power than the imaging adhesive layer 20. To effectively control the width of the modified layer, the laser power is typically adjusted to 1.5-4W when the laser acts on the wafer sample 10, and to 0.8-1.5W when the laser acts on the imaging adhesive layer 20.

[0094] In one embodiment of the present invention, preferably, the laser is an ultrashort pulse laser beam, using an infrared laser with a pulse width of 15ps to 500fs and a wavelength of 1064nm.

[0095] According to one aspect of the present invention, a wafer laser refining system is provided, comprising:

[0096] A multi-axis working platform 65 is provided, which is equipped with a vacuum adsorption stage 64 on which a wafer sample 10 with a steel ring 30 is loaded.

[0097] The laser system 61 outputs laser light and adjusts the position of its laser focus 60 in the longitudinal direction of the Z-axis through an optical lens 62, and finally transmits it to the wafer sample 10 and incident from the upper surface of the wafer sample 10.

[0098] The wafer dicing apparatus mainly consists of a liner 70 and an external mechanical force. It is used to apply mechanical force to the wafer sample 10 along the processing trajectory of the wafer 50, causing the brittle material to fracture with high quality, thus separating the wafer 50.

[0099] The main control unit stores a computer program that can be executed to perform the steps of any of the methods described in the above technical solutions, so as to control one or more of the working platform, laser, and dicing device to operate.

[0100] The specific steps of the wafer laser refining method and system of the present invention to produce a wafer 50 with a size of 30×10mm are as follows:

[0101] Step S101: A glass wafer sample 10 with a thickness of 0.8 mm, a diameter of 6 inches, and an imaging adhesive layer 20 thickness of 100 μm is fixed to the vacuum adsorption stage of the laser modification equipment through the expansion ring 30 (Wafer Frames / Wafer Ring) and the tape 40.

[0102] In step S102, after the sample is loaded into the working platform 65, the CCD camera is used to align the wafer sample 10 along the predetermined position and direction of the quality modification channel, and the laser focus position 60 is adjusted and gradually focused on the upper surface of the sample.

[0103] Step S103: The repetition frequency of the ultrashort pulse infrared laser is 100kHz, the pulse train energy is 180uJ, the laser power is adjusted to 2W, the vacuum adsorption stage moving speed is 500mm / s, and the laser focus position is adjusted to 90° longitudinal position in seven steps, moving 50μm each time.

[0104] Step S104: Adjust the laser frequency to 1W, the vacuum adsorption stage moving speed to 150mm / s, and adjust the laser focus position to 90° longitudinal position to modify the image adhesive layer 20.

[0105] Step S105: Move the vacuum adsorption stage or laser laterally multiple times, each time by 10mm. For each movement, execute steps S103 and S104 once.

[0106] Step S106: After rotating the vacuum adsorption stage by 90°, move the vacuum adsorption stage or laser laterally multiple times, moving 30mm each time. For each movement, execute steps S103 and S104 once.

[0107] Step S107: After the modification is completed, the wafer sample 10 is subjected to external mechanical force by the cleaving device along the modification path to cause brittle fracture of the material and separate it into a wafer 50 with actual length and width dimensions of 30×10mm.

[0108] In this example, the segmented wafers were placed on a professional universal testing machine to test their three-point bending values, and the results were compared with those obtained using a conventional single-layer modification method. The stage span was 22 mm, and the load application rate was 5 mm / min.

[0109]

[0110]

[0111] Table 1

[0112] Table 1 shows the three-point bending strength data for conventional modification and the modification method in this embodiment, where the unit is N.

[0113] As can be seen from the data in Table 1, the average three-point bending strength of the conventional method is 14.48N, while the average three-point bending strength of this embodiment is 25.60N, which is an increase of about 76.79%. Moreover, the standard deviation of the three-point bending strength of the embodiment is smaller, and the data is more centralized.

[0114] This invention discloses a wafer laser modification structure, method, and system. It involves multi-layer modification within a wafer sample, forming a repeating structure of multiple wafer modification layers and multiple first blank layers. By controlling the laser heat-affected zone (HAZ) of the wafer modification layers, the superposition of HAZ regions between adjacent wafer modification layers is reduced. This ensures that thermal cracks generated by the wafer modification layers are locally confined within the first blank layer, reducing the potential for hidden damage areas within the material and the uncontrolled propagation of cracks due to nearby heat sources. It also avoids problems such as reduced bending strength and edge chipping caused by longitudinal-lateral thermal crack propagation. This approach ensures both the hidden modification properties and the appearance and physicochemical properties, significantly improving sample strength and thus enhancing sample appearance quality and processing accuracy.

[0115] The use of cutting wheels, which eliminates the need for traditional cutting processes, reduces the consumption of cutting wheels and eliminates the need for large amounts of deionized water, thereby lowering production costs. It also avoids dust generated during the production process, ensuring product cleanliness and improving the working environment for operators.

[0116] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wafer laser-modified structure, characterized in that, The wafer sample (10) is covered with an imaging adhesive layer (20) on its upper surface. The imaging adhesive layer (20) serves as a carrier for optical imaging. The wafer laser-modified structure further includes: Multiple wafer modification layers (11) are arranged in parallel along the vertical direction of the wafer sample (10), and a first blank layer (12) is provided between two adjacent wafer modification layers (11). An imaging adhesive modifier layer (21) is disposed parallel to the wafer modifier layer (11) within the imaging adhesive layer (20); The thickness of the wafer modification layer (11) is greater than the thickness of the first blank layer (12); Also includes: Two third blanking layers (22) are respectively disposed on the upper and lower sides of the imaging adhesive modification layer (21); The second blank layer (13) is disposed between the wafer modification layer (11) and the imaging adhesive layer (20); A fourth blank layer (14) is disposed between the lower surface of the wafer sample (10) and the wafer modification layer (11).

2. The wafer laser-modified structure according to claim 1, characterized in that, The wafer modification layer (11) includes a high-density dislocation region (111), a pulse hole (112), and a thermal crack (113).

3. The wafer laser-modified structure according to claim 2, characterized in that, The longitudinal length of the hot crack (113) is 0~15 μm.

4. The wafer laser-modified structure according to claim 1, characterized in that, The wafer sample (10) has a size of 4 to 12 inches and a thickness of 0.2 to 2.4 mm.

5. The wafer laser-modified structure according to claim 1, characterized in that, Any two of the wafer modification layers (11) are of equal size, and the thickness of the wafer modification layer (11) is 40-100 μm; The thickness of the first blank layer (12) is 20~30 μm.

6. A wafer laser modification method for obtaining the wafer laser modification structure as described in any one of claims 1 to 5, characterized in that, include: Step S10: Load the wafer sample (10) onto the tape (40) with the expansion ring (30) and place it on the vacuum adsorption stage; Step S20: Control the vacuum adsorption stage (64) and the laser system (61) to move relative to each other, and adjust the position of the laser focus (60) in the vertical direction multiple times through the optical lens (62) to form a multilayer wafer modification layer (11) and an imaging adhesive modification layer (21). Step S30: According to the required wafer (50) size, move the vacuum adsorption stage (64), adjust the position of the laser focus in the horizontal direction, and repeat step S20. Step S40: After rotating the vacuum adsorption stage (64) by 90°, repeat steps S20 and S30. Step S50: Apply mechanical force to the wafer sample (10) to separate and obtain the wafer (50).

7. The wafer laser refining method according to claim 6, characterized in that, Before step S20, the sample is aligned along the predetermined modification position and direction using a vision camera, and the laser focus (60) is adjusted to focus on the upper surface of the wafer sample (10).

8. The wafer laser refining method according to claim 6, characterized in that, In step S20, by controlling the moving speed of the vacuum adsorption stage (64), the laser power, and the focusing depth, the thickness of the multilayer wafer modification layer (11), the thickness of the imaging adhesive modification layer (21), the thickness of the first blank layer (12) between adjacent wafer modification layers (11), the thickness of the third blank layer (22) on the upper and lower sides of the imaging adhesive modification layer (21), and the thickness of the fourth blank layer (14) between the lower surface of the wafer sample (10) and the wafer modification layer (11) are controlled.

9. The wafer laser refining method according to claim 6, characterized in that, Laser-treated wafer sample (10) with vacuum adsorption stage moving at a speed of 400-600 mm / s; The laser-assisted imaging adhesive layer (20) is moved at a speed of 100-200 mm / s using a vacuum adsorption stage.

10. The wafer laser refining method according to claim 6, characterized in that, The laser focusing depth is -500~30 μm, and the laser repetition frequency is 50~150 KHz.

11. The wafer laser refining method according to claim 6, characterized in that, Laser treatment of wafer samples (10) with a power of 1.5-4 W; Laser-assisted imaging of the adhesive layer (20) with a power of 0.8-1.5 W.

12. The wafer laser refining method according to claim 6, characterized in that, The laser is an ultrashort pulse laser beam, using an infrared laser with a pulse width of 15 ps to 500 fs and a wavelength of 1064 nm.

13. A wafer laser refining system, comprising: A multi-axis working platform (65) is equipped with a vacuum adsorption stage (64). A laser system (61) outputs a laser beam to a wafer sample (10) and incident from the upper surface of the wafer sample (10); A dicing apparatus is provided with a liner (70) for supporting the wafer sample (10). The dicing apparatus is used to apply mechanical force to the wafer sample (10) along the modified trajectory to separate it into wafers (50). The main control unit stores a computer program that can be executed to implement the steps of the wafer laser refining method as described in claim 6 or 12, in order to control one or more of the working platform, laser system, and dicing device to operate.

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