Laser lift-off apparatus

Abstract

The utility model discloses a kind of laser stripping equipment, it is related to laser equipment technical field, the laser stripping equipment includes laser modification optical device, laser cleaving optical device and transfer device, laser modification optical device is configured to form modification layer on sample ingot;Laser cleaving optical device is configured to heat the modification layer of sample ingot after modification is completed;Transfer device is used to transport sample ingot located in laser modification optical device to laser cleaving optical device.The utility model aims at improving the processing efficiency of silicon carbide ingot.

Description

Technical Field

[0001] This utility model relates to the field of laser equipment technology, and in particular to a laser stripping device. Background Technology

[0002] Silicon carbide (SiC), as a core representative of third-generation semiconductor materials, has become a key substrate for high-frequency, high-voltage, high-power, and low-loss electronic devices due to its excellent physicochemical properties. However, its Mohs hardness of 9.5 poses a severe challenge to traditional processing techniques—profuse material loss and low processing efficiency have long constrained the large-scale development of the industry. Laser ablation technology is an advanced processing technique that utilizes the high-energy characteristics of a laser beam to treat the surface of a material, separating specific layers from the substrate. Laser ablation technology is widely used in silicon carbide processing.

[0003] Currently, existing laser ablation equipment typically consists of a laser generating unit, a beam transmission unit, and a focusing unit. The laser generating unit produces a laser beam with a specific wavelength and energy, the beam transmission unit is responsible for transmitting the laser beam to the area to be processed, and the focusing unit focuses the laser beam onto the material surface to achieve the ablation operation. Some devices are also equipped with a motion control platform to support the material to be processed and to move and position it.

[0004] However, existing laser ablation equipment is insufficient to meet the requirements of modern large-scale production for processing efficiency and quality. Utility Model Content

[0005] The main objective of this invention is to propose a laser stripping device, which aims to improve the processing efficiency of silicon carbide ingots.

[0006] To achieve the above objectives, this utility model proposes a laser ablation device, comprising:

[0007] An optical device for laser refining, the optical device being configured to form a refining layer on a sample ingot;

[0008] An optical device for laser dicing, the optical device being configured to heat the modified layer of the sample ingot after modification; and

[0009] A transfer device for transferring the sample ingot located in the laser-modified optical device to the laser-cleaving optical device.

[0010] In one embodiment, the optical device for laser refining includes:

[0011] A first laser, configured to emit a first laser beam;

[0012] A first polarizing beam splitter is configured to split the first laser beam into a first P-state polarized light extending along a first optical axis and a first S-state polarized light extending along a second optical axis.

[0013] A first reflecting mirror is configured to reflect the first P-state polarized light so that the first P-state polarized light extends along a third optical axis, the third optical axis being parallel to the second optical axis;

[0014] A second reflector is configured to reflect the first S-state polarized light so that the first S-state polarized light extends along a fourth optical axis, which is parallel to the first optical axis.

[0015] A second polarizing beam splitter is located on the light-emitting side of the first and second reflecting mirrors. The second polarizing beam splitter is configured to combine the first P-state polarized light reflected by the first reflecting mirror and the first S-state polarized light reflected by the second reflecting mirror.

[0016] A focusing lens, located on the light-emitting side of the second polarizing beam splitter, is used to focus the first S-state polarized light and the first P-state polarized light after they are combined by the second polarizing beam splitter onto the interior of the sample ingot to form two modified layers.

[0017] In one embodiment, the optical device for laser quality modification further includes a half-wave plate disposed between the first laser and the first polarizing beam splitter.

[0018] In one embodiment, the optical device for laser refining further includes a wedge prism disposed between the second reflector and the second polarizing beam splitter, the wedge prism being configured to deflect the first S-state polarized light;

[0019] The second polarizing beam splitter is located on the light-emitting side of the first reflecting mirror and the wedge prism. The second polarizing beam splitter is configured to combine the first P-state polarized light reflected by the first reflecting mirror and the first S-state polarized light deflected by the wedge prism.

[0020] In one embodiment, the wavelength range of the first laser beam is 300nm-2000nm, and the pulse width of the first laser beam is 100fs-200ps.

[0021] In one embodiment, the beam splitting ratio of the first polarizing beam splitter is 1:1.

[0022] In one embodiment, the optical device for laser dicing includes:

[0023] A second laser, configured to emit a second laser beam;

[0024] A third reflecting mirror, configured to reflect the second laser beam; and

[0025] A scanning galvanometer is disposed on the light-emitting side of the third reflecting mirror, and the scanning galvanometer includes a galvanometer and a field mirror;

[0026] The second laser beam is guided to the modified layer after entering the galvanometer and the field mirror in sequence.

[0027] In one embodiment, the laser stripping apparatus further includes a cooling and rinsing device, the nozzle of which is aligned with the modified layer on the sample ingot after heating.

[0028] In one embodiment, the temperature of the water flow in the cooling flushing device is 5°C-25°C.

[0029] The laser ablation device provided by this invention separates the laser refining and laser dicing functions and incorporates a transfer device, enabling highly efficient ablation processing of silicon carbide materials. Specifically, the laser refining optical device first forms a refining layer on the sample ingot, preparing it for ablation; the transfer device then transports the ingot to the laser dicing optical device, which heats the refining layer to separate it from the substrate. The process involves the ingot first being processed by the refining device, and then transported by the transfer device to the dicing device to complete the ablation. This structure avoids the inefficiency caused by the functional integration of existing devices, reduces energy loss and incomplete ablation, significantly improves processing efficiency, solves the processing difficulties caused by the high hardness of silicon carbide, and promotes the large-scale development of related industries. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0031] Figure 1 A schematic diagram of an embodiment of the optical device for laser refining provided by this utility model;

[0032] Figure 2 This is a schematic diagram of an embodiment of the optical device for laser dicing provided by this utility model.

[0033] Explanation of icon numbers:

[0034] 1. Optical device for laser-induced refining; 11. First laser; 12. Half-wave plate; 13. First polarizing beam splitter; 14. First reflecting mirror; 15. Second reflecting mirror; 16. Second polarizing beam splitter; 17. Focusing lens; 18. Sample ingot; 19. Wedge prism;

[0035] 2. Optical apparatus for laser dicing; 21. Second laser; 22. Third mirror; 23. Galvanometer; 24. Field mirror;

[0036] 3. Cooling and rinsing device.

[0037] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0039] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0040] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0041] This application provides a laser ablation device.

[0042] Please see Figure 1 and Figure 2In one embodiment of the present invention, the laser ablation device includes a laser refining optical device 1, a laser dicing optical device 2, and a transfer device. The laser refining optical device 1 is configured to form a refining layer on a sample ingot 18. The laser dicing optical device 2 is configured to heat the refining layer of the sample ingot 18 after refining. The transfer device is used to transfer the sample ingot 18 located in the laser refining optical device 1 to the laser dicing optical device 2.

[0043] In this embodiment, the transfer device is a mechanical or automated system in the laser ablation equipment used to precisely move the sample ingot 18 from one processing position (such as the laser refining position) to another processing position (such as the laser cleaving position). The design of this device needs to ensure the stability and accuracy of the ingot during movement to avoid any vibrations or displacements that may affect the processing quality. The transfer device can be an automated conveyor belt, a linear guide system, a robotic arm, a rotary table, a pneumatic or hydraulic system, a stepper motor drive system, a robotic transfer system, or a vacuum adsorption system, etc.

[0044] The laser ablation device provided by this invention separates the laser refining and laser dicing functions and incorporates a transfer device, enabling efficient ablation processing of silicon carbide materials. Specifically, the laser refining optical device 1 first forms a refining layer on the sample ingot 18 to prepare for ablation; the transfer device then transports the ingot to the laser dicing optical device 2, which heats the refining layer to separate it from the substrate. The process involves the ingot being processed by the refining device and then transferred to the dicing device by the transfer device to complete the ablation. This structure avoids the inefficiency caused by the functional integration of existing devices, reduces energy loss and incomplete ablation, significantly improves processing efficiency, solves the processing difficulties caused by the high hardness of silicon carbide, and promotes the large-scale development of related industries.

[0045] Please see Figure 1 In one embodiment, the optical device 1 for laser refining includes:

[0046] A first laser 11 is configured to emit a first laser beam;

[0047] A first polarizing beam splitter 13 is configured to split the first laser beam into a first P-state polarized light extending along a first optical axis and a first S-state polarized light extending along a second optical axis.

[0048] A first reflecting mirror 14 is configured to reflect the first P-state polarized light so that the first P-state polarized light extends along a third optical axis, the third optical axis being parallel to the second optical axis.

[0049] The second reflector 15 is configured to reflect the first S-state polarized light so that the first S-state polarized light extends along a fourth optical axis, which is parallel to the first optical axis.

[0050] A second polarizing beam splitter 16 is located on the light-emitting side of the first reflecting mirror 14 and the second reflecting mirror 15. The second polarizing beam splitter 16 is configured to combine the first P-state polarized light reflected by the first reflecting mirror 14 and the first S-state polarized light reflected by the second reflecting mirror 15.

[0051] A focusing lens 17 is located on the light-emitting side of the second polarizing beam splitter 16. It is used to focus the first S-state polarized light and the first P-state polarized light after they are combined by the second polarizing beam splitter 16 into the interior of the sample ingot 18 to form two modified layers.

[0052] In this embodiment, the first laser beam is split into a first P-state polarized light and a first S-state polarized light by the first polarizing beam splitter 13, achieving precise control of the laser beam polarization state. The first reflecting mirror 14 and the second reflecting mirror 15 reflect the first P-state polarized light and the first S-state polarized light respectively to change their propagation direction and optimize the beam transmission path. The second polarizing beam splitter 16 combines the first S-state polarized light and the first P-state polarized light to form a laser beam with the required polarization characteristics, improving the beam utilization efficiency. The focusing lens 17 focuses the combined laser beam into the sample ingot 18 to form two modified layers, ensuring the precise distribution of laser energy inside the sample, thereby improving the formation quality and processing accuracy of the modified layers. The synergistic work of this series of components not only significantly improves processing efficiency and quality but also enhances the adaptability and flexibility of the device, providing an effective solution for laser ablation processing. It can adapt to different processing requirements and material properties and has broad application prospects.

[0053] In one embodiment, the optical device 1 for laser refining further includes a half-wave plate 12, which is disposed between the first laser 11 and the first polarizing beam splitter 13. In this embodiment, the function of the half-wave plate 12 is to adjust the initial power (typically 1:1) of the first P-state polarized light and the first S-state polarized light. By adjusting the angle of the half-wave plate 12, the ratio of the first P-state polarized light to the first S-state polarized light can be changed to optimize the characteristics of the laser beam. This adjustment of power distribution helps to improve the quality of the laser beam, making it more stable and consistent during focusing and refining processes, thereby improving the formation quality and processing accuracy of the refining layer.

[0054] In one embodiment, the optical device 1 for laser refining further includes a half-wave plate 12 and a wedge prism 19, which is disposed between the second reflector 15 and the second polarizing beam splitter 16, and is configured to deflect the first P-state polarized light.

[0055] The core function of the wedge prism 19 is to precisely shift the beam of light with a specific polarization state laterally. Specifically, after the first P-state polarized light is reflected by the second mirror 15, it enters the wedge prism 19. Due to the inclined structure of the wedge prism, the physical path lengths of different parts of the beam traveling inside the prism differ. This difference causes a slight angular deflection of the entire beam, thereby achieving precise offset control of the beam position. In this embodiment, the laser beam emitted by the first laser 11 first passes through the first polarizing beam splitter 13 and is decomposed into first P-state polarized light and first S-state polarized light. The first S-state polarized light is guided to the second mirror 15. This redirected first S-state polarized light then passes through the wedge prism 19, during which its position is finely shifted by the wedge prism 19. At the same time, the first P-state polarized light also travels along the corresponding path. Finally, the two beams converge at the second polarizing beam splitter 16.

[0056] The key advantage of introducing the wedge prism 19 lies in its provision of a flexible means of controlling the relative positions of the two beams. By adjusting the orientation or position of the wedge prism 19, the degree of spatial overlap or spacing between the first S-state polarized light (after being offset by the wedge prism) and the first P-state polarized light can be precisely set. This results in two advantages: firstly, significantly improved processing efficiency when both beams act simultaneously on the workpiece for collaborative processing; and secondly, greatly enhanced system process compatibility, allowing engineers to freely adjust the relative arrangement of the beams within a certain range to adapt to various processing requirements or optimize specific process schemes.

[0057] In one embodiment, the wavelength range of the first laser beam is 300nm-2000nm, and the pulse width of the first laser beam is 100fs-200ps. Within this wavelength range, lasers in the 300-1100nm band have strong material penetration capabilities, enabling them to penetrate deep into the sample ingot 18, while lasers in the 1100-2000nm band can effectively excite the optical and thermal responses of the material when interacting with it. The ultrashort pulse width of 100fs-200ps allows the laser energy to be released in a concentrated manner within a very short time, instantly generating high peak power and avoiding thermal diffusion and thermal damage problems caused by prolonged heating of the material.

[0058] In one embodiment, the beam splitting ratio of the first polarizing beam splitter 13 is 1:1.

[0059] In this embodiment, the first polarizing beam splitter 13, as a key component of the optical device 1 for laser modification, proportionally divides the first laser beam emitted by the first laser 11 into first P-state polarized light and first S-state polarized light, ensuring that the two beams have the same energy. This balanced energy distribution ensures that during subsequent reflection, beam combining, and focusing processes, the first S-state polarized light and the first P-state polarized light, transformed from the first P-state polarized light and the first S-state polarized light, produce a uniform and symmetrical energy distribution when acting on the interior of the sample ingot 18 to form the modified layer. In actual operation, the two beams of equal energy are focused into the interior of the sample ingot 18, allowing for synchronous and balanced changes to the material structure, avoiding problems such as uneven thickness and irregular shape of the modified layer due to energy differences.

[0060] Please see Figure 2 In one embodiment, the optical device 2 for laser dicing includes:

[0061] The second laser 21 is configured to emit a second laser beam;

[0062] The third reflector 22 is configured to reflect the second laser beam; and

[0063] The scanning galvanometer 23 is located on the light-emitting side of the third reflecting mirror 22. The scanning galvanometer 23 includes a galvanometer 23 and a field mirror 24.

[0064] The second laser beam is guided to the modified layer after entering the galvanometer 23 and the field mirror 24 in sequence.

[0065] In this embodiment, the second laser 21 serves as an energy source, emitting a second laser beam for heating the modified layer. The third reflecting mirror 22 changes the propagation direction of the second laser beam through reflection, allowing it to smoothly enter the scanning galvanometer 23. The galvanometer 23, driven by a motor, rapidly and precisely changes the laser beam reflection angle, while the field lens 24 focuses the reflected laser beam onto the modified layer, enabling the second laser beam to perform rapid two-dimensional scanning on the surface of the modified layer. In actual operation, the modified sample ingot 18 is uniformly heated by the laser beam emitted by the second laser 21 after reflection and scanning, generating uniform thermal stress between the modified layer and the substrate, promoting their separation. Compared to traditional cleaving devices, this structure achieves flexible scanning of the laser beam through the scanning galvanometer 23, avoiding uneven local heating. This not only expands the heating area but also allows for adjustment of the scanning pattern according to requirements, significantly improving cleaving efficiency and quality. It also enhances the equipment's adaptability to different samples, meeting diverse processing needs. The galvanometer 23 is a rapidly oscillating square sheet, and the field lens 24 is a large-aperture circular lens.

[0066] Please see Figure 2In one embodiment, the laser stripping device further includes a cooling and rinsing device 3, the nozzle of which is aligned with the modified layer of the sample ingot 18 after heating.

[0067] In this embodiment, after laser dicing is completed, the modified layer and surrounding area are at a high temperature due to laser heating. At this time, the cooling and rinsing device 3 is activated, and the water jet from the nozzle quickly removes the heat from the modified layer and sample surface. During the thermal expansion and contraction process, the crack will extend rapidly, eventually achieving full-surface peeling, thus avoiding dicing, and at the same time washing away surface debris and impurities.

[0068] In one embodiment, the temperature of the water flow in the cooling flushing device 3 is 5°C-25°C.

[0069] In this embodiment, the temperature range of 5℃-25℃ ensures that the water flow has good cooling capacity, avoids thermal stress damage to the material due to excessively low temperature, and also prevents excessively high temperature from affecting cooling efficiency and crack propagation effect.

[0070] The above are merely exemplary embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the technical concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A laser ablation device, characterized in that, include: An optical device for laser refining, the optical device being configured to form a refining layer on a sample ingot; An optical device for laser dicing, wherein the optical device for laser dicing is configured to heat the modified layer of the sample ingot after modification; as well as A transfer device for transferring the sample ingot located in the laser-modified optical device to the laser-cleaving optical device.

2. The laser ablation device as described in claim 1, characterized in that, The optical device for laser modification includes: A first laser, configured to emit a first laser beam; A first polarizing beam splitter is configured to split the first laser beam into a first P-state polarized light extending along a first optical axis and a first S-state polarized light extending along a second optical axis. A first reflecting mirror is configured to reflect the first P-state polarized light so that the first P-state polarized light extends along a third optical axis, the third optical axis being parallel to the second optical axis; A second reflector is configured to reflect the first S-state polarized light so that the first S-state polarized light extends along a fourth optical axis, which is parallel to the first optical axis. A second polarizing beam splitter is located on the light-emitting side of the first and second reflecting mirrors. The second polarizing beam splitter is configured to combine the first P-state polarized light reflected by the first reflecting mirror and the first S-state polarized light reflected by the second reflecting mirror. A focusing lens, located on the light-emitting side of the second polarizing beam splitter, is used to focus the first S-state polarized light and the first P-state polarized light after they are combined by the second polarizing beam splitter onto the interior of the sample ingot to form two modified layers.

3. The laser ablation device as described in claim 2, characterized in that, The optical device for laser quality improvement also includes a half-wave plate, which is disposed between the first laser and the first polarizing beam splitter.

4. The laser ablation device as described in claim 2, characterized in that, The optical device for laser refining further includes a wedge prism, which is disposed between the second reflector and the second polarizing beam splitter, and is configured to deflect the first S-state polarized light; The second polarizing beam splitter is located on the light-emitting side of the first reflecting mirror and the wedge prism. The second polarizing beam splitter is configured to combine the first P-state polarized light reflected by the first reflecting mirror and the first S-state polarized light deflected by the wedge prism.

5. The laser ablation device as described in claim 2, characterized in that, The wavelength range of the first laser beam is 300nm-2000nm, and the pulse width of the first laser beam is 100fs-200ps.

6. The laser ablation device as described in claim 2, characterized in that, The beam splitting ratio of the first polarizing beam splitter is 1:

1.

7. The laser ablation device as described in claim 1, characterized in that, The optical device for laser dicing includes: A second laser, configured to emit a second laser beam; A third reflecting mirror, configured to reflect the second laser beam; and A scanning galvanometer is disposed on the light-emitting side of the third reflecting mirror, and the scanning galvanometer includes a galvanometer and a field mirror; The second laser beam is guided to the modified layer after entering the galvanometer and the field mirror in sequence.

8. The laser ablation device as described in claim 1, characterized in that, The laser stripping equipment also includes a cooling and rinsing device, the nozzle of which is aligned with the modified layer located on the sample ingot after heating.

9. The laser ablation device as described in claim 8, characterized in that, The temperature of the water flow in the cooling and rinsing device is 5℃-25℃.

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