Laser debonding device
By designing a laser debonding device including a two-dimensional stage, a fixed assembly, a laser system and a disc, the problem of poor laser debonding efficiency and quality in the prior art is solved, and the uniformity and stability of laser processing are achieved.
Patent Information
- Application Number
- CN202421399505.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-18
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-06-18
AI Technical Summary
While improving efficiency, existing laser debonding devices are difficult to ensure the uniformity of spot quality and energy distribution, resulting in poor quality of wafer debonding.
A laser debonding device including a two-dimensional stage, a fixing assembly, a laser system and a disk are designed. Through the linkage between the two-dimensional stage and the laser system, the laser beam is scanned in the bonding layer of the bonding part to be dissolved, combined with the use of a vacuum pump and air holes, uniform heating and separation of the bonding layer is achieved.
The quality and efficiency of wafer laser debonding are improved, the uniformity of laser processing is ensured, the cooling and re-adhesion of the bonding layer are avoided, and the stability of the process is maintained.
Smart Images
Figure CN222939901U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of semiconductor laser manufacturing, in particular to a laser debonding device. Background Art
[0002] With the rapid development of economy and technology and the continuous increase in the market demand for semiconductors, wafers are the basic materials for manufacturing semiconductor chips. After wafer processing is completed, the wafer and the substrate need to be debonded before the subsequent process of dicing the wafer can be carried out. Laser debonding is a method of surface treatment of materials using laser technology. By instantaneously heating the surface of the adhesive material with a high-energy laser beam, it reaches the evaporation temperature to cause partial separation, thereby separating the temporary substrate from the wafer. Currently, there are two common methods for laser debonding devices. One is that the laser is stationary and the wafer stage moves; the other is that the wafer stage is fixed and the laser moves. The former is slow in speed and low in efficiency; the latter has poor spot quality and uneven energy distribution. Summary of the Utility Model
[0003] Based on this, it is necessary to provide a laser debonding device that can improve the quality and efficiency of wafer laser debonding at the same time in view of the above technical problems.
[0004] A laser debonding device provided by the utility model includes:
[0005] A two-dimensional stage;
[0006] A fixing component for fixing the workpiece to be debonded, including a positioning disk and a hollow rod, and the hollow rod is used to connect to a vacuum pump;
[0007] A laser system, which is linked with the two-dimensional stage, is used to generate a laser beam that passes through the workpiece to be debonded, and control the focus of the laser beam to scan on the bonding layer of the workpiece to be debonded, so as to debond the bonding layer;
[0008] A disk is arranged on the positioning disk and moves with the positioning disk. One side close to the positioning disk has air holes distributed in an array, and the disk has first air channels distributed in an array inside. Each first air channel is communicated with the corresponding air hole and connected to a vacuum pump.
[0009] In one embodiment, the workpiece to be debonded includes a first layer structure fixed on the surface of the two-dimensional stage and a second layer structure bonded through a bonding layer. One of the first layer structure and the second layer structure is a wafer, and the other layer structure is a sapphire carrier.
[0010] In one embodiment, the laser system includes a digital infrared temperature sensor, a transmissive mirror, a scanning galvanometer, a field lens, and a control system. Among them, the digital infrared temperature sensor is used to monitor the temperature during the laser processing. The transmissive mirror is used to reflect the ultraviolet laser onto the surface of the component to be debonded and allow the infrared light energy during the processing to pass through and reach the digital infrared temperature sensor. The scanning galvanometer and the field lens are used to adjust the laser to enter the field lens and focus on the surface of the component to be debonded. The control system is used to collect the temperature data of the digital infrared temperature sensor, control the scanning range of the scanning galvanometer and the field lens, and control the start and stop of the two-dimensional stage.
[0011] In one embodiment, the control system includes an industrial control computer and a PLC. The industrial control computer is used to schedule and manage various internal components or sub-devices. The PLC realizes the control and monitoring of various devices and processes through programming. The industrial control computer and the PLC coordinate to complete the parameter setting and communication control of the scanning galvanometer, the field lens, the digital infrared temperature sensor, the stepping motor, etc., so as to realize the automatic control of the component to be debonded.
[0012] In one embodiment, a valve assembly is provided in each of the first air ducts. The valve assembly is used to control the negative pressure in the corresponding first air duct.
[0013] In one embodiment, a linear telescopic structure and a lifting plate are provided inside the two-dimensional stage. The hollow rod is installed on the lifting plate, and the two-dimensional stage has a mounting hole adapted to the hollow rod.
[0014] In one embodiment, a second air duct is provided inside the lifting plate, and the inside of the hollow rod communicates with the second air duct.
[0015] In one embodiment, a cooling plate is provided inside the two-dimensional stage. A water channel is provided inside the cooling plate. The water channel has a water inlet and a water outlet, and both the water inlet and the water outlet are used to connect to a water source.
[0016] The above laser debonding device positions the workpiece to be debonded on the positioning disk. After the position of the workpiece to be debonded is determined, the negative pressure inside the hollow rod is used to fix the bottom surface of the workpiece to be debonded, so that it does not shift relative to the positioning disk. Then, the laser system can be used to heat the workpiece to be debonded to make the temperature of the workpiece to be debonded meet the set requirements. During the debonding process, the two-dimensional stage and the laser system move simultaneously, and the entire processing area is covered by splicing. This method not only ensures the uniformity of laser processing but also improves the processing efficiency. During the splicing process, after the laser beam completes debonding one row of areas of the bonding layer, the vacuum pump is controlled to form a negative pressure inside the first air passage and adsorb the surface of the workpiece to be debonded through the air holes. The bonding layer generates gaps and separates, and is separated sequentially from one side until it is completely separated, avoiding the cooling phenomenon of the bonding layer and preventing re-adhesion. At the same time, the molten gas generated by heating can be effectively discharged, which helps to maintain the stability of the laser debonding process. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0018] Figure 1 is a schematic structural diagram of a laser debonding device for an embodiment;
[0019] Figure 2 is Figure 1 a schematic structural diagram of the two-dimensional stage in
[0020] Figure 3 is Figure 1 a schematic structural diagram of the disk in
[0021] Figure 4 is Figure 1 a schematic structural diagram of the workpiece to be debonded in
[0022] Figure 5 is Figure 1 a schematic diagram of the laser system in
[0023] Figure 6 is Figure 5 a schematic diagram of the spliced light spot of the laser debonding device in
[0024] Figure 7 is Figure 1 a schematic structural diagram of the fixing component in
[0025] Figure 8 isFigure 1 Schematic diagram of the internal structure of the cooling plate.
[0026] Reference numerals:
[0027] 100, two-dimensional stage; 110, cooling plate; 112, water channel; 111, water inlet; 113, water outlet; 200, fixing component; 210, positioning plate; 220, hollow rod; 230, linear telescopic structure; 240, lifting plate; 242, second air duct; 300, laser system; 310, digital infrared temperature sensor; 320, light-transmitting mirror; 330, scanning galvanometer and field lens; 340, control system; 400, disc; 410, air hole; 420, first air duct; 10, key bonding part to be solved; 101, first layer structure; 102, second layer structure. Detailed implementation manners
[0028] In order to make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0029] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the description of the present utility model are only for the purpose of illustration and do not represent the only implementation manner.
[0030] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.
[0031] In the present utility model, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may mean that the first feature is in direct contact with the second feature, or the first feature is in indirect contact with the second feature through an intermediate medium. Moreover, the first feature being "above", "over" or "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" or "beneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the horizontal height of the first feature is lower than that of the second feature.
[0032] Unless otherwise defined, all technical and scientific terms used in the description of the present utility model have the same meaning as commonly understood by those skilled in the technical field to which the present utility model belongs. The terms used in the description of the present utility model are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. The term "and / or" used in the description of the present utility model includes any and all combinations of one or more of the related listed items.
[0033] To facilitate the understanding of the laser debonding device provided in the embodiments of the present utility model, the application scenarios of the laser debonding device provided in the embodiments of the present utility model will be described first. The laser debonding device is applied in the semiconductor manufacturing process to debond and peel two temporarily bonded layer structures. In the embodiments of the present utility model, the two layer structures are specifically a wafer and a substrate, and a bonding layer is temporarily bonded between the wafer and the substrate. That is, during the wafer processing, the temporarily bonded wafer and substrate are debonded to peel the wafer from the substrate.
[0034] The following will be combined with Figures 1-8 to describe the laser debonding device of the present utility model.
[0035] As Figure 1 shown, in one embodiment, a laser debonding device includes a two-dimensional stage 100, a fixing component 200, a laser system 300 and a disk 400;
[0036] The fixing component 200 is installed on the two-dimensional stage 100 and is used to fix the bonding component 10 to be debonded. It includes a positioning disk 210 and a hollow rod 220. The hollow rod 220 is used to connect to a vacuum pump; a laser system 300, which is linked with the two-dimensional stage 100 and is used to generate a laser beam passing through the bonding component 10 to be debonded, and control the focus of the laser beam to scan on the bonding layer of the bonding component 10 to debond the bonding layer; a disk 400 is arranged on the positioning disk 210 and moves along with the positioning disk 210. One side close to the positioning disk 210 has air holes 410 distributed in an array. The inside of the disk 400 has first air channels 420 distributed in an array. Each first air channel 420 is communicated with the corresponding air hole 410 and is connected to the vacuum pump. The material of the disk 400 is the same as that of the bonding layer and can transmit the laser beam. Refer to Figure 2 and Figure 3 .
[0037] It should be noted that the two-dimensional stage 100 is composed of an X-axis guiding system, a Y-axis guiding system, a driving system, a regulating system and a sensor. The X-axis guiding system and the Y-axis guiding system have the same structure, specifically including a guide rail, a guide rail seat and a linear bearing to ensure smooth and precise movement. The X-axis guiding system and the Y-axis guiding system are both driven by the corresponding driving system. The driving system is usually driven by a stepping motor, a servo motor or other types of motors. The regulating system is responsible for managing and controlling the movement of the platform and is usually composed of a microcontroller, a driver, an encoder and control software. The sensor is used to monitor the position, speed and other parameters of the platform to provide feedback and ensure the accuracy and stability of the movement.
[0038] In the laser debonding device of this embodiment, the bonding component 10 to be debonded is positioned on the positioning disk 210. After the position of the bonding component 10 is determined, the bottom surface of the bonding component 10 is fixed by the negative pressure inside the hollow rod 220 so that it does not shift relative to the positioning disk 210. Then, the bonding component 10 can be heated by the laser system 300 to make the temperature of the bonding component 10 meet the set requirements. During the debonding process, the two-dimensional stage 100 and the laser system 300 move simultaneously and cover the entire processing area through splicing. This method not only ensures the uniformity of laser processing but also improves the processing efficiency. And during the splicing process, after the laser beam completes the debonding of one row of areas of the bonding layer, the vacuum pump is controlled to form a negative pressure inside the first air channels 420 and adsorb the surface of the bonding component 10 through the air holes 410. The bonding layer generates gaps and separates, and is separated sequentially from one side until it is completely separated. This avoids the cooling phenomenon of the bonding layer and prevents re-adhesion. At the same time, it enables the molten gas generated by heating to be effectively discharged, which helps to maintain the stability of the laser debonding process.
[0039] The following introduces each structure in detail with reference to the drawings.
[0040] In many advanced semiconductor manufacturing and optoelectronic applications, in order to improve the overall performance and reliability of devices, with reference to Figure 4 , the debonding component 10 to be solved includes a first-layer structure 101 fixed on the surface of a two-dimensional stage 100 and a second-layer structure 102 bonded through a bonding layer. One of the first-layer structure 101 and the second-layer structure 102 is a wafer, and the other is a sapphire carrier. The thermal expansion coefficient of sapphire is relatively matched with many semiconductor materials (such as GaN, SiC), which can reduce the stress and deformation caused by the difference in thermal expansion coefficients during temperature changes, thereby improving the reliability of the device.
[0041] As an alternative, with reference to Figure 5 and Figure 6 , the laser system 300 includes a digital infrared temperature sensor 310, a transmissive mirror 320, a scanning galvanometer and a field lens 330, and a control system 340. Among them, the digital infrared temperature sensor 310 is used to monitor the temperature during the laser processing. The transmissive mirror 320 is used to reflect the ultraviolet laser onto the surface of the debonding component 10 to be solved and allow the infrared light energy during the processing to pass through and reach the digital infrared temperature sensor 310. The scanning galvanometer and the field lens 330 are used to adjust the laser to enter the field lens and focus on the surface of the debonding component 10 to be solved. The control system 340 is used to collect the temperature data of the digital infrared temperature sensor 310, control the scanning range of the scanning galvanometer and the field lens 330, and control the start and stop of the two-dimensional stage 100.
[0042] Specifically, the control system 340 includes an industrial computer and a PLC. The industrial computer is used to schedule and manage each internal component or sub-device, and the PLC realizes the control and monitoring of various devices and processes through programming. The industrial computer and the PLC coordinate to complete the parameter setting and communication control of the scanning galvanometer and the field lens 330, the digital infrared temperature sensor 310, and the two-dimensional stage 100, so as to realize the automatic control of the debonding to be solved.
[0043] The digital infrared temperature sensor 310 uses non-contact technology to detect the surface temperature of the debonding component 10 to be solved, has high sensitivity, a fast response rate, and high stability. It can adjust the detection range by adjusting the detection distance, has extremely strong flexibility, and the highest detection temperature can reach 1350 °C. A protection window piece is installed at the sensor inlet to block the influence of the ultraviolet laser on the sensor.
[0044] The transmissive mirror 320 is used to reflect the ultraviolet laser and transmit the infrared rays. Using 45° reflection, the ultraviolet reflectivity is greater than 85%, the infrared transmittance is greater than 90%, and it has a high damage threshold and can finely adjust the angle to calibrate the laser optical path.
[0045] The scanning galvanometer and the field lens 330 include an ultraviolet scanning galvanometer and an ultraviolet flat-field lens. Among them, the ultraviolet scanning galvanometer has a light passing aperture of 14 mm, a maximum scanning speed greater than 5000 mm / s, and high stability; the ultraviolet flat-field lens is a telecentric lens. Compared with ordinary field lenses, it has smaller parallax and distortion, and can reduce the impact on the energy uniformity of the flat-top light spot.
[0046] During the entire processing process, the laser passes through the ultraviolet flat-field lens to output a square flat-top light spot (4.4) with a size of 300 μm × 300 μm on the focal plane. The square flat-top light spot (4.4) reaches the working plane (4.1) through the regulation of the ultraviolet scanning galvanometer and the reflection of the light-transmitting mirror 320. The energy density of the light spot on this plane is the largest. The control system 340 generates the best trajectory through the total laser ablation area (4.2). The entire laser system 300 moves at a step length of 30 mm. The control system 340 sends instructions to the ultraviolet scanning galvanometer to control the laser to perform a filling scan within a range of 30 mm × 30 mm on the focal plane of the scanning area and the temperature measurement area (4.3) of the ultraviolet scanning galvanometer. The scanning interval is 0.3 mm. At the same time, the digital infrared temperature sensor 310 starts to collect temperature. The user can continuously adjust the laser processing parameters based on the analysis results of the digital infrared temperature sensor 310 until it is found that the bonded wafer pair can be easily separated and there is no thermal damage on the wafer surface. With the above device, the laser will produce uniform ablation on the bonded wafer pair and there is no thermal damage to the wafer surface. The entire processing device can not only maintain good light spot quality but also improve the overall processing efficiency.
[0047] A valve assembly is arranged in each first air duct 420, and the valve assembly is used to control the negative pressure in the corresponding first air duct 420.
[0048] Through the setting of the valve assembly, the first air duct 420 generates suction in sequence. Through the debonding method of heating from one side to the other side in sequence, the molten gas generated inside can be effectively discharged, which helps to maintain the stability of the laser debonding process.
[0049] Refer to Figure 7 , a linear telescopic structure 230 and a lifting plate 240 are arranged in the two-dimensional stage 100, and the hollow rod 220 is installed on the lifting plate 240.
[0050] The lifting plate 240 has a second air duct 242 inside, and the inside of the hollow rod 220 is communicated with the second air duct 242.
[0051] It should be noted that the linear telescopic structure 230 can be set as a cylinder, a hydraulic cylinder or an electric screw structure, etc.
[0052] When fixing the bonding part 10 to be disassembled, the linear telescopic structure 230 drives the lifting plate 240 and the hollow rod 220 to rise as a whole. The vacuum pump pumps the second air duct 242 in the lifting plate 240 to negative pressure, so that the hollow rod 220 adsorbs the bonding part 10 to be disassembled, preventing the wafer from shifting during the laser processing, and helping to peel the sapphire carrier from the wafer using mechanical tension.
[0053] Refer to Figure 8 , a cooling plate 110 is provided inside the two-dimensional stage 100. A water channel 112 is provided inside the cooling plate 110. The water channel 112 has a water inlet 111 and a water outlet 113. Both the water inlet 111 and the water outlet 113 are used to connect to a water source.
[0054] In the debonding process, in order to effectively control the temperature, a cooling plate 110 is provided inside the two-dimensional stage 100. There is a water channel 112 inside the cooling plate 110. The water channel 112 is connected to a water source, and cooling water is circulated through the water inlet 111 and the water outlet 113 to take away heat.
[0055] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.
[0056] The above-described embodiments only represent several implementation manners of the present utility model. The description is relatively specific and detailed, but it should not be construed as a limitation to the scope of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several deformations and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the appended claims.
Claims
1. A laser debonding device, characterized in that: include: Two-dimensional stage; A fixing assembly, used to fix the to-be-debonded parts, comprising a positioning plate and a hollow rod, wherein the hollow rod is used to be connected to a vacuum pump; A laser system, linked with the two-dimensional stage, is used to generate a laser beam that passes through the to-be-debonded component, and control the focus of the laser beam to scan the bonding layer of the to-be-debonded component to debond the bonding layer; The disc is arranged on the positioning disc and moves with the positioning disc. A side close to the positioning disc has array-distributed air holes. The inside of the disc has array-distributed first air channels. Each first air channel is connected to a corresponding air hole and is connected to a vacuum pump.
2. The laser debonding device according to claim 1, characterized in that: The to-be-debonded component includes a first layer structure fixed on the surface of the two-dimensional carrier, and a second layer structure bonded via a bonding layer, wherein one of the first layer structure and the second layer structure is a wafer, and the other layer structure is a sapphire carrier.
3. The laser debonding device according to claim 1, characterized in that: The laser system includes a digital infrared temperature sensor, a light-transmitting mirror, a scanning galvanometer and a field lens, and a control system, wherein the digital infrared temperature sensor is used to monitor the temperature during laser processing, the light-transmitting mirror is used to reflect ultraviolet laser onto the surface of the bonded part to be debonded and allow infrared light energy during processing to pass through and reach the digital infrared temperature sensor, the scanning galvanometer and the field lens are used to adjust the laser to be incident on the field lens and focus on the surface of the bonded part to be debonded, and the control system is used to collect temperature data of the digital infrared temperature sensor, control the scanning range of the scanning galvanometer and the field lens, and control the start and stop of the two-dimensional stage.
4. The laser debonding device according to claim 3, characterized in that: The control system includes an industrial computer and a PLC. The industrial computer is used to schedule and manage various internal components or sub-equipment, while the PLC controls and monitors various equipment and processes through programming. The industrial computer and the PLC coordinate to complete the parameter setting and communication control of the scanning galvanometer and field mirror, digital infrared temperature sensor, and stepper motor, thereby realizing automatic control of the bond to be debonded.
5. The laser debonding device according to claim 1, characterized in that: An air valve assembly is disposed in each of the first air channels, and the air valve assembly is used to control the negative pressure in the corresponding first air channel.
6. The laser debonding device according to claim 1, characterized in that: A linear telescopic structure and a lifting plate are arranged inside the two-dimensional carrier, the hollow rod is mounted on the lifting plate, and the two-dimensional carrier has a mounting hole matched with the hollow rod.
7. The laser debonding device according to claim 6, characterized in that: The lifting plate has a second air passage in it, and the interior of the hollow rod is communicated with the second air passage.