Wafer edge polishing method

Abstract

The application discloses a wafer edge polishing method, comprising the following steps: positioning an edge polishing device, the edge polishing device having a pair of edge polishing balls arranged opposite to each other in a vertical direction; controlling the two edge polishing balls to rotate at a first preset rotating speed and make the arc surfaces of the two edge polishing balls contact each other to form a pair of pressing and produce deformation; sucking a wafer and making the wafer rotate at a second preset rotating speed; moving the wafer to an edge polishing station to make the edge polishing balls cover the edge of the wafer and polish the edge of the wafer. The application makes the arc surfaces of the two edge polishing balls contact each other to form a pair of pressing and produce deformation, and when the wafer contacts the edge polishing balls, the edge polishing balls can completely cover the edge of the wafer to complete the edge polishing treatment of the wafer, thereby solving the problem that manual edge polishing has high technical requirements for operators; meanwhile, the above automatic operation improves the edge polishing efficiency and avoids the problem that manual edge polishing of employees is easy to be injured.

Description

Technical Field

[0001] This invention relates to the field of semiconductor substrate manufacturing technology, and in particular to a wafer edge polishing method. Background Technology

[0002] Indium phosphide (IP) substrates have applications in multiple fields, including high-frequency, high-power devices, fiber optic communication, wireless transmission, and radio frequency (RF) devices in radio astronomy. RF devices manufactured using IPP substrates exhibit superior performance in applications such as satellites and radar, and are particularly competitive in the RF front-end of radar and communication systems, as well as in analog / mixed-signal wide-bandwidth circuits. They are suitable for applications such as high-speed data processing and high-precision, wide-bandwidth A / D conversion.

[0003] Indium phosphide (IP)-based radio frequency (RF) devices, such as low-noise amplifiers, modules, and receivers, are widely used in satellite communications, millimeter-wave radar, and active and passive millimeter-wave imaging equipment. At bandwidth levels above 100 GHz, IPT-based RF devices demonstrate significant advantages in wireless transmission for backhaul and point-to-point communication networks. It is anticipated that IPT substrates will become the mainstream substrate material for RF devices in future 6G and even 7G wireless transmission networks.

[0004] However, the indium phosphide edge polishing process is currently a time-consuming and labor-intensive process. Existing indium phosphide edge polishing methods mainly rely on manual operation. Employees must first verify the wafer information, then hold sandpaper in one hand and the wafer in the other, and use sandpaper to polish the edge of the wafer. This process is inefficient and requires a high level of technical skill from the operators. Summary of the Invention

[0005] The technical problem to be solved by this invention is that the existing wafer edge polishing is a manual operation, which is inefficient and requires high technical skills from the operators.

[0006] To address the aforementioned technical problems, this invention provides a wafer edge polishing method, comprising the following steps:

[0007] The edge-polishing device is in place, the edge-polishing device having a pair of edge-polishing balls arranged opposite each other in a vertical direction;

[0008] The two ball-shaped balls are controlled to rotate in place at a first preset speed, and the arc surfaces of the two ball-shaped balls are made to contact each other to form a counter-pressure and produce deformation.

[0009] The wafer is picked up and rotated at a second preset speed.

[0010] The wafer is moved to the edge polishing station so that the edge polishing ball covers the edge of the wafer and polishes the edge of the wafer.

[0011] In some embodiments, the counter-pressure of the two ball-on-the-edge balls is 400-600 N.

[0012] In some embodiments, the first preset rotational speed is 15-25 rpm.

[0013] In some embodiments, the wafer aspiration includes: using a vacuum adsorption method on the wafer, wherein the vacuum adsorption force is -25 to -65 kPa.

[0014] In some embodiments, the second preset rotational speed is 30-50 rpm.

[0015] In some embodiments, the two ball-launched balls rotate in the same direction.

[0016] In some embodiments, the edges of the wafer are continuously flushed to remove debris generated during polishing.

[0017] In some embodiments, the continuous rinsing of the edge of the wafer includes: the water flow rate of the rinsing water is 800-1200 ml / min.

[0018] In some embodiments, after the edge polishing is completed, the polished wafer is cleaned.

[0019] In some embodiments, the wafer ablation includes:

[0020] The robotic arm is in place; the robotic arm has an adsorption head.

[0021] Obtain the position coordinates of the wafer;

[0022] The robot adjusts its pose according to the position coordinates and picks up the wafer.

[0023] Compared with the prior art, the wafer edge polishing method of this invention has the following advantages:

[0024] The edge-polishing device of this invention is positioned and includes a pair of edge-polishing balls arranged opposite each other along its height direction. The two edge-polishing balls are controlled to rotate in place at a first preset speed, causing their curved surfaces to contact each other, forming pressure and causing deformation. A wafer is picked up and rotated at a second preset speed. The wafer is moved to the edge-polishing station so that the edge-polishing balls cover the edge of the wafer and polish it. Since the wafer edge is a curved surface rather than a vertical surface, compared to conventional manual edge-polishing methods which can only polish the flat surface of the edge and cannot polish curved surfaces, this invention allows the curved surfaces of the two edge-polishing balls to contact each other, forming pressure and causing deformation. When the wafer contacts the edge-polishing balls, the balls completely cover the wafer edge to complete the edge-polishing process, solving the problem of high technical requirements for operators in manual edge-polishing. Simultaneously, the above-mentioned automated operation improves edge-polishing efficiency and avoids the problem of employee injury during manual edge-polishing. Attached Figure Description

[0025] Figure 1 This is a schematic flowchart of the wafer edge polishing method provided in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the first angle structure of the edge-throwing device provided in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the second angle structure of the edge-throwing device provided in an embodiment of the present invention;

[0028] Figure 4 This is a top view of the edge-polishing device provided in an embodiment of the present invention;

[0029] Figure 5 This is provided by the embodiments of the present invention. Figure 3 A magnified view of part A circled in the diagram;

[0030] Figure 6 This is provided by the embodiments of the present invention. Figure 4 A magnified view of part B circled in the diagram;

[0031] In the diagram, 1. Ball with side impact; 11. Turntable; 12. Polishing pad; 2. Robotic arm; 21. Adsorption head; 22. Robotic arm; 221. Second mounting rod; 222. First bracket; 23. Connecting rod; 3. Base; 31. Mounting slot; 32. Waste trough; 4. First mounting frame; 5. Rotating shaft; 6. Nozzle. Detailed Implementation

[0032] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0033] like Figure 1and Figure 2 As shown, this embodiment of the invention provides a wafer edge polishing method, applied to the edge polishing process of wafers after grinding and before rough polishing. The wafer edge polishing method includes the following steps:

[0034] S110, The edge-polishing device is in place, and the edge-polishing device has a pair of edge-polishing balls 1 arranged opposite each other in the vertical direction;

[0035] This step is the preparation stage, where the edge polishing equipment is placed in a suitable position. The edge polishing ball 1 on the equipment is a key component for polishing the wafer edges. The two edge polishing balls 1 are set opposite each other along the vertical direction, which ensures that the wafer edges can be effectively processed from two directions during the polishing process.

[0036] S120: Control the two ball balls 1 to rotate at a first preset speed in their original position, and make the arc surfaces of the two ball balls 1 contact each other to form a counter-pressure and generate deformation.

[0037] This step involves setting the first preset rotation speed of the two edge-polishing balls 1 through the control system, causing them to start rotating. When the curved surfaces of the two edge-polishing balls 1 come into contact with each other, they will squeeze against each other. Due to the pressure, the edge-polishing balls 1 will produce a slight deformation, increasing the contact area and friction with the edge of the wafer, which helps to improve polishing efficiency and effect.

[0038] S130: Pick up the wafer and make the wafer rotate at a second preset speed;

[0039] In this step, the control system uses a specialized pick-up device to safely pick up the wafer to be polished. The wafer then rotates at a second preset speed. It should be noted that this second preset speed is coordinated with the first preset speed of the polishing ball 1 to ensure that the wafer edge makes uniform contact with the polishing ball 1, thereby achieving a comprehensive and uniform polishing effect.

[0040] S140. Move the wafer to the edge polishing station so that the edge polishing ball 1 covers the edge of the wafer and polishes the edge of the wafer.

[0041] In this step, the control system precisely moves the wafer to the edge polishing station, ensuring that the edge polishing balls 1 completely cover the edge of the wafer. As the edge polishing balls 1 continue to rotate and press, they polish the edge of the wafer, removing edge defects and unevenness, thereby improving the quality and performance of the wafer.

[0042] Since the wafer edge is a curved surface rather than a vertical surface, conventional manual edge polishing methods can only polish the flat surface of the edge and cannot polish the curved surface. Based on the above steps, this embodiment makes the curved surfaces of the two polishing balls 1 contact each other to form pressure and generate deformation. When the wafer contacts the polishing balls 1, the polishing balls 1 can completely cover the wafer edge to complete the edge polishing process, solving the problem that manual edge polishing requires high technical skills from operators. At the same time, through the above-mentioned automated operation, the edge polishing efficiency is improved, and the problem of employees being easily injured during manual edge polishing is also avoided.

[0043] In some embodiments, the counter-pressure of the two ball-on-side balls 1 is 400-600N.

[0044] When the two polishing balls 1 come into contact with each other under this pressure, they undergo a certain degree of deformation. This deformation helps to increase the polishing area and improve polishing efficiency. Understandably, the deformed polishing balls 1 can better adapt to and conform to the edge shape of the wafer, allowing the balls 1 to better wrap around and cover the wafer edge when the wafer contacts them for polishing. This ensures that the entire wafer edge receives uniform and sufficient polishing, improving polishing quality and consistency. Furthermore, the pressure within the aforementioned range ensures that the polishing process effectively removes defects and unevenness from the wafer edge without causing excessive wear or damage, thus achieving good polishing quality and efficiency.

[0045] In some embodiments, the first preset rotational speed is 15-25 rpm.

[0046] Understandably, during the rotary edge polishing process, the polishing ball 1 rotates at a speed of 15-25 revolutions per minute. This ensures that the contact time and force between the polishing ball 1 and the wafer edge are relatively uniform. It can reduce the uneven polishing caused by excessively fast rotation speed or the low polishing efficiency caused by excessively slow rotation speed, maintain the stability and consistency of the polishing process, and thus achieve uniform polishing of the wafer edge. Uniform polishing can avoid local over-polishing or under-polishing, and ensure the overall quality and appearance of the wafer edge.

[0047] In some embodiments, wafer pick-up includes using vacuum adsorption. During wafer pick-up, a negative pressure is generated by the vacuum suction head of the pick-up device, tightly adsorbing the wafer onto the suction head, thereby achieving non-destructive clamping and handling of the wafer. The vacuum adsorption force is -25 to -65 kPa to ensure sufficient adsorption force to stably clamp the wafer, preventing it from falling off due to insufficient adsorption force during handling or processing, while also avoiding damage to the wafer due to excessive adsorption force. Furthermore, the vacuum pressure of the vacuum suction head is stable to prevent positional changes or slippage of the wafer due to vacuum pressure fluctuations during adsorption, handling, or processing.

[0048] In some embodiments, the second preset rotational speed is 30-50 rpm.

[0049] Understandably, the wafer edge approaches the polishing ball 1 at a rotation speed of 30-50 rpm, coordinating with the first preset rotation speed to uniformly generate contact friction with the polishing ball 1. A higher rotation speed will lead to uneven wafer polishing, while an insufficient rotation speed will result in poor edge roughness and uniformity. By using the aforementioned rotation speed, it can be ensured that the contact time and force between the polishing ball 1 and the wafer edge are relatively uniform. This can reduce the uneven polishing caused by excessively high rotation speed or the low polishing efficiency caused by excessively low rotation speed, maintain the stability and consistency of the polishing process, and thus achieve uniform polishing of the wafer edge. Uniform polishing can avoid local over-polishing or under-polishing, ensuring the overall quality and appearance of the wafer edge.

[0050] In some embodiments, the two projectile balls 1 rotate in the same direction.

[0051] When the two polishing balls 1 rotate in the same direction, they perform a coordinated and consistent polishing process on the wafer edge. This synchronized rotation ensures uniform polishing on both sides of the wafer, avoiding inconsistencies or conflicts caused by different rotation directions. Simultaneously, the polishing balls 1 rotating in the same direction receive balanced polishing pressure and friction at the wafer edge, resulting in a stable polishing action and improved polishing efficiency. Since both balls apply force to the wafer edge simultaneously, it helps improve polishing quality and consistency, reducing problems such as localized over-polishing or insufficient polishing caused by inconsistent directions. This allows for faster removal of defects and unevenness, shortening polishing time.

[0052] During wafer polishing, material is removed from the wafer surface due to mechanical or chemical action, forming fine particles and debris. If these debris are not removed promptly, they may re-adhere to the wafer surface, leading to a decrease in surface quality or causing contamination in subsequent process steps. In practical applications, the wafer edges are continuously rinsed to remove polishing debris, promptly washing away polished particles and debris, and preventing damage caused by wear on the polishing ball 1.

[0053] In some embodiments, continuous rinsing of the wafer edges includes a water flow rate of 800-1200 ml / min to provide sufficient water flow to ensure adequate force to flush away debris and particles generated during polishing from the wafer edges, preventing them from re-adhering to the wafer surface or causing further wear. Understandably, excessively high water flow rates may exert impact on the wafer, potentially causing surface damage or deformation. A water flow rate of 800-1200 ml / min ensures effective cleaning without causing unnecessary physical damage to the wafer.

[0054] In some embodiments, after edge polishing, the polished wafer is cleaned to remove particles, debris, and other impurities that may adhere to the wafer surface generated during the edge polishing process. If these impurities are not removed, they may affect subsequent rough polishing methods. Furthermore, this process prevents residual particles or debris from causing further physical damage to the wafer.

[0055] It should be noted that the wafer can also be cleaned before edge polishing to remove particles, debris, other impurities or chemical residues that may adhere to the wafer surface during the polishing process.

[0056] In some embodiments, wafer extraction includes:

[0057] The robotic arm 2 is positioned, and the robotic arm 2 has a suction head 21; in this step, the robotic arm 2 (that is, the suction device mentioned above) is moved to a suitable position to pick up the wafer. The robotic arm 2 is equipped with a suction head 21 (that is, a vacuum suction head mentioned above), which uses vacuum suction or other methods to ensure that the wafer is not damaged during the picking and placing process.

[0058] Obtain the position coordinates of the chip;

[0059] In this step, the specific location of the wafer to be picked up needs to be determined by some positioning system (such as a vision system, sensor or preset program).

[0060] The robot arm 2 adjusts its pose based on its position coordinates and picks up the chip.

[0061] The robotic arm 2 adjusts its position and orientation (e.g., rotation or lifting) according to the position coordinates to ensure that the adsorption head 21 can be accurately aligned and adsorb the wafer. Then, the robotic arm 2 performs a suction operation, using the adsorption head 21 to pick up the wafer from its current position.

[0062] The main purpose of this process is to automate the handling of wafers. By using a robotic arm 2 to pick up the wafers and polish their edges, work efficiency can be improved, human error can be reduced, the accuracy and stability of the production process can be guaranteed, and production costs can be reduced to a certain extent.

[0063] like Figure 2 and Figure 5 As shown, the edge-polishing device used in the above method also includes a base 3, a first mounting frame 4 mounted on the base 3, and two edge-polishing balls 1. The two edge-polishing balls 1 are disposed opposite to each other at the first end of the first mounting frame 4, and the edge-polishing balls 1 can rotate in place relative to the first mounting frame 4. Each edge-polishing ball 1 is provided with a rotating shaft 5 and a first driving member. The output shaft of the first driving member is connected to the rotating shaft 5, and the end of the rotating shaft 5 away from the first driving member is connected to the edge-polishing ball 1 to drive the edge-polishing ball 1 to rotate in place.

[0064] Understandably, in this embodiment, the polishing ball 1 consists of a turntable 11 and a polishing pad 12. An air-filled cavity is formed between the turntable 11 and the polishing pad 12. An air-filled structure inflates the cavity, controlling the curvature of the polishing pad 12's arc surface to change. When the two polishing balls 1 come into contact due to the change in their arc surfaces caused by inflation, they deform, thus meeting the requirements of different polishing methods. That is, in step S120, the arc surfaces of the two polishing balls 1 come into contact to form pressure and deformation. This contact occurs through the aforementioned inflation that creates different volumes of the polishing balls 1, resulting in pressure. Furthermore, in this embodiment, a first driving member controls the two polishing balls 1 to rotate 360° in place at a first preset rotation speed.

[0065] like Figure 4 and Figure 6 As shown, the edge-polishing device also includes the robotic arm 2 mentioned in the above method. The robotic arm 2 has a robotic arm 22 for adjusting its posture, an adsorption head 21 for adsorbing wafers, a connecting rod 23, a vacuum pump, and a second driving component. The robotic arm 22 is mounted on the base 3, the connecting rod 23 is connected to the end of the robotic arm 22, the adsorption head 21 is disposed on the connecting rod 23, and the second driving component is connected to the adsorption head 21 to drive the adsorption head 21 to rotate. The vacuum pump is connected to the adsorption head 21 to adsorb wafers. Understandably, in this embodiment, the vacuum pump controls the vacuum adsorption force of the adsorption head 21 to stably pick up wafers, and the second driving component drives the adsorption head 21 to rotate, thereby causing the wafer to rotate at a second preset speed.

[0066] See also Figure 3The robotic arm 22 includes a second mounting rod 221, a third driving component, a guide rail, a slider, a first support 222, and a fourth driving component. The base 3 has a mounting groove 31 for mounting the second mounting rod 221. The groove wall of the mounting groove 31 is provided with a guide rail, and the slider is slidably mounted on the guide rail. The third driving component is connected to the slider, driving the slider to slide on the guide rail, thereby driving the second mounting rod 221 to extend or retract from the mounting groove 31. The first support 222 is connected to the end of the second mounting rod 221 away from the mounting groove 31, so that the lifting and lowering of the second mounting rod 221 drives the lifting and lowering of the first support 222. The wafer's vertical position is adjusted so that it can accurately fall into the edge-polishing station. The first support 222 is connected to the fourth driving component to drive the first support 222 to rotate, thereby adjusting the wafer's horizontal position. This, combined with the vertical position adjustment, ensures the wafer accurately falls into the edge-polishing station. The suction head 21 is mounted on the end of the first support 222 away from the second mounting rod 221 and is used to grasp or suction objects. As the first support 222 rotates and the second mounting rod 221 rises and falls, the suction head 21 can reach different positions and angles, thus completing the corresponding operation tasks. In other words, based on the above structure, the method mentioned above achieves the goal of adjusting the corresponding pose according to the wafer's coordinate position to pick up the wafer.

[0067] like Figure 5 As shown, the edge polishing device also includes a nozzle 6, which is mounted on the first mounting frame 4. The nozzle of the nozzle 6 is directed toward the center of the line connecting the axes of the two edge polishing balls 1, so as to spray water to carry away the debris generated during edge polishing. The force of the water flow is used to wash away or rinse away the debris, thereby keeping the equipment clean and operating normally, and preventing the damage caused by the wear of the edge polishing pad by the debris of the wafer.

[0068] In addition, the base 3 has a waste trough 32 (such as...) Figure 2 As shown, the waste trough 32 collects and holds waste or debris generated during equipment operation. The presence of the waste trough 32 helps maintain the cleanliness of the work area and facilitates the management and disposal of this waste. The waste trough 32 is located below the sling ball 1 for easy collection. During the sling ball operation, any generated debris, waste materials, or other waste fall downwards with the water flow, and the waste trough 32 effectively catches and holds this waste, preventing it from scattering to other parts of the equipment or the work environment. This design helps improve work efficiency, maintain equipment cleanliness, and ensure a safe working environment.

[0069] The working principle of this invention is as follows: The robotic arm 2 can pick up wafers of different sizes and thicknesses. The robotic arm 2 holds the wafer against the edge of the edge-polishing ball 1. The suction head 21 of the robotic arm 2 automatically picks up the wafer, achieving automatic wafer pick-up and drop-off. The suction head 21 holds the wafer with a vacuum suction force of -25 to -65 kPa, ensuring the wafer will not fall off. Driven by a second driving component, the suction head 21 can rotate automatically (independently). By rotating the suction head 21, the edge of the wafer can uniformly contact and rub against the edge-polishing ball 1. The wafer approaches the edge-polishing ball 1 at a rotation speed of 30-50 rpm, and the edge-polishing ball 1 can rotate 360° at 15-25 rpm, ensuring uniform polishing of the wafer edge and avoiding uneven polishing. With both rotating simultaneously, the edge-polishing ball 1 can effectively and uniformly polish the entire edge of the wafer, achieving the purpose of edge polishing. The pressure applied by the edge-polishing ball 1 is 400-600 N, ensuring a certain degree of deformation. Because the wafer edge is curved rather than vertical, conventional manual edge polishing methods can only polish the flat surface of the edge, not the curved surface. By applying a certain pressure to the polishing ball 1, the polishing ball 1 can completely cover the edge of the wafer when it comes into contact with the wafer, ensuring the accuracy and effect of the edge polishing process. The nozzle 6 sprays water at a flow rate of 800-1200 ml / min. During the polishing process, sufficient water flow is needed to continuously rinse the edge of the wafer, washing away polished particles and other materials in time, and preventing damage caused by the wafer's wear on the polishing ball 1. After the edge polishing operation is completed, the first support 222 rotates 180 degrees to take the wafer away from the edge polishing station, and the second mounting rod 221 can move up and down to lift the wafer and put it back at the wafer pick-up point.

[0070] In summary, the embodiments of the present invention provide a wafer edge polishing method. Compared with conventional manual edge polishing methods, which can only polish the flat surface of the edge and cannot polish curved surfaces, the present invention enables the arc surfaces of two polishing balls 1 to contact each other, so as to form pressure and generate deformation. When the wafer contacts the polishing balls 1, the polishing balls 1 can completely cover the edge of the wafer to complete the edge polishing process. This solves the problem that manual edge polishing requires high technical skills from operators. At the same time, through the above-mentioned automated operation, the edge polishing efficiency is improved, and the problem of employees being easily injured by manual edge polishing is also avoided.

[0071] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A method for polishing the edges of a wafer, characterized in that, Includes the following steps: The edge-polishing device is in place, the edge-polishing device having a pair of edge-polishing balls arranged opposite each other in a vertical direction; The two ball-shaped balls are controlled to rotate in place at a first preset speed, and the arc surfaces of the two ball-shaped balls are made to contact each other to form a counter-pressure and produce deformation; wherein, the counter-pressure of the two ball-shaped balls is 400-600N, and the first preset speed is 15-25 rpm. The wafer is picked up and rotated at a second preset speed of 30-50 revolutions per minute; The wafer is moved to the edge polishing station so that the edge polishing ball covers the edge of the wafer and polishes the edge of the wafer.

2. The wafer edge polishing method according to claim 1, characterized in that, The process of adsorbing the wafer includes: adsorbing the wafer by vacuum adsorption, wherein the vacuum adsorption force is -25 to -65 kPa.

3. The wafer edge polishing method according to claim 1, characterized in that, The two projectiles rotate in the same direction.

4. The wafer edge polishing method according to claim 1, characterized in that, The edges of the wafer are continuously rinsed to remove debris generated during polishing.

5. The wafer edge polishing method according to claim 4, characterized in that, The continuous rinsing of the edge of the wafer includes a water flow rate of 800-1200 ml / min.

6. The wafer edge polishing method according to claim 1, characterized in that, After the edge polishing is completed, the polished wafer is cleaned.

7. The wafer edge polishing method according to claim 1, characterized in that, The wafer being absorbed includes: The robotic arm is in place; the robotic arm has an adsorption head. Obtain the position coordinates of the wafer; The robot adjusts its pose according to the position coordinates and picks up the wafer.

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