UV curing equipment and UV curing methods

Abstract

This invention discloses a UV curing apparatus and a UV curing method. The UV curing apparatus includes a vacuum chamber, the interior of which is used to house a wafer; multiple detection sensors are arranged around the periphery of the vacuum chamber and detect the position of the wafer by emitting detection light; a magnetic levitation drive device is electrically connected to the multiple detection sensors; a first Fresnel lens is drivably connected to the magnetic levitation drive device; the magnetic levitation drive device, in response to signals sent by the multiple detection sensors after detecting the wafer position, drives the first Fresnel lens to move, so that the first Fresnel lens is coaxially positioned with the wafer, thereby allowing UV light to pass through the first Fresnel lens and irradiate the surface of the wafer; this invention, by driving the first Fresnel lens to move through the magnetic levitation drive device, keeps the first Fresnel lens coaxial with the wafer, ensuring that UV light can accurately irradiate the wafer surface, thus improving the utilization rate of UV light irradiation.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically to a UV curing apparatus and a UV curing method. Background Technology

[0002] In the semiconductor field, UV curing technology, with its ability to induce rapid photochemical reactions in photosensitive materials using ultraviolet light, is widely used in several key stages of chip manufacturing. For example, after photolithography and development, photoresist needs to be UV cured. Ultraviolet energy cross-links the polymer materials within the photoresist, increasing its strength and preventing the collapse of the lithographic pattern in subsequent processes. In semiconductor packaging, protective adhesives can be rapidly cured by UV irradiation at low temperatures, effectively preventing thermal damage to the chip and achieving chip sealing protection. Furthermore, UV light can be used for wafer surface cleaning and modification, such as UV ozone cleaning technology. This technology uses ultraviolet light to excite ozone, generating strong oxidizing substances that efficiently remove organic contaminants from the wafer surface. UV light can also alter the physicochemical properties of wafer materials, improving the adhesion and coverage of subsequent coatings.

[0003] However, in the actual UV curing process, the wafer placement position is prone to shift, which means that the UV light emitted by the UV light source cannot completely cover the surface of the wafer, reducing the utilization rate of UV light irradiation. For areas that have not been fully irradiated by UV light, the curing quality is poor or the cleaning and modification effect is poor, which in turn has an adverse effect on subsequent manufacturing processes, thereby reducing the yield and reliability of the product. Summary of the Invention

[0004] The present invention aims to solve the technical problem in existing UV curing devices where the light emitted by the UV light source cannot completely cover the surface of the irradiated wafer due to wafer position misalignment, resulting in low light utilization and reduced product yield and reliability. The invention provides a UV curing device and a UV curing method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A UV curing apparatus, comprising:

[0007] A vacuum chamber, the interior of which is used to house a wafer;

[0008] Multiple detection sensors are arranged around the periphery of the vacuum chamber and detect the position of the wafer by emitting detection light.

[0009] A magnetic levitation drive device is electrically connected to multiple of the aforementioned detection sensors;

[0010] A first Fresnel lens is drivably connected to the magnetic levitation drive device and suspended above the vacuum chamber for projecting UV light onto the surface of the wafer.

[0011] The magnetic levitation drive device is configured to: in response to an offset signal generated after the plurality of detection sensors detect the position of the wafer, drive the first Fresnel lens to move by adjusting the generated electromagnetic force so that the first Fresnel lens and the wafer remain coaxial.

[0012] Furthermore, the UV curing device also includes a cavity, a support frame, and a second Fresnel lens;

[0013] The support frame is disposed within the cavity, and the second Fresnel lens is disposed on the support frame. The cavity, the support frame, and the second Fresnel lens enclose and form the vacuum chamber.

[0014] Furthermore, the radial dimension of the first Fresnel lens is configured to be the same as the radial dimension of the wafer and smaller than the radial dimension of the second Fresnel lens.

[0015] Furthermore, the UV curing device also includes a pressure ring, which is disposed on the top of the support frame and cooperates with the support frame to form an annular space with a radial opening;

[0016] The magnetic levitation drive device is disposed within the annular space, and the first Fresnel lens is drivably connected to the magnetic levitation drive device through the radial opening.

[0017] Furthermore, the magnetic levitation drive device includes:

[0018] A coil assembly includes multiple coils and a coil frame, wherein the multiple coils are wound on the coil frame and electrically connected to the multiple detection sensors one by one via wires;

[0019] A sensing magnet is disposed on the top and bottom surfaces of the edge of the first Fresnel lens, and a plurality of coils are arranged radially around the sensing magnet;

[0020] A driving magnet is positioned opposite to the top and bottom of the annular space. The driving magnets are located on the upper and lower sides of the sensing magnet, respectively, to maintain the first Fresnel lens in a suspended state driven by the sensing magnet.

[0021] Furthermore, the driving magnet includes a first magnet, an insulating partition, and a second magnet arranged sequentially from the inside to the outside, and the first magnet and the second magnet have opposite polarities.

[0022] Furthermore, the detection sensor includes:

[0023] The detection module is used to emit detection light to detect the position of the wafer and generate an offset signal based on the position of the wafer;

[0024] The control module is used to receive the offset signal and generate control commands;

[0025] The driving module is used to receive the control command and adjust the direction and magnitude of the current flowing through the corresponding coil, and then drive the induction magnet to move the first Fresnel lens by adjusting the generated electromagnetic force.

[0026] Furthermore, the support frame includes an inner ring wall, an outer ring wall, and a bottom wall connecting the inner ring wall and the outer ring wall. The outer ring wall is fitted and fixed to the side wall of the cavity. The inner ring wall has a stepped portion on the side away from the outer ring wall, and the second Fresnel lens is disposed on the stepped portion.

[0027] Furthermore, multiple detection sensors are disposed between the inner ring wall and the outer ring wall. The inner ring wall is provided with a detection sensor window corresponding to the position of each detection sensor. The detection sensor window is made of transparent material, so that the detection light emitted by each detection sensor can penetrate the corresponding detection sensor window to detect the position of the wafer.

[0028] Furthermore, the UV curing device also includes a power supply ring, which is disposed between the inner ring wall and the outer ring wall and connected to multiple detection sensors via wires. The power supply ring is a rechargeable power source, which helps maintain the vacuum performance of the entire device.

[0029] The present invention also provides a UV curing method, comprising the following steps:

[0030] S1. Place the wafer to be cured inside the vacuum chamber and make the vacuum chamber a sealed space;

[0031] S2. Activate multiple detection sensors arranged around the perimeter of the vacuum chamber to detect the position of the wafer by emitting detection light and generate an offset signal;

[0032] S3. In response to the offset signal, the magnetic levitation drive device drives the first Fresnel lens to move by adjusting the generated electromagnetic force until the first Fresnel lens and the wafer are coaxially positioned.

[0033] S4. UV light is projected onto the surface of the wafer through the first Fresnel lens, and the UV curing process continues for a preset time.

[0034] The present invention has the following beneficial effects:

[0035] This invention utilizes the principle of magnetic levitation, enabling the magnetic levitation drive device to respond to the offset signal generated by the detection sensor and adjust the resulting electromagnetic force to keep the lens coaxial with the wafer. Specifically, the magnetic levitation drive device drives the first Fresnel lens to move, ensuring that the first Fresnel lens remains coaxial with the wafer. This ensures that UV light passing through the first Fresnel lens accurately illuminates the wafer surface, improving the utilization rate of UV light irradiation.

[0036] This invention utilizes detection sensors to detect the actual offset of a wafer. Multiple detection sensors are arranged around the perimeter of the vacuum chamber, enabling comprehensive and accurate detection of wafer positional offset.

[0037] This invention utilizes a double-layer Fresnel lens to solve the problem of scattered and weak ultraviolet light, achieving a better UV curing effect. The first Fresnel lens can be adjusted according to the wafer offset, while the second Fresnel lens refocuses the light, further ensuring that the light can completely cover the wafer and improving the quality of UV curing. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the cross-sectional structure of the UV curing device in an embodiment of the present invention.

[0039] Figure 2 This is a partial cross-sectional structural diagram of the UV curing device in an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the internal partial structure of the UV curing device in an embodiment of the present invention.

[0041] Figure 4 for Figure 3 Enlarged structural diagram of part A in the middle.

[0042] Figure 5 This is a schematic diagram showing the positional relationship between the power supply ring and the support frame of the UV curing device in an embodiment of the present invention.

[0043] Figure 6 This is a schematic diagram of the coil assembly in an embodiment of the present invention.

[0044] Figure 7 This is a schematic diagram of the installation structure of the coil and the detection sensor in an embodiment of the present invention.

[0045] Figure 8 for Figure 4 A schematic diagram showing the positions of the S or N poles of the induction magnet and the driving magnet.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1-Vacuum chamber, 2-Detection sensor, 3-Magnetic levitation drive device, 4-First Fresnel lens, 5-Cavity, 6-Support frame, 7-Second Fresnel lens, 8-Pressure ring, 9-Annular space, 10-Coil assembly, 11-Induction magnet, 12-Drive magnet, 13-First magnet, 14-Insulating partition, 15-Second magnet, 16-Inner ring wall, 17-Outer ring wall, 18-Bottom wall, 19-Step section, 20-Detection sensor window, 21-Power supply ring, 22-Coil, 23-Coil frame, 24-Wafer, 25-Heater, 26-Pressure plate, 27-S pole, 28-N pole. Detailed Implementation

[0048] The present invention will now be further described in conjunction with the accompanying drawings and relevant knowledge, and will be described clearly and completely. Obviously, the described applications are only some embodiments of the present invention, and not all embodiments.

[0049] In existing technologies, wafer position offset is mainly caused by the following factors:

[0050] Equipment accuracy factors: During wafer transfer, insufficient alignment accuracy of the robotic arm when grasping the wafer, or uneven distribution of vacuum adsorption force of the suction cup, can cause the wafer to shift after placement.

[0051] Process parameter factors: During process execution, uneven temperature distribution or pressure fluctuations inside the cavity can cause uneven thermal expansion or contraction of the wafer, indirectly causing positional displacement; for thin wafers of 12 inches and above, the lateral thrust generated by uneven airflow distribution inside the cavity can also cause wafer displacement.

[0052] Physical characteristics: During wafer manufacturing, substrate defects or thin film stress can cause uneven stress on the wafer, resulting in warping and making it unable to fully adhere to the equipment's suction cup, making it prone to slippage and displacement during positioning. In addition, unstable power supply voltage and fluctuations in compressed air pressure can affect the movement speed of the robotic arm and the suction force of the suction cup, which can also indirectly lead to wafer displacement.

[0053] In traditional UV curing equipment, the UV light source is typically fixed, and plane mirrors are often used for light transmission. Plane mirrors easily cause light divergence, preventing the light from being concentrated on the wafer area. When the wafer shifts, the fixed light source and the diverging light cannot track the wafer's positional change, resulting in incomplete UV coverage of the wafer surface and localized under-illumination. Areas that are not adequately irradiated exhibit poor curing quality or ineffective cleaning and modification, impacting not only the performance of semiconductor devices but also reducing product yield and reliability, becoming a key issue restricting the development of semiconductor UV curing processes. Furthermore, traditional UV curing methods lack a dynamic adjustment process for wafer shift, relying solely on initial positioning and fixed illumination, further exacerbating the problem of insufficient illumination coverage.

[0054] To solve the above problems, such as Figure 1 As shown, the present invention provides a UV curing device, including a vacuum chamber 1, multiple detection sensors 2, a magnetic levitation drive device 3, and a first Fresnel lens 4.

[0055] The interior of vacuum chamber 1 houses wafer 24, providing the necessary vacuum environment for the UV curing process and preventing airborne impurities from interfering with the photochemical reaction. Multiple detection sensors 2 are arranged around the periphery of vacuum chamber 1, emitting detection light to detect the position of wafer 24 and establishing a correspondence between the light signal and position. For example, standard optical features of wafer 24, such as edge contours and reference point positions, can be preset. When wafer 24 shifts, the path or intensity of the detection light changes, and the detection sensors 2 obtain the offset by comparing the actual signal with the standard signal. Figure 1 A heater 25 is provided below the wafer 24 for heating the wafer 24.

[0056] A magnetic levitation drive 3 is electrically connected to multiple detection sensors 2. A first Fresnel lens 4 is drivably connected to the magnetic levitation drive 3 and levitates above the vacuum chamber 1 to project UV light onto the surface of the wafer 24. The magnetic levitation drive 3 is configured to: in response to an offset signal generated after the multiple detection sensors 2 detect the position of the wafer 24, drive the first Fresnel lens 4 to move by adjusting the generated electromagnetic force, so that the first Fresnel lens 4 remains coaxial with the wafer 24.

[0057] In response to the offset signal generated by the detection sensor 2, the magnetic levitation drive device 3 adjusts the generated electromagnetic force to drive the first Fresnel lens 4 to move, ultimately keeping the first Fresnel lens 4 coaxial with the wafer 24. This ensures that the UV light accurately covers the surface of the wafer 24 after being focused by the lens. Utilizing its thinness and high light-gathering efficiency, the magnetic levitation drive device 3 focuses the UV light onto the surface of the wafer 24, reducing light divergence and improving light intensity utilization. This invention uses the detection sensor 2 to capture the offset of the wafer 24 in real time, and the magnetic levitation drive device 3 drives the first Fresnel lens 4 to dynamically track it, achieving coaxial alignment between the first Fresnel lens 4 and the wafer 24. This significantly improves the UV light irradiation coverage and utilization, ensures curing uniformity, and improves product yield.

[0058] More specifically, after wafer 24 is transferred into vacuum chamber 1, vacuum chamber 1 is sealed and evacuated to a preset pressure. Multiple detection sensors 2 are activated, and the emitted detection light penetrates the transparent detection window of vacuum chamber 1, illuminating the edge of wafer 24 and reference points. If wafer 24 is not offset, the light intensity distribution and imaging profile received by detection sensors 2 perfectly match the preset standard, and a normal signal is output. If wafer 24 is offset due to misalignment of the robotic arm, uneven suction force of the suction cup, etc., such as an offset of 0.3mm along the X-axis or 0.2mm along the Y-axis, the area where the light is blocked changes, causing the voltage signal or pixel coordinates output by detection sensors 2 to deviate from the preset value. Detection sensors 2 analyze the specific offset amount through internal algorithms. After calculating the adjustment amount based on the offset amount, an offset signal is generated. In response to the offset signal, the magnetic levitation drive device 3 adjusts the generated electromagnetic force to drive the first Fresnel lens 4 to move until the first Fresnel lens 4 and wafer 24 are coaxially aligned. At this point, the light emitted by the UV light source, after being focused by the first Fresnel lens 4, completely covers the surface of the wafer 24. In this invention, the high-precision detection of the detection sensor 2 provides a precise adjustment basis for the magnetic levitation drive device 3. The rapid response of the magnetic levitation drive device 3 ensures real-time synchronization between the first Fresnel lens 4 and the wafer 24. The first Fresnel lens 4 then efficiently focuses the adjusted light, forming a synergy of detection, drive, and focusing, fundamentally solving the problem of low light utilization caused by offset and overcoming the limitations of traditional fixed light sources. Through the real-time linkage between the detection sensor 2 and the magnetic levitation drive device 3, closed-loop control of detection and adjustment is achieved, significantly improving the light coverage. The focusing effect of the first Fresnel lens 4 improves both the uniformity of UV light intensity and curing efficiency, avoiding curing defects in un-irradiated areas.

[0059] In one embodiment of the present invention, the UV curing apparatus further includes a cavity 5, a support frame 6, and a second Fresnel lens 7. The support frame 6 is disposed within the cavity 5, and the second Fresnel lens 7 is disposed on the support frame 6. The cavity 5, the support frame 6, and the second Fresnel lens 7 enclose a vacuum chamber 1. This arrangement allows UV light to pass sequentially through the first Fresnel lens 4 and the second Fresnel lens 7, irradiating the surface of the wafer 24. In other words, a single lens has limited focusing effect on UV light, and the structural stability of the vacuum chamber 5 is insufficient. The double-layer Fresnel lens forms a secondary focusing effect, further compressing the beam divergence angle, resulting in a more uniform UV light distribution and higher irradiation intensity.

[0060] More specifically, an annular step is machined at the axial center of the support frame 6, and the second Fresnel lens 7 is fixed on the annular step, preferably by a pressure plate 26, forming a sealed vacuum chamber 1 together with the cavity 5 and the support frame 6. After the UV light is initially focused by the first Fresnel lens 4, the light enters the second Fresnel lens 7 at a more concentrated angle; the synergistic focusing of the double-layer Fresnel lens of the present invention improves the uniformity of light intensity on the surface of the wafer 24, and the curing quality of the edge area is consistent with that of the center. The first Fresnel lens 4 dynamically tracks the offset of the wafer 24 to ensure that the light center is aligned; the second Fresnel lens 7 is fixedly focused to compensate for the edge light intensity deviation that may occur due to dynamic adjustment.

[0061] In one embodiment of the present invention, the radial dimension of the first Fresnel lens 4 is configured to be the same as the radial dimension of the wafer 24 and smaller than the radial dimension of the second Fresnel lens 7. More specifically, the radial dimension of the second Fresnel lens 7 is larger than that of the first Fresnel lens 4, and its aperture must cover the maximum adjustment range of the first Fresnel lens 4 to ensure unobstructed light transmission. For example, light emitted from a UV light source is projected vertically onto the second Fresnel lens 7 after passing through the first Fresnel lens 4, and then focused by the second Fresnel lens 7 onto the surface of the wafer 24. In other words, the effective optical aperture of the first Fresnel lens is adapted to the radial dimension of the wafer and is smaller than the effective optical aperture of the second Fresnel lens.

[0062] It should be noted that if only the fixed second Fresnel lens 7 is used, when wafer 24 is misaligned, UV light will irradiate the carrier material (such as ceramic / metal trays or supports) surrounding wafer 24, causing the following serious problems: Trace amounts of organic contaminants may remain on the tray surface; the high energy of the UV light will solidify and firmly adhere to them, potentially leading to particulate contaminants that subsequently detach. These particles, landing on wafer 24, can cause obstruction during critical processes such as photolithography and etching, resulting in point defects, short circuits, or open circuits, directly reducing chip yield. The tray surface is typically coated with a special coating (for electrostatic adsorption or chemical stability); UV light can degrade the coating's functionality. Even without a coating, UV irradiation may alter the microstructure of the metal / ceramic, affecting its flatness, adsorption capacity, and thermal conductivity. Frequent mis-irradiation accelerates tray aging, increasing equipment maintenance costs and downtime.

[0063] Furthermore, in this invention, the first Fresnel lens 4 tracks the position of the wafer 24 in real time through the magnetic levitation drive device 3, always maintaining coaxiality with the offset wafer 24. This ensures that the central axis of the UV light after passing through the first Fresnel lens 4 is consistent with the central axis of the wafer 24, preventing the light from deviating from the overall range of the wafer 24. Additionally, the size of the first Fresnel lens 4 is adapted to the wafer 24, and with dynamic adjustment, the light projection range can be strictly controlled. After being refocused by the second Fresnel lens 7, the light only covers the surface of the wafer 24, completely avoiding the surrounding carrier. In this invention, the second Fresnel lens 7, through its large-aperture design, receives the emitted light from the first Fresnel lens 4, achieving secondary focusing and homogenization. Meanwhile, the first Fresnel lens 4, through dynamic tracking, ensures that the light is aimed at the wafer 24. The combination of these two features solves the irradiation deviation problem caused by the offset of the wafer 24 and prevents the light from accidentally irradiating peripheral components, ultimately ensuring the stability and reliability of the UV curing process.

[0064] In one embodiment of the present invention, the UV curing apparatus further includes a pressure ring 8, which is disposed on the top of the support frame 6 and cooperates with the support frame 6 to form an annular space 9 with a radial opening. A magnetic levitation drive device 3 is disposed within the annular space 9, and a first Fresnel lens 4 is drivably connected to the magnetic levitation drive device 3 through the radial opening.

[0065] Reference Figure 2 , Figure 4 , Figure 6 , Figure 7 As shown, in one embodiment of the present invention, the magnetic levitation drive device 3 is electrically connected to multiple detection sensors 2. The magnetic levitation drive device 3 includes a coil assembly 10, a sensing magnet 11, and a drive magnet 12. The coil assembly 10 includes multiple coils 22 and a coil frame 23. The multiple coils 22 are wound on the coil frame 23 and connected to the multiple detection sensors 2 one-to-one via wires. The sensing magnet 11 is correspondingly disposed on the top and bottom surfaces of the edge of the first Fresnel lens 4, and the multiple coils 22 are arranged radially around the sensing magnet 11. The drive magnet 12 is disposed opposite to each other at the top and bottom of the annular space 9. The oppositely disposed drive magnets 12 are located on the upper and lower sides of the sensing magnet 11, respectively, to maintain the sensing magnet 11 driving the first Fresnel lens 4 in a levitation state.

[0066] This invention achieves precise driving through the corresponding design of coil 22 and induction magnet 11. Each coil 22 responds to the offset signal generated by the corresponding detection sensor 2, independently adjusting the local magnetic field, and thus adjusting the generated electromagnetic force, making the lens displacement more precise. The driving magnet 12 is used to form a stable levitation magnetic field, which, together with the dynamic electromagnetic force generated by the coil 22, ensures that the lens moves smoothly in a non-contact state. The coil assembly 10 changes the magnetic field strength and direction by adjusting the magnitude and direction of the current, thereby adjusting the generated push / pull electromagnetic force, which is the power source for driving the lens movement. The one-to-one correspondence between coil 22 and detection sensor 2 ensures the targeted adjustment. The magnetic field of the induction magnet 11 interacts with that of the coil 22, transmitting the electromagnetic force to the first Fresnel lens 4 to achieve non-contact driving. The driving magnet 12 provides static levitation force to balance the weight of the lens, keeping it in a stable levitation state and reducing motion resistance.

[0067] More specifically, in some embodiments, the coils 22 of the coil assembly 10 are evenly distributed on the coil frame 23. The induction magnet 11 is a ring-shaped permanent magnet made of neodymium iron boron and is attached to the top and bottom surfaces of the edge of the first Fresnel lens 4. The driving magnets 12 are fixed on the pressure ring 8 and the bottom support frame 6, respectively, forming a static magnetic field with the induction magnets 11, which attracts upwards and repels downwards, thus suspending the lens. For example, the first magnet 13 of the upper driving magnet 12 has its N pole facing outwards and the second magnet 15 has its S pole facing outwards, forming a balanced force of upward repulsion and downward attraction with the induction magnet 11 having its N pole facing upwards. When the detection sensor 2 detects that the wafer 24 is offset along the positive Y-axis, the current of the two coils 22 corresponding to the positive Y-axis increases, generating a magnetic field in the same direction, which repels the induction magnets 11 and pushes the lens to move along the positive Y-axis. At the same time, the current of the two coils 22 in the negative Y-axis decreases, the magnetic field weakens, and the reverse resistance is reduced, ensuring that the lens completes the adjustment in a short time. The coil assembly 10 corresponds one-to-one with the detection sensor 2 to achieve precise point-to-point driving. It should be noted that it is not limited to two coils 22.

[0068] In one embodiment of the present invention, reference is made to... Figure 2 , Figure 3 , Figure 4 , Figure 8As shown, the driving magnet 12 includes a first magnet 13, an insulating partition 14, and a second magnet 15 arranged sequentially from the inside out, with the first magnet 13 and the second magnet 15 having opposite polarities. Furthermore, the double-layered magnets with opposite polarities form a stronger gradient magnetic field through magnetic field superposition, which can stably support the large-size lens; the insulating partition 14 avoids magnetic field interference between the magnets, ensuring uniform magnetic field distribution and preventing the lens from tilting or shaking during levitation. In other words, the first magnet 13 and the second magnet 15 enhance the overall magnetic field strength through magnetic field interaction, forming a stable levitation force field. The insulating partition 14 is made of a non-magnetic material, such as ceramic, to isolate the magnetic fields of the two magnets, preventing magnetic field cancellation or disorder and ensuring levitation stability. The N pole of the top first magnet 13 faces outward, and the S pole of the top second magnet 15 faces outward, bonded together by the insulating partition 14 to form a double-layered magnet structure. When the top-side induction magnet 11 (N pole facing upwards) is positioned between them, the first magnet 13 exerts an upward attractive force on the induction magnet 11, while the second magnet 15 generates a repulsive force. The combined force of these two forces forms a stable levitation force. Similarly, the polarities of the bottom-side induction magnet 11 and the bottom-side drive magnet 12 are correspondingly arranged. The first magnet 13 and the second magnet 15 form a push-pull force through opposite polarities, and the insulating partition 14 ensures the stability of the combined force, providing a high-strength and high-stability levitation foundation for the magnetic levitation drive device 3. Together with the coil assembly 10 and the induction magnet 11, it achieves precise driving of the large-size lens.

[0069] In one embodiment of the present invention, the detection sensor 2 includes a detection module, a control module, and a drive module. The detection module emits detection light to detect the position of the wafer 24 and generates an offset signal based on the position of the wafer 24. The control module receives the offset signal and generates control commands. The drive module receives the control commands and adjusts the direction and magnitude of the current flowing through the corresponding coil 22, thereby adjusting the generated electromagnetic force to drive the induction magnet 11 to move the first Fresnel lens 4. Furthermore, the detection sensor 2 is used to accurately identify the offset direction and magnitude of the wafer 24. A Hall effect sensor is preferred, providing high-precision detection capabilities. A detection window 20 (transparent material) is provided between the sensor and the wafer 24 to maintain a vacuum environment while ensuring detection. In this invention, the detection module captures the positional changes of the edge or reference point of the wafer 24 using optical principles and outputs the original offset signal. The control module uses a PID algorithm to process the offset signal, calculates the optimal adjustment amount, and generates current control commands to ensure the speed and accuracy of the adjustment. The drive module converts the control commands into specific parameters of the current in the coil 22, directly driving the magnetic field change.

[0070] More specifically, the light source emitter of the detection module emits a laser beam that penetrates the detection window 20 of the detection sensor and illuminates the edge of the wafer 24. The photosensitive element simultaneously collects the reflected light to form an image. If the wafer 24 is not offset, the edge of the wafer 24 in the image coincides with the preset coordinates, such as X=150mm, Y=150mm. If the wafer 24 is offset by 0.3mm along the X-axis due to uneven vacuum adsorption force of the suction cup, the edge coordinates in the image become X=150.3mm. The detection module converts this pixel data into a voltage signal, such as 3.2V (standard value is 3.0V), and transmits it to the control module. The control module calculates the deviation of 0.3mm using a PID algorithm and generates a command to change the current of the coil 22. The drive module converts the command into an actual current signal and transmits it to the coil assembly 10 of the magnetic levitation drive device 3 through a wire. The detection module provides high-precision raw data, the control module realizes the accurate conversion of deviation and command, and the drive module connects the detection sensor 2 and the magnetic levitation drive device 3 to form a closed loop of detection, calculation and execution. Together with the coil assembly 10, it realizes the seamless connection of the detection sensor 2 signal → current change → magnetic field adjustment → lens displacement, which significantly improves the adjustment response speed compared with non-modular adjustment.

[0071] Reference Figure 3 As shown, in one embodiment of the present invention, the support frame 6 includes an inner ring wall 16, an outer ring wall 17, and a bottom wall 18 connecting the inner ring wall 16 and the outer ring wall 17. The outer ring wall 17 is fitted and fixed to the side wall of the cavity 5. A step portion 19 is provided on the side of the inner ring wall 16 away from the outer ring wall 17, and the second Fresnel lens 7 is disposed on the step portion 19. In the present invention, the step portion 19 provides an axial positioning reference for the second Fresnel lens 7, precisely controlling the installation height of the second Fresnel lens 7; the double-layer structure of the inner ring wall 16 and the outer ring wall 17 enhances the deformation resistance of the support frame 6 and adapts to fluctuations in temperature and pressure within the cavity.

[0072] In one embodiment of the present invention, a plurality of detection sensors 2 are disposed between the inner ring wall 16 and the outer ring wall 17. The inner ring wall 16 has a detection sensor window 20 corresponding to the position of each detection sensor 2. The detection sensor window 20 is made of a transparent material, allowing the detection light emitted by each detection sensor 2 to penetrate the corresponding detection sensor window 20 to detect the position of the wafer 24. Furthermore, the detection sensor window 20 is made of high-transmittance quartz material with a transmittance of over 95%, ensuring no attenuation of the detection light. The sealed connection between the window and the inner ring wall 16 maintains a vacuum environment and isolates internal and external interference.

[0073] More specifically, the detection sensor 2 is fixed to the inner side of the outer ring wall 17 by a bracket, and its detection optical path is aligned with the center of the detection window 20 of the detection sensor. When the wafer 24 shifts slightly due to uneven temperature in the chamber, the light emitted by the detection sensor 2 illuminates the edge of the wafer 24 through the detection window. The photosensitive element captures the positional change of the reflected light from the edge and converts it into an offset signal through the detection module. The 360° surround mounting of the detection sensor 2 eliminates detection blind spots and achieves a high offset detection rate. The surround layout of the detection sensor 2 and the precise alignment of the detection window ensure real-time capture of the entire circumference offset of the wafer 24.

[0074] Reference Figures 4-5 As shown, in one embodiment of the present invention, the UV curing device further includes a power supply ring 21, which is disposed between the inner ring wall 16 and the outer ring wall 17 and connected to a plurality of detection sensors 2 via wires. The power supply ring 21 is a rechargeable power source that provides power support to the detection sensors 2. The rechargeable power source does not require wires to be connected to an external power source, which helps to maintain the vacuum performance of the entire device.

[0075] To further explain: The coil assembly 10 of the present invention is disposed within an annular space 9 formed by the cooperation of the pressure ring 8 and the support frame 6, and surrounds the radial periphery of the induction magnet 11. The coil assembly 10 includes multiple coils 22 and a coil frame 23, wherein the multiple coils 22 are evenly wound on the coil frame 23, and the coil frame 23 serves to fix the position of the coils 22, so that the coils 22 are distributed in a ring; the driving magnet 12 is disposed opposite to the top and bottom of the annular space 9, respectively located on the upper and lower sides of the induction magnet 11 (the induction magnet 11 is fixed on the top and bottom surfaces of the edge of the first Fresnel lens 4, and is used to drive the lens to levitate). The driving magnet 12 consists of a first magnet 13, an insulating partition 14 and a second magnet 15 from the inside to the outside, and the three are coaxially arranged to form a double-layer magnet structure. Coil 22 is the core functional component of coil assembly 10. It is wound on coil frame 23. Coil frame 23 provides mechanical support for coil 22, so that multiple coils 22 maintain a surrounding distribution. Coil 22 and coil frame 23 together constitute coil assembly 10. Coil 22 is electrically connected to detection sensor 2 one by one through wires to receive current control signals from the sensor.

[0076] Furthermore, the first magnet 13 and the second magnet 15 of the driving magnet 12 are permanent magnets with opposite polarities (e.g., the N pole of the first magnet 13 faces outward, and the S pole of the second magnet 15 faces outward). They are isolated by an insulating partition 14. The insulating partition 14 is made of a non-magnetic material (such as ceramic), and its function is to block the magnetic field interference between the first magnet 13 and the second magnet 15, ensuring that the magnetic fields of the two are superimposed to form a stable gradient magnetic field, providing a balanced levitation force (upward attraction and downward repulsion or upward repulsion and downward attraction) for the induction magnet 11. The coil assembly 10 surrounds the radial periphery of the induction magnet 11, and the driving magnet 12 is located on the upper and lower sides of the induction magnet 11, forming a spatial layout of upper and lower clamping and radial circling. The static magnetic field of the driving magnet 12 maintains the levitation state of the induction magnet 11 and the first Fresnel lens 4. The coil assembly 10 changes the magnetic field strength and direction by adjusting the magnitude and direction of the current, and works in conjunction with the magnetic field of the driving magnet 12 to generate an electromagnetic force to drive the induction magnet 11 (and the first Fresnel lens 4) to move radially, achieving coaxial alignment with the wafer 24.

[0077] More specifically, the coil assembly 10 is arranged radially around the induction magnet 11, forming a ring-shaped layout in which the coil assembly 10 surrounds the induction magnet 11. The induction magnet 11 is correspondingly positioned on the top and bottom surfaces of the edge of the first Fresnel lens 4, moving synchronously with the lens; the coil assembly 10 (composed of multiple coils 22 wound on a coil frame 23) is embedded in the annular space 9 formed by the pressure ring 8 and the support frame 6, its annular structure precisely surrounding the radial outer side of the induction magnet 11, with no direct contact between them, maintaining a certain gap to achieve magnetic levitation drive; the coil assembly 10 generates a dynamic magnetic field through current changes, interacting with the induction magnet 11 through electromagnetic force—when the coil assembly 10 receives a signal from the detection sensor 2 and adjusts the current, the magnetic field it generates exerts a pushing or pulling force on the induction magnet 11, thereby driving the first Fresnel lens 4 to achieve levitation displacement, ultimately achieving coaxial alignment with the wafer 24. (Refer to...) Figure 8 The image shows one embodiment of the S pole 27 and N pole 28 of the induction magnet 11 and the driving magnet 12 in this invention, but it is not limited to this embodiment.

[0078] The present invention also provides a UV curing method, which uses the above-mentioned UV curing apparatus and includes the following steps:

[0079] S1. Place the wafer 24 to be cured inside the vacuum chamber 1, and make the vacuum chamber 1 a sealed space;

[0080] S2. Activate multiple detection sensors 2 arranged around the periphery of the vacuum chamber 1 to detect the position of the wafer 24 by emitting detection light and generate an offset signal;

[0081] S3. In response to the offset signal, the magnetic levitation drive device 3 drives the first Fresnel lens 4 to move by adjusting the generated electromagnetic force until the first Fresnel lens 4 and the wafer 24 are coaxially positioned.

[0082] S4. UV light is projected onto the surface of the wafer 24 through the first Fresnel lens 4, and the UV curing process continues for a preset time.

[0083] In summary, this invention effectively solves the problem of low UV light irradiation utilization caused by wafer 24 offset by detecting wafer 24 position offset in real time through detection sensor 2, and uses magnetic levitation drive device 3 to drive the first Fresnel lens 4 for adjustment. Combined with the light-concentrating effect of double Fresnel lens, it improves the quality and efficiency of UV curing and has important application value in the semiconductor manufacturing field.

[0084] Although some embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and all such changes and variations should be within the scope of the present invention.

Claims

1. A UV curing apparatus, characterized in that, include: A vacuum chamber, the interior of which is used to house a wafer; Multiple detection sensors are arranged around the periphery of the vacuum chamber and detect the position of the wafer by emitting detection light. A magnetic levitation drive device is electrically connected to multiple of the aforementioned detection sensors; A first Fresnel lens is drivably connected to the magnetic levitation drive device and suspended above the vacuum chamber for projecting UV light onto the surface of the wafer. The magnetic levitation drive device is configured to: in response to an offset signal generated after the multiple detection sensors detect the position of the wafer, drive the first Fresnel lens to move by adjusting the generated electromagnetic force so that the first Fresnel lens and the wafer are kept coaxially aligned; the UV curing device also includes a cavity, a support frame and a second Fresnel lens. The support frame is disposed within the cavity, and the second Fresnel lens is disposed on the support frame. The cavity, the support frame, and the second Fresnel lens enclose the vacuum chamber. The radial dimension of the first Fresnel lens is configured to be the same as the radial dimension of the wafer and smaller than the radial dimension of the second Fresnel lens.

2. The UV curing apparatus according to claim 1, characterized in that, The UV curing device also includes a pressure ring, which is disposed on the top of the support frame and cooperates with the support frame to form an annular space with a radial opening; The magnetic levitation drive device is disposed within the annular space, and the first Fresnel lens is drivably connected to the magnetic levitation drive device through the radial opening.

3. The UV curing apparatus according to claim 2, characterized in that, The magnetic levitation drive device includes: The coil assembly includes multiple coils and a coil frame, wherein the multiple coils are wound on the coil frame and electrically connected to the multiple detection sensors one by one via wires; A sensing magnet is disposed on the top and bottom surfaces of the edge of the first Fresnel lens, and a plurality of coils are arranged radially around the sensing magnet; A driving magnet is positioned opposite to the top and bottom of the annular space. The driving magnets are located on the upper and lower sides of the sensing magnet, respectively, to maintain the first Fresnel lens in a suspended state driven by the sensing magnet.

4. The UV curing apparatus according to claim 3, characterized in that, The driving magnet includes a first magnet, an insulating partition, and a second magnet arranged sequentially from the inside out, and the first magnet and the second magnet have opposite polarities.

5. The UV curing apparatus according to claim 3, characterized in that, The detection sensor includes: The detection module is used to emit detection light to detect the position of the wafer and generate an offset signal based on the position of the wafer; The control module is used to receive the offset signal and generate control commands; The driving module is used to receive the control command and adjust the direction and magnitude of the current flowing through the corresponding coil, and then drive the induction magnet to move the first Fresnel lens by adjusting the generated electromagnetic force.

6. The UV curing apparatus according to claim 1, characterized in that, The support frame includes an inner ring wall, an outer ring wall, and a bottom wall connecting the inner ring wall and the outer ring wall. The outer ring wall is fitted and fixed to the side wall of the cavity. The inner ring wall has a stepped portion on the side away from the outer ring wall, and the second Fresnel lens is disposed on the stepped portion.

7. The UV curing apparatus according to claim 6, characterized in that, Multiple detection sensors are disposed between the inner ring wall and the outer ring wall. The inner ring wall has a detection sensor window corresponding to the position of each detection sensor. The detection sensor window is made of transparent material, so that the detection light emitted by each detection sensor can penetrate the corresponding detection sensor window to detect the position of the wafer.

8. The UV curing apparatus according to claim 7, characterized in that, The UV curing device also includes a power supply ring, which is disposed between the inner ring wall and the outer ring wall and connected to multiple detection sensors via wires. The power supply ring is a rechargeable power source.

9. A UV curing method, characterized in that, The UV curing method employs the UV curing apparatus as described in any one of claims 1-8, and the UV curing method includes the following steps: S1. Place the wafer to be cured inside the vacuum chamber and make the vacuum chamber a sealed space; S2. Activate multiple detection sensors arranged around the perimeter of the vacuum chamber to detect the position of the wafer by emitting detection light and generate an offset signal; S3. In response to the offset signal, the magnetic levitation drive device drives the first Fresnel lens to move by adjusting the generated electromagnetic force until the first Fresnel lens and the wafer are coaxially positioned. S4. UV light is projected onto the surface of the wafer through the first Fresnel lens, and the UV curing process continues for a preset time.

Images