Magnetic levitation-based heating plate alignment device and thin film deposition equipment

Abstract

This utility model discloses a heating plate centering device and a thin film deposition equipment based on magnetic levitation. The device includes a heating plate, a first permanent magnet, a second permanent magnet, a magnetic levitation assembly, a displacement detection unit, and a controller. The heating plate includes a handle. The first permanent magnet is fixed to the outer wall of the handle. The second permanent magnet is disposed on the outer periphery of the handle and is spaced apart from the first permanent magnet along the radial direction of the handle. The magnetic levitation assembly includes a shell and multiple sets of electromagnetic windings. The shell is fitted around the outer periphery of the handle. The multiple sets of electromagnetic windings are fixed inside the shell and distributed around the circumference of the handle. Each set of electromagnetic windings is spaced apart from the first permanent magnet along the radial direction of the handle. The displacement detection unit is disposed on the shell for detecting the position of the handle. The controller is used to control the electromagnetic windings to generate electromagnetic force to drive the first permanent magnet to move and adjust the position of the heating plate according to the position of the handle. This enables real-time online centering of the heating plate during high-temperature processes.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a heating plate centering device and thin film deposition equipment based on magnetic levitation. Background Technology

[0002] The alignment of the heating plate and the cavity is crucial for ensuring process uniformity and stability, especially in high-temperature vacuum processes, where the concentricity of the heating plate directly affects the heat treatment effect and process consistency of the wafer. Currently, the horizontal alignment adjustment of the heating plate mainly relies on offline manual operation before the start of the process. This is not only cumbersome and has limited accuracy, but also prone to displacement in the high-temperature vacuum environment due to insufficient structural rigidity and thermal deformation. This causes the pre-adjusted alignment to gradually become ineffective over a long process, making real-time precise adjustment impossible. Existing technologies struggle to maintain the dynamic alignment of the heating plate under high-temperature process conditions, necessitating a real-time online alignment solution that resists thermal deformation. Utility Model Content

[0003] The present invention provides a heating plate centering device and a thin film deposition equipment based on magnetic levitation, which aims to solve the problem that the existing heating plate is prone to displacement during long-term high-temperature processes and is difficult to maintain the centering state.

[0004] In a first aspect, this utility model provides a heating plate centering device based on magnetic levitation, comprising:

[0005] Heating plate, including the handle;

[0006] A first permanent magnet is fixed to the outer wall of the handle;

[0007] The second permanent magnet is disposed on the outer periphery of the handle and is arranged at intervals with the first permanent magnet along the radial direction of the handle;

[0008] A magnetic levitation assembly includes a housing and multiple sets of electromagnetic windings. The housing is sleeved on the outer periphery of the handle, and the multiple sets of electromagnetic windings are fixed inside the housing and distributed around the handle in a circumferential direction. Each set of electromagnetic windings is arranged at intervals with the first permanent magnet along the radial direction of the handle.

[0009] A displacement detection unit, disposed on the outer casing, is used to detect the position of the handle;

[0010] The controller is used to control the current flowing through the electromagnetic winding according to the position of the handle to generate electromagnetic force to drive the first permanent magnet to move and adjust the position of the heating plate.

[0011] Furthermore, a first direction and a second direction that are perpendicular to each other are defined along the radial direction of the disk handle. The electromagnetic winding is provided in four groups. The first electromagnetic winding and the second electromagnetic winding are symmetrically arranged relative to the first permanent magnet along the first direction, and the third electromagnetic winding and the fourth electromagnetic winding are symmetrically arranged relative to the first permanent magnet along the second direction.

[0012] Furthermore, the first electromagnetic winding and the second electromagnetic winding are connected in series.

[0013] Furthermore, the third electromagnetic winding and the fourth electromagnetic winding are connected in series.

[0014] Furthermore, the displacement detection unit includes a first laser sensor, a second laser sensor, a third laser sensor, and a fourth laser sensor. The first laser sensor and the second laser sensor are symmetrically arranged relative to the first permanent magnet along the first direction, and the third laser sensor and the fourth laser sensor are symmetrically arranged relative to the first permanent magnet along the second direction.

[0015] Furthermore, the controller is configured to adjust the magnitude and direction of the current flowing into the first electromagnetic winding and the second electromagnetic winding based on the detection signals of the first laser sensor and the second laser sensor; and the controller is configured to adjust the magnitude and direction of the current flowing into the third electromagnetic winding and the fourth electromagnetic winding based on the detection signals of the third laser sensor and the fourth laser sensor.

[0016] Furthermore, the second permanent magnet is fixed inside the outer casing, and the second permanent magnet and the electromagnetic winding are distributed along the axial direction of the handle. The second permanent magnet is a bias permanent magnet, and a bias magnetic field is generated between the second permanent magnet and the first permanent magnet.

[0017] Furthermore, the second permanent magnet is ring-shaped.

[0018] Furthermore, the first permanent magnet is ring-shaped and is sleeved on the outer wall of the handle.

[0019] Secondly, the present invention also provides a semiconductor thin film deposition apparatus, comprising: a cavity and a magnetically levitated heating plate alignment device, wherein the magnetically levitated heating plate alignment device is the aforementioned magnetically levitated heating plate alignment device, and the magnetically levitated heating plate alignment device is used to adjust the position of the heating plate so that the heating plate is aligned with the cavity.

[0020] This invention provides a magnetically levitated heating plate centering device and a thin film deposition apparatus. The magnetically levitated heating plate centering device includes a heating plate and its handle, a first permanent magnet fixed to the outer wall of the handle, a second permanent magnet disposed on the outer periphery of the handle, a magnetic levitation assembly, a displacement detection unit, and a controller. The magnetic levitation assembly includes a housing and multiple sets of electromagnetic windings distributed circumferentially around the handle, each set of electromagnetic windings being radially aligned with the first permanent magnet. The displacement detection unit is mounted on the housing to detect the position of the handle. The controller, based on the detection results, controls the current flowing through the electromagnetic windings to generate electromagnetic force, driving the first permanent magnet to displace and thus adjusting the position of the heating plate. This invention, through the cooperation of the magnetic levitation assembly and the displacement detection unit, enables real-time online centering adjustment of the heating plate during high-temperature processes, effectively solving the problem of centering failure of the heating plate under high-temperature conditions, and significantly improving process stability and product yield. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a heating plate centering device based on magnetic levitation according to an embodiment of the present invention is shown;

[0023] Figure 2 This invention presents a partial cross-sectional schematic diagram of a heating plate centering device based on magnetic levitation according to an embodiment of the present invention;

[0024] Figure 3 A top view schematic diagram showing the distribution of laser sensors in the magnetically levitated heating plate centering device according to an embodiment of this utility model;

[0025] Figure 4 This invention illustrates a flowchart of the heating plate centering method based on magnetic levitation according to an embodiment of the present invention.

[0026] Figure label:

[0027] 1. Heating plate; 2. First permanent magnet; 3. Second permanent magnet; 4. Electromagnetic winding; 5. Outer shell; 6. Displacement detection unit; 7. Cavity. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0029] The directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are merely for reference to the accompanying drawings. Therefore, the directional terms used are for explanation and understanding of this invention, and not for limiting it. Furthermore, in the accompanying drawings, structures that are similar or identical are indicated by the same reference numerals.

[0030] In industrial processes such as thin film deposition and material heat treatment that rely on high-temperature vacuum environments, the heating plate, as a core component, directly impacts process quality due to its horizontal alignment accuracy with the cavity. Currently, the industry primarily employs offline manual calibration before process startup for heating plate alignment. This method is not only complex and highly dependent on operator experience, but its calibration accuracy is also susceptible to human error. More importantly, during prolonged high-temperature processes, the heating plate and surrounding structures are prone to thermal deformation due to temperature gradients. Furthermore, the reduced structural stiffness under vacuum conditions further exacerbates heating plate misalignment, causing the offline calibration alignment to become continuously ineffective and failing to meet the requirement for real-time, precise alignment throughout the entire process.

[0031] Therefore, this utility model provides a heating plate centering device and thin film deposition equipment based on magnetic levitation. By using magnetic levitation technology, the heating plate can be actively centered and adjusted, which solves the problem of insufficient centering accuracy of the heating plate under high temperature conditions in the prior art, and can significantly improve the position control accuracy and process stability of the heating plate.

[0032] This utility model embodiment aims to solve the above-mentioned problem of heating plate centering, and the specific approach is as follows:

[0033] By fixing a first permanent magnet on the outer wall of the heating plate handle as a force carrier, and simultaneously setting a second permanent magnet radially spaced from the first permanent magnet on the outer periphery of the handle, the bias magnetic field generated by the second permanent magnet provides initial centering balance for the heating plate. Next, a shell sleeved on the outer periphery of the handle and multiple sets of circumferentially distributed electromagnetic windings are designed, so that each set of windings corresponds radially to the first permanent magnet, forming an actuator for dynamically adjusting the position of the handle. In addition, a displacement detection unit on the shell captures the handle offset in real time. The controller adjusts the magnitude and direction of the winding current according to the offset, so that the control magnetic flux and bias magnetic flux generated by the windings are superimposed or canceled in the corresponding air gap, generating a reset electromagnetic force to drive the first permanent magnet to move the heating plate to reset, ultimately achieving online precise centering of the heating plate during the high-temperature process.

[0034] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0035] Please see Figures 1-3 This utility model embodiment demonstrates a magnetic levitation-based heating plate 1 centering device, comprising: a heating plate 1, including a plate handle; a first permanent magnet 2, fixed to the outer wall of the plate handle; a second permanent magnet 3, disposed on the outer periphery of the plate handle and spaced apart from the first permanent magnet 2 along the radial direction of the plate handle; a magnetic levitation assembly, including a housing 5 and multiple sets of electromagnetic windings 4, the housing 5 being sleeved on the outer periphery of the plate handle, the multiple sets of electromagnetic windings 4 being fixed inside the housing 5 and distributed around the circumference of the plate handle, each set of electromagnetic windings 4 being spaced apart from the first permanent magnet 2 along the radial direction of the plate handle; a displacement detection unit 6, disposed on the housing 5, for detecting the position of the plate handle; and a controller for controlling the electromagnetic windings 4 to supply current according to the position of the plate handle to generate electromagnetic force to drive the first permanent magnet 2 to displacement, thereby adjusting the position of the heating plate 1.

[0036] Specifically, the handle of the heating plate 1 serves as a support and force transmission component for the heating plate 1. Its structure can be cylindrical or other adaptable shapes. The handle extends in a direction away from the heating plate 1 and passes through the central hole of the cavity 7. The handle is made of non-magnetic material, such as aluminum.

[0037] The first permanent magnet 2 serves as a magnetic force carrier, cooperating with the magnetic field generated by the second permanent magnet 3 and the electromagnetic winding 4 to achieve force transmission. It is fixed to the outer wall of the handle and its structural form can include ring-shaped (such as a complete circular ring or a ring with an opening), block-shaped (single block or multiple blocks evenly distributed along the circumference of the handle), or arc-shaped (multiple arc segments spliced ​​together to form a ring). The material can be high-temperature resistant permanent magnet materials such as neodymium iron boron permanent magnets and samarium cobalt permanent magnets. The first permanent magnet 2 can be fixed to the handle by sleeve fixing (the ring-shaped permanent magnet is directly sleeved on the outer wall of the handle and limited by interference fit or fastening structure), adhesive fixing (adheded to the outer wall of the handle by high-temperature resistant adhesive), or bolt connection fixing (the block-shaped or arc-shaped permanent magnet is connected to the pre-set mounting holes on the outer wall of the handle by bolts). The first permanent magnet 2 is spaced apart from the second permanent magnet 3 and each set of electromagnetic windings 4 along the radial direction of the handle to form the air gap required for the magnetic field to act.

[0038] The second permanent magnet 3 is used to provide a bias magnetic field to provide an initial centering balance for the heating plate 1. It is located on the outer periphery of the plate handle. Its structure can be configured as a ring, a multi-segment arc splicing structure, or multiple blocks distributed along the circumference of the plate handle, corresponding to the first permanent magnet 2. The material can also be a high-temperature resistant permanent magnet material. The positional relationship between the second permanent magnet 3 and the plate handle is such that it corresponds to the first permanent magnet 2 at intervals along the radial direction of the plate handle. The size of the air gap formed by this interval can be flexibly set according to the magnetic field strength requirements. The second permanent magnet 3 can also form a fixed connection with the outer shell 5. The fixing methods include bonding to the inner wall of the outer shell 5, embedding into the mounting groove of the inner wall of the outer shell 5 through a snap-fit ​​structure, or fixing to the outer shell 5 with bolts to ensure its positional stability.

[0039] The outer shell 5 in the magnetic levitation assembly is used to provide an installation carrier for the second permanent magnet 3, the electromagnetic winding 4, and the displacement detection unit 6. It is sleeved on the outer periphery of the handle. The structure can be designed as a cylindrical tube, a square tube, or other hollow structure that is adapted to the shape of the handle. The material can be metal (such as stainless steel) or high-temperature resistant composite material to adapt to the high-temperature process environment. Multiple sets of electromagnetic windings 4 are used to generate an adjustable control magnetic field after being energized. They are fixed inside the outer casing 5 and distributed circumferentially around the handle. The number of windings can be set to 4, 6, 8, etc., according to the centering adjustment accuracy requirements. The structure of each set of electromagnetic windings 4 is that the coil is wound on a high-temperature resistant insulating frame (the frame material can be ceramic, high-temperature resistant plastic, etc.). The coil is wound with high-temperature resistant wire. The electromagnetic windings 4 can be fixed to the outer casing 5 by embedding (embedding the windings and their frames into the preset grooves on the inner wall of the outer casing 5), bolting (connecting the winding frame to the inner wall of the outer casing 5 with bolts), or binding (fixing the windings to the support structure on the inner wall of the outer casing 5 with high-temperature binding tape). Each set of electromagnetic windings 4 corresponds to the first permanent magnet 2 at intervals along the radial direction of the handle.

[0040] The displacement detection unit 6 is used to detect the position of the handle in real time to obtain the offset information of the handle. It is located on the housing 5 and can be a laser displacement sensor, a Hall displacement sensor or a capacitive displacement sensor, etc. The number can be set to 2, 4 or more groups. The distribution pattern can be evenly distributed along the circumference of the handle (such as the distribution direction corresponding to the electromagnetic winding 4). The installation position can be the inner wall of the housing 5 (directly facing the handle or the first permanent magnet 2 to improve the detection accuracy) or the outer wall of the housing 5 (detecting the position of the handle through the detection hole on the housing 5). The displacement detection unit 6 can be fixed to the housing 5 by bolt connection or snap-fit ​​to ensure that its detection direction is aligned with the handle or the first permanent magnet 2 to accurately obtain the position signal of the handle.

[0041] The controller is used to control the entire centering adjustment process. It can be a PLC (Programmable Logic Controller), a microcontroller, a dedicated control chip, or an industrial computer. The controller and the displacement detection unit 6 are connected by wires or wireless communication (such as a high-temperature resistant wireless module) to transmit signals to receive the disk handle position signal output by the displacement detection unit 6. The controller and the electromagnetic winding 4 are connected by wires or a power module to output control current to the electromagnetic winding 4. The controller can also preset the centering reference position parameters for comparison and judgment with the detected disk handle position.

[0042] The existing heating plate 1 relies on offline manual operation before the start of the process for centering adjustment. This is cumbersome, has limited accuracy, and suffers from centering failure due to thermal deformation and insufficient structural rigidity during prolonged high-temperature processes, making real-time and precise adjustment impossible. This embodiment addresses this problem by having the displacement detection unit 6 detect the position of the handle in real time and transmit the signal to the controller. The controller, based on the deviation between the handle position and a preset centering reference, controls multiple sets of electromagnetic windings 4 to supply corresponding currents. The control magnetic field generated by the electromagnetic windings 4 interacts with the bias magnetic field generated by the second permanent magnet 3 at the first permanent magnet 2, forming an electromagnetic force that drives the first permanent magnet 2 to move. The first permanent magnet 2 then moves the handle and heating plate 1, thereby adjusting the position of the heating plate 1. This solves the technical problem of traditional structures failing to adjust in real time due to thermal deformation at high temperatures, enabling real-time online centering adjustment of the heating plate 1 during high-temperature processes. This improves process stability and product consistency, while avoiding manual intervention and enhancing the automation level of the equipment.

[0043] Reference Figure 2In one embodiment, the second permanent magnet 3 is fixed inside the outer casing 5. The second permanent magnet 3 and the electromagnetic winding 4 are distributed along the axial direction of the handle. The second permanent magnet 3 is a bias permanent magnet, and a bias magnetic field is generated between the second permanent magnet 3 and the first permanent magnet 2. Specifically, in this embodiment, the second permanent magnet 3 is fixed inside the outer casing 5. Its fixing to the outer casing 5 can take various forms, such as directly bonding it to a pre-set installation area on the inner wall of the outer casing 5 with a high-temperature resistant adhesive, or achieving a snap-fit ​​fixation through an annular groove on the inner wall of the outer casing 5. Alternatively, it can be connected by bolts passing through the mounting holes on the edge of the second permanent magnet 3 and the threaded holes on the inner wall of the outer casing 5 to ensure the stability of the second permanent magnet 3 under high-temperature processing conditions and avoid displacement due to vibration or thermal deformation. The second permanent magnet 3 and the electromagnetic winding 4 are distributed along the axial direction of the handle, that is, they are arranged vertically in the axial direction of the handle. The specific arrangement can be flexibly determined according to the internal space of the outer casing 5 and the requirements of the magnetic field. For example, the second permanent magnet 3 can be placed on the side of the electromagnetic winding 4 closer to the heating plate 1, or on the side of the electromagnetic winding 4 farther from the heating plate 1, as long as both are radially aligned with the first permanent magnet 2. Simultaneously, the second permanent magnet 3 is a bias permanent magnet, which generates a bias magnetic field in the air gap between itself and the first permanent magnet 2 through its inherent magnetism. This bias magnetic field provides an initial balancing force for the first permanent magnet 2, allowing the heating plate 1 to maintain a preset centering position when undisturbed. This eliminates the need for continuous energization of the electromagnetic winding 4 to maintain static balance, effectively reducing the static energy consumption of the device. Furthermore, it provides a stable magnetic field reference for subsequent adjustment of the heating plate 1 position by the electromagnetic winding 4, ensuring smoother and more precise changes in electromagnetic force during adjustment.

[0044] In this embodiment, the second permanent magnet 3 is ring-shaped. Specifically, the specific form of the ring structure of the second permanent magnet 3 can be selected from various embodiments according to actual needs. For example, a complete closed ring structure can be adopted, with the inner diameter of the ring adapted to the outer diameter of the handle to ensure a uniform radial spacing between it and the first permanent magnet 2; alternatively, a non-closed ring structure with a notch can be adopted, the position and size of which can be adjusted according to the installation requirements of other components inside the housing 5, as long as the main body of the ring structure can be distributed around the handle circumferentially and form an effective bias magnetic field with the corresponding area of ​​the first permanent magnet 2. The ring-shaped second permanent magnet 3 can uniformly generate a bias magnetic field in the circumferential direction, so that the bias force on the first permanent magnet 2 at each position in the circumferential direction remains consistent, generating a uniform and stable bias magnetic field, and avoiding tilting or offset of the initial alignment state of the heating plate 1 due to uneven bias magnetic field. This design not only simplifies the installation process and improves structural reliability, but also ensures that a consistent bias magnetic force can be provided in all adjustment directions, providing a basic guarantee for the symmetrical adjustment of the system.

[0045] In one embodiment, the first permanent magnet 2 is ring-shaped and is sleeved on the outer wall of the handle. Specifically, in this embodiment, the first permanent magnet 2 adopts a ring structure, which is directly sleeved and fixed to the outer wall surface of the handle. This ring structure design allows the first permanent magnet 2 to form a uniform magnetic field coupling with the circumferentially distributed electromagnetic windings 4, ensuring that a consistent electromagnetic force is generated in all adjustment directions. At the same time, the ring structure installation method improves the connection strength between the permanent magnet and the handle, avoiding connection failure caused by thermal stress under high temperature conditions, and providing a guarantee for the stable operation of the system.

[0046] Reference Figure 3 In one embodiment, a first direction and a second direction, perpendicular to each other, are defined along the radial direction of the handle. The electromagnetic winding 4 has four sets: the first and second electromagnetic windings are symmetrically arranged relative to the first permanent magnet 2 along the first direction; the third and fourth electromagnetic windings are symmetrically arranged relative to the first permanent magnet 2 along the second direction. Specifically, in this embodiment, a first direction and a second direction, perpendicular to each other, are defined along the radial direction of the handle. These first and second directions can be set according to actual alignment adjustment requirements. For example, the first direction can be set as a horizontal X-axis direction, and the second direction as a horizontal Y-axis direction. Together, they constitute a two-dimensional adjustment plane for the radial direction of the handle, ensuring that all possible offset directions of the heating plate 1 on the horizontal plane are covered. The electromagnetic winding 4 has four sets: a first electromagnetic winding, a second electromagnetic winding, a third electromagnetic winding, and a fourth electromagnetic winding. The first and second electromagnetic windings are symmetrically arranged relative to the first permanent magnet 2 along the first direction, that is, they are located on opposite sides of the first direction with the axis of the handle as the center of symmetry (e.g., the first electromagnetic winding is located on the positive side X+ of the first direction, and the second electromagnetic winding is located on the negative side X- of the first direction), and their radial distances from the first permanent magnet 2 are consistent. The third and fourth electromagnetic windings are symmetrically arranged relative to the first permanent magnet 2 along the second direction, and similarly located on the positive and negative sides of the second direction, and their radial distances from the first permanent magnet 2 are the same. This symmetrical layout allows the electromagnetic force adjustment in the first and second directions to be independent of each other, avoiding interference between adjustments in different directions. When the heating plate 1 is offset along the first direction, the first and second electromagnetic windings can be controlled to precisely apply the reset electromagnetic force in the first direction. When it is offset along the second direction, the third and fourth electromagnetic windings are used for adjustment, ensuring the directionality and accuracy of the centering adjustment. At the same time, the four sets of windings can also cover the full range of adjustment requirements of the handle radial direction, adapting to different offset scenarios.

[0047] In this embodiment, the first electromagnetic winding and the second electromagnetic winding are connected in series. Specifically, the series connection can be implemented in various ways. For example, the output terminal of the first electromagnetic winding and the input terminal of the second electromagnetic winding can be directly connected through a high-temperature resistant wire, and then the input terminal of the first electromagnetic winding and the output terminal of the second electromagnetic winding can be connected to the current output terminal of the controller to form a complete series circuit. Alternatively, the series connection can be achieved through terminals located inside the housing 5. After the first and second electromagnetic windings are connected in series, the magnitude of the current flowing through them is exactly the same, which ensures that the magnetic field strength generated by them is consistent. Combined with their symmetrical layout relative to the first permanent magnet 2 along the first direction, a symmetrical and balanced control magnetic field can be formed on both sides of the first permanent magnet 2 in the first direction, avoiding magnetic field imbalance caused by the difference in current between the two windings, which could lead to tilting or over-adjustment of the heating plate 1 during adjustment. At the same time, the series connection simplifies the current control logic of the controller. Only one current output channel is needed to simultaneously control the two windings, reducing the number of controller interfaces and control complexity, and lowering the circuit design difficulty and cost of the device. Therefore, the series structure not only simplifies the complexity of the control system, but also ensures good consistency of the electromagnetic forces generated by the two windings, improving the adjustment accuracy and stability in the first direction.

[0048] In this embodiment, the third and fourth electromagnetic windings are connected in series. Specifically, the series connection structure of the third and fourth electromagnetic windings is the same as that of the series connection structure of the first and second electromagnetic windings, and will not be described again here. This design is the same as the winding connection method in the first direction, which allows the two windings in the second direction to obtain completely synchronized current control. When position adjustment is required in the second direction, the series-connected third and fourth windings can generate a coordinated control magnetic field, ensuring that the adjustment force in the second direction is balanced and symmetrical. This symmetrical series connection design enables the device to achieve precise and stable centering adjustment in two orthogonal directions, improving the overall control performance of the system.

[0049] In one embodiment, the displacement detection unit 6 includes a first laser sensor, a second laser sensor, a third laser sensor, and a fourth laser sensor. The first laser sensor and the second laser sensor are symmetrically arranged relative to the first permanent magnet 2 along the first direction, and the third laser sensor and the fourth laser sensor are symmetrically arranged relative to the first permanent magnet 2 along the second direction. Specifically, the displacement detection unit 6 includes a first laser sensor, a second laser sensor, a third laser sensor, and a fourth laser sensor. The first laser sensor and the second laser sensor are symmetrically arranged relative to the first permanent magnet 2 along the first direction, that is, they are mounted on opposite sides of the first direction with the axis of the handle when aligned as the center of symmetry (e.g., the first laser sensor is located on the outer shell 5 on the positive side X+ of the first direction, and the second laser sensor is located on the outer shell 5 on the negative side X- of the first direction). The detection optical paths of both sensors are perpendicularly pointed to the corresponding area of ​​the first permanent magnet 2. By detecting the distances X1 and X2 between the sensors and the surface of the first permanent magnet 2, the position information of the handle in the first direction is obtained. The third and fourth laser sensors are symmetrically arranged relative to the first permanent magnet 2 along the second direction, and similarly mounted on the outer casing 5 on the positive Y+ and negative Y- sides of the second direction, respectively. The detection optical path also points towards the first permanent magnet 2 to obtain the position information Y1 and Y2 of the handle in the second direction. This symmetrical arrangement of the laser sensor group can accurately calculate the offset and direction of the handle in the first and second directions by measuring the difference in detection distance between the two sensors (for example, in the first direction, if the detection distance of the first laser sensor is less than that of the second laser sensor, it indicates that the handle is offset in the positive direction of the first direction). This orthogonal symmetrical sensor layout matches the arrangement of the electromagnetic winding 4, enabling real-time and accurate detection of the displacement changes of the handle in two mutually perpendicular directions. Each laser sensor group uses a non-contact measurement principle, obtaining position information by measuring the reflected signal from the surface of the handle or the first permanent magnet 2, avoiding friction and wear caused by mechanical contact. Simultaneously, the symmetrical arrangement of the four sensors ensures the reliability and consistency of the measurement data, providing accurate position feedback for the closed-loop control system.

[0050] In this embodiment, the controller is configured to adjust the magnitude and direction of the current flowing into the first electromagnetic winding and the second electromagnetic winding based on the detection signals from the first laser sensor and the second laser sensor; and the controller is configured to adjust the magnitude and direction of the current flowing into the third electromagnetic winding and the fourth electromagnetic winding based on the detection signals from the third laser sensor and the fourth laser sensor. Specifically, the controller is configured to establish a corresponding logic between the displacement detection signal and the winding current control. For the adjustment of the first direction, after receiving the detection signals from the first laser sensor and the second laser sensor, the controller first calculates the difference between their detection distances, determines the offset of the handle in the first direction based on the magnitude of the difference (the larger the difference, the larger the offset), determines the offset direction based on the sign of the difference (e.g., if the difference is positive, it means the handle is offset in the positive direction of the first direction), and then determines the magnitude (the larger the offset, the larger the current to generate a stronger reset electromagnetic force) and direction of the current flowing into the first electromagnetic winding and the second electromagnetic winding based on a preset control algorithm (e.g., proportional control, proportional-integral-derivative control, fuzzy control, etc.). For example, when the handle deflects in the first positive direction, the control current direction causes the control flux generated by the first electromagnetic winding to cancel out the bias flux on that side in the air gap (weakening the magnetic field), while simultaneously causing the control flux generated by the second electromagnetic winding to superimpose the bias flux on the corresponding side in the air gap (strengthening the magnetic field). The difference in magnetic field strength on both sides forms a reset electromagnetic force pointing in the negative first direction, pulling the heating plate 1 back to the center position. Similarly, for adjustment in the second direction, the controller receives detection signals from the third and fourth laser sensors, calculates the difference in their detection distances to determine the amount and direction of the deflection in the second direction, and then adjusts the magnitude and direction of the current flowing into the third and fourth electromagnetic windings. When the handle deflects in the second positive direction, the control current direction causes the control flux on the third electromagnetic winding side to cancel out the bias flux, and the control flux on the fourth electromagnetic winding side to superimpose the bias flux, forming a reset force pointing in the negative second direction. This "sensor group detection - corresponding winding current control" configuration achieves complete independence of the first and second direction adjustments, avoids mutual interference between adjustments in different directions, ensures that the controller can accurately output current control signals according to the offset in each direction, so that the heating plate 1 can quickly and smoothly return to the centering position. At the same time, it simplifies the control logic, reduces the problem of over-adjustment or adjustment lag caused by cross-direction adjustment, and improves the response speed and accuracy of the device's centering adjustment.

[0051] This utility model embodiment also provides a thin film deposition apparatus, including: a cavity 7 and a magnetically levitated heating plate 1 alignment device. The magnetically levitated heating plate 1 alignment device is the aforementioned magnetically levitated heating plate 1 alignment device, which is used to adjust the position of the heating plate 1 to align the heating plate 1 with the cavity 7. This magnetically levitated heating plate 1 alignment device has been described in detail in the above embodiments, and for the sake of brevity, it will not be repeated here.

[0052] Specifically, cavity 7 provides a closed high-temperature vacuum environment for thin film deposition processes. It has a central hole at its bottom, and heating plate 1 is located inside cavity 7 to support the wafer and provide the heat required for deposition. The handle of heating plate 1 extends axially along cavity 7 and passes through the central hole at the bottom of cavity 7, allowing part of the handle to extend outside cavity 7. A magnetically levitated centering device for heating plate 1 is located outside cavity 7. Its outer shell 5 is fixed to the bottom outer wall of cavity 7 by bolts, flanges, or welding, and the outer shell 5 is coaxially aligned with the central hole at the bottom of cavity 7. This ensures that the handle extending out of cavity 7 is located inside the outer shell 5, guaranteeing that the electromagnetic winding 4, the second permanent magnet 3, and other components of the centering device can correspond and engage with the first permanent magnet 2 radially along the handle. The displacement detection unit 6 is aligned with the handle or the first permanent magnet 2 to achieve position detection. By employing the magnetically levitated heating plate 1 alignment device of this embodiment, during the high-temperature process of thin film deposition, the offset of the heating plate 1 caused by thermal deformation and the influence of the vacuum environment can be detected in real time, and the position of the heating plate 1 can be dynamically corrected through the magnetic levitation adjustment mechanism to ensure that the heating plate 1 and the cavity 7 are always aligned. This continuous alignment control can avoid problems such as uneven temperature distribution in different areas of the wafer caused by the offset of the heating plate 1, thereby improving the thickness uniformity and composition consistency of the thin film deposition, reducing thin film defects, and ultimately improving the quality and performance stability of the thin film product.

[0053] Reference Figure 4 This application also provides a magnetic levitation-based heating plate centering method, applied to the magnetic levitation-based heating plate centering device described above. The method includes:

[0054] S1. Obtain the first offset of the disk handle in the first direction and the second offset in the second direction;

[0055] S2. Determine whether the first offset and the second offset exceed a preset offset threshold;

[0056] S3. If so, adjust the current magnitude of the first electromagnetic winding and the second electromagnetic winding according to the first offset to adjust the position of the handle in the first direction, and control the current magnitude of the third electromagnetic winding and the fourth electromagnetic winding according to the second offset to adjust the position of the handle in the second direction, until the first offset and the second offset do not exceed the preset offset threshold.

[0057] In this embodiment, firstly, the second permanent magnet acts as a bias permanent magnet, and the bias magnetic field it generates acts radially along the disk handle on the first permanent magnet. This creates a bias magnetic flux pointing from X+ to X- in the X+ side and air gap in the first direction (e.g., the X direction), a bias magnetic flux pointing from X- to X+ in the X- side air gap, a bias magnetic flux pointing from Y+ to Y- in the Y+ side air gap in the second direction (e.g., the Y direction), and a bias magnetic flux pointing from Y- to Y+ in the Y- side air gap. These symmetrical bias magnetic fluxes provide an initial balancing force for the first permanent magnet, ensuring that the heating disk remains aligned with the cavity when undisturbed. Based on this, the first, second, third, and fourth laser sensors detect the distances to the first permanent magnet in real time, correspondingly obtaining X1 (X+ side distance), X2 (X- side distance), Y1 (Y+ side distance), and Y2 (Y- side distance). The controller calculates a first offset as X1-X2 (reflecting the first directional offset, with positive values ​​indicating offset towards X+ and negative values ​​indicating offset towards X-) and a second offset as Y1-Y2 (reflecting the second directional offset, with positive values ​​indicating offset towards Y+ and negative values ​​indicating offset towards Y-) based on the detected values. The controller then compares the absolute values ​​of the first and second offsets with preset offset thresholds (such as the alignment accuracy threshold required by the process). If the offset does not exceed the threshold, the current state is maintained. If it exceeds the threshold, the controller adjusts the current magnitude of the first and second electromagnetic windings according to the first offset (the larger the offset, the larger the current to enhance the adjustment force), and controls the current direction to make the control flux and bias flux on the corresponding side superimpose or cancel each other out. Simultaneously, it adjusts the current of the third and fourth electromagnetic windings according to the second offset. This magnetic force drives the first permanent magnet to move the handle and heating plate until both the first and second offsets do not exceed the preset thresholds, completing one alignment adjustment.

[0058] For example, when the heating plate is disturbed and shifts in the X+ direction, the first offset X1-X2 is positive and exceeds the threshold. At this time, X1 decreases (the air gap on the X+ side becomes smaller) and X2 increases (the air gap on the X- side becomes larger). The controller controls the first electromagnetic winding (X+ side) and the second electromagnetic winding (X- side) to pass current in a specific direction, so that the direction of the control magnetic flux generated by the first electromagnetic winding (X- to X+) is opposite to the direction of the bias magnetic flux on the X+ side (X+ to X-). The two cancel each other out in the air gap on the X+ side, weakening the magnetic field strength on that side. At the same time, the direction of the control magnetic flux generated by the second electromagnetic winding (X- to X+) is the same as the direction of the bias magnetic flux on the X- side (X- to X+). The two are superimposed in the air gap on the X- side, enhancing the magnetic field strength on that side. The magnetic field force on the X- side is greater than the magnetic field force on the X+ side, forming a restoring force pointing in the X- direction, pulling the heating plate to move in the X- direction until the absolute value of X1-X2 does not exceed the preset threshold.

[0059] For example, when the heating plate shifts in the X- direction, the first shift X1-X2 is negative and exceeds the threshold. X1 increases and X2 decreases. The controller reverses the direction of the control current, so that the control flux of the first electromagnetic winding is superimposed with the bias flux on the X+ side (enhancing the magnetic field on the X+ side), and the control flux of the second electromagnetic winding cancels out the bias flux on the X- side (weakening the magnetic field on the X- side), forming a reset electromagnetic force pointing in the X+ direction, which pushes the heating plate to move in the X+ direction until the shift reaches the target.

[0060] For example, when the heating plate shifts in the Y+ direction, the second shift Y1-Y2 is positive and exceeds the threshold, Y1 decreases and Y2 increases; the controller controls the third electromagnetic winding (Y+ side) and the fourth electromagnetic winding (Y- side) to pass current, so that the control magnetic flux of the third electromagnetic winding cancels out the bias magnetic flux of the Y+ side (weakening the Y+ side magnetic field), and the control magnetic flux of the fourth electromagnetic winding is superimposed on the bias magnetic flux of the Y- side (enhancing the Y- side magnetic field), forming a reset electromagnetic force pointing in the Y- direction, pulling the heating plate to reset.

[0061] For example, when the heating plate shifts in the Y- direction, the second shift Y1-Y2 is negative and exceeds the threshold, Y1 increases and Y2 decreases; the controller reverses the direction of the control current, so that the control flux of the third electromagnetic winding is superimposed with the bias flux on the Y+ side (enhancing the magnetic field on the Y+ side), and the control flux of the fourth electromagnetic winding cancels out the bias flux on the Y- side (weakening the magnetic field on the Y- side), forming a reset electromagnetic force pointing in the Y+ direction, pushing the heating plate to reset until the absolute value of Y1-Y2 does not exceed the preset threshold.

[0062] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A magnetic levitation based heating tray centering device, characterized in that, include: Heating plate, including the handle; The first permanent magnet is fixed to the outer wall of the handle; The second permanent magnet is disposed on the outer periphery of the handle and is arranged at intervals with the first permanent magnet along the radial direction of the handle; A magnetic levitation assembly includes a housing and multiple sets of electromagnetic windings. The housing is sleeved on the outer periphery of the handle, and the multiple sets of electromagnetic windings are fixed inside the housing and distributed around the handle in a circumferential direction. Each set of electromagnetic windings is arranged at intervals with the first permanent magnet along the radial direction of the handle. A displacement detection unit, disposed on the outer casing, is used to detect the position of the handle; The controller is used to control the current flowing through the electromagnetic winding according to the position of the handle to generate electromagnetic force to drive the first permanent magnet to move and adjust the position of the heating plate.

2. The magnetic levitation-based heating plate centering device according to claim 1, characterized in that, The disk handle is defined with a first direction and a second direction that are perpendicular to each other. The electromagnetic winding is provided in four groups. The first electromagnetic winding and the second electromagnetic winding are symmetrically arranged relative to the first permanent magnet along the first direction. The third electromagnetic winding and the fourth electromagnetic winding are symmetrically arranged relative to the first permanent magnet along the second direction.

3. The magnetic levitation-based heating plate centering device according to claim 2, characterized in that, The first electromagnetic winding is connected in series with the second electromagnetic winding.

4. The magnetic levitation-based heating plate centering device according to claim 2, characterized in that, The third and fourth electromagnetic windings are connected in series.

5. The magnetically levitated heating plate centering device according to claim 2, characterized in that, The displacement detection unit includes a first laser sensor, a second laser sensor, a third laser sensor, and a fourth laser sensor. The first laser sensor and the second laser sensor are symmetrically arranged relative to the first permanent magnet along the first direction, and the third laser sensor and the fourth laser sensor are symmetrically arranged relative to the first permanent magnet along the second direction.

6. The magnetic levitation-based heating plate centering device according to claim 5, characterized in that, The controller is configured to adjust the magnitude and direction of the current flowing into the first electromagnetic winding and the second electromagnetic winding based on the detection signals from the first laser sensor and the second laser sensor; and, The controller is configured to adjust the magnitude and direction of the current supplied to the third and fourth electromagnetic windings based on the detection signals from the third and fourth laser sensors.

7. The magnetically levitated heating plate centering device according to any one of claims 1-6, characterized in that, The second permanent magnet is fixed inside the outer casing. The second permanent magnet and the electromagnetic winding are distributed along the axial direction of the handle. The second permanent magnet is a bias permanent magnet, and a bias magnetic field is generated between the second permanent magnet and the first permanent magnet.

8. The magnetic levitation-based heating plate centering device according to claim 7, characterized in that, The second permanent magnet is ring-shaped.

9. The magnetically levitated heating plate centering device according to any one of claims 1-6, characterized in that, The first permanent magnet is ring-shaped and is sleeved on the outer wall of the handle.

10. A thin film deposition apparatus, characterized in that, include: A cavity and a magnetically levitated heating plate alignment device, wherein the magnetically levitated heating plate alignment device is the magnetically levitated heating plate alignment device according to any one of claims 1-9, and the magnetically levitated heating plate alignment device is used to adjust the position of the heating plate so that the heating plate is aligned with the cavity.

Images