A real-time deformable shield system and method for coating a rotating substrate

Abstract

This invention discloses a real-time deformable shielding system and method for rotating substrate coating, belonging to the field of coating technology. The system includes a substrate rotation mechanism, comprising a rotating stage for supporting the substrate, a rotation driver, and an angle sensor; the output of the rotation driver is connected to the rotating stage; the angle sensor is mounted on the central rotation axis of the rotating stage; a shielding plate assembly is disposed between the evaporation source and the substrate; the shielding plate assembly includes a fixed support, multiple fan-shaped blades, and multiple motors; the multiple fan-shaped blades are uniformly distributed circumferentially on the fixed support; the outputs of the multiple motors are connected one-to-one with the multiple fan-shaped blades; a controller, the input of which is connected to the angle sensor, and the output of which is connected to the motors. This invention can precisely control the spatiotemporal distribution of the deposition beam, thereby effectively solving the problems of radial uniformity and compositional uniformity in the coating process.

Description

Technical Field

[0001] This invention belongs to the field of coating technology and relates to a real-time deformable shielding system and method for coating rotating substrates. Background Technology

[0002] In rotating substrate deposition systems, shielding plates (also known as baffles or shields) are key components for controlling the deposition area and improving film uniformity. Currently, existing shielding plates are mainly divided into two categories: fixed partitioned shielding plates and simple open / closed baffles. Fixed partitioned shielding plates, such as the scheme disclosed in patent US20170226641A1, involve placing a fixed shielding plate below the substrate, dividing the bottom evaporation source into multiple fan-shaped regions. Each region corresponds to an evaporation source for a different material. The substrate passes through different regions sequentially during rotation, thus achieving alternating layer deposition. The other type is the simple open / closed baffle, which is typically installed at the evaporation source outlet or below the substrate. Its function is limited to controlling the start and end of the deposition process and lacks spatial modulation capabilities.

[0003] However, the aforementioned existing technologies all have significant drawbacks. First, the structure of a fixed shielding plate cannot be adjusted once designed and manufactured; its partition shape and size remain unchanged, making it difficult to adapt to changes in substrate size, evaporation source distribution, or different process requirements. When it is necessary to produce components of different specifications or replace materials with significantly different evaporation characteristics, the uniformity of the film layer will decrease significantly. Second, even with a fixed partitioned shielding plate, it can only macroscopically limit the deposition areas of different materials, but cannot solve the problem of radial uneven distribution of a single material. For example, even if PbI2 is confined to a specific fan-shaped area for deposition, a radial gradient with a thicker center and thinner edges still exists within that area. Furthermore, existing shielding plates remain stationary during substrate rotation, and their opening shape and position do not change with the substrate rotation angle. However, the geometric relationship between different positions on the substrate and the evaporation source varies at different angles. Ideally, the deposition beam modulation should be angle-dependent, and existing solutions lack the ability to dynamically adjust in sync with substrate rotation. In addition, in order to obtain better uniformity, existing solutions are often forced to design the opening of the shield plate to be small, resulting in a large amount of evaporated material being deposited on the shield plate rather than on the substrate, and the material utilization rate is usually less than 30%. Summary of the Invention

[0004] This invention provides a real-time deformable shielding system and method for coating rotating substrates. By setting a deformable shielding plate that is linked in real time with the rotation angle of the substrate, this invention can precisely control the spatiotemporal distribution of the deposition beam, thereby effectively solving the problems of radial uniformity and composition uniformity in the coating process.

[0005] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a real-time deformable shielding system for rotating substrate coating, comprising: A substrate rotation mechanism includes a rotary table for carrying a substrate, a rotary driver, and an angle sensor; the output end of the rotary driver is connected to the rotary table in a driving connection; the angle sensor is mounted on the central rotation axis of the rotary table. A shielding plate assembly is disposed between the evaporation source and the substrate; the shielding plate assembly includes a fixed bracket, multiple fan-shaped blades, and multiple motors; the multiple fan-shaped blades are evenly distributed circumferentially on the fixed bracket; the output terminals of the multiple motors are connected to the multiple fan-shaped blades one by one; The controller has its input terminal connected to the angle sensor and its output terminal connected to the motor.

[0006] Furthermore, the shielding plate assembly also includes multiple radial moving guides and multiple sliders; the radial moving guides are fixed to the fixed bracket and extend along the radial direction of the fixed bracket; each slider is slidably engaged with a corresponding radial moving guide; each fan-shaped blade is fixed to a corresponding slider; the motor includes a first motor and a second motor; the output end of the first motor is drivenly connected to the slider; the output end of the second motor is drivenly connected to the fan-shaped blade.

[0007] Furthermore, the first motor is connected to the slider via a lead screw and nut mechanism; the second motor is connected to the sector blade via a coupling.

[0008] Furthermore, the fixed bracket is a circular bracket, and a plurality of radial moving guide rails are distributed at equal angular intervals along the circumference of the circular bracket, and each radial moving guide rail points to the center of the circular bracket.

[0009] Furthermore, the angle sensor is a rotary encoder.

[0010] Secondly, the present invention provides a real-time deformable shielding method for coating a rotating substrate, comprising the following steps: S1. Detect the current rotation angle of the rotary table using the angle sensor, and send the angle signal to the controller; S2. The controller determines the target position of each of the fan-shaped blades corresponding to the current rotation angle according to the preset blade position-angle correspondence. S3. The controller controls each of the motors to drive the fan-shaped blades corresponding to the motors to move to the target position, so as to adjust the degree of obstruction of the evaporation beam by each fan-shaped blade. S4. During the substrate rotation coating process, repeat S1~S3 to make the position of the fan-shaped blades change dynamically in real time with the rotation angle, thereby realizing the periodic modulation of the deposition beam.

[0011] Furthermore, the preset blade position-angle correspondence is obtained in the following way: Calibrate the evaporation source at different emission angles Deposition rate distribution function ; Establish any radial position on the substrate rotation angle deposition rate model ,in The radial position The polar angle relative to the evaporation source; For all radial positions The cumulative deposited dose received within a complete rotation cycle is equal, that is

[0012] in, , where is the opening function to be determined; It is a constant; Rotation angle Discretize into N sampling points , , , , radial position Discretized into M sampling points , , , Discretize the opening function into a matrix ; With the goal of minimizing the cumulative dose variance at each radial position and the constraint of the smoothness of the blade position change between adjacent angles, a numerical optimization algorithm is used to solve for the optimal opening value at each radial position under each discrete angle. Based on the geometry of each sector blade, the matrix is ​​converted into radial position commands for each blade at different rotation angles, forming the blade position-angle correspondence.

[0013] Furthermore, when using a numerical optimization algorithm to solve for the optimal opening value at each radial position under each discrete angle, the method further includes: The second derivative constraint of the blade position change between adjacent angles is added to ensure that the blade motion trajectory satisfies the acceleration continuity. The controller drives each motor with an S-curve acceleration and deceleration control algorithm according to the smooth trajectory obtained by the solution, so that the dynamic tracking error between the actual motion position of the fan blade and the theoretical target position of the current rotation angle is less than the radial offset corresponding to 1 / 360 of the substrate rotation period.

[0014] Furthermore, the process of the controller controlling each of the motors and driving the fan-shaped blades corresponding to the motors to move to the target position can adopt an angle-dependent modulation mode or a material partitioning deposition mode. Angle-dependent modulation mode: The controller dynamically adjusts the opening ratio of each fan-shaped blade in each rotation cycle of the substrate according to the preset blade position-angle correspondence, to compensate for the radial deposition rate difference caused by the evaporation source angle distribution, and to achieve radial uniform deposition of a single material. Material partitioning deposition mode: The substrate is divided into multiple fan-shaped deposition zones by rotation. Each fan-shaped deposition zone corresponds to a type of evaporation material. Each fan-shaped blade independently adjusts its radial position according to the fan-shaped deposition zone it is in at the current rotation angle, so that each material can achieve radial uniform deposition in its corresponding fan-shaped deposition zone. The deposition thickness ratio of different materials can be controlled by adjusting the angle width of each fan-shaped deposition zone.

[0015] Furthermore, the material partitioning deposition mode also includes: Multiple fan-shaped blades are divided into boundary blade groups and radial adjustment blade groups. The boundary blade groups are used to separate adjacent fan-shaped deposition zones, and their radial positions remain unchanged during the coating process or are only switched at the partition boundaries in a predefined manner. The radial adjustment blade groups move independently within each fan-shaped deposition zone. When the substrate rotates past the boundary of the fan-shaped deposition zone, the controller controls the radial adjustment blade group to gradually change the opening ratio according to the boundary transition algorithm, which is either linear interpolation or cosine interpolation.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The real-time deformable shielding system provided by this invention acquires the precise angular position of the rotating stage in real time through an angle sensor in the substrate rotation mechanism. A controller then links the angle signal with multiple independently driven fan-shaped blades, transforming the shielding plate assembly from a passive, fixed shielding structure into an active control device capable of dynamically changing the opening shape and radial transmission distribution according to the substrate's rotation angle. In this system, the fan-shaped blades are uniformly distributed circumferentially and each is driven by an independent motor, allowing for arbitrary radial position adjustment under controller commands. This creates an angle-dependent, continuously variable beam modulation between the evaporation source and the substrate. Specifically, on one hand, the system can accurately compensate for the non-uniformity of the deposition rate angular distribution caused by the geometric layout in biased evaporation sources or multi-source co-evaporation processes, ensuring a consistent cumulative deposition dose at different radial positions on the substrate surface within a complete rotation cycle. On the other hand, because the transmission channel is opened only in specific radial regions within the required rotation angle window, the proportion of ineffective shielding of the evaporating material is significantly reduced, resulting in a substantial increase in material utilization.

[0017] The real-time deformable shielding method provided by this invention utilizes an angle sensor to acquire the current rotation angle in real time. A controller quickly calculates the target radial position of each fan-shaped blade based on a preset blade position-angle correspondence. Subsequently, a drive motor precisely moves the blades, thereby dynamically adjusting the transmission ratio of the evaporation beam in different radial regions within each minute angular increment. Repeating these steps ensures that the blade position continuously changes according to a preset pattern within each complete rotation cycle of the substrate, forming a periodic spatial-temporal joint modulation of the deposition beam. This method, through real-time linkage between the rotation angle and the shielding blades, can improve film thickness uniformity to within ±2.4%, increase material utilization to over 50%, and support precise control of single-material radial homogenization and multi-material zoned co-evaporation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a real-time deformable shielding system for rotating substrate coating according to the present invention.

[0020] The components include: 1. Substrate rotation mechanism; 2. Angle sensor; 3. Central rotation shaft; 4. Shielding plate assembly; 5. Fan-shaped blades; 6. Motor; 7. Controller. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply refers to its direction relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings: This invention provides a real-time deformable shielding system for rotating substrate coating, such as... Figure 1 As shown, the device includes a substrate rotation mechanism 1, a shielding plate assembly 4, and a controller 7. The substrate rotation mechanism 1 includes a rotating table for carrying the substrate, a rotation driver, and an angle sensor 2; the output end of the rotation driver is connected to the rotating table; the angle sensor 2 is mounted on the rotating table; the shielding plate assembly 4 is disposed between the evaporation source and the substrate; the shielding plate assembly 4 includes a fixed bracket, multiple fan-shaped blades 5, and multiple motors 6; the multiple fan-shaped blades 5 are evenly distributed circumferentially on the fixed bracket; the output ends of the multiple motors 6 are connected one-to-one with the multiple fan-shaped blades 5; the input end of the controller 7 is connected to the angle sensor 2, and the output end of the controller 7 is connected to the motors 6.

[0028] Specifically, the present invention includes: The substrate rotation mechanism 1 includes a rotating table for carrying the substrate, a rotary driver that is drivenly connected to the rotating table, and an angle sensor 2 mounted on the central rotating shaft 3 of the rotating table. The angle sensor 2 can be a high-precision rotary encoder to obtain the angular position of the substrate in real time. The shielding plate assembly 4 is disposed between the evaporation source and the substrate. The assembly includes a fixed bracket, multiple fan-shaped blades 5 evenly distributed on the fixed bracket along the circumference, and multiple motors 6 (preferably vacuum-compatible stepper motors or servo motors) corresponding one-to-one with the fan-shaped blades 5. Each fan-shaped blade 5 is connected to the output end of the corresponding motor 6 through a radial sliding guide or linkage mechanism, so that it can move independently along the radial direction or swing around its own axis at a small angle under the drive of the motor 6, so as to realize the continuous adjustment of the radial position of the blade edge and the opening shape. The controller 7 has its input end connected to the angle sensor 2 to receive the real-time rotation angle signal of the substrate, and its output end connected to each motor 6. The controller 7 has a pre-stored blade position-angle mapping table calculated based on the evaporation source beam angle distribution and the desired deposition uniformity. During the coating process, the controller 7 dynamically calculates and drives each motor 6 to adjust the position of the fan-shaped blades 5 according to the current angle signal, so that the transmission opening of the shielding plate changes synchronously with the substrate rotation angle, thereby realizing the spatiotemporal distribution modulation of the deposition beam.

[0029] This invention, through independent control of multiple blades that are linked in real time with the rotation angle of the substrate, can accurately compensate for the inherent non-uniformity of the angular distribution of the evaporation source, so that different radial positions on the substrate surface obtain equal cumulative deposition dose within a complete rotation cycle, thereby improving the film thickness uniformity to within ±2%; at the same time, since the beam is only directed to the radial region to be deposited within the required time window, the amount of evaporation material ineffectively blocked by the shielding plate is greatly reduced.

[0030] In one feasible embodiment of the present invention, the shielding plate assembly 4 further includes a plurality of radial moving guide rails and a plurality of sliders; the radial moving guide rails are fixed on the fixed bracket and extend along the radial direction of the fixed bracket; each slider is slidably engaged with a corresponding radial moving guide rail; each fan-shaped blade 5 is fixed on a corresponding slider; the motor 6 includes a first motor and a second motor; the output end of the first motor is drivenly connected to the slider; the output end of the second motor is drivenly connected to the fan-shaped blade 5.

[0031] Specifically, the shielding plate assembly 4 also includes multiple radial moving guides and multiple sliders. Each radial moving guide is fixed to a fixed bracket and extends along the radial direction of the fixed bracket. Each slider slides with a corresponding radial moving guide, and each fan-shaped blade 5 is fixed to a corresponding slider. To achieve precise control with two degrees of freedom, the motor 6 includes a first motor and a second motor. The output end of the first motor is connected to the slider via a lead screw or gear rack mechanism to drive the slider and the fan-shaped blade 5 on it to perform radial displacement along the radial moving guide, thereby controlling the radial blocking position of the blade edge relative to the center of the substrate. The output end of the second motor is directly or via a drive shaft connected to the fan-shaped blade 5 to drive the fan-shaped blade 5 to rotate or swing around its own axis at a small angle, thereby adjusting the azimuth angle of the blade and the gap shape between it and adjacent blades. This structure, through two independent adjustable degrees of freedom—radial movement and circumferential oscillation—can not only change the obstruction boundary of each blade in the radial direction in real time according to the substrate rotation angle, but also finely adjust the circumferential overlap and opening profile between blades, thereby achieving customized control of beam transmittance distribution at any radial position and any angle direction from the center to the edge. The division of labor drive of the dual motors avoids the motion coupling and accuracy loss that may occur in a single composite motion mechanism. At the same time, the cooperation between the radial guide rail and the slider ensures the smoothness and positioning repeatability of the blades during long-term operation in atmospheric or vacuum environments, enabling the system to quickly respond to the real-time signal of angle sensor 2 and complete high-precision position closed loop.

[0032] The first motor is connected to the slider via a lead screw and nut mechanism. The lead screw is coaxially fixed to the output shaft of the first motor, and the nut is fixedly connected to the slider. When the first motor rotates, it drives the lead screw to rotate, which in turn drives the slider and the fan-shaped blades 5 on it to make precise linear reciprocating motion along the radial moving guide rail. The lead screw and nut mechanism can use a ball screw to reduce friction and improve transmission efficiency, or a trapezoidal lead screw to achieve self-locking and simplify control, thereby achieving sub-millimeter radial positioning accuracy and repeatability in a vacuum environment. The second motor is connected to the fan-shaped blades 5 via a coupling. The coupling is preferably a bellows type or diaphragm type elastic coupling, which can compensate for the coaxiality deviation and angular deviation between the output shaft of the second motor and the rotating shaft of the fan-shaped blades 5 while transmitting torque, avoiding jamming or additional load caused by installation errors or temperature changes. At the same time, the presence of the coupling allows the fan-shaped blades 5 to be designed independently as a structure that is easy to disassemble and replace, without having to be rigidly fixed to the motor shaft.

[0033] The lead screw and nut mechanism efficiently converts the rotational motion of motor 6 into linear motion. Its inherent transmission ratio amplifies the torque of motor 6 and enables precise control of minute displacements. This allows the system to adjust the radial boundaries of each blade in real time based on feedback from angle sensor 2, quickly responding to the target position command issued by controller 7. At the same time, its excellent repeatability ensures the consistency of the opening at the same angular position within different rotation cycles. The coupling connection not only simplifies the assembly and alignment between the second motor 6 and the sector blade 5, but also absorbs the impact and vibration during transmission, protecting the bearings of motor 6 and the blade shaft from additional bending moments, and maintaining stable angle adjustment performance during long-term vacuum operation.

[0034] In one feasible embodiment of the present invention, the fixed bracket is a circular bracket, and a plurality of radial moving guide rails are distributed at equal angular intervals along the circumference of the circular bracket, and each radial moving guide rail points to the center of the circular bracket.

[0035] Specifically, the fixed support is a circular support with an inner diameter greater than or equal to the substrate diameter to avoid obstructing the transmission path of the evaporation beam. Multiple radial moving guides are distributed at equal angular intervals along the circumference of this circular support, and each radial moving guide precisely points to the center of the circular support; that is, the centerlines of all guides intersect at the center of the ring. This circumferentially equal-angled, radially aligned-with-the-center layout design ensures that the fan-shaped blades 5 mounted on each slider always move along the radial direction of the ring during radial movement. This guarantees that the shielding boundary formed by the blade edges is strictly radially straight relative to the center of the substrate, eliminating circumferential unevenness or opening function distortion that may be caused by the blade movement trajectory deviating from the radial direction. The equiangularly spaced distribution ensures that all blades uniformly cover the entire 360° circumference in the circumferential direction, preventing excessively large shielding gaps or overlapping areas from forming at certain angles due to the limited number of blades.

[0036] In one feasible embodiment of the present invention, the fan-shaped blades 5 are made of high-temperature resistant materials such as molybdenum, stainless steel, or titanium alloy. Molybdenum has excellent high-temperature strength, low vapor pressure, and good thermal stability, making it suitable for high-melting-point material vapor deposition or long-term continuous coating processes. Stainless steel has lower cost and is easy to process and form, making it suitable for conventional process requirements. Titanium alloy combines high strength and low density, ensuring rigidity while reducing the inertia of moving parts. The surfaces of all fan-shaped blades 5 are precision polished to reduce surface roughness and decrease the adhesion and accumulation of deposited material on the blade surface, thereby avoiding the risk of increased internal stress, blade deformation, or even particle shedding and contamination of the substrate due to film accumulation. In terms of geometry, the blades can be designed as trapezoidal, triangular, or special curved shapes: trapezoidal blades have varying widths in their radial direction, enabling a large radial adjustment range within a small circumferential space, while also facilitating circumferential overlap between blades to eliminate gap leakage; triangular blades have sharp tips, which can form finer shielding boundaries, suitable for beam modulation requiring high spatial resolution; special curved shapes allow the blades to automatically match the required opening profile at specific angles, thereby reducing dynamic adjustment stroke or lowering the requirements for control system response speed.

[0037] This invention also provides a real-time deformable shielding method for rotating substrate coating, comprising the following steps: S1. The current rotation angle of the rotary table is detected by the angle sensor 2, and the angle signal is sent to the controller 7; S2. The controller 7 determines the target position of each of the fan-shaped blades 5 corresponding to the current rotation angle according to the preset blade position-angle correspondence. S3. The controller 7 controls each of the motors 6 to drive the fan-shaped blades 5 corresponding to the motors 6 to move to the target position, thereby changing the radial extension of the blade edge and the shape of the gap between it and the adjacent blades, so as to adjust the degree of obstruction of the evaporation beam by each fan-shaped blade 5. S4. During the substrate rotation coating process, repeat S1~S3 to make the position of the fan-shaped blade 5 change dynamically in real time with the rotation angle, so as to realize the periodic modulation of the deposition beam.

[0038] This method directly links beam modulation to the substrate rotation angle. Through real-time feedback control, the transmission characteristics of the shielding plate are no longer fixed but exhibit an angle-dependent variation with substrate rotation. This accurately compensates for the inherent non-uniformity of the evaporation source's angular distribution and the differences in geometric relationships between different radial positions on the substrate at different angles. This makes the accumulated deposition dose of each tiny area element tend to be consistent in each rotation, improving the film thickness uniformity across the entire substrate to within ±2% without significantly sacrificing the deposition rate. Simultaneously, since the opening shape is only open to specific radial regions within the required time window, a large amount of material that would otherwise be blocked by the fixed shielding plate can be effectively deposited on the substrate, increasing material utilization from 20%~30% in traditional methods to over 50%. Furthermore, this method can adapt to different evaporation source characteristics, substrate sizes, or material combinations by modifying the pre-stored correspondence in controller 7 without replacing any hardware components. It has extremely high process flexibility and automation, fundamentally overcoming the technical bottlenecks of existing fixed or simple open / closed shielding methods, such as the inability to dynamically adjust radial distribution, difficulty in achieving precise control of multi-material co-evaporation components, and serious material waste.

[0039] In a feasible embodiment of the present invention, the preset blade position-angle correspondence is obtained in the following way: Calibrate the evaporation source at different emission angles Deposition rate distribution function ; Establish any radial position on the substrate rotation angle deposition rate model ,in The radial position The polar angle relative to the evaporation source; For all radial positions The cumulative deposited dose received within a complete rotation cycle is equal, that is

[0040] in, ; It is a constant; Rotation angle Discretize into N sampling points , , , , radial position Discretized into M sampling points , , , Discretize the opening function into a matrix ; With the goal of minimizing the cumulative dose variance at each radial position and the constraint of the smoothness of the blade position change between adjacent angles, a numerical optimization algorithm is used to solve for the optimal opening value at each radial position under each discrete angle. Based on the geometry of each sector blade 5, the matrix is ​​converted into radial position commands for each blade at different rotation angles, forming the blade position-angle correspondence.

[0041] Specifically, it includes: First, the evaporation source is calibrated using an angle-resolved detection system (such as a rotatable quartz crystal microbalance QCM or a Faraday cup) to obtain its emission angles. Deposition rate distribution function This function can usually be expressed as In the form of, The evaporation source is in the vertical direction (i.e., the emission angle). Deposition rate (at 0° direction), It is determined by the geometry and material properties of the evaporation source; Then, based on the spatial geometric relationship between the substrate and the evaporation source, the position of any radial location on the substrate is established. substrate rotation angle Instantaneous deposition rate model ,in The polar angle of this position relative to the evaporation source can be accurately calculated based on geometric parameters such as the relative offset and perpendicular distance between the evaporation source and the substrate center. Based on this, to ensure uniformity across all radial positions during the coating process, the following integral constraint condition is set: For each radial position... The cumulative deposition dose received within a complete rotation cycle (0 to 2π) should be equal to the same constant C, i.e.:

[0042] in, Let be the opening function to be determined, representing the opening angle at . Radial position at time Transmission ratio at that location; It is a constant.

[0043] To solve for this continuous function, the rotation angle is... Discretize into N sampling points (e.g., one point every 1° or 5°, for a total of 360 / N points), and then use the radial position... Discretize the continuous opening function into M sampling points (e.g., 10-20 points at equal intervals along the radial direction), thus discretizing the continuous opening function into an N-row M-column matrix. Then, minimizing the variance between the discretized cumulative dose and the target constant C at each radial position is used as the optimization objective (e.g., minimizing the root mean square error). Simultaneously, a smoothness constraint on the change in blade position between adjacent angles is introduced (e.g., limiting the difference in radial position of the blades at adjacent angles to no more than a certain threshold to avoid excessive acceleration or impact during motor 6 drive). Numerical optimization algorithms such as gradient descent, sequential quadratic programming, or genetic algorithms are used to solve for each discrete angle. each radial position The optimal opening value.

[0044] Finally, based on the actual geometry of the fan-shaped blade 5 (e.g., the blade edge is a straight line or a specific curve) and kinematic relationships, the solved matrix is ​​converted into a set of specific control commands, i.e., each blade at different rotation angles... The radial position or angular attitude that should be achieved is determined, thereby forming a complete blade position-angle correspondence table and pre-storing it in the controller 7.

[0045] This step transforms the originally complex problem of solving continuous functions into a discrete numerical optimization problem, making full use of the digital processing capabilities of modern control systems. It not only obtains an opening pattern that approximates the theoretical optimal solution, but also ensures the feasibility and reliability of mechanical motion by introducing smoothness constraints, avoiding motor overload or positioning loss caused by drastic jumps between adjacent blade angles.

[0046] In a feasible embodiment of the present invention, when using a numerical optimization algorithm to solve for the optimal opening value at each radial position under each discrete angle, the method further includes: The second derivative constraint of the blade position change between adjacent angles is added to ensure that the blade motion trajectory satisfies the acceleration continuity; the controller 7 drives each motor 6 with the S-curve acceleration and deceleration control algorithm according to the smooth trajectory obtained by the solution, so that the dynamic tracking error between the actual motion position of the fan-shaped blade 5 and the theoretical target position of the current rotation angle is less than the radial offset corresponding to 1 / 360 of the substrate rotation period.

[0047] Specifically, when solving for the optimal opening value at each radial position under each discrete angle, a second derivative constraint on the change of blade position between adjacent angles is added. That is, the second derivative of the blade position with respect to the rotation angle is required to be continuous, thereby ensuring that there is no abrupt change in the acceleration level of the blade motion trajectory and avoiding the sudden jump phenomenon that would cause the motor 6 to drive unsteadily in the theoretical opening function. Based on the smooth motion trajectory obtained by solving for this constraint, the controller 7 further adopts an S-curve acceleration and deceleration control algorithm to drive each motor 6. This algorithm plans the blade velocity curve as an S-shaped profile that gradually accelerates from zero, maintains a constant speed in the middle, and finally gradually decelerates to zero, so that the rate of change of acceleration is continuously controllable, thereby achieving accurate tracking of blade motion during the continuous rotation of the substrate.

[0048] Based on this, by optimizing the control parameters, the dynamic tracking error between the actual movement position of the fan-shaped blade 5 and the theoretical target position obtained by looking up the table from the current rotation angle is strictly controlled within the radial offset corresponding to 1 / 360 of the substrate rotation period. For example, if the substrate rotates at a speed of 30 revolutions per minute with a rotation period of 2 seconds, then 1 / 360 of the period is approximately 5.56 milliseconds. During this period, the substrate rotates by an angle of 1°, and the corresponding maximum radial offset is typically less than 0.5 mm according to geometric relationships. This accuracy requirement ensures that the influence of blade position error on deposition uniformity is negligible.

[0049] In one feasible embodiment of the present invention, the process of the controller 7 controlling each of the motors 6 and driving the fan-shaped blades 5 corresponding to the motors 6 to move to the target position can be carried out using an angle-dependent modulation mode or a material partitioning deposition mode. Angle-dependent modulation mode: The controller 7 dynamically adjusts the opening ratio of each fan-shaped blade 5 in each rotation cycle of the substrate according to the preset blade position-angle correspondence, thereby changing the opening ratio of the shielding plate to accurately compensate for the radial deposition rate difference caused by the inherent angle distribution of the evaporation source, so that the deposition dose accumulated at different radial positions on the substrate surface is equal in a complete rotation cycle, and finally achieves highly radially uniform deposition of a single material on the entire substrate area. Material partitioning deposition mode: This mode is suitable for process scenarios where multiple materials are co-evaporated. It divides the rotating circumference of the substrate into multiple fan-shaped deposition zones. Each fan-shaped deposition zone corresponds to an evaporation material (e.g., PbI2 zone). Each fan-shaped blade 5 independently adjusts its radial position according to the fan-shaped deposition zone it is in at the current rotation angle, so that each material can achieve radial uniform deposition in its corresponding fan-shaped deposition zone. By adjusting the angle width of each fan-shaped deposition zone (i.e., controlling the exposure time ratio corresponding to each material evaporation source), the deposition thickness ratio of different materials can be controlled, thereby achieving free control of the film stoichiometry.

[0050] Among them, the angle-dependent modulation mode fundamentally solves the problem that traditional fixed shielding plates cannot compensate for the radial gradient of the evaporation source, enabling film thickness uniformity to reach within ±2% and material utilization to increase to over 50%. On the other hand, the material partitioning deposition mode further integrates the complex process of multi-material co-evaporation, not only achieving independent radial uniformity within each material partition, but also flexibly adjusting the proportion of each component. This breaks through the limitation of existing static partitioning shielding plates, which can only achieve simple partitioning and cannot improve the uniformity within each partition or adjust the deposition ratio. It provides a highly automated solution for the precise preparation of components of multi-component compound thin films such as perovskite solar cells.

[0051] In one feasible embodiment of the present invention, the material partitioning deposition mode further includes: Multiple fan-shaped blades 5 are divided into boundary blade groups and radial adjustment blade groups. The boundary blade groups are used to separate adjacent fan-shaped deposition areas, and their radial positions remain unchanged during the coating process or are only switched at the partition boundaries in a predefined manner. The radial adjustment blade groups move independently within each fan-shaped deposition area. When the substrate rotates past the boundary of the fan-shaped deposition zone, the controller 7 controls the radial adjustment blade group to gradually change the opening ratio according to the boundary transition algorithm, which is either linear interpolation or cosine interpolation.

[0052] Specifically, it includes: Multiple fan-shaped blades 5 are divided into boundary blade groups and radial adjustment blade groups. The boundary blade groups are used to physically separate adjacent fan-shaped deposition areas of different materials. Their radial positions remain constant throughout the coating process, or they only need to perform a predefined step switch at the partition boundary when the partition layout needs to be adjusted, thereby forming a clear and stable shielding boundary between each material area to prevent cross-contamination between materials from different evaporation sources. The radial adjustment blade groups move independently inside each fan-shaped deposition area and dynamically adjust the opening ratio according to the angle-dependent modulation principle to compensate for the non-uniform angle distribution of the evaporation source of the material itself, ensuring the radial deposition uniformity of each material in its corresponding deposition area.

[0053] Furthermore, when the substrate rotates through the boundary between two fan-shaped deposition zones of different materials, the controller 7 does not require a sudden change in the opening ratio of the radial adjustment blade group. Instead, it gradually changes the opening ratio according to a preset boundary transition algorithm (such as linear interpolation or cosine interpolation), so that the deposition rate transitions smoothly in the boundary region rather than changing abruptly.

[0054] This step involves grouping the blades by function. The boundary blade group is responsible for isolating the material regions, and its relatively fixed position helps maintain the clarity and stability of the interface. The radial adjustment blade group focuses on the uniformity adjustment within the partition. The two groups have clear division of labor and work together, reducing the complexity of the control system and the burden of frequent operation of each motor. At the same time, the introduction of the boundary transition algorithm avoids the deposition thickness spikes or depressions that may be caused by abrupt changes in the opening ratio at the partition boundary. Linear interpolation ensures that the linear change characteristics of the transition zone are easy to predict and control, while cosine interpolation further provides a smooth transition with a slope of zero at the endpoint. This effectively suppresses the thickness fluctuations that may be caused by mechanical motion lag or response delay, so that the film obtained by multi-material co-evaporation still maintains good compositional gradient controllability and structural integrity in the material interface region.

[0055] Example This embodiment uses a typical bias point evaporation source as an example to illustrate how to use the deformable shielding method described in this invention to achieve uniformity of radial deposition dose on the substrate surface.

[0056] This embodiment uses the following system configuration and process parameters: Substrate: Circular substrate with radius R = 300 mm.

[0057] Substrate rotation mechanism 1: The center of the rotating stage is located directly above the evaporation source, with a vertical distance H=400mm.

[0058] Evaporation source layout: An offset point source is used, located horizontally at a position d=150mm off the center of rotation (in polar coordinates). (instead of the position directly below the center, which is commonly used in traditional techniques).

[0059] Evaporation source angle distribution: The deposition rate of the evaporation source is distributed with respect to the emission angle. This distribution is an approximate model for typical small-area point sources (such as Knudsen pools or electron beam evaporation).

[0060] The shielding plate assembly 4 consists of 8 fan-shaped blades 5 evenly distributed around the circumference. Each fan-shaped blade 5 can move independently along the radial direction, and the position of each blade is controlled in a closed loop by the controller 7 based on the real-time angle of the rotary table.

[0061] Controller 7: Built-in blade position-angle correspondence, sampling angle resolution is 15° (i.e., the blade position is updated once every 15° rotation).

[0062] This embodiment provides a real-time deformable shielding method for rotating substrate coating, including the following steps: First, establish the geometric relationship. Any point P on the substrate is determined by polar coordinates. It means that among them For radial position (0≤r≤300mm). This represents the current rotation angle of the substrate. The evaporation source is located at a fixed coordinate. Place.

[0063] The distance L and polar angle of point P relative to the evaporation source satisfy:

[0064]

[0065] Therefore, the instantaneous deposition rate (deposition thickness per unit time) generated by the evaporation source at point P is:

[0066] It should be noted that for a traditional central point source (d=0), the above equation simplifies to: Its relationship with the rotation angle Irrelevant. This is precisely the fundamental reason why existing technologies cannot improve radial uniformity through angle-dependent modulation. However, this embodiment employs a biased evaporation source (d > 0), making... Follow Significant changes: when When = 0, point P is closest to the evaporation source, and the deposition rate is the highest; when When π = π, point P is far from the evaporation source, and the deposition rate is at its minimum.

[0067] The substrate rotates one revolution at a constant angular velocity ω (period T = 2π / ω), and the cumulative deposition dose at point P is:

[0068] Numerical integration (discretization) Calculate the integral value for different values ​​of r for 360 points. The dose was normalized based on the dose at the center point r=0, and the results are shown in Table 1.

[0069] Table 1. Normalized cumulative dose at different radial positions without shielding.

[0070] As shown in Table 1, the cumulative dose received at the substrate edge (r=300mm) is approximately 57.9% higher than that at the center. This indicates that without any shielding measures, the film thickness will exhibit a significant uneven distribution, with thicker edges and a thinner center. Therefore, the opening of the shielding plate must be dynamically adjusted during substrate rotation, ensuring that the edge point is directly aligned with the evaporation source. When the value is near 0, increase the shading, and when it is away from the evaporation source ( Reduce occlusion when the dose is near π to balance the cumulative dose over the entire cycle.

[0071] Let the opening function of the shielding plate be... , indicating the angle Radial position at time The transmission ratio at that location. After adding the shielding plate, the cumulative dose should meet the following requirements:

[0072] in, It is a constant independent of r.

[0073] To solve This embodiment uses the following simplified form of the opening function:

[0074] in, The modulation depth varies with radial position r. This form is... When =0, the opening is the smallest ( ),exist The opening is largest when =π ( (It needs to be truncated to 1), which is consistent with physical intuition.

[0075] Substituting the above form into the uniformity condition:

[0076] Take constant =4.8 (slightly below the center point) =4.825, to retain a certain design margin), numerical calculations of each Below and The results are shown in Table 2.

[0077] Table 2 Modulation Depth Numerical calculation results

[0078] At r=0 in the table =0 (due to symmetry, (If the function is odd and the integrand is even, and the integral is zero), this point cannot be defined by the above formula. In practice, the extrapolated value of a nearby point can be used, or it can be directly set. =0 (no modulation required for the center point).

[0079] For a given rotation angle The aperture function, along with the radial position r, determines the transmission profile that the blade should form. To simplify control, this embodiment adopts a "step aperture model": assuming the aperture region of the shielding plate extends from the center to a certain radial boundary. The circular region, i.e., when r ≤ Complete transmission occurs when r > When completely occluded. In this case, the opening function degenerates to:

[0080] The uniformity condition then becomes: for each You need to choose the appropriate one. This ensures that the integral dose is equal at different r values. This is a one-dimensional optimization problem, which can be solved numerically for each discrete angle using methods such as the bisection method. .

[0081] Rotation angle Discretized into 24 sampling points (interval 15°), for each Solve the corresponding The relationships shown in Table 3 are obtained.

[0082] Table 3 Blade Radial Boundary Relationship Table

[0083] Note: For >180°, due to geometric symmetry .

[0084] During the coating process, angle sensor 2 reads the current angle of the rotary table in real time. The controller 7 obtains the currently required radial boundary by using Table 3 and combining linear interpolation. Subsequently, an S-curve acceleration / deceleration algorithm is used to drive the motors 6 of all the sector blades 5, causing the blade tip edges to move synchronously to... Positioning is used to form a circular transmission area centered on the center; the above steps are repeated every time the substrate is rotated by a small angle (e.g., 1°) to ensure that the blade position changes dynamically and continuously with the rotation angle.

[0085] After adopting the above dynamic control strategy, numerical simulations show that the maximum deposition dose deviation on the substrate surface is reduced from +57.9% (edge ​​to center) to within ±4.8% without shielding, and the film thickness uniformity (defined as half-width difference) reaches ±2.4%, which can meet the coating requirements of most optical thin films and electronic devices. At the same time, the material utilization rate (the ratio of substrate receiving mass to total evaporation mass) is about 52%, which is significantly higher than the 20%~30% of traditional fixed shielding plates. In contrast, the maximum deviation of fixed circular shielding plates is usually still greater than ±20%, while fixed sector-divided shielding plates cannot improve the radial gradient of a single material itself.

[0086] This embodiment achieves precise modulation of the deposition beam in an "angle-dependent, radially partitioned" manner by working in concert with the biased evaporation source and the dynamically deformable shielding plate, thus solving the problem of difficult control of radial uniformity in the prior art.

[0087] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A real-time deformable shield system for use in the coating of a rotating substrate, comprising: The system comprises: a substrate rotating mechanism (1) comprising a rotating table for carrying a substrate, a rotating driver, and an angle sensor (2); an output end of the rotating driver is in transmission connection with the rotating table; the angle sensor (2) is installed on a central rotating shaft (3) of the rotating table; a shielding plate assembly (4) arranged between an evaporation source and the substrate; the shielding plate assembly (4) comprises a fixed support, a plurality of fan-shaped blades (5), and a plurality of motors (6); the plurality of fan-shaped blades (5) are uniformly distributed on the fixed support in a circumferential direction; output ends of the plurality of motors (6) are in one-to-one corresponding connection with the plurality of fan-shaped blades (5); a controller (7) having an input end connected with the angle sensor (2) and an output end connected with the motors (6).

2. A real-time deformable shield system for use in the coating of a rotating substrate as defined in claim 1, wherein, The shielding plate assembly (4) further comprises a plurality of radial movement guide rails and a plurality of sliders; the radial movement guide rails are fixed on the fixed support and extend in a radial direction of the fixed support; each of the sliders is in sliding fit with a corresponding one of the radial movement guide rails; each of the fan-shaped blades (5) is fixed on a corresponding one of the sliders; the motors (6) comprise first motors and second motors; output ends of the first motors are in transmission connection with the sliders; output ends of the second motors are in transmission connection with the fan-shaped blades (5).

3. A real-time deformable shield system for coating a rotating substrate as defined in claim 2, wherein, The first motors are in transmission connection with the sliders through screw-nut mechanisms; the second motors are in transmission connection with the fan-shaped blades (5) through shaft couplings.

4. A real-time deformable shield system for use in coating a rotating substrate as defined in claim 1, wherein, The fixed support is a circular support, the plurality of radial movement guide rails are distributed at equal angles in a circumferential direction of the circular support, and each of the radial movement guide rails points to a center of the circular support.

5. A real-time deformable shield system for use in the coating of a rotating substrate as defined in claim 1, wherein, The angle sensor (2) is a rotary encoder.

6. A real-time deformable shield method for coating a rotating substrate, comprising: The system according to claims 1-5, comprising the following steps: S1, detecting a current rotating angle of the rotating table through the angle sensor (2) and sending an angle signal to the controller (7); S2, determining target positions of each of the fan-shaped blades (5) corresponding to the current rotating angle according to a preset blade position-angle correspondence relationship by the controller (7); S3, controlling each of the motors (6) to drive the fan-shaped blade (5) corresponding to the motor (6) to move to the target position to adjust a shielding degree of each fan-shaped blade (5) to an evaporation beam by the controller (7); S4, repeating S1-S3 during a substrate rotating coating process, so that the positions of the fan-shaped blades (5) dynamically change with the rotating angle in real time to realize periodic modulation to a deposition beam.

7. A method for real-time deformable shielding for coating of a rotating substrate as defined in claim 6, wherein, The preset blade position-angle correspondence relationship is obtained by: Calibrating deposition rate distribution functions of an evaporation source at different exit angles ;​ establishing a deposition rate model at any radial position on the substrate at a rotation angle wherein wherein is the radial position relative to a polar angle of the evaporation source For all radial positions The cumulative deposited dose received over one complete rotation period is equal, i.e. wherein is the opening function to be found; is a constant; rotational angle discretized into N sampling points , , , radial position discretized into M sampling points , , , discretizing the opening function into a matrix ; taking minimum cumulative dose variance of each radial position as a target and taking smoothness of blade position change between adjacent angles as a constraint, and solving optimal opening values of each radial position under each discrete angle by using a numerical optimization algorithm. Based on the geometry of each sector blade (5), the matrix is ​​converted into radial position commands for each blade at different rotation angles, forming the blade position-angle correspondence.

8. A method for real-time deformable shielding for coating a rotating substrate as recited in claim 7, wherein, The method of using numerical optimization algorithms to solve for the optimal opening value at each radial position under each discrete angle also includes: The second derivative constraint of the blade position change between adjacent angles is added to make the blade motion trajectory satisfy the acceleration continuity; the controller (7) drives each motor (6) according to the smooth trajectory obtained by the solution using the S-curve acceleration and deceleration control algorithm, so that the dynamic tracking error between the actual motion position of the fan blade (5) and the theoretical target position of the current rotation angle is less than the radial offset corresponding to 1 / 360 of the substrate rotation period.

9. The method of claim 6, wherein the shield is deformed in real time. The process of the controller (7) controlling each of the motors (6) and driving the fan-shaped blades (5) corresponding to the motors (6) to move to the target position can be carried out using an angle-dependent modulation mode or a material partitioning deposition mode. Angle-dependent modulation mode: The controller (7) dynamically adjusts the opening ratio of each fan-shaped blade (5) in each rotation cycle of the substrate according to the preset blade position-angle correspondence, to compensate for the radial deposition rate difference caused by the evaporation source angle distribution, and to achieve radial uniform deposition of a single material. Material partitioning deposition mode: The substrate is divided into multiple fan-shaped deposition zones by rotating the circumference. Each fan-shaped deposition zone corresponds to a type of evaporation material. Each fan-shaped blade (5) independently adjusts its radial position according to the fan-shaped deposition zone where it is located at the current rotation angle, so that each material can achieve radial uniform deposition in its corresponding fan-shaped deposition zone. The deposition thickness ratio of different materials is controlled by adjusting the angle width of each fan-shaped deposition zone.

10. The method of claim 9, wherein the shield is deformed in real time. The material partitioning deposition mode also includes: Multiple fan-shaped blades (5) are divided into boundary blade groups and radial adjustment blade groups. The boundary blade groups are used to separate adjacent fan-shaped deposition areas. Their radial positions remain unchanged during the coating process or are only predefined and switched at the partition boundaries. The radial adjustment blade groups move independently within each fan-shaped deposition area. When the substrate rotates past the boundary of the fan-shaped deposition area, the controller (7) controls the radial adjustment blade group to gradually change the opening ratio according to the boundary transition algorithm, which is linear interpolation or cosine interpolation.

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