Test platform of wafer lifting structure

Abstract

The invention discloses a test platform of a wafer lifting structure, which comprises a test cavity capable of simulating a vacuum environment, a position detection unit, a single lifting unit, a lifting rotating unit and a control unit, and is characterized in that the position detection unit is arranged in the test cavity, and the single lifting unit is arranged at the bottom of the test cavity and is used for driving a wafer to move up and down; the lifting rotation unit is installed at the bottom of the test cavity and used for driving the wafer to rotate and move up and down at the same time, and the control unit is connected with the position detection unit and used for calculating the repeated positioning precision and stability of the wafer according to detection data; the single lifting unit and the lifting rotating unit can be installed in a switchable mode. The detection platform of the wafer lifting structure provided by the invention can comprehensively and quantitatively evaluate the reliability, the position offset and the performance degradation of each part of the lifting mechanism under the simulated real working condition, provides a basis for improving the design and predicting the maintenance period, and finally helps to solve the problems of thin film nonuniformity and yield reduction caused by the problem of the lifting mechanism.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a test platform for a wafer lifting structure. Background Art

[0002] As semiconductor manufacturing processes become increasingly sophisticated, the uniformity of thin films on the wafer surface has an increasingly significant impact on device performance. Film uniformity depends on environmental parameters such as the airflow distribution, temperature field, and plasma field within the reaction chamber. The reliability of the wafer lift mechanism directly determines the positioning accuracy and stability of the wafer during transport. If the lift mechanism experiences positional deviation, jamming, or sealing failure during long-term operation, it will lead to uneven film thickness and composition across the wafer surface, resulting in reduced device yield.

[0003] In existing technologies, wafer lift mechanisms must operate in a vacuum environment for extended periods of time. The reliability, repeatability, and lifespan of their components (such as linear guides, seals, and servo systems) directly impact wafer position stability. However, the current lack of dedicated test platforms capable of simultaneously simulating a vacuum environment and integrating both lift and rotation modes makes it impossible to fully assess lift mechanism performance degradation, positional offset, and component failure under real-world operating conditions, impacting the yield and maintenance costs of semiconductor equipment. Summary of the Invention

[0004] An embodiment of the present invention provides a test platform for a wafer lifting structure, which solves the technical problem that traditional test platforms cannot simultaneously simulate a vacuum environment and integrate lifting / rotation dual-mode testing, resulting in incomplete testing, which in turn affects the yield and maintenance cost of semiconductor equipment.

[0005] In order to solve the above problems, according to one aspect of the present application, an embodiment of the present invention provides a test platform for a wafer lifting structure, wherein the test platform includes a test chamber capable of simulating a vacuum environment, a position detection unit, a single lifting unit, a lifting and rotating unit, and a control unit. The position detection unit is arranged in the test chamber for detecting the displacement and inclination of the wafer in real time, the single lifting unit is installed at the bottom of the test chamber for driving the wafer to move up and down, and the lifting and rotating unit is installed at the bottom of the test chamber for driving the wafer to rotate and move up and down at the same time. The control unit is connected to the position detection unit for calculating the wafer repeatability and stability based on the detection data; wherein the single lifting unit and the lifting and rotating unit can be installed switchably.

[0006] In some embodiments, the test chamber has a vacuum pump connection port and a backfill gas line connection port. The test chamber is connected to an external vacuum pump through the vacuum pump connection port, and the test chamber is connected to a process gas backfill pipeline through the backfill gas line connection port. The test chamber has a vacuum gauge installed on the inner wall of the test chamber for real-time monitoring of the chamber pressure and transmitting data to the control unit.

[0007] In some embodiments, the single lifting unit includes a first motor, a linear slide, a first coupling, a lifting bracket and a first limit module. The output end of the first motor is connected to the linear slide through a first coupling. The lifting bracket is fixed on the slider of the linear slide for carrying the test wafer. The first limit module is arranged at the travel end point of the linear slide.

[0008] In some embodiments, the lifting and rotating unit includes a lifting drive module, which includes a second motor, a first reducer, a second coupling, a lifting slide rail and a wafer holder. The output end of the second motor is coaxially connected to the input end of the first reducer through the second coupling, and the output end of the first reducer is connected to the lifting slide rail. The wafer holder is fixed on the slider of the lifting slide rail and realizes vertical lifting movement along the lifting slide rail. The upper and lower travel end points of the lifting slide rail are respectively provided with second limit modules.

[0009] In some embodiments, the lifting and rotating unit also includes a rotation drive module, which includes a third motor, a second reducer and a third coupling. The output end of the third motor is coaxially connected to the input end of the second reducer through the third coupling. The output end of the second reducer is fixed to the wafer holder, and the wafer holder is connected to the top of the slider of the lifting rail.

[0010] In some embodiments, the rotation driving module further includes a bellows and a rotation seal, wherein the bellows seals and covers the lifting rail, and the rotation seal is disposed at the rotation axis of the wafer holder.

[0011] In some embodiments, the position detection unit includes at least two laser ranging modules arranged above the wafer, each of the laser ranging modules includes a laser transmitter, a laser receiver and a processor, the laser transmitter transmits a detectable laser to the wafer, the laser receiver receives the diffusely reflected laser from the wafer surface, and the processor calculates the real-time position and inclination of the wafer based on the laser reflection time difference; wherein, the processor is configured to: when the position difference between the two detection points is greater than 0.1mm, it is determined that the wafer has a position offset; when the position deviation before and after lifting is greater than ±0.1mm, it is determined that the repeat positioning accuracy is unqualified.

[0012] In some embodiments, the control unit is configured to: perform more than one million cycle tests on the single lifting unit or the lifting and rotating unit; record position data after each lifting, and calculate the repeat positioning accuracy.

[0013] In some embodiments, the single lifting unit and the lifting and rotating unit are replaceably installed at the bottom of the test chamber through a quick-release structure.

[0014] In some embodiments, the first limit module is a travel switch or a photoelectric sensor.

[0015] Compared with the prior art, the test platform of the wafer lifting structure of the present invention has at least the following beneficial effects:

[0016] The test platform for the wafer lifting structure provided by the present invention includes a test chamber capable of simulating a vacuum environment, a position detection unit, a single lifting unit, a lifting and rotating unit, and a control unit. The position detection unit is arranged in the test chamber for detecting the displacement and inclination of the wafer in real time. The single lifting unit is installed at the bottom of the test chamber for driving the wafer to move up and down. The lifting and rotating unit is installed at the bottom of the test chamber for driving the wafer to rotate and move up and down at the same time. The control unit is connected to the position detection unit and is used to calculate the wafer repeatability and stability based on the detection data; wherein, the single lifting unit and the lifting and rotating unit can be installed switchably.

[0017] The present invention simulates a real vacuum working environment through a test chamber, solving the problem of lack of vacuum environment simulation in the background. The position detection unit directly and in real time detects the displacement and tilt of the wafer in a vacuum environment, providing a direct means of quantifying performance degradation and position offset. The switchable installation design of the single lifting unit and the lifting and rotating unit enables the platform to test the performance of the two key motion modes of pure lifting and lifting plus rotation of the wafer under vacuum separately or in combination, solving the problem of lack of integrated dual-mode testing capabilities in the background. The control unit uses the data from the position detection unit to accurately calculate the repeatability and stability indicators that are crucial for long-term operation. Therefore, the entire detection platform can comprehensively and quantitatively evaluate the reliability, position offset and performance degradation of each component of the lifting mechanism under simulated real working conditions, provide a basis for improving the design and predicting the maintenance cycle, and ultimately help solve the problems of film unevenness and yield reduction caused by problems with the lifting mechanism.

[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A schematic structural diagram of a test platform for a wafer lifting structure provided by an embodiment of the present invention is shown;

[0021] Figure 2 A front view of a test platform for a wafer lifting structure provided by an embodiment of the present invention is shown;

[0022] Figure 3 A schematic structural diagram of a single lifting unit in a test platform for a wafer lifting structure provided by an embodiment of the present invention is shown;

[0023] Figure 4 A schematic structural diagram of a rotary lifting unit in a test platform for a wafer lifting structure provided by an embodiment of the present invention is shown;

[0024] Figure 5 A partial cross-sectional view of a test platform for a wafer lifting structure provided by an embodiment of the present invention is shown;

[0025] Figure 6 A schematic structural diagram of a position detection unit in a test platform for a wafer lifting structure provided by an embodiment of the present invention is shown;

[0026] Figure 7 A functional block diagram of a wafer lifting structure test platform provided by an embodiment of the present invention is shown;

[0027] Reference numerals:

[0028] 1. Test chamber; 11. Vacuum pump connection port; 12. Backfill gas line connection port; 13. Vacuum gauge; 2. Position detection unit; 21. Laser transmitter; 22. Laser receiver; 23. Processor; 3. Single lifting unit; 4. Lifting and rotating unit; 5. Control unit; 31. First motor; 32. Linear guide rail; 33. First coupling; 34. Lifting bracket; 35. First limit module; 41. Lifting drive module; 42. Rotation drive module; 411. Second motor; 412. First reducer; 413. Second coupling; 414. Lifting guide rail; 415. Wafer bracket; 416. Second limit module; 417. Support member; 421. Third motor; 422. Second reducer; 423. Third coupling; 424. Bellows; 425. Rotating seal; 6. Frame; 7. Wafer. DETAILED DESCRIPTION

[0029] To further illustrate the technical means and effects employed by the present invention to achieve its intended objectives, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention is provided in conjunction with the accompanying drawings and preferred embodiments. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0030] In the description of the present invention, it should be clarified that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence; the terms "vertical", "transverse", "longitudinal", "front", "back", "left", "right", "up", "down", "horizontal", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, and do not mean that the devices or elements referred to must have a specific direction or position, and therefore cannot be understood as limiting the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0032] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0033] This embodiment provides a test platform for a wafer lifting structure, such as Figure 1-Figure 7 As shown, the test platform includes a test chamber 1 capable of simulating a vacuum environment, a position detection unit 2, a single lifting unit 3, a lifting and rotating unit 4, and a control unit 5. The position detection unit 2 is disposed within the test chamber 1 for real-time detection of wafer displacement and tilt. The single lifting unit 3 is mounted at the bottom of the test chamber 1 for driving the wafer to move up and down. The lifting and rotating unit 4 is mounted at the bottom of the test chamber 1 for driving the wafer to rotate and move up and down simultaneously. The control unit 5 is connected to the position detection unit 2 and is used to calculate the wafer's repeatability and stability based on the detection data. The single lifting unit 3 and the lifting and rotating unit 4 can be installed interchangeably. The test platform also includes a frame 6 for supporting the test chamber 1.

[0034] The test chamber 1 is the basic structure of the entire test and provides a vacuum environment inside; the position detection unit 2 is directly installed above the inside of the test chamber 1 or at a specific position, so that its sensing surface can directly observe the wafer in the chamber; the single lifting unit 3 and the lifting and rotating unit 4 are both installed at the bottom of the test chamber 1, and their motion execution components extend upward into the interior of the chamber to carry and drive the wafer 7, and these two units are designed to be interchangeable and installed at the same position at the bottom of the chamber; the control unit 5 is usually located outside the test chamber 1, and is electrically connected to the position detection unit 2, the single lifting unit 3, and the lifting and rotating unit 4 through cables or interfaces for sending control instructions and receiving detection data.

[0035] The main function of the test chamber 1 is to provide a closed space that can be evacuated to simulate the vacuum environment in which the wafer lifting mechanism actually works. The function of the position detection unit 2 is to measure the position and tilt angle of the wafer in the test chamber 1 in real time and with high precision during the movement. The function of the single lifting unit 3 is to drive the wafer to perform pure vertical lifting movement in the test chamber 1. The function of the lifting and rotating unit 4 is to drive the wafer to perform rotational movement and vertical lifting movement at the same time in the test chamber 1, or a combination of the two movements. The function of the control unit 5 is to coordinate the entire test process. It controls the single lifting unit 3 or the lifting and rotating unit 4 to execute the specified movement mode, receives and processes the detection data from the position detection unit 2, and finally calculates and outputs key performance indicators such as the repeatability accuracy and movement smoothness of the wafer 7.

[0036] In the specific working process, a vacuum environment is first established in the test chamber 1. According to the test requirements, a single lifting unit 3 or a lifting and rotating unit 4 is installed at the bottom of the chamber. The control unit 5 sends a motion instruction to the selected unit (single lifting unit 3 or lifting and rotating unit 4) to drive the wafer 7 carried by it to move in the vacuum chamber according to the set mode (such as pure lifting, lifting and rotation). During this process, the position detection unit 2 continuously monitors the real-time position and inclination of the wafer 7, and transmits these data to the control unit 5 in real time. The control unit 5 receives and processes these data, calculates the repeatability accuracy by analyzing the consistency of the wafer 7 reaching the target position in multiple motion cycles, and evaluates the smoothness of the movement by analyzing the changes in position and inclination during the movement.

[0037] This embodiment simulates a real vacuum working environment through the test chamber 1, solving the problem of lack of vacuum environment simulation in the background. The position detection unit 2 directly and in real time detects the displacement and inclination of the wafer 7 under a vacuum environment, providing a direct means of quantifying performance degradation and position offset. The switchable installation design of the single lifting unit 3 and the lifting and rotating unit 4 enables the platform to test the performance of the two key motion modes of pure lifting and lifting plus rotation of the wafer 7 under vacuum separately or in combination, solving the problem of lack of integrated dual-mode testing capabilities in the background. The control unit 5 uses the data from the position detection unit 2 to accurately calculate the repeatability and stability indicators that are crucial for long-term operation. Therefore, the entire detection platform can comprehensively and quantitatively evaluate the reliability, position offset and performance degradation of each component of the lifting mechanism under simulated real working conditions, provide a basis for improving the design and predicting the maintenance cycle, and ultimately help solve the problems of film unevenness and yield reduction caused by problems with the lifting mechanism.

[0038] In a specific embodiment, the test chamber 1 has a vacuum pump connection port 11 and a backfill gas line connection port 12. The test chamber 1 is connected to an external vacuum pump through the vacuum pump connection port 11, and the test chamber 1 is connected to a process gas backfill pipeline through the backfill gas line connection port 12. The test chamber 1 has a vacuum gauge 13, which is installed on the inner wall of the test chamber 1 for real-time monitoring of the chamber pressure and transmitting data to the control unit 5.

[0039] Both the vacuum pump connection port 11 and the backfill gas line connection port 12 are located on the shell of the test chamber 1, typically on the sidewall or top of the chamber, serving as interfaces for gas flow in and out of the chamber. The vacuum pump connection port 11 is connected to an external vacuum pump system via a pipe. The backfill gas line connection port 12 is connected to a process gas backfill line via a pipe. A vacuum gauge 13 is mounted directly on the inner wall of the test chamber 1, with its sensor portion exposed within the chamber's interior. It is used to directly sense internal pressure and electrically connect to an external control unit 5 via a cable or interface to transmit pressure data. The vacuum pump connection port 11 provides an interface for connecting the test chamber 1 to an external vacuum pump, allowing the external vacuum pump to extract air from the test chamber 1 to achieve and maintain the desired vacuum level. The backfill gas line connection port 12 provides an interface for connecting the test chamber 1 to an external process gas line, allowing precise introduction of a specific type and flow rate of process gas into the chamber under vacuum conditions or after reaching a specific vacuum level to simulate the actual gas environment in semiconductor manufacturing equipment. The function of the vacuum gauge 13 is to directly measure the vacuum pressure inside the test chamber 1 in real time and transmit accurate pressure data to the control unit 5 for monitoring and feedback control of the vacuum state of the chamber.

[0040] The vacuum pump connector 11, the backfill gas line connector 12 and the vacuum gauge 13 work together to achieve precise control of the internal environment of the test chamber 1. First, the external vacuum pump evacuates the test chamber 1 through the vacuum pump connector 11, and the vacuum gauge 13 monitors the internal pressure in real time and transmits the data to the control unit 5. When the pressure reaches the target vacuum level, the control unit 5 can instruct to stop the evacuation or maintain the vacuum pump to stabilize the pressure. Then, according to the test requirements, the control unit 5 can instruct to inject a specific process gas into the vacuum chamber through the backfill gas line connector 12, while the vacuum gauge 13 continuously monitors the pressure changes to ensure that the pressure after the gas is introduced is stable at the set value. The effect of this combined work is that it can dynamically and accurately establish and maintain various required vacuum environments in the test chamber 1, and flexibly simulate the real process gas atmosphere in semiconductor equipment, thereby providing environmental conditions that are closer to actual working conditions for the wafer lifting mechanism test, significantly improving the authenticity and reliability of the test results.

[0041] In a specific embodiment, the single lifting unit 3 includes a first motor 31, a linear slide 32, a first coupling 33, a lifting bracket 34 and a first limiting module 35. The output end of the first motor 31 is connected to the linear slide 32 through the first coupling 33. The lifting bracket 34 is fixed on the slider of the linear slide 32 for carrying the test wafer 7. The first limiting module 35 is arranged at the travel end point of the linear slide 32.

[0042] The first motor 31 is a servo motor. It is mounted outside or at the bottom of the test chamber 1, and its output shaft is directly connected to the drive shaft of the linear slide 32 via a first coupling 33. The main body of the linear slide 32 is fixed to the bottom of the test chamber 1, and its slider can perform precise linear motion on the slide. A lifting bracket 34 is mounted on the slider and moves up and down with the slider. Its top is located inside the test chamber 1 and is used to support the wafer 7. The first limit module 35 is mounted on the base of the linear slide 32 and is precisely set near the highest and lowest points of the slide's travel to detect or limit the extreme positions of the slider. The function of the first motor 31 is to provide power to drive the movement of the lifting mechanism. The function of the linear slide 32 is to convert the rotational motion of the first motor 31 into precise and smooth linear lifting motion and provide guidance and support for the lifting bracket 34. The function of the first coupling 33 is to connect the output shaft of the first motor 31 and the drive shaft of the linear slide 32, transmitting torque and allowing a certain degree of compensation for installation deviation. The lift bracket 34 directly supports and secures the wafer 7 to be tested, serving as a platform for the wafer's lifting motion. The first limiter module 35 defines the upper and lower physical limits of the lift bracket 34's motion, preventing the slider from exceeding its safe travel range and potentially damaging the equipment. It also provides a position signal.

[0043] The first motor 31 starts to rotate after receiving the instruction from the control unit 5, and its torque is transmitted to the drive shaft of the linear slide 32 through the first coupling 33. The rotational motion of the drive shaft is converted by the linear slide 32 into the precise vertical linear motion of the slider on it. The lifting bracket 34 fixed on the slider moves up and down synchronously, thereby driving the wafer 7 it carries to move up and down in the test chamber 1. When the lifting bracket 34 approaches the highest point or the lowest point of its stroke, the first limit module 35 is triggered, sending a signal to the control unit 5 or physically preventing it from continuing to move. The effect of the combined work of these components is that they can drive the wafer 7 to complete high-precision and high-repeatability vertical lifting motion according to the control instructions in a vacuum environment, and ensure that the motion process is carried out within the set safe stroke range, providing basic motion guarantee for testing the positioning accuracy and stability of the wafer 7.

[0044] In a specific embodiment, the lifting and rotating unit 4 includes a lifting drive module 41, which includes a second motor 411, a first reducer 412, a second coupling 413, a lifting rail 414, and a wafer holder 415. The output end of the second motor 411 is coaxially connected to the input end of the first reducer 412 via the second coupling 413. The output end of the first reducer 412 is connected to the lifting rail 414. The wafer holder 415 is fixed to the slider of the lifting rail 414 and achieves vertical lifting motion along the lifting rail 414. The upper and lower travel endpoints of the lifting rail 414 are respectively provided with second limit modules 416. The second motor 411 is a servo motor. The lifting rail 414 is fixed to a support member 417.

[0045] The second motor 411 is mounted outside or at the bottom of the test chamber 1. Its output shaft is coaxially connected to the input shaft of the first reducer 412 via a second coupling 413. The output shaft of the first reducer 412 is connected to the drive shaft of the lifting rail 414. The main body of the lifting rail 414 is fixed to the bottom of the test chamber 1. The wafer holder 415 is mounted on the slider of the lifting rail 414 and moves vertically within the test chamber 1 along with the slider. The second limit modules 416 are respectively arranged near the top and bottom end points of the travel of the lifting rail 414. The function of the second motor 411 is to provide the raw power required for the lifting movement. The function of the first reducer 412 is to reduce the output speed of the second motor 411 while increasing the output torque to meet the lifting movement requirements of greater driving force and smoother speed. The function of the second coupling 413 is to connect the output shaft of the second motor 411 to the input shaft of the first reducer 412, transmitting torque and compensating for possible installation deviations. The lifting rail 414 converts the motion output by the first reducer 412 into precise, stable linear lifting motion and provides guidance for the wafer holder 415. The wafer holder 415 directly supports and secures the wafer to be tested, serving as a platform for the wafer's lifting motion.

[0046] When it is necessary to drive the wafer to move up and down, the second motor 411 rotates according to the instructions of the control unit 5. Its rotational motion is transmitted to the first reducer 412 through the second coupling 413. After the first reducer 412 reduces the input speed and increases the torque, it drives the drive shaft of the lifting slide 414 to rotate. The lifting slide 414 converts this rotational motion into vertical linear motion of its slider. The wafer holder 415 fixed on the slider then moves up and down precisely in the test chamber 1. The second limit module in the stroke ensures that the movement does not exceed the set safety range. These components are combined to provide the lifting and rotating unit 4 with a powerful, smooth and precisely controllable vertical lifting and lowering motion capability, ensuring that the wafer can reach and stabilize in the required vertical position during the test process, laying the foundation for evaluating its positioning accuracy and stability under compound motion.

[0047] In a specific embodiment, the lifting and rotating unit 4 also includes a rotation drive module 42, which includes a third motor 421, a second reducer 422 and a third coupling 423. The output end of the third motor 421 is coaxially connected to the input end of the second reducer 422 through the third coupling 423, and the output end of the second reducer 422 is fixed to the wafer holder 415. The wafer holder 415 is connected to the top of the slider of the lifting slide rail 414.

[0048] The third motor 421, second reducer 422, and third coupling 423 are mounted as a unit on top of the slider of the lifting rail 414. Specifically, the output shaft of the third motor 421 is coaxially connected to the input shaft of the second reducer 422 via the third coupling 423. The output shaft of the second reducer 422 is directly fixedly connected upward to the wafer carrier 415 located above it. Therefore, the entire rotation drive module 42 moves up and down along with the slider of the lifting rail 414. The function of the third motor 421 is to provide the original rotational power required for the wafer rotation. The function of the second reducer 422 is to reduce the output speed of the third motor 421 while increasing the output torque to meet the requirements of more precise speed control and the required driving force for wafer rotation. The function of the third coupling 423 is to connect the output shaft of the third motor 421 to the input shaft of the second reducer 422, transmitting the rotational torque and compensating for any minor installation deviations between the two, ensuring smooth power transmission.

[0049] When the wafer needs to be driven to rotate, the third motor 421 starts to rotate according to the instructions of the control unit 5. Its rotational motion is transmitted to the input shaft of the second reducer 422 through the third coupling 423. After the second reducer 422 reduces the input speed and increases the torque, its output shaft drives the wafer holder 415 fixedly connected to it to rotate. This setting enables the wafer holder 415 to achieve precise and controllable rotational motion while moving up and down with the lifting slide 414. This provides the test platform with the ability to simulate the composite motion mode of the wafer both lifting and rotating in a vacuum environment, so that the performance of the lifting and rotating unit under such complex real working conditions can be fully evaluated.

[0050] In a specific embodiment, the rotation driving module 42 further includes a bellows 424 and a rotation seal 425 . The bellows 424 seals and covers the lifting rail 414 . The rotation seal 425 is disposed at the rotation axis of the wafer holder 415 .

[0051] The primary function of bellows 424 is to dynamically seal the gap between the slider and the fixed base of lift rail 414 through its own expansion and contraction deformation as the slider moves up and down. This prevents leakage of the vacuum environment of test chamber 1 due to the slider's movement, while also protecting the internal mechanisms of lift rail 414 from possible contamination by process gases within the chamber. The primary function of rotary seal 425 is to form a reliable dynamic seal at the interface between the rotating shaft and the fixed support component when wafer carrier 415 rotates. This prevents leakage of vacuum or process gases along the rotating shaft gap, thereby ensuring chamber pressure stability during rotation.

[0052] When the slider of the lifting rail 414 drives the wafer holder 415 to move up and down, the bellows 424 expands and contracts synchronously, always tightly covering and sealing the annular gap between the moving path of the slider and the fixed base. At the same time, when the third motor 421 drives the wafer holder 415 to rotate, the rotating seal 425 continues to work at the root of its rotating shaft to form an effective rotating dynamic seal. The effect of the combined work of the two is that during the process of the wafer holder 415 performing lifting and rotation movements simultaneously or separately, a double dynamic sealing guarantee is provided for the moving parts of the lifting and rotating unit 4. This effectively isolates the gas exchange channel between the moving parts and the internal environment of the test chamber 1, ensuring that the high vacuum degree or specific process gas atmosphere inside the test chamber 1 can be maintained stably for a long time and is not affected by the movement inside the unit, thereby creating a reliable and stable environmental foundation for the precise testing of the wafer lifting and rotation performance in a real vacuum / gas environment.

[0053] In a specific embodiment, the position detection unit 2 includes at least two laser ranging modules arranged above the wafer, each of the laser ranging modules includes a laser emitter 21, a laser receiver 22 and a processor 23, the laser emitter emits a detectable laser onto the wafer, the laser receiver 22 receives the diffusely reflected laser from the wafer surface, and the processor 23 calculates the real-time position and inclination of the wafer based on the laser reflection time difference; wherein, the processor 23 is configured to: when the position difference between the two detection points is greater than 0.1mm, it is determined that the wafer has a position offset; when the position deviation before and after lifting is greater than ±0.1mm, it is determined that the repeat positioning accuracy is unqualified.

[0054] The laser transmitter 21 and its paired laser receiver 22 together constitute a laser ranging module. They are fixedly installed in pairs at a specific position above the interior of the test chamber 1, usually directly above the wafer holder, and their laser beams are projected vertically downward onto the wafer surface. The processor 23 can be integrated into each laser ranging module, or it can be installed as an external independent unit outside the test chamber 1 or integrated into the control unit 5. The laser transmitter 21 and laser receiver 22 of each laser ranging module are connected to the corresponding processor 23 via a cable to transmit laser emission and reception signals and processing results. The processor 23 ultimately transmits the wafer position and tilt information to the control unit 5 via a data line. The function of the laser transmitter 21 is to emit a laser beam of a specific wavelength, which is vertically irradiated onto the test point of the wafer below. The function of the laser receiver 22 is to receive the diffusely reflected laser signal reflected back from the wafer surface. The function of the processor 23 is to accurately control the emission timing of the laser emitter 21, record the time difference between the emission of the laser beam and the reception by the laser receiver 22, and calculate the real-time distance from the laser emitter 21 to the measured point of the wafer based on the speed of light (that is, the height of the wafer at that point). At the same time, when at least two modules are used, the processor 23 will compare the height data of different detection points to calculate the tilt angle of the wafer.

[0055] Each laser ranging module works independently: its laser transmitter 21 emits a laser pulse to illuminate a certain point on the surface of the wafer, and the diffuse reflected light generated by this point is captured by the corresponding laser receiver 22. The processor 23 accurately measures the flight time between the emission and reception of the laser pulse, and calculates the absolute distance from this point to the laser ranging module using the principle of the constant speed of light. When at least two such modules are configured to measure the position height of different points on the wafer respectively, the processor 23 can calculate the real-time overall height change of the wafer and the inclination angle of the wafer plane relative to the horizontal plane by comparing the height values ​​of these points. The effect of the combined work is that the position height and stability of the wafer during lifting and / or rotational movement can be dynamically monitored in a vacuum environment in a non-contact, high-precision and real-time manner, providing direct and quantitative data for evaluating the repeatability of the lifting mechanism and the stability of the movement.

[0056] Processor 23 is programmed to set a specific judgment threshold: when the wafer is at a certain target position, whether stationary or in motion, if the height difference between two different detection points (for example, two symmetrical points on the edge of the wafer) measured simultaneously exceeds 0.1 mm, processor 23 will determine that the wafer has tilted or shifted, indicating that there is a problem with the smoothness of the movement or that there is a deviation in the mechanism. In addition, when testing the repeatability of the wafer positioning accuracy, after the wafer is instructed to move up and down multiple times to reach the same theoretical target position, processor 23 detects that the deviation between the actual position (height) reached and the target position (or the maximum deviation range of multiple times reaching the position) exceeds the set tolerance range of ±0.1 mm, processor 23 will determine that the repeatability of the lifting mechanism is unqualified, indicating that its motion accuracy does not meet the standard.

[0057] In a specific embodiment, the control unit 5 is configured to: perform more than one million cycle tests on the single lifting unit 3 or the lifting and rotating unit 4; record the position data after each lifting, and calculate the repeat positioning accuracy.

[0058] The control unit 5 is configured to perform a high-intensity durability test on a single lifting unit 3 or a lifting and rotating unit 4 installed in the test chamber 1, driving the wafer it carries to perform more than one million continuous lifting and lowering motion cycles (for the lifting and rotating unit 4, this may include a compound lifting and lowering cycle with rotation). After each lifting cycle, the control unit 5 receives and records in real time the height data of the actual arrival position of the wafer measured by the position detection unit 2. Based on this massive amount of position data accumulated over a long period of time, the control unit 5 statistically analyzes the repeatability of the wafer at the set target position, specifically by calculating the maximum deviation range (e.g., the difference between the maximum and minimum values) of the actual arrival position of the same target position in multiple cycles to quantitatively evaluate the degree of attenuation of the position stability of the lifting mechanism after long-term operation.

[0059] In a specific embodiment, the single lifting unit 3 and the lifting and rotating unit 4 are replaceably installed at the bottom of the test chamber 1 through a quick-release structure.

[0060] The quick-release mechanism may be a mechanical interface designed to facilitate rapid installation and removal of units, such as a precision flange with locating pins and guide slots coupled with pneumatic or manual locking clips, or a standardized modular base with preloaded bolts. This structure allows operators to precisely align the single lift unit 3 or lift-and-rotate unit 4 with the corresponding interface on the bottom of the test chamber 1 through its base, physically secure it, and connect the necessary electrical and pneumatic connections, without complex tools or lengthy operation. This allows for quick detachment and replacement when necessary.

[0061] The single lifting unit 3 and the lifting and rotating unit 4 are replaceably installed at the bottom of the test chamber 1 through a quick-release structure in order to achieve the versatility and efficiency of the test platform. This design allows users to quickly switch and install corresponding functional units in the same test chamber 1 according to specific test requirements. This not only avoids the huge cost of building an entire test chamber and environmental system separately for each motion mode, but more importantly, it ensures that both test modes are carried out under exactly the same vacuum environment, position detection benchmark and control conditions, so that the performance test results of the single lifting unit 3 and the lifting and rotating unit 4 (such as repeatable positioning accuracy and long-term attenuation) are directly comparable, greatly improving the test efficiency and data consistency.

[0062] In a specific embodiment, the first limiting module 35 is a travel switch or a photoelectric sensor.

[0063] The wafer lift structure test platform's testing process is as follows: First, select either the single lift unit 3 or the lift-and-rotate unit 4 based on the test requirements and secure it to the base at the bottom of the test chamber 1 using a quick-release mechanism. After closing the chamber, the control unit 5 activates an external vacuum pump to evacuate the test chamber 1 through the vacuum pump connector 11. Simultaneously, a vacuum gauge 13 monitors the pressure in real time and provides feedback to the control unit. Once the target vacuum level is reached, specific process gases can be injected as needed through the backfill gas line connector 12. Control unit 5 sends instructions to the selected unit: If testing the single lift unit 3, first motor 31 drives linear slide 32 via first coupling 33, driving lift bracket 34 to perform vertical lifting motion, with first limiter module 35 ensuring travel safety. If testing the lift rotation unit 4, second motor 411 drives lift rail 414 via second coupling 413 and first reducer 412 to achieve lift motion of the wafer holder. Simultaneously, third motor 421 rotates wafer holder 415 via third coupling 423 and second reducer 422. Bellows 424 expands and contracts with the slider of lift rail 414 to maintain a vacuum seal, while rotary seal 425 ensures dynamic sealing at the rotating shaft. During this motion, at least two laser ranging modules operate continuously: their laser transmitters project laser light onto the wafer surface, laser receivers capture diffusely reflected signals, and a processor calculates the real-time height and wafer tilt of each detection point. The control unit 5 records the position data after each movement cycle. Position deviation is detected when the height difference between two points exceeds 0.1mm. Repeatability is considered unsatisfactory when the lifting position deviation exceeds ±0.1mm. Ultimately, the lifting mechanism undergoes over one million cycles of testing to comprehensively evaluate its long-term position stability, repeatability, and sealing reliability in both vacuum and process gas environments.

[0064] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention 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 the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A test platform for a wafer lifting structure, characterized in that: The test platform includes a test chamber capable of simulating a vacuum environment, a position detection unit, a single lifting unit, a lifting and rotating unit, and a control unit. The position detection unit is arranged in the test chamber for detecting the displacement and inclination of the wafer in real time. The single lifting unit is installed at the bottom of the test chamber for driving the wafer to move up and down. The lifting and rotating unit is installed at the bottom of the test chamber for driving the wafer to rotate and move up and down at the same time. The control unit is connected to the position detection unit for calculating the wafer repeatability and stability based on the detection data. The single lifting unit and the lifting and rotating unit can be installed switchably.

2. The test platform for the wafer lifting structure according to claim 1, characterized in that: The test chamber has a vacuum pump connection port and a backfill gas line connection port, the test chamber is connected to an external vacuum pump through the vacuum pump connection port, and the test chamber is connected to a process gas backfill pipeline through the backfill gas line connection port; The test chamber is provided with a vacuum gauge, which is installed on the inner wall of the test chamber and is used to monitor the chamber pressure in real time and transmit data to the control unit.

3. The test platform for the wafer lifting structure according to claim 1, characterized in that: The single lifting unit includes a first motor, a linear slide, a first coupling, a lifting bracket and a first limit module. The output end of the first motor is connected to the linear slide through the first coupling. The lifting bracket is fixed on the slider of the linear slide for carrying the test wafer. The first limit module is arranged at the travel end point of the linear slide.

4. The test platform for the wafer lifting structure according to claim 1, characterized in that: The lifting and rotating unit includes a lifting drive module, which includes a second motor, a first reducer, a second coupling, a lifting slide rail and a wafer holder. The output end of the second motor is coaxially connected to the input end of the first reducer through the second coupling, and the output end of the first reducer is connected to the lifting slide rail. The wafer holder is fixed on the slider of the lifting slide rail and realizes vertical lifting movement along the lifting slide rail. The upper and lower travel end points of the lifting slide rail are respectively provided with second limit modules.

5. The test platform for the wafer lifting structure according to claim 4, characterized in that: The lifting and rotating unit also includes a rotation drive module, which includes a third motor, a second reducer and a third coupling. The output end of the third motor is coaxially connected to the input end of the second reducer through the third coupling. The output end of the second reducer is fixed to the wafer holder, and the wafer holder is connected to the top of the slider of the lifting slide rail.

6. The test platform for the wafer lifting structure according to claim 5, characterized in that: The rotation driving module further includes a bellows and a rotation seal. The bellows seals and covers the lifting rail. The rotation seal is arranged at the rotation axis of the wafer holder.

7. The test platform for the wafer lifting structure according to claim 1, characterized in that: The position detection unit includes at least two laser ranging modules arranged above the wafer, each of the laser ranging modules includes a laser transmitter, a laser receiver and a processor, the laser transmitter emits a detectable laser onto the wafer, the laser receiver receives the diffusely reflected laser from the wafer surface, and the processor calculates the real-time position and inclination of the wafer based on the laser reflection time difference; wherein, the processor is configured to: when the position difference between the two detection points is greater than 0.1mm, determine that the wafer has a position offset; when the position deviation before and after lifting is greater than ±0.1mm, determine that the repeat positioning accuracy is unqualified.

8. The test platform for the wafer lifting structure according to claim 7, characterized in that: The control unit is configured to: perform a cycle test on the single lifting unit or the lifting and rotating unit for more than one million times; record position data after each lifting, and calculate the repeated positioning accuracy.

9. The test platform for the wafer lifting structure according to claim 1, characterized in that: The single lifting unit and the lifting and rotating unit are replaceably installed at the bottom of the test chamber through a quick-release structure.

10. The test platform for the wafer lifting structure according to claim 3, characterized in that: The first limit module is a travel switch or a photoelectric sensor.

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