Test methods for the reliability of Bernoulli chucks

Abstract

The proposed method for testing the reliability of a Bernoulli chuck first uses a laser displacement meter to detect the level and runout of the Bernoulli chuck, eliminating the influence of the chuck's structure and assembly on its level and runout performance. Then, the laser displacement meter is used to detect the level and runout of the test piece when it is held in the Bernoulli chuck, eliminating the influence of the chuck's air path on its level and runout performance. Using this method to test the reliability of the Bernoulli chuck effectively simplifies the operation process and improves the accuracy of Bernoulli chuck testing and maintenance.

Description

[Technical Field]

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically, to a method for testing the reliability of a Bernoulli chuck. [Previous Technology]

[0002] Backside cleaning equipment is used for wafer backside cleaning or wet etching processes. The backside cleaning equipment includes a cavity and a wafer holding device located inside the cavity. The wafer holding device has a Bernoulli chuck with several vents on its surface, which are connected to gas passages. The gas passages supply gas, such as N2, to the vents, causing the wafer to levitate and remain above the Bernoulli chuck, ensuring that the front side of the wafer does not contact the Bernoulli chuck during the entire process.

[0003] When performing wet etching on the back side of a wafer, it is necessary to pay attention to the minute etching width and uniformity of the etching width at the edge of the front side of the wafer. The uniformity of the etching width at the edge of the front side of the wafer is directly related to the reliability of the Bernoulli chuck. The reliability of the Bernoulli chuck refers to the levelness and runout of the Bernoulli chuck itself, as well as the levelness and runout of the wafer when the Bernoulli chuck is carrying the wafer during operation.

[0004] Currently, the industry uses a level and a micrometer to characterize the level of a Bernoulli chuck (or wafer), respectively. Using a level to measure the level of a Bernoulli chuck (or wafer) has several drawbacks: 1) It requires opening the cavity for operation; 2) It requires wearing safety protective equipment; 3) The center position of the chuck is manually determined, which can introduce errors; 4) The data obtained will differ depending on the placement of the level, resulting in significant measurement errors. Using a micrometer to measure the runout of a Bernoulli chuck (or wafer) has the following drawbacks: 1) It requires opening the cavity for operation; 2) It requires wearing safety protective equipment; 3) Micrometer measurement of chuck runout is a contact method, and the chuck rotation speed cannot be too high; 4) Micrometers have low accuracy and large measurement errors; 5) It requires specially designed fixtures, making operation inconvenient.

[0005] Therefore, it is necessary to develop a simple, easy-to-operate, and accurate method for measuring the reliability of Bernoulli chucks. [Summary of the Invention]

[0006] The purpose of this invention is to provide a method for testing the reliability of a Bernoulli chuck, which can easily and accurately detect the level and runout of the Bernoulli chuck, as well as the level and runout of the test piece when the test piece is carried by the Bernoulli chuck. The test piece can be a wafer.

[0007] To achieve the above objective, the present invention provides a method for testing the reliability of a Bernoulli chuck, comprising the following steps: Step 1, using a laser displacement meter to detect the level and / or runout of the Bernoulli chuck; Step 2, determining whether the level and runout of the Bernoulli chuck are within a set range. If the level and runout of the Bernoulli chuck exceed the set range, the equipment is deemed abnormal, the test is suspended, the Bernoulli chuck is repaired, and then Step 1 is repeated; if the level and runout of the Bernoulli chuck are within the set range, then Step 3 is executed; Step 3, providing a test piece, holding the test piece with the Bernoulli chuck, and using a laser displacement meter to detect the level and / or runout of the test piece; Step 4, determining whether the level and runout of the test piece are within a set range. If the level and runout of the test piece exceed the set range, the equipment is deemed abnormal, the test is suspended, the Bernoulli chuck is repaired, and then Step 3 is repeated; if the level and runout of the test piece are within the set range, the test ends.

[0008] A color laser coaxial displacement meter can be selected. Utilizing the principle of spectral confocality, the visible light generated by the optical unit of the color laser coaxial displacement meter passes through the lens group (probe) and is dispersed into seven colors: red, orange, yellow, green, blue, indigo, and violet. Then, the reflected wavelength is converted into the corresponding displacement value using the principle of reflection. The color laser coaxial displacement meter has high measurement accuracy, small error, and is a non-contact measurement method. When measuring the reliability of the Bernoulli chuck, the Bernoulli chuck rotation speed can be higher, and compared with contact measurement methods, it is no longer limited by the Bernoulli chuck rotation speed.

[0009] The color laser coaxial displacement meter is applied to the inside of the back cleaning equipment to measure the runout and level of the Bernoulli chuck (and test piece) in real time. The measurement does not require opening the cavity, and the operation is simple. It can be used to monitor the status of the Bernoulli chuck during the monthly maintenance of the equipment, and can also be used as a daily monitoring item for the equipment.

[0010] As an optional solution of the present invention, in the runout detection of the Bernoulli chuck (or test piece), while the Bernoulli chuck (or test piece) is rotating, displacement information of each point on the edge position of the Bernoulli chuck (or test piece) is collected by a first laser displacement meter. Based on the displacement information collected by the first laser displacement meter, the runout waveform of the Bernoulli chuck (or test piece) is simulated to complete the runout detection of the Bernoulli chuck (or test piece).

[0011] As an optional solution of the present invention, in the horizontal detection of the Bernoulli chuck (or test piece), the first laser displacement meter and the second laser displacement meter are positioned at the same height. While the Bernoulli chuck (or test piece) rotates, the first laser displacement meter collects displacement information of each point on the edge of the Bernoulli chuck (or test piece), and the second laser displacement meter collects displacement information of the center of the Bernoulli chuck (or test piece). Taking the displacement of the center of the Bernoulli chuck (or test piece) as the base point, the tilt angle of each point on the edge of the Bernoulli chuck (or test piece) is calculated based on the displacement information collected by the first laser displacement meter and the second laser displacement meter, and the horizontal waveform of the Bernoulli chuck (or test piece) is simulated to complete the horizontal test of the Bernoulli chuck (or test piece).

[0012] As an optional solution of the present invention, in the horizontal detection of the Bernoulli chuck (or test piece), the first laser displacement meter and the second laser displacement meter are positioned at the same height. While the Bernoulli chuck (or test piece) rotates, the first laser displacement meter moves radially from the edge position to the center position along the Bernoulli chuck (or test piece). The displacement information of each point on the Bernoulli chuck (or test piece) is collected by the first laser displacement meter, and the displacement information of the center position of the Bernoulli chuck (or test piece) is collected by the second laser displacement meter. Taking the displacement of the center position of the Bernoulli chuck (or test piece) as the base point, the tilt angle of each point on the Bernoulli chuck (or test piece) is calculated according to the displacement information collected by the first laser displacement meter and the second laser displacement meter, simulating a spatial 3D stereoscopic image of the horizontal Bernoulli chuck (or test piece), and completing the horizontal test of the Bernoulli chuck (or test piece).

[0013] In this invention, the level and runout of the Bernoulli chuck are first detected by a laser displacement meter to eliminate the influence of the structure and assembly of the Bernoulli chuck itself on its level and runout performance. Then, the level and runout of the test piece are detected by the laser displacement meter when the Bernoulli chuck is holding the test piece to eliminate the influence of the air path of the Bernoulli chuck on its level and runout performance. This method is used to test the reliability of the Bernoulli chuck, which effectively simplifies the operation process and improves the accuracy of the Bernoulli chuck testing and maintenance.

Implementation Method

[0015] To explain in detail the technical content, structural features, objectives and effects of the present invention, the following will provide a detailed description in conjunction with embodiments and drawings.

[0016] Referring to Figures 1 and 2, the back-side cleaning equipment includes a cavity 101 and a wafer holding device 102, which is located inside the cavity 101. The wafer holding device 102 has a Bernoulli chuck 1021, a rotating shaft 1022, and a driver 1023. The driver 1023 drives the Bernoulli chuck 1021 to rotate via the rotating shaft 1022. Typically, a protective cover 103 is provided around the wafer holding device 102 to prevent liquid splashing during wafer handling. The Bernoulli chuck 1021 has several vents 10211, which are inclined relative to the axis of the Bernoulli chuck 1021. The vents 10211 are connected to an air passage 104, which is used to supply gas, such as N2, to the vents 10211. Referring to Figure 2, the Bernoulli chuck 1021 supplies gas to the front side of the wafer through several vents 10211, so that the wafer is suspended and held above the Bernoulli chuck 1021.

[0017] Referring again to Figures 1 and 2, in one embodiment of the present invention, a testing device 105 for detecting the reliability of the Bernoulli chuck 1021 is further provided inside the cavity 101. The testing device 105 includes a drive shaft 1051 and a swing arm 1052. The drive shaft 1051 is used to drive the swing arm 1052 to swing. A first laser displacement meter 1053 and a second laser displacement meter 1054 are movably mounted on the swing arm 1052. Specifically, a drive motor (not shown) and a guide rail (not shown) are provided on the swing arm 1052. The drive motor drives the first laser displacement meter 1053 and the second laser displacement meter 1054 to translate along the guide rail on the swing arm 1052, as shown by the dashed arrow in Figure 1 or Figure 2. The testing device 105 can be connected to a controller (not shown) for signal control. The controller controls the operation of the testing device 105. For example, the controller controls the drive shaft 1051 to swing the swing arm 1052 between the initial position and the working position according to a preset program. When the swing arm 1052 is in the working position, the projection of the swing arm 1052 on the Bernoulli chuck 1021 overlaps with the diameter of the Bernoulli chuck 1021. The controller has a data receiver, a data processor, and a display. The data receiver is used to receive displacement information collected by the first laser displacement meter or the second laser displacement meter. The data processor is used to process the collected displacement information and simulate and generate corresponding graphs. The display is used to display the results of the data processor processing the collected displacement information. In addition, the controller is also connected to the wafer holding device for signal control of the rotation of the Bernoulli chuck and the air supply path to the Bernoulli chuck.

[0018] Referring to Figure 3, a test method for detecting the reliability of a Bernoulli chuck according to an embodiment of the present invention is disclosed. The test method includes the following steps: Step 1, using a laser displacement meter to detect the level and / or runout of the Bernoulli chuck; Step 2, determining whether the level and runout of the Bernoulli chuck are within a set range. If the level and runout of the Bernoulli chuck exceed the set range, the equipment is deemed abnormal, the test is suspended, the Bernoulli chuck is repaired, and then Step 1 is repeated; if the level and runout of the Bernoulli chuck are within the set range, then Step 3 is executed; Step 3, providing a test piece, which is held and rotated by the Bernoulli chuck, and using a laser displacement meter to detect the level and / or runout of the test piece; Step 4, determining whether the level and runout of the test piece are within a set range. If the level and runout of the test piece exceed the set range, the equipment is deemed abnormal, the test is suspended, the Bernoulli chuck is repaired, and then Step 3 is repeated; if the level and runout of the test piece are within the set range, the test ends.

[0019] In step 2, if the level and runout of the Bernoulli chuck exceed the set range, the equipment is determined to be abnormal, the test is suspended, and the structure of the Bernoulli chuck is inspected.

[0020] In step 4, if the level and movement of the test piece exceed the set range, the equipment is determined to be abnormal, the test is suspended, and the air passage of the Bernoulli chuck is inspected.

[0021] After the Bernoulli chuck reliability test is completed and the equipment is found to be normal, it can be shipped and used normally. Furthermore, the Bernoulli chuck reliability test method can also be used for daily monitoring or monthly maintenance at the user end. The test wafer can be a dedicated test wafer or a wafer awaiting processing. If the test wafer is a wafer awaiting processing, and the wafer's level and runout are within the set range, the back-side cleaning process can be directly performed on the wafer. In other embodiments, steps 3 and 4 can be performed on each wafer before and during the back-side cleaning process to monitor whether the wafer's level and runout are within the set range in real time, and to promptly identify any problems.

[0022] The steps for detecting Bernoulli chuck runout using a laser displacement meter in one embodiment will be described in detail below with reference to Figure 1.

[0023] A laser beam emitted by the first laser displacement meter 1053 is directed onto the edge of the Bernoulli chuck 1021. As shown in Figure 1, the swing arm 1052 of the testing device 105 swings to the working position, and the first laser displacement meter 1053 is positioned directly above the edge of the Bernoulli chuck 1021. The laser beam emitted by the first laser displacement meter 1053 is directed onto the edge of the Bernoulli chuck 1021.

[0024] Next, the rotating shaft 1022 drives the Bernoulli chuck 1021 to rotate. Simultaneously with the rotation of the Bernoulli chuck 1021, the first laser displacement meter 1053 collects displacement information at various points on the edge of the Bernoulli chuck 1021. This displacement information represents the displacement of each point on the edge of the Bernoulli chuck 1021 relative to the first laser displacement meter 1053. The displacement information collected by the first laser displacement meter 1053 is calculated in cycles of one revolution of the Bernoulli chuck 1021. Marks can be set on the Bernoulli chuck 1021 as the starting point of the data collection cycle of the first laser displacement meter 1053.

[0025] Then, based on the displacement information collected by the first laser displacement gauge 1053, the runout waveform of the Bernoulli chuck 1021 is simulated to complete the runout test of the Bernoulli chuck 1021. Figure 4 shows the runout waveform of the Bernoulli chuck test, where the x-axis is the rotation angle of the Bernoulli chuck 1021 and the y-axis is the runout amplitude of the test point of the Bernoulli chuck 1021. Observe the difference between the peaks and troughs in each cycle of the runout waveform. If the difference exceeds the set maximum runout amplitude, it is determined that the runout of the Bernoulli chuck 1021 is abnormal, and the structure and assembly of the Bernoulli chuck 1021 need to be inspected.

[0026] The steps for detecting the level of Bernoulli chuck 1021 using a laser displacement meter in one embodiment will be described in detail below with reference to Figure 1.

[0027] As shown in Figure 1, the swing arm 1052 of the testing device 105 swings to the working position, and the first laser displacement gauge 1053 and the second laser displacement gauge 1054 are positioned at the same height. The first laser displacement gauge 1053 is positioned at the edge of the Bernoulli chuck 1021, and the second laser displacement gauge 1054 is positioned at the center of the Bernoulli chuck 1021. The laser emitted by the first laser displacement gauge 1053 illuminates the edge of the Bernoulli chuck 1021, and the laser emitted by the second laser displacement gauge 1054 illuminates the center of the Bernoulli chuck 1021.

[0028] Next, the Bernoulli chuck 1021 is driven to rotate, and the displacement information of each point on the edge of the Bernoulli chuck 1021 is collected by the first laser displacement meter 1053, and the displacement information of the center position of the Bernoulli chuck 1021 is collected by the second laser displacement meter 1054.

[0029] Then, taking the displacement of the center position of the Bernoulli chuck 1021 as the base point, and based on the displacement information collected by the first laser displacement meter 1053 and the second laser displacement meter 1054, the tilt angle of each point on the edge position of the Bernoulli chuck 1021 is calculated to simulate the horizontal waveform of the Bernoulli chuck 1021, thus completing the horizontal test of the Bernoulli chuck 1021. Figure 5 shows the horizontal waveform of the Bernoulli chuck test, where the x-axis is the rotation angle of the Bernoulli chuck 1021 and the y-axis is the tilt angle of the test point of the Bernoulli chuck 1021. Observe the tilt angle in each cycle of the horizontal waveform. If the tilt angle exceeds the set maximum tilt angle, it is determined that the level of the Bernoulli chuck 1021 is abnormal, and the structure and assembly of the Bernoulli chuck 1021 need to be inspected.

[0030] In this embodiment, the level and runout of the Bernoulli chuck 1021 can be tested simultaneously. Specifically, the data processor simulates the level waveform of the Bernoulli chuck 1021 based on the displacement information collected by the first laser displacement meter 1053 and the second laser displacement meter 1054, and simulates the runout waveform of the Bernoulli chuck 1021 based on the displacement information of each point on the edge of the Bernoulli chuck 1021 collected by the first laser displacement meter 1053, thereby realizing the synchronous testing of the level and runout of the Bernoulli chuck 1021 and simplifying the testing process and steps.

[0031] The steps for detecting the level of the Bernoulli chuck 1021 using a laser displacement meter in another embodiment will be described in detail below with reference to Figure 1.

[0032] As shown in Figure 1, the swing arm 1052 of the testing device 105 swings to the working position, and the first laser displacement gauge 1053 and the second laser displacement gauge 1054 are positioned at the same height. The first laser displacement gauge 1053 is positioned at the edge of the Bernoulli chuck 1021, and the second laser displacement gauge 1054 is positioned at the center of the Bernoulli chuck 1021. The laser emitted by the first laser displacement gauge 1053 illuminates the edge of the Bernoulli chuck 1021, and the laser emitted by the second laser displacement gauge 1054 illuminates the center of the Bernoulli chuck 1021.

[0033] Next, the Bernoulli chuck 1021 is driven to rotate, and the displacement information of the center position of the Bernoulli chuck 1021 is collected by the second laser displacement meter 1054. The first laser displacement meter 1053 moves radially from the edge position to the center position of the Bernoulli chuck 1021, and the displacement information of each point on the Bernoulli chuck 1021 is collected by the first laser displacement meter 1053.

[0034] Then, taking the displacement of the center position of the Bernoulli chuck 1021 as the reference point, and based on the displacement information collected by the first laser displacement meter 1053 and the second laser displacement meter 1054, the tilt angle of each point on the Bernoulli chuck 1021 is calculated to simulate a 3D spatial image of the Bernoulli chuck 1021 being horizontal, thus completing the horizontal test of the Bernoulli chuck 1021. The 3D spatial image of the Bernoulli chuck 1021 being horizontal can more intuitively display the test results of the Bernoulli chuck 1021 being horizontal. Observing the tilt angle of each test point on the 3D image, if the tilt angle exceeds the set maximum tilt angle, it is determined that the level of the Bernoulli chuck 1021 is abnormal, and the structure and assembly of the Bernoulli chuck 1021 need to be inspected.

[0035] Similarly, in this embodiment, the horizontality and jumping of the Bernoulli chuck 1021 can be tested simultaneously. Specifically, the data processor simulates a 3D spatial image of the horizontal position of the Bernoulli chuck 1021 based on the displacement information collected by the first laser displacement meter 1053 and the second laser displacement meter 1054, and simulates a jumping waveform of the Bernoulli chuck 1021 based on the displacement information of each point on the edge of the Bernoulli chuck 1021 collected by the first laser displacement meter 1053.

[0036] The steps for detecting the level and runout of the test piece using a laser displacement meter are basically the same as those for detecting the level and runout of the Bernoulli chuck using a laser displacement meter. The difference is that in the steps for detecting the level and runout of the test piece using a laser displacement meter, the test piece must first be held on the Bernoulli chuck before the level and runout test is performed. Other steps can refer to the steps for detecting the level and runout of the Bernoulli chuck using a laser displacement meter.

[0037] The steps for detecting the jump of the test piece using a laser displacement meter in one embodiment will be described in detail below with reference to Figure 2.

[0038] The Bernoulli chuck 1021 supplies gas to the front of the test piece through the gas passage 104 and several gas holes 10211, so that the test piece is held above the Bernoulli chuck 1021 in a non-contact manner.

[0039] The swing arm 1052 of the testing device 105 swings to the working position, and the first laser displacement meter 1053 is positioned at the edge of the test piece. The laser emitted by the first laser displacement meter 1053 is exactly irradiated at the edge of the test piece.

[0040] Next, the rotating shaft 1022 drives the Bernoulli chuck 1021 and the test piece to rotate synchronously. Simultaneously, the first laser displacement meter 1053 collects displacement information at various points on the edge of the test piece. This displacement information represents the displacement of each point on the edge of the test piece relative to the first laser displacement meter 1053. The displacement information collected by the first laser displacement meter 1053 is recorded in cycles of one revolution of the test piece. When the laser emitted by the first laser displacement meter 1053 illuminates the notch position of the test piece, the data receiver begins recording data. One revolution of the test piece, and when the laser emitted by the first laser displacement meter 1053 illuminates the notch position of the test piece again, constitutes one data recording cycle.

[0041] Then, based on the displacement information collected by the first laser displacement gauge 1053, the runout waveform of the test piece is simulated to complete the runout test of the test piece. Based on the runout waveform of the test piece, it is determined whether the runout of the test piece is normal when the Bernoulli chuck 1021 carries the test piece and rotates.

[0042] The steps for detecting the level of the test piece using a laser displacement meter in another embodiment will be described in detail below with reference to Figure 2.

[0043] The Bernoulli chuck 1021 supplies gas to the front of the test piece through the gas passage 104 and several gas holes 10211, so that the test piece is held above the Bernoulli chuck 1021 in a non-contact manner.

[0044] As shown in Figure 2, the swing arm 1052 of the testing device 105 swings to the working position, and the first laser displacement gauge 1053 and the second laser displacement gauge 1054 are positioned at the same height. The first laser displacement gauge 1053 is positioned at the edge of the test piece, and the second laser displacement gauge 1054 is positioned at the center of the test piece. The laser emitted by the first laser displacement gauge 1053 illuminates the edge of the test piece, and the laser emitted by the second laser displacement gauge 1054 illuminates the center of the test piece.

[0045] Next, the Bernoulli chuck 1021 and the test piece are driven to rotate synchronously. The displacement information of each point on the edge of the test piece is collected by the first laser displacement meter 1053, and the displacement information of the center of the test piece is collected by the second laser displacement meter 1054.

[0046] Then, taking the displacement of the center position of the test piece as the base point, and based on the displacement information collected by the first laser displacement meter 1053 and the second laser displacement meter 1054, the tilt angle of each point on the edge position of the test piece is calculated, and a horizontal waveform diagram of the test piece is simulated to complete the horizontal test of the test piece. Based on the horizontal waveform diagram of the test piece, it is determined whether the horizontal position of the test piece is abnormal when the Bernoulli chuck 1021 carries the test piece and rotates.

[0047] In this embodiment, the horizontal and agitation of the test piece can be tested simultaneously. Specifically, the data processor simulates the horizontal waveform of the test piece based on the displacement information collected by the first laser displacement meter 1053 and the second laser displacement meter 1054, and simulates the agitation waveform of the test piece based on the displacement information collected by the first laser displacement meter 1053 at each point on the edge of the test piece.

[0048] The steps for detecting the level of the test piece using a laser displacement meter in another embodiment will be described in detail below with reference to Figure 2.

[0049] The Bernoulli chuck 1021 supplies gas to the front of the test piece through the gas passage 104 and several gas holes 10211, so that the test piece is held above the Bernoulli chuck 1021 in a non-contact manner.

[0050] As shown in Figure 2, the swing arm 1052 of the testing device 105 swings to the working position, and the first laser displacement gauge 1053 and the second laser displacement gauge 1054 are positioned at the same height. The first laser displacement gauge 1053 is positioned at the edge of the test piece, and the second laser displacement gauge 1054 is positioned at the center of the test piece. The laser emitted by the first laser displacement gauge 1053 illuminates the edge of the test piece, and the laser emitted by the second laser displacement gauge 1054 illuminates the center of the test piece.

[0051] Next, the Bernoulli chuck 1021 and the test piece are driven to rotate synchronously. The displacement information of the center position of the test piece is collected by the second laser displacement meter 1054. The first laser displacement meter 1053 moves radially from the edge position to the center position of the test piece. The displacement information of each point on the test piece is collected by the first laser displacement meter 1053.

[0052] Then, taking the displacement of the center position of the test piece as the base point, and based on the displacement information collected by the first laser displacement meter 1053 and the second laser displacement meter 1054, the tilt angle of each point on the test piece is calculated to simulate a 3D spatial image of the test piece being horizontal, thus completing the horizontal test of the test piece. The 3D spatial image of the test piece being horizontal can more intuitively display the test results of the test piece being horizontal. Observing the tilt angle of each test point on the 3D spatial image of the test piece being horizontal, if the tilt angle exceeds the set maximum tilt angle, it is determined that the horizontality of the test piece is abnormal, and the air passage 104 of the Bernoulli chuck 1021 needs to be repaired.

[0053] Similarly, in this embodiment, the horizontality and agitation of the test piece can be tested simultaneously. Specifically, the data processor simulates a 3D spatial image of the horizontal position of the test piece based on the displacement information collected by the first laser displacement meter 1053 and the second laser displacement meter 1054, and simulates the agitation waveform of the test piece based on the displacement information of each point on the edge of the test piece collected by the first laser displacement meter 1053.

[0054] In summary, the present invention has specifically and thoroughly disclosed the relevant technology through the above embodiments and related drawings, enabling those skilled in the art to implement it accordingly. The above embodiments are merely illustrative of the present invention and not intended to limit it. The scope of the present invention should be defined by the claims in the patent application. Changes in the number of elements or substitutions of equivalent elements described herein should still fall within the scope of the present invention. [Simplified Explanation of the Diagram]

[0014] Figure 1 is a schematic diagram of testing the level and runout of the Bernoulli chuck using a back-side cleaning device according to an embodiment of the present invention; Figure 2 is a schematic diagram of testing the level and runout of a test piece using a back-side cleaning device according to an embodiment of the present invention, wherein the test piece is held on the Bernoulli chuck; Figure 3 is a flowchart of the reliability test of the Bernoulli chuck according to an embodiment of the present invention; Figure 4 is a runout waveform diagram of the Bernoulli chuck according to an embodiment of the present invention; and Figure 5 is a level waveform diagram of the Bernoulli chuck according to an embodiment of the present invention.

Claims

1. A method for testing the reliability of a Bernoulli chuck, comprising the following steps: Step 1, using a laser displacement meter to detect the level and / or runout of the Bernoulli chuck; Step 2, determining whether the level and runout of the Bernoulli chuck are within a set range; if the level and runout of the Bernoulli chuck exceed the set range, the equipment is deemed abnormal, the test is paused, the Bernoulli chuck is repaired, and then Step 1 is repeated; if the level and runout of the Bernoulli chuck are within the set range, then Step 3 is executed; Step 3, providing a test piece, holding the test piece with the Bernoulli chuck, and using a laser displacement meter to detect the level and / or runout of the test piece; Step 4, determining whether the level and runout of the test piece are within a set range; if the level and runout of the test piece exceed the set range, the equipment is deemed abnormal, the test is paused, the Bernoulli chuck is repaired, and then Step 3 is repeated; if the level and runout of the test piece are within the set range, the test ends.

2. The test method for the reliability of the Bernoulli chuck according to claim 1, wherein, In step 2, if the level and runout of the Bernoulli chuck exceed the set range, the equipment is deemed abnormal, the test is suspended, and the structure of the Bernoulli chuck is inspected. In step 4, if the level and runout of the test piece exceed the set range, the equipment is deemed abnormal, the test is suspended, and the air passage of the Bernoulli chuck is inspected.

3. The test method for the reliability of the Bernoulli chuck according to claim 1, wherein, The method of detecting the runout of the Bernoulli chuck using a laser displacement meter includes the following steps: emitting a laser beam through a first laser displacement meter to illuminate the edge of the Bernoulli chuck; driving the Bernoulli chuck to rotate, and collecting displacement information at various points on the edge of the Bernoulli chuck using the first laser displacement meter; simulating the runout waveform of the Bernoulli chuck based on the displacement information collected by the first laser displacement meter, thus completing the runout test of the Bernoulli chuck.

4. The test method for the reliability of the Bernoulli chuck according to claim 1, wherein, The method of detecting the level of the Bernoulli chuck using laser displacement meters includes the following steps: A laser beam is emitted from a first laser displacement meter and irradiated at the edge of the Bernoulli chuck, while a laser beam is emitted from a second laser displacement meter and irradiated at the center of the Bernoulli chuck, wherein the first and second laser displacement meters are positioned at the same height; The Bernoulli chuck is driven to rotate, and displacement information of each point at the edge of the Bernoulli chuck is collected using the first laser displacement meter and displacement information of the center of the Bernoulli chuck is collected using the second laser displacement meter; Using the displacement of the center of the Bernoulli chuck as a reference point, the tilt angle of each point at the edge of the Bernoulli chuck is calculated based on the displacement information collected by the first and second laser displacement meters, simulating a horizontal waveform of the Bernoulli chuck, thus completing the level test of the Bernoulli chuck.

5. The test method for the reliability of the Bernoulli chuck according to claim 1, wherein, The method of detecting the level of the Bernoulli chuck using laser displacement meters includes the following steps: A laser beam is emitted from a first laser displacement meter and irradiated at the edge of the Bernoulli chuck, while a laser beam is emitted from a second laser displacement meter and irradiated at the center of the Bernoulli chuck, wherein the first and second laser displacement meters are positioned at the same height; The Bernoulli chuck is driven to rotate, and displacement information at the center of the Bernoulli chuck is collected using the second laser displacement meter. The first laser displacement meter moves radially from the edge of the Bernoulli chuck towards the center, collecting displacement information at various points on the Bernoulli chuck; Using the displacement at the center of the Bernoulli chuck as a reference point, the tilt angle of each point on the Bernoulli chuck is calculated based on the displacement information collected by the first and second laser displacement meters, simulating a 3D spatial image of the level of the Bernoulli chuck, thus completing the level test of the Bernoulli chuck.

6. The test method for the reliability of the Bernoulli chuck according to claim 4 or 5, wherein, It also includes simulating the runout waveform of the Bernoulli chuck based on the displacement information of each point on the edge of the Bernoulli chuck collected by the first laser displacement meter, and completing the runout test of the Bernoulli chuck.

7. The test method for the reliability of the Bernoulli chuck according to claim 1, wherein, The method of detecting the runout of the test piece using a laser displacement meter includes the following steps: The test piece is held on a Bernoulli chuck; A laser beam is emitted from a first laser displacement meter and irradiates the edge of the test piece; The Bernoulli chuck and the test piece are driven to rotate synchronously, and displacement information of each point on the edge of the test piece is collected by the first laser displacement meter; Based on the displacement information collected by the first laser displacement meter, a runout waveform of the test piece is simulated to complete the runout test of the test piece.

8. The test method for the reliability of the Bernoulli chuck according to claim 1, wherein, The process of detecting the level of the test piece using a laser displacement meter includes the following steps: The test piece is held on the Bernoulli chuck; a laser beam is emitted from a first laser displacement meter to illuminate the edge of the test piece, and a laser beam is emitted from a second laser displacement meter to illuminate the center of the test piece, wherein the first and second laser displacement meters are positioned at the same height; the Bernoulli chuck and the test piece are driven to rotate synchronously, and the displacement information of each point on the edge of the test piece is collected by the first laser displacement meter, and the displacement information of the center of the test piece is collected by the second laser displacement meter; using the displacement of the center of the test piece as the reference point, the tilt angle of each point on the edge of the test piece is calculated based on the displacement information collected by the first and second laser displacement meters, and a horizontal waveform diagram of the test piece is simulated to complete the horizontal test of the test piece.

9. The test method for the reliability of the Bernoulli chuck according to claim 1, wherein, The horizontal test of the test piece using laser displacement gauges includes the following steps: The test piece is held on a Bernoulli chuck; A laser beam is emitted from a first laser displacement gauge and irradiated at the edge of the test piece, while a laser beam is emitted from a second laser displacement gauge and irradiated at the center of the test piece, wherein the first and second laser displacement gauges are positioned at the same height; The Bernoulli chuck and the test piece are driven to rotate synchronously, and the displacement information of the center position of the test piece is collected by the second laser displacement gauge, while the first laser displacement gauge moves radially from the edge to the center of the test piece, collecting displacement information of various points on the test piece; Using the displacement of the center position of the test piece as a reference point, the tilt angle of each point on the test piece is calculated based on the displacement information collected by the first and second laser displacement gauges, simulating a 3D spatial image of the test piece's horizontal position, thus completing the horizontal test of the test piece.

10. The test method for the reliability of the Bernoulli chuck according to claim 8 or 9, wherein, It also includes simulating the jump waveform of the test piece based on the displacement information of each point on the edge of the test piece collected by the first laser displacement meter, and completing the jump test of the test piece.

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