Wafer alignment device and method and semiconductor equipment

Abstract

The invention provides a wafer alignment device and method and semiconductor equipment. The wafer alignment method comprises the following steps: firstly, fitting a first circle center coordinate of a wafer by adopting a multispectral polarization imaging module, and adjusting the horizontal position of the wafer by adopting a manipulator according to a first coordinate deviation value between the first circle center coordinate and a center coordinate of a bearing table so as to realize preliminary alignment. And then, fitting a second circle center coordinate of the wafer by adopting a laser ranging array module, and adjusting the horizontal position of the bearing table by adopting a micro motor according to a second coordinate deviation value between the second circle center coordinate and the center coordinate so as to realize further alignment. And finally, a heat engine coupling compensation module is adopted to realize fine adjustment, and thermal deformation is prevented from influencing the alignment precision of the wafer and the bearing table. Therefore, according to the method provided by the invention, automatic positioning and high-precision alignment of the wafer and the bearing table are realized in a sequentially progressive three-level alignment mode, so that the process effect is guaranteed, and the rejection rate of products is reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor fabrication technology, and in particular to a wafer alignment apparatus and method, and semiconductor equipment. Background Technology

[0002] Laser annealing equipment is an advanced thermal processing device that rapidly heats and cools the surface or localized areas of a wafer to achieve effects such as grain refinement, stress relief, and improved surface properties. However, in the laser annealing process, deviation from the wafer's center position can affect the process outcome and even lead to wafer scrap.

[0003] like Figure 1 and Figure 2 As shown, before performing the laser annealing process, the robot first transports the wafer 100 to a preset position for alignment, and then transports the aligned wafer 100 to the carrier stage 101 in the machine for laser annealing. The existing alignment method uses a through-beam sensor with optical positioning technology. Specifically, a through-beam sensor is placed at a preset V-shaped notch 100a on the edge of the wafer 100. The sensor identifies the feature position by the difference in occlusion duration, assisting in the angular alignment of the wafer 100; and it quickly detects the edge or position of the wafer 100 by detecting whether the optical path is blocked. However, this alignment method is susceptible to interference from reflections on the wafer 100 surface and is affected by factors such as the mechanical fixtures used for transporting the wafer 100, causing the deviation between the center point O1 of the wafer 100 and the center point O2 of the carrier stage 101 to exceed 2mm, which cannot meet the sub-micron level accuracy required by advanced processes. Therefore, due to the deviation in the center alignment of wafer 100, the die cells on one side of wafer 100 will not be subjected to laser annealing, resulting in the scrapping of wafer 100. Current methods rely on manual visual adjustment of the wafer 100's center, which is not only time-consuming (up to several hours) but also prone to subjective errors, making it difficult to effectively improve wafer alignment accuracy.

[0004] Therefore, there is an urgent need for a new wafer alignment device and method to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a wafer alignment apparatus and method, and a semiconductor device, to solve the problem of how to improve the alignment accuracy between the wafer and the carrier stage.

[0006] To address the aforementioned technical problems, the present invention provides a wafer alignment device for aligning a wafer with a carrier stage, wherein the carrier stage has a carrier surface and the wafer is located on the carrier surface; the carrier stage includes a micro motor for adjusting the position of the carrier stage; the wafer alignment device includes: a multispectral polarization imaging module, a laser ranging array module, a thermomechanical coupling compensation module, and a control module;

[0007] The multispectral polarization imaging module is located above the support surface and is used to acquire edge images of the wafer and / or the support stage; and to fit the first center coordinates of the wafer based on the edge images of the wafer; and / or to fit the center coordinates of the support surface based on the edge images of the support stage.

[0008] The laser ranging array module is disposed on the bearing surface and distributed along the edge of the bearing surface, and is used to measure the edge distance of the wafer and fit the second center coordinates of the wafer based on the edge distance of the wafer;

[0009] The thermo-mechanical coupling compensation module is integrated into the support platform and located below the support surface. It is used to measure the temperature of each area in the support surface and adjust the vertical position of the support surface at least according to the temperature.

[0010] The control module is used to acquire the first center coordinates and / or the center coordinates fitted by the multispectral polarization imaging module, and control a robotic arm to adjust the horizontal position of the wafer or control the thermomechanical coupling compensation module to adjust the vertical position of the bearing surface based on the first coordinate deviation value between the first center coordinates and the center coordinates; and to acquire the second center coordinates fitted by the laser ranging array module, and control the micro-motor to adjust the horizontal position of the bearing platform based on the second coordinate deviation value between the second center coordinates and the center coordinates.

[0011] Optionally, in the wafer alignment apparatus, the multispectral polarization imaging module includes a detection unit and a processing unit; wherein,

[0012] The detection unit includes a light source and an area array detector; the light source is used to emit detection light with multiple wavelengths and multiple polarization states toward the edge of the wafer and / or the support stage; the area array detector is used to receive the reflected light of the detection light reflected by the wafer and / or the support stage, and to acquire multispectral data based on the reflected light;

[0013] The processing unit is configured to fuse the multispectral data using a deep learning algorithm to extract the edge features of the wafer and form an edge image of the wafer, and / or extract the edge features of the support platform and form an edge image of the support platform; and, based on the edge image, to use a random sampling consistency algorithm to remove outliers, and to use the least squares method to fit the coordinates of the first circle center and / or the center coordinates.

[0014] Optionally, in the wafer alignment apparatus, the multiple wavelength bands include operating wavelengths of 450nm, 520nm, 650nm, and 850nm; the multiple polarization states include polarization directions of 0°, 45°, 90°, and 135°; and the switching frequency range of the light source includes ≥1kHz.

[0015] Optionally, in the wafer alignment apparatus, the multispectral polarization imaging module includes a plurality of the detection units; and the plurality of detection units are uniformly distributed relative to the edge of the stage, so as to be able to detect the entire edge of the wafer and / or the stage; and,

[0016] Multiple detection units are connected to the processing unit to provide the multispectral data to the processing unit.

[0017] Optionally, in the wafer alignment apparatus, the laser ranging array includes multiple laser ranging sensors and a data processor;

[0018] The plurality of laser ranging sensors are evenly distributed around the edge of the bearing surface to detect the entire edge of the wafer; and the laser ranging sensors are used to measure the edge distance between themselves and a portion of the edge of the wafer using a femtosecond laser interferometry method.

[0019] The data processor is connected to the plurality of laser ranging sensors; and the data processor is used to fit the coordinates of the second circle center using the least squares method based on all the edge distances provided by the plurality of laser ranging sensors.

[0020] The measurement accuracy range of the laser ranging sensor includes -1μm to 1μm.

[0021] Optionally, in the wafer alignment apparatus, the thermomechanical coupling compensation module includes multiple micro thermocouples and multiple piezoelectric ceramic actuators; each micro thermocouple is disposed at the top of one of the piezoelectric ceramic actuators, forming a combined adjustment element; and the multiple combined adjustment elements are uniformly distributed relative to the bearing surface; and,

[0022] The miniature thermocouple is used to measure the temperature of the portion of the bearing surface in contact with itself, and at least based on the temperature, to obtain the deformation of the portion of the bearing surface in contact with itself.

[0023] The piezoelectric ceramic actuator is used to adjust the expansion and contraction based on the deformation obtained from the connected micro thermocouple, so that the corresponding part of the bearing surface will have a vertical displacement.

[0024] The measurement accuracy range of the miniature thermocouple includes -0.1℃ to 0.1℃; the sampling frequency range includes ≥100Hz.

[0025] Optionally, in the wafer alignment apparatus, the control module is further configured to control the operating sequence of the multispectral polarization imaging module, the laser ranging array module, and the thermomechanical coupling compensation module, such that the multispectral polarization imaging module first fits the first center coordinates, and the first coordinate deviation is adjusted by the robotic arm to be within a first threshold range; the laser ranging array module then fits the second center coordinates, and the second coordinate deviation is adjusted by the micro-motor to be within a second threshold range; the thermomechanical coupling compensation module then adjusts the bearing surface; and...

[0026] After the thermomechanical coupling compensation module adjusts the bearing surface, the control module is further configured to control the multispectral polarization imaging module to refit the first circle center coordinates and the center coordinates, and reacquire the first coordinate deviation value. Based on the reacquired first coordinate deviation value, the control module is configured to adjust the bearing surface so that the reacquired first coordinate deviation value is within the third threshold range.

[0027] The first threshold range includes -50μm to 50μm, the second threshold range includes -10μm to 10μm, and the third threshold range includes -8μm to 8μm.

[0028] Based on the same inventive concept, the present invention also provides a wafer alignment method, comprising:

[0029] Step 1: Use a multispectral polarization imaging module to acquire the edge image of the wafer, and fit the first center coordinates of the wafer based on the edge image of the wafer;

[0030] Step 2: Use the control module to obtain the coordinates of the first circle center, and determine whether the first coordinate deviation value between the first circle center coordinates and the center coordinates of the support platform exceeds the first threshold range; if yes, use a robotic arm to adjust the horizontal position of the wafer and execute Step 1; if no, execute Step 3;

[0031] Step 3: Measure the edge distance of the wafer using a laser ranging array module, and fit the second center coordinates of the wafer based on the edge distance;

[0032] Step 4: Use the control module to obtain the coordinates of the second center of the circle, and determine whether the second coordinate deviation between the second center coordinates and the center coordinates exceeds the second threshold range; if yes, use the micro motor in the support platform to adjust the horizontal position of the support platform, and execute Step 3; if no, execute Step 5;

[0033] Step 5: Measure the temperature of each region in the bearing surface using a thermo-mechanical coupling compensation module, and adjust the vertical position of the bearing surface at least according to the temperature.

[0034] Step 6: Use the multispectral polarization imaging module to refit the coordinates of the first circle center and the center coordinates;

[0035] Step 7: The control module re-obtains the first coordinate deviation value based on the refitted first circle center coordinates and the center coordinates, and determines whether the re-obtained first coordinate deviation value exceeds the third threshold range; if yes, proceed to step 5; if no, end the determination and complete the alignment of the wafer and the carrier stage.

[0036] Optionally, in the wafer alignment method, during the execution of step one, a preset center coordinate is provided; or the multispectral polarization imaging module is used to acquire the edge image of the support stage, and the center coordinate of the support surface is fitted based on the edge image of the support stage; and,

[0037] After performing step four, and during the re-execution of step three, the multispectral polarization imaging module is used to refit the center coordinates so that the control module can re-obtain the second coordinate deviation value based on the refitted center coordinates and the second circle center coordinates.

[0038] Based on the same inventive concept, the present invention also provides a semiconductor device, including the aforementioned wafer alignment device, robotic arm, and reaction chamber; wherein,

[0039] A support platform is provided inside the reaction chamber;

[0040] The wafer alignment device is located inside the reaction chamber and is used to align the wafer and the carrier stage; the multispectral polarization imaging module in the wafer alignment device is disposed on the inner wall of the reaction chamber and is opposite to the carrier surface of the carrier stage;

[0041] The robotic arm is used to carry the wafer and place it on the support surface of the support platform, or pick up the wafer from the support platform; and to transport the wafer into and out of the reaction chamber.

[0042] In summary, this invention provides a wafer alignment apparatus and method, and a semiconductor device. Compared to existing technologies, the wafer alignment method first uses the multispectral polarization imaging module to fit the first center coordinates of the wafer, and then uses a robotic arm to adjust the horizontal position of the wafer based on the first coordinate deviation between the first center coordinates and the center coordinates of the support stage, to achieve preliminary alignment. Next, the laser ranging array module fits the second center coordinates of the wafer, and uses a micro-motor to adjust the horizontal position of the support stage based on the second coordinate deviation between the second center coordinates and the center coordinates of the support stage, to achieve further alignment. Finally, the thermomechanical coupling compensation module achieves fine-tuning, preventing thermal deformation from affecting the alignment accuracy of the wafer and the support stage. Therefore, the method provided by this invention achieves automatic positioning and high-precision alignment of the wafer and the support stage through a three-level progressive alignment process, which helps ensure process quality and reduce product scrap rates. Attached Figure Description

[0043] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention.

[0044] Figure 1 This is a three-dimensional schematic diagram of the positional deviation of the wafer relative to the support stage in the existing technology.

[0045] Figure 2 This is a planar schematic diagram of the positional deviation of the wafer relative to the support stage in the prior art.

[0046] Figure 3 This is a schematic diagram of the wafer alignment device in an embodiment of the present invention.

[0047] Figure 4 This is a schematic diagram showing the distribution of the thermo-mechanical coupling compensation module in an embodiment of the present invention.

[0048] Figure 5 This is a schematic diagram of the detection unit and processing unit in an embodiment of the present invention.

[0049] Figure 6 This is a schematic diagram showing the positions of the first circle's center coordinates and the center coordinates in an embodiment of the present invention.

[0050] Figure 7 This is a schematic diagram of the laser ranging sensor and data processor in an embodiment of the present invention.

[0051] Figure 8 This is a schematic diagram showing the positions of the second center coordinates and the center coordinates in an embodiment of the present invention.

[0052] Figure 9 This is a schematic diagram showing the connection between the miniature thermocouple and the piezoelectric ceramic actuator in an embodiment of the present invention.

[0053] Figure 10 This is a flowchart of the wafer alignment method in an embodiment of the present invention.

[0054] And, in the attached image:

[0055] 100 - Wafer; 100a - V-notch; 101 - Stage;

[0056] 20-Wafer; 30-Stage; 40-Multispectral polarization imaging module; 401-Detection unit; 402-Processing unit; 50-Laser ranging array module; 501-Laser ranging sensor; 502-Data processor; 60-Thermomechanical coupling compensation module; 601-Miniature thermocouple; 602-Piezoelectric ceramic actuator; 70-Control module;

[0057] O1 - Wafer center point; O2 - Platform center point; A1 - First wafer coordinates; A2 - Second wafer coordinates; B1 - Center coordinates; D - Edge distance. Detailed Implementation

[0058] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clearly illustrate the objectives of the embodiments of the present invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and sometimes use different scales. It should also be understood that, unless specifically stated or indicated, the terms "first," "second," "third," etc., in the specification are only used to distinguish the various components, elements, steps, etc., in the specification, and are not used to indicate the logical or sequential relationships between the various components, elements, steps, etc.

[0059] In this application specification, the X-axis, Y-axis, and Z-axis refer to three mutually perpendicular directions in three-dimensional space. The horizontal position refers to the position along the X-axis and / or Y-axis; the vertical position refers to the position along the Z-axis; and the connection refers to either a wired connection or a wireless connection.

[0060] Please see Figure 3 and Figure 4This embodiment provides a wafer alignment device for aligning a wafer 20 with a carrier stage 30. The carrier stage 30 has a carrier surface, and the wafer 20 is located on the carrier surface 30. The carrier stage 30 includes a micro motor for adjusting the position of the carrier stage 30. The wafer alignment device includes: a multispectral polarization imaging module 40, a laser ranging array module 50, a thermomechanical coupling compensation module 60, and a control module 70; the multispectral polarization imaging module 40 is located above the support surface and is used to acquire edge images of the wafer 20 and / or the support stage 30; and to fit the first center coordinates of the wafer 20 based on the edge images of the wafer 20; and / or to fit the center coordinates B1 of the support surface based on the edge images of the support stage 30; the laser ranging array module 50 is disposed on the support surface and distributed along the edge of the support surface, and is used to measure the edge distance D of the wafer 20, and fit the second center coordinates of the wafer 20 based on the edge distance D; the thermomechanical coupling compensation module 60 is integrated into the support stage. Within 30, and located below the bearing surface of the bearing platform 30, it is used to measure the temperature of each area in the bearing surface, and adjust the vertical position of the bearing surface at least according to the temperature; the control module 70 is used to obtain the first center coordinate A1 and / or the center coordinate B1 fitted by the multispectral polarization imaging module 40, and control a robot to adjust the horizontal position of the wafer 20 or control the thermomechanical coupling compensation module 60 to adjust the vertical position of the bearing surface according to the first coordinate deviation value between the first center coordinate A1 and the center coordinate B1; and, obtain the second center coordinate A2 fitted by the laser ranging array module 50, and control the micro motor to adjust the horizontal position of the bearing platform 30 according to the second coordinate deviation value between the second center coordinate A2 and the center coordinate B1.

[0061] Based on this, the wafer alignment device provided in this embodiment achieves three progressively advanced alignment levels through a multispectral polarization imaging module 40, a laser ranging array module 50, and a thermomechanical coupling compensation module 60. This ensures automatic positioning and high-precision alignment between the wafer 20 and the support stage 30, which helps to guarantee process results and reduce product scrap rate.

[0062] The wafer alignment device provided in this embodiment will be described in detail below with reference to the accompanying drawings.

[0063] Please continue reading. Figure 3 and Figure 4The wafer alignment device provided in this embodiment includes: a multispectral polarization imaging module 40, a laser ranging array module 50, a thermomechanical coupling compensation module 60, and a control module 70. The multispectral polarization imaging module 40 uses multispectral imaging principles to achieve precise positioning of the wafer 20 and / or the support stage 30. The laser ranging array module 50 uses laser ranging principles to further position the wafer 20. The thermomechanical coupling compensation module 60, based on the temperature-deformation relationship, measures the temperature of the support stage 30 to obtain its deformation distribution, and then levels the support stage 30 accordingly to ensure the alignment accuracy between the wafer 20 and the support stage 30. The control module 70 is the data processing center and operation control center for all modules in the wafer alignment device.

[0064] For details, please refer to Figure 3 , Figure 5 and Figure 6 The multispectral polarization imaging module 40 includes a detection unit 401 and a processing unit 402. The detection unit 401 includes a light source and an area array detector. The light source emits detection light with multiple wavelengths and polarization states toward the edge of the wafer 20 and / or the stage 30. The area array detector receives reflected light from the wafer 20 and / or the stage 30 and acquires multispectral data based on the reflected light.

[0065] It should be noted that the core of multispectral imaging is to simultaneously capture the optical information of a target at multiple wavelengths and different polarization states, combining the wavelength response and polarization response characteristics of a material to light to achieve high-contrast imaging of the target's fine features. Therefore, the light source needs to emit light beams of multiple wavelengths, and each wavelength beam is adjusted to multiple polarization states by a polarization modulator within the light source. For example, the light source emits four light waves with operating wavelengths of 450nm, 520nm, 650nm, and 850nm; and each of these light waves corresponds to four polarization states with polarization directions of 0°, 45°, 90°, and 135°. The switching frequency range of the light source includes ≥1kHz. Based on this, the detection light emitted by the light source has specific wavelength and polarization properties, resulting in a total of 16 possible combinations: detection light with a polarization direction of 0° and a working wavelength of 450nm, detection light with a polarization direction of 0° and a working wavelength of 520nm, detection light with a polarization direction of 0° and a working wavelength of 650nm, detection light with a polarization direction of 0° and a working wavelength of 850nm, detection light with a polarization direction of 45° and a working wavelength of 450nm, detection light with a polarization direction of 45° and a working wavelength of 520nm, detection light with a polarization direction of 45° and a working wavelength of 650nm, detection light with a polarization direction of 45° and a working wavelength of 650nm, and detection light with a polarization direction of 45° and a working wavelength of 650nm. The detection light has the following polarization directions: 850nm, 450nm, 520nm, 650nm, 850nm, 135nm, 520nm, 650nm, 850nm, 135nm, 650nm, and 850nm.

[0066] Based on this, when the light source emits the detection light in one of the 16 possible combinations toward the edge of the wafer 20 and / or the support stage 30, the detection light is reflected by the edge of the wafer 20 and / or the support stage 30 to form reflected light, and the reflected light carries information about the edge of the wafer 20 and / or the support stage 30. The reflected light is received and processed by the area array detector to form multispectral data. The multispectral data includes three-dimensional data of "spatial position-wavelength-polarization state". To obtain an edge image of the wafer 20 and / or the support stage 30, image fusion processing is also required on the multispectral data. Therefore, the processing unit 402 in the multispectral polarization imaging module 40 provided in this embodiment can use a deep learning algorithm to fuse the multispectral data, thereby extracting the edge features of the wafer 20 and forming the edge image of the wafer 20, and / or extracting the edge features of the support stage 30 and forming the edge image of the support stage 30; and, based on the edge image, firstly using a random sampling consistency algorithm to remove outliers, and then using the least squares method to fit the first center coordinate A1 and / or the center coordinate B1 of the support stage 30.

[0067] Preferably, the multispectral polarization imaging module 40 includes a plurality of detection units 401. The plurality of detection units 401 are uniformly distributed relative to the edge of the stage 30 and spaced apart from each other, enabling the detection of all edges of the wafer 20 and / or the stage 30. Furthermore, each of the plurality of detection units 401 is connected to the processing unit 402 to provide the multispectral data to the processing unit 402, thereby acquiring a more comprehensive and accurate edge image. In one example, the processing unit 402 may be integrated within the detection unit 401 or within the control module 70. Alternatively, in other examples, the processing unit 402 is integrated into the machine's control system. Preferably, the polarization adjuster in the light source includes, but is not limited to, a rotating polarizer or a liquid crystal tunable polarizer. And, the area array detector includes a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS), etc.

[0068] Please see Figure 3 , Figure 4 , Figure 7 and Figure 8The laser ranging array module 50 is disposed on the bearing surface of the support platform 30 and distributed along the edge of the bearing surface of the support platform 30. It is used to measure the edge distance D of the wafer 20 on the support platform 30 and fit the second center coordinate A2 of the wafer 20 based on the edge distance D. Specifically, the laser ranging array module 50 includes multiple laser ranging sensors 501 and a data processor 502. The multiple laser ranging sensors 501 are evenly distributed around the edge of the bearing surface of the support platform 30 to detect all edges of the wafer 20. Among them, the laser ranging sensors 501 are used to measure the edge distance D between themselves and a part of the edge of the wafer 20 using a femtosecond laser interferometry method, so that the multiple laser ranging sensors 501 can obtain the edge distance D of the entire wafer 20. Based on the edge distance D of the entire wafer 20 and the coordinate information of the plurality of laser ranging sensors 501, the edge coordinate information of the wafer 20 can be obtained, and then the second center coordinate A2 of the wafer 20 can be fitted. Therefore, the laser ranging array module 50 is also provided with a data processor 502, which is connected to the plurality of laser ranging sensors 501. The data processor 502 is used to fit the second center coordinate A2 using the least squares method based on all the edge distances D provided by the plurality of laser ranging sensors 501. The measurement accuracy range of the laser ranging sensors 501 includes -1μm to 1μm.

[0069] Preferably, the data processor 502 can be integrated into the laser rangefinder 501, the control module 70, or the machine's control system. Furthermore, the laser rangefinder 501 has a thin film thickness, can be a patch structure, and the diameter of the circle formed around the support platform 30 is much larger than the diameter of the wafer 20, effectively avoiding interference from the robotic arm during the placement and picking up of the wafer 20.

[0070] Furthermore, temperature deviations can cause deformation in different areas of the support stage 30, affecting the alignment accuracy of the wafer 20 and the support stage 30. Therefore, the wafer alignment device provided in this embodiment also includes the thermomechanical coupling compensation module 60, which measures the temperature of each area in the support surface and levels the support surface according to the temperature.

[0071] Please see Figure 4 and Figure 9The thermomechanical coupling compensation module 60 is integrated within the support platform 30 and located below the support surface of the support platform 30. Specifically, the thermomechanical coupling compensation module 60 includes multiple miniature thermocouples 601 and multiple piezoelectric ceramic actuators 602. Each miniature thermocouple 601 is disposed at the top of a piezoelectric ceramic actuator 602, forming a combined adjustment component. The multiple combined adjustment components are evenly distributed relative to the support surface of the support platform 30. The miniature thermocouples 601 are used to measure the temperature of the portion of the support surface in contact with them, and, based on the obtained temperature and the relationship between temperature difference and deformation, to obtain the deformation of the portion of the support surface in contact with them. The temperature difference is the deviation between the temperature of the corresponding area and the preset temperature of the machine platform; the existence of a temperature difference will cause thermal deformation of the support surface of the support platform 30. Through extensive data detection, a data table on the correlation between the temperature difference and the deformation of the support surface can be obtained, and this can be used as a data dictionary. Therefore, by obtaining the temperature of the corresponding area of ​​the bearing surface, the corresponding temperature difference can be obtained, and by querying the data dictionary, the deformation of the corresponding area of ​​the bearing surface can be obtained. Preferably, the measurement accuracy range of the miniature thermocouple 601 includes -0.1℃ to 0.1℃; the sampling frequency range includes ≥100Hz.

[0072] The piezoelectric ceramic actuator 602 is used to adjust the stretching based on the deformation obtained from the connected micro thermocouple 601, so that the corresponding portion of the bearing surface produces a vertical displacement; that is, a displacement in the Z-axis direction. The core principle of the piezoelectric ceramic actuator 602 is the inverse piezoelectric effect. When a voltage is applied to the piezoelectric ceramic, the internal lattice deforms (the direct piezoelectric effect does the opposite), producing a nanometer-level displacement. For example, in one of the combined adjustment components, the micro thermocouple 601 determines the deformation of a portion of the corresponding bearing surface to be -2nm based on the obtained temperature; then the adjustment parameter of the piezoelectric ceramic actuator 602 is +2nm to counteract the thermal deformation of the corresponding region. Similarly, multiple combined adjustment components adjust the bearing surface in the same manner to counteract the thermal deformation of the entire surface of the bearing surface, reduce the positioning error of the center coordinate B1 of the bearing stage 30, and thus reduce the alignment error between the wafer 20 and the bearing stage 30.

[0073] As described above, both the multispectral polarization imaging module 40 and the laser ranging array module 50 can fit the required center point coordinates. However, to achieve the alignment of the wafer 20 and the support stage 30, it is necessary to control the coordinated operation of each module. Therefore, the wafer alignment device provided in this embodiment also includes the control module 70, which serves as the control center. Please refer to... Figures 3 to 10 The control module 70 regulates the operating order of each module, and its specific functions are as follows:

[0074] First, the control module 70 controls a robotic arm carrying the wafer 20 to place the wafer 20 onto the support surface of the support platform 30. Then, the control module 70 controls the multispectral polarization imaging module 40 to operate and acquire the first center coordinate A1 of the wafer 20 fitted by the multispectral polarization imaging module 40. The control module 70 compares the first center coordinate A1 with the pre-acquired center coordinate B1 of the support platform 30 and determines whether the first coordinate deviation value between the first center coordinate A1 and the center coordinate B1 exceeds a first threshold range. If not, the control module 70 controls the laser ranging array module 50 to operate, as detailed below. If yes, the control module 70 controls the robotic arm to pick up the wafer 20 and adjusts the horizontal position of the wafer 20 according to the first coordinate deviation value. Furthermore, the control module 70 controls the robotic arm to reposition the adjusted wafer 20 onto the support stage 30, and then controls the multispectral polarization imaging module 40 to measure and refit the first center coordinate A1. Based on this, the control module 70 continues to determine whether the first coordinate deviation value between the first center coordinate A1 and the center coordinate B1 exceeds the first threshold range. If the first coordinate deviation value still exceeds the first threshold range, the above adjustment and judgment process is repeated until the first coordinate deviation value is within the first threshold range. The pre-obtained center coordinate B1 of the support stage 30 can be manually set and adjusted to the corresponding position by the micro-motor built into the support stage 30; or it can be synchronously fitted and obtained by the multispectral polarization imaging module 40. Preferably, the first threshold range includes -50μm to 50μm; that is, the coordinate difference range in both the X-axis and Y-axis directions is -50μm to 50μm. In short, the distance between the center of the wafer 20 fitted by the multispectral polarization imaging module 40 and the center of the support stage 30 in both the X-axis and Y-axis directions is less than or equal to 50 μm.

[0075] Since the accuracy of the first threshold range differs from the required alignment accuracy, further fine-tuning of the position between the wafer 20 and the support stage 30 is still necessary. When the first coordinate deviation value is within the first threshold range, the control module 70 controls the laser ranging array module 50 to operate and acquires the second center coordinate A2 of the wafer 20 fitted by the laser ranging array module 50. The control module 70 compares the second center coordinate A2 with the pre-acquired center coordinate B1 of the support stage 30 and determines whether the second coordinate deviation value between the second center coordinate A2 and the center coordinate B1 exceeds the second threshold range. If not, the control module 70 controls the thermomechanical coupling compensation module 60 to operate, as detailed below. If yes, the control module 70 controls the micro-motor of the support stage 30 to operate and adjusts the horizontal position of the support stage 30 according to the second coordinate deviation value so that the center coordinate B1 of the support stage 30 moves closer to the second center coordinate A2. After the micro-motor adjustment, the control module 70 continues to control the laser ranging array module 50 to refit the second center coordinate A2 of the wafer 20; and controls the multispectral polarization imaging module 40 to fit the adjusted center coordinate B1 of the support stage 30. Based on the refitted second center coordinate A2 and center coordinate B1, the control module 70 re-obtains the second coordinate deviation value and re-determines whether the second coordinate deviation value exceeds the second threshold range. If the second coordinate deviation value still exceeds the second threshold range, the above adjustment and determination process is repeated until the second coordinate deviation value is within the second threshold range. Preferably, the second threshold range includes -10μm to 10μm; that is, the coordinate difference range in both the X-axis and Y-axis directions is -10μm to 10μm. In short, the distance between the center of the wafer 20 and the center of the support stage 30 in both the X-axis and Y-axis directions is less than or equal to 10μm.

[0076] When the second coordinate deviation value is within the second threshold range, it indicates that the alignment error between the wafer 20 and the carrier stage 30 is within 10 μm. However, to further improve the alignment accuracy between the wafer 20 and the carrier stage 30, the wafer alignment device is also equipped with the thermo-mechanical coupling compensation module 60. Therefore, the control module 70 also controls the operation of the thermo-mechanical coupling compensation module 60, and the thermo-mechanical coupling compensation module 60 adjusts the bearing surface of the carrier stage 30 according to the temperature measurement distribution. Since the center of the adjusted wafer 20 and the center of the support stage 30 will inevitably change to a certain extent, the control module 70 also controls the multispectral polarization imaging module 40 to refit and obtain the first center coordinate A1 of the adjusted wafer 20 and the center coordinate B1 of the support stage 30, and determines whether the first coordinate deviation value between the refitted first center coordinate A1 and the center coordinate B1 exceeds the third threshold range; if not, the judgment ends, and the high-precision automatic alignment of the wafer 20 and the support stage 30 is completed; if so, the control module 70 continues to control the thermomechanical coupling compensation module 60 to continue to measure the temperature and adjust the deformation of the support stage 30, and after the adjustment is completed, the control module 70 controls the multispectral polarization imaging module 40 to re-obtain the first center coordinate A1 and the center coordinate B1; and determines whether the re-obtained first coordinate deviation value exceeds the third threshold range. If the first coordinate deviation value still exceeds the third threshold range, the above adjustment and judgment process is repeated until the first coordinate deviation value is within the third threshold range. Preferably, the third threshold range includes -8μm to 8μm; that is, the coordinate difference range in both the X-axis and Y-axis directions is -8μm to 8μm. In short, the distance between the center of the wafer 20 and the center of the support stage 30 in both the X-axis and Y-axis directions is less than or equal to 8μm.

[0077] In summary, the wafer alignment device provided in this embodiment first uses the multispectral polarization imaging module 40 to achieve initial position adjustment, then uses the laser ranging array module 50 to further achieve position alignment, and finally uses the thermomechanical coupling compensation module 60 to achieve fine adjustment, thus avoiding the impact of thermal deformation on the alignment accuracy of the wafer 20 and the support stage 30. Preferably, the signal delay of each module and its included devices in the wafer alignment device is controlled within 1μs to further ensure alignment accuracy.

[0078] Based on the same concept, this embodiment also provides a wafer alignment method. The wafer alignment method uses the wafer alignment device described above to achieve high-precision alignment between the wafer 20 and the support stage 30. For details, please refer to... Figures 3 to 10 The wafer alignment method includes:

[0079] Step 1 S10: Use the multispectral polarization imaging module 40 to acquire the edge image of the wafer 20, and fit the first center coordinate A1 of the wafer 20 based on the edge image of the wafer 20.

[0080] It should be noted that in step S10, the center coordinates B1 of the support platform 30 also need to be determined. Therefore, the center coordinates B1 can be preset manually, or the multispectral polarization imaging module 40 can acquire the edge image of the support platform 30 and fit the center coordinates B1 of the support surface 30 based on the edge image of the support platform 30.

[0081] Step 2 S20: The control module 70 obtains the first center coordinate A1 and determines whether the first coordinate deviation between the first center coordinate A1 and the center coordinate B1 of the support platform 30 exceeds the first threshold range; if so, a robot arm is used to adjust the horizontal position of the wafer 20 and the first step S10 is executed; if not, the third step S30 is executed.

[0082] In short, the control module 70 acquires data and determines whether the first coordinate deviation between the first center coordinate A1 and the center coordinate B1 of the support platform 30 meets the requirements of the first threshold range. If it does not meet the requirements, the robot arm is used to adjust the horizontal position of the wafer 20 and the above detection process is repeated until the first coordinate deviation meets the requirements of the first threshold range and the initial alignment requirements are met. Only then can the subsequent step three S30 be executed.

[0083] Step 3 S30: Use the laser ranging array module 50 to measure the edge distance D of the wafer 20, and fit the second center coordinate A2 of the wafer 20 based on the edge distance D of the wafer 20.

[0084] In step three (S30), it is also necessary to determine the center coordinates B1 of the support platform 30. Since the center coordinates B1 of the support platform 30 were not adjusted in steps one (S10) and two (S20), the center coordinates B1 of the support platform 30 in steps one (S10) and two (S20) can continue to be used.

[0085] Step 4 S40: The control module 70 obtains the second center coordinate A2 and determines whether the second coordinate deviation between the second center coordinate A2 and the center coordinate B1 exceeds the second threshold range; if so, the micro motor in the support platform 30 is used to adjust the horizontal position of the support platform 30 and Step 3 S30 is executed; if not, Step 5 S50 is executed.

[0086] It is understood that step four, S40, is intended to further align the wafer 20 and the support stage 30. That is, the control module 70 acquires data and determines whether the second coordinate deviation value between the second center coordinate A2 and the center coordinate B1 of the support stage 30 meets the requirements of the second threshold range. If it does not meet the requirements, the micro motor is used to adjust the horizontal position of the support stage 30, and the above detection process is repeated until the second coordinate deviation value meets the requirements of the second threshold range before proceeding to step five, S50.

[0087] Furthermore, after executing step four S40 and during the re-execution of step three S30, since the horizontal position of the support platform 30 is readjusted by the micro-motor, the original center coordinate B1 changes. Therefore, the multispectral polarization imaging module 40 needs to refit the center coordinate B1 of the support surface so that the control module 70 can re-obtain the second coordinate deviation value based on the refitted center coordinate B1 and the second circle center coordinate A2.

[0088] Step 5S50: Use the thermomechanical coupling compensation module 60 to measure the temperature of each region in the bearing surface, and adjust the vertical position of the bearing surface at least according to the temperature.

[0089] Since the bearing platform 30 may deform due to temperature deviation, affecting the accurate positioning of the center coordinate B1, the wafer alignment method provided in this embodiment uses the thermomechanical coupling compensation module 60 to compensate for the deformation of the bearing surface, thereby further improving the alignment accuracy.

[0090] Step 6S60: The first center coordinates A1 and the center coordinates B1 are refitted using the multispectral polarization imaging module 40.

[0091] Because the thermomechanical coupling compensation module 60 adjusts the bearing surface, the first center coordinate A1 and the center coordinate B1 will change. Therefore, the multispectral polarization imaging module 40 needs to refit the first center coordinate A1 and the center coordinate B1 so as to accurately determine the alignment of the wafer 20 and the bearing stage 30 in step seven S70.

[0092] Step 7S70: The control module 70 re-acquires the first coordinate deviation value based on the refitted first center coordinate A1 and the center coordinate B1, and determines whether the re-acquired first coordinate deviation value exceeds the third threshold range; if yes, execute step 5S50; if no, end the determination and complete the position alignment of the wafer 20 and the carrier stage 30.

[0093] Steps S50 to S70 involve a more precise alignment adjustment of the wafer 20 and the support stage 30 to eliminate the interference of deformation caused by temperature deviation on the alignment of the wafer 20 and the support stage 30. During this alignment process, the control module 70 acquires data and determines whether the first coordinate deviation value between the refitted first center coordinate A1 and the center coordinate B1 of the support stage 30 meets the requirements of the third threshold range. If not, the thermomechanical coupling compensation module 60 adjusts the vertical position of the support surface, and the above detection process is repeated until the support surface is leveled and the re-acquired first coordinate deviation value meets the requirements of the third threshold range; that is, the alignment of the wafer 20 and the support stage 30 is completed.

[0094] Based on the same concept, this embodiment also provides a semiconductor device. The semiconductor device includes the aforementioned wafer alignment device for aligning the wafer 20 and the stage 30. The semiconductor device also includes a robotic arm and a reaction chamber. The stage 30 is disposed within the reaction chamber; the wafer alignment device is located within the reaction chamber, and the multispectral polarization imaging module 40 of the wafer alignment device is disposed on the inner wall of the reaction chamber, opposite to the bearing surface of the stage 30; the robotic arm is used to carry the wafer 20 and place it on the stage 30, or pick up the wafer 20 from the stage 30; and to transport the wafer 20 in and out of the reaction chamber.

[0095] Preferably, the semiconductor device includes, but is not limited to, a laser annealing device.

[0096] In summary, this embodiment provides a wafer alignment apparatus and method, and a semiconductor device. The wafer alignment method first uses the multispectral polarization imaging module 40 to fit the first center coordinate A1 of the wafer 20, and based on the first coordinate deviation between the first center coordinate A1 and the center coordinate B1 of the support stage 30, a robotic arm adjusts the horizontal position of the wafer 20 to achieve preliminary alignment. Then, the laser ranging array module 50 uses the second center coordinate A2 of the wafer 20, and based on the second coordinate deviation between the second center coordinate A2 and the center coordinate B1 of the support stage 30, a micro-motor adjusts the horizontal position of the support stage 30 to achieve further alignment. Finally, the thermomechanical coupling compensation module 60 performs fine adjustment to prevent thermal deformation from affecting the alignment accuracy of the wafer 20 and the support stage 30. Therefore, the method provided in this embodiment achieves automatic positioning and high-precision alignment of the wafer 20 and the support stage 30 through a three-level progressive alignment process, which is beneficial for improving process efficiency and reducing product scrap rates.

[0097] Furthermore, it should be understood that although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the scope of protection of the present invention.

Claims

1. A wafer alignment apparatus for aligning a wafer with a carrier stage, wherein the carrier stage has a carrier surface, and the wafer is located on the carrier surface; the carrier stage includes a micro motor for adjusting the position of the carrier stage, characterized in that, The wafer alignment device includes: a multispectral polarization imaging module, a laser ranging array module, a thermomechanical coupling compensation module, and a control module; The multispectral polarization imaging module is located above the support surface and is used to acquire edge images of the wafer and / or the support stage; and to fit the first center coordinates of the wafer based on the edge images of the wafer; and / or to fit the center coordinates of the support surface based on the edge images of the support stage. The laser ranging array module is disposed on the bearing surface and distributed along the edge of the bearing surface, and is used to measure the edge distance of the wafer and fit the second center coordinates of the wafer based on the edge distance of the wafer; The thermo-mechanical coupling compensation module is integrated into the support platform and located below the support surface. It is used to measure the temperature of each area in the support surface and adjust the vertical position of the support surface at least according to the temperature. The control module is used to acquire the first center coordinates and / or the center coordinates fitted by the multispectral polarization imaging module, and control a robotic arm to adjust the horizontal position of the wafer or control the thermomechanical coupling compensation module to adjust the vertical position of the bearing surface based on the first coordinate deviation value between the first center coordinates and the center coordinates; and to acquire the second center coordinates fitted by the laser ranging array module, and control the micro-motor to adjust the horizontal position of the bearing platform based on the second coordinate deviation value between the second center coordinates and the center coordinates.

2. The wafer alignment apparatus according to claim 1, characterized in that, The multispectral polarization imaging module includes a detection unit and a processing unit; wherein... The detection unit includes a light source and an area array detector; the light source is used to emit detection light with multiple wavelengths and multiple polarization states toward the edge of the wafer and / or the support stage; the area array detector is used to receive the reflected light of the detection light reflected by the wafer and / or the support stage, and to acquire multispectral data based on the reflected light; The processing unit is configured to fuse the multispectral data using a deep learning algorithm to extract the edge features of the wafer and form an edge image of the wafer, and / or extract the edge features of the support platform and form an edge image of the support platform; and, based on the edge image, to use a random sampling consistency algorithm to remove outliers, and to use the least squares method to fit the coordinates of the first circle center and / or the center coordinates.

3. The wafer alignment apparatus according to claim 2, characterized in that, The multiple wavelength bands include operating wavelengths of 450nm, 520nm, 650nm, and 850nm; the multiple polarization states include polarization directions of 0°, 45°, 90°, and 135°; and the switching frequency range of the light source includes ≥1kHz.

4. The wafer alignment apparatus according to claim 2 or 3, characterized in that, The multispectral polarization imaging module includes multiple detection units; and the multiple detection units are uniformly distributed relative to the edge of the support stage, so as to detect the entire edge of the wafer and / or the support stage; and, Multiple detection units are connected to the processing unit to provide the multispectral data to the processing unit.

5. The wafer alignment apparatus according to claim 1, characterized in that, The laser ranging array includes multiple laser ranging sensors and a data processor; The plurality of laser ranging sensors are evenly distributed around the edge of the bearing surface to detect the entire edge of the wafer; and the laser ranging sensors are used to measure the edge distance between themselves and a portion of the edge of the wafer using a femtosecond laser interferometry method. The data processor is connected to the plurality of laser ranging sensors; and the data processor is used to fit the coordinates of the second circle center using the least squares method based on all the edge distances provided by the plurality of laser ranging sensors. The measurement accuracy range of the laser ranging sensor includes -1μm to 1μm.

6. The wafer alignment apparatus according to claim 1, characterized in that, The thermomechanical coupling compensation module includes multiple miniature thermocouples and multiple piezoelectric ceramic actuators; each miniature thermocouple is disposed at the top of one of the piezoelectric ceramic actuators, forming a combined adjustment component; and the multiple combined adjustment components are evenly distributed relative to the bearing surface; and, The miniature thermocouple is used to measure the temperature of the portion of the bearing surface in contact with itself, and at least based on the temperature, to obtain the deformation of the portion of the bearing surface in contact with itself. The piezoelectric ceramic actuator is used to adjust the expansion and contraction based on the deformation obtained from the connected micro thermocouple, so that the corresponding part of the bearing surface will have a vertical displacement. The measurement accuracy range of the miniature thermocouple includes -0.1℃ to 0.1℃; the sampling frequency range includes ≥100Hz.

7. The wafer alignment apparatus according to claim 1, characterized in that, The control module is also used to control the operating sequence of the multispectral polarization imaging module, the laser ranging array module, and the thermomechanical coupling compensation module, so that the multispectral polarization imaging module first fits the first circle center coordinates, and the first coordinate deviation is adjusted by the robotic arm to be within a first threshold range; the laser ranging array module then fits the second circle center coordinates, and the second coordinate deviation is adjusted by the micro-motor to be within a second threshold range; the thermomechanical coupling compensation module then adjusts the bearing surface; and, After the thermomechanical coupling compensation module adjusts the bearing surface, the control module is further configured to control the multispectral polarization imaging module to refit the first circle center coordinates and the center coordinates, and reacquire the first coordinate deviation value. Based on the reacquired first coordinate deviation value, the control module is configured to adjust the bearing surface so that the reacquired first coordinate deviation value is within the third threshold range. The first threshold range includes -50μm to 50μm, the second threshold range includes -10μm to 10μm, and the third threshold range includes -8μm to 8μm.

8. A wafer alignment method, characterized in that, Using the wafer alignment apparatus as described in any one of claims 1 to 7, and the wafer alignment method comprising: Step 1: Use a multispectral polarization imaging module to acquire the edge image of the wafer, and fit the first center coordinates of the wafer based on the edge image of the wafer; Step 2: Use the control module to obtain the coordinates of the first circle center, and determine whether the first coordinate deviation value between the first circle center coordinates and the center coordinates of the support platform exceeds the first threshold range; if yes, use a robotic arm to adjust the horizontal position of the wafer and execute Step 1; if no, execute Step 3; Step 3: Measure the edge distance of the wafer using a laser ranging array module, and fit the second center coordinates of the wafer based on the edge distance; Step 4: Use the control module to obtain the coordinates of the second center of the circle, and determine whether the second coordinate deviation between the second center coordinates and the center coordinates exceeds the second threshold range; if yes, use the micro motor in the support platform to adjust the horizontal position of the support platform, and execute Step 3; if no, execute Step 5; Step 5: Measure the temperature of each region in the bearing surface using a thermo-mechanical coupling compensation module, and adjust the vertical position of the bearing surface at least according to the temperature. Step 6: Use the multispectral polarization imaging module to refit the coordinates of the first circle center and the center coordinates; Step 7: The control module re-obtains the first coordinate deviation value based on the refitted first circle center coordinates and the center coordinates, and determines whether the re-obtained first coordinate deviation value exceeds the third threshold range; if yes, proceed to step 5; if no, end the determination and complete the alignment of the wafer and the carrier stage.

9. The wafer alignment method according to claim 8, characterized in that, During the execution of step one, a preset center coordinate is provided; or the multispectral polarization imaging module is used to acquire the edge image of the support stage, and the center coordinate of the support surface is fitted based on the edge image of the support stage; and, After performing step four, and during the re-execution of step three, the multispectral polarization imaging module is used to refit the center coordinates so that the control module can re-obtain the second coordinate deviation value based on the refitted center coordinates and the second circle center coordinates.

10. A semiconductor device, characterized in that, Includes the wafer alignment apparatus, robotic arm, and reaction chamber as described in any one of claims 1 to 7; wherein, A support platform is provided inside the reaction chamber; The wafer alignment device is located inside the reaction chamber and is used to align the wafer and the carrier stage; the multispectral polarization imaging module in the wafer alignment device is disposed on the inner wall of the reaction chamber and is opposite to the carrier surface of the carrier stage; The robotic arm is used to carry the wafer and place it on the support surface of the support platform, or pick up the wafer from the support platform; and to transport the wafer into and out of the reaction chamber.

Images