Method of parallelism adjustment for a worktable, system and e-beam metrology apparatus
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DONGFANG JINGYUAN ELECTRON LTD
- Filing Date
- 2023-05-23
- Publication Date
- 2026-07-14
Smart Images
Figure CN116576752B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of collimation parameters for the surface of metrology equipment, with a focus on semiconductor equipment, and particularly to a method, system, and electron beam measurement device for adjusting the parallelism of a worktable. Background Technology
[0002] Electron beam scanning microscopy is a commonly used technique in semiconductor integrated circuit measurement equipment. Its principle is to use an electron beam to scan the sample surface, obtaining high-resolution images, elemental composition, and crystal structure information through reflected and transmitted electrons. During scanning, the stage can move horizontally and vertically to measure different areas of the sample surface. In this mode, to ensure the electron beam stably measures every detection position on the wafer surface, the relative parallelism between the stage surface and the moving plane needs to be adjusted during horizontal and vertical movement. This is crucial for ensuring stable electron beam measurement at every detection position on the wafer surface. If the stage surface and the moving plane are not parallel, the electron beam will lose focus, affecting the accuracy and precision of the measurement.
[0003] The existing method involves manually locating measurement points. This involves using a height gauge to determine a reference height at the center of the workbench surface, then moving the workbench to measure the height of different areas and comparing these measurements with the reference height to obtain the height difference. Height adjustment is considered complete when the height difference between all measured areas on the workbench surface and the center is less than or close to a certain threshold. This method has the following technical drawbacks:
[0004] 1. Manual operation requires multiple working hours to complete the leveling, and it relies too heavily on experience, making it impossible to guarantee repeatability when measuring different positions repeatedly. That is, the measurement position may be different each time, and different positions will not reflect the true parallelism of the workbench, and may even cause deviations between the adjustment position and the measurement position.
[0005] 2. Due to the differences in measurement positions, the required adjustment amount for the same parallelism may be different at different measurement positions. However, with existing technology, each measurement position is manually adjusted to the reference height. After adjusting one position, the other positions will actually change, which requires the worktable to be adjusted repeatedly. Summary of the Invention
[0006] Therefore, the purpose of this application is to overcome these shortcomings at least partially by proposing an automatic parallelism adjustment method, providing a simple, reliable, effective, and rapid solution. This method enables rapid and reliable automatic adjustment of the worktable, aiming to replace the time-consuming and labor-intensive manual process, improve the accuracy of leveling, and achieve automated operation to increase efficiency. Another objective is to improve the repeatability and reliability of the leveling process, making process data recordable, improving process completeness, and better meeting the expected leveling requirements.
[0007] Therefore, the first aspect of this application provides a method for adjusting the parallelism of a worktable, comprising: obtaining the reference coordinates of a reference position on the worktable; obtaining the calibration coordinates of multiple calibration positions on the worktable; performing a circle center fitting calculation on the reference coordinates and the multiple calibration coordinates to obtain the leveling target value to be adjusted for the calibration position; and sequentially adjusting the height of the multiple calibration positions on the worktable according to the corresponding leveling target value.
[0008] In a further embodiment of this application, the center position of the worktable surface is the reference position, and obtaining the reference coordinates of the reference position on the worktable includes: controlling the worktable to move so that the measurement signal of the non-contact measuring device is aligned with the reference position; and reading and recording the reference coordinates of the reference position.
[0009] In a further embodiment of this application, both the reference coordinates and the calibration coordinates include planar coordinates and height coordinates. The height of multiple calibration positions on the worktable is adjusted sequentially according to the corresponding leveling target value, including: for each calibration position, adjusting the calibration position according to the difference between the height coordinate of the calibration position and the corresponding leveling target value.
[0010] In a further embodiment of this application, multiple edge positions on the worktable surface are calibration positions. Obtaining the calibration coordinates of multiple calibration positions on the worktable includes: controlling the worktable to move so that the measurement signal of the non-contact measuring device is sequentially aligned with each edge position.
[0011] In a further embodiment of this application, the reference coordinates and multiple calibration coordinates are used to perform a circle center fitting calculation to obtain the leveling target value required for the calibration position. This includes: in a further embodiment of this application, fitting the center of the worktable based on the reference coordinates and multiple calibration coordinates to obtain the center coordinates of the fitted circle; calculating the first distance between each calibration coordinate and the center coordinates; calculating the second distance between each calibration coordinate and the reference coordinates; and calculating the leveling target value required for the calibration position based on the first and second distances.
[0012] In a further embodiment of this application, the multiple calibration positions include a first position, a second position, and a third position. The height of the multiple calibration positions on the worktable is adjusted sequentially according to the corresponding leveling target values. This includes: controlling the worktable to move so that the first position is located at the corresponding calibration coordinates, and adjusting the worktable according to the leveling target value corresponding to the first position; controlling the worktable to move so that the second position is located at the corresponding calibration coordinates, and adjusting the worktable according to the leveling target value corresponding to the second position; and controlling the worktable to move so that the third position is located at the corresponding calibration coordinates, and adjusting the worktable according to the leveling target value corresponding to the third position.
[0013] In a further embodiment of this application, adjustable support columns are respectively provided below the first, second, and third positions.
[0014] In a further embodiment of this application, the method further includes: controlling the movement of the worktable so that the reference position of the worktable is located at the reference coordinates, and obtaining the first height coordinates of the reference position after the worktable is adjusted; controlling the movement of the worktable so that multiple calibration positions of the worktable are sequentially located at the calibration coordinates, and obtaining the second height coordinates of the multiple calibration positions after the worktable is adjusted; when the first height coordinates of the reference position after the worktable is leveled are consistent with the height coordinates before leveling, calculating the height difference between the second height coordinates and the first height coordinates of each calibration position after the worktable is adjusted; when the height difference is not greater than a first threshold, the parallelism adjustment of the worktable is completed.
[0015] In a further embodiment of this application, if the height difference is greater than a first threshold, the calibration coordinates of the calibration position of the workbench are obtained repeatedly until the height difference is less than or equal to the first threshold.
[0016] A second aspect of this application also provides a parallelism adjustment system for a worktable, comprising: a worktable; a non-contact measuring device for measuring the height coordinates of a reference position and a calibration position of the worktable; and a host computer connected to the non-contact measuring device and the worktable, the host computer being configured to perform the above-described parallelism adjustment method.
[0017] In summary, the present invention provides a method for adjusting the parallelism of a worktable. This method acquires a reference coordinate and multiple calibration coordinates on the worktable, performs a circle-fitting calculation between the reference coordinate and the calibration coordinates, obtains the target leveling value required for the calibration position, and then sequentially adjusts the height of the calibration position. This parallelism adjustment method improves upon existing manual positioning by transforming it into automatic positioning, and possesses at least the following technical advantages:
[0018] l. The coordinate parameters of the measuring worktable can be recorded, and during adjustment, it can return to the accurate calibration position twice for adjustment, which has reference value and repeatability;
[0019] 2. A circle center fitting algorithm is introduced to obtain the leveling target value of the calibration position. The leveling target value provides a clear guiding target point when adjusting the height of a single calibration position, no longer relying solely on human experience, thus optimizing the work process and improving work accuracy.
[0020] 3. Compared to manually adjusting the parallelism of the workbench, the adjustment process is optimized, improving work efficiency.
[0021] Other features and advantages of the embodiments of the present invention will be described in the following detailed description section. Attached Figure Description
[0022] To more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 A flowchart illustrating the parallelism adjustment method for a worktable provided in an embodiment of the present invention;
[0024] Figure 2 This is a schematic diagram of a workbench and its related connecting parts adapted to the above-mentioned parallelism adjustment method provided in an embodiment of the present invention.
[0025] Figure 3 This is a flowchart illustrating step S1 in the parallelism adjustment method provided in this embodiment of the invention.
[0026] Figure 4 This is a flowchart illustrating step S2 in the parallelism adjustment method provided in this embodiment of the invention.
[0027] Figure 5 This is a schematic diagram showing the location of the measuring points on the workbench as demonstrated in an embodiment of the present invention;
[0028] Figure 6 This is a flowchart illustrating step S3 in the parallelism adjustment method provided in this embodiment of the invention.
[0029] Figure 7 This is a schematic diagram illustrating the first and second distances provided on the workbench in an embodiment of the present invention;
[0030] Figure 8 This is a flowchart illustrating step S31 of the parallelism adjustment method provided in this embodiment of the invention.
[0031] Figure 9This is a flowchart illustrating step S33 in the parallelism adjustment method provided in this embodiment of the invention.
[0032] Figure 10 This is a flowchart illustrating step S4 in the parallelism adjustment method provided in this embodiment of the invention.
[0033] Figure 11 This is another flowchart of the parallelism adjustment method provided in the embodiment of the present invention;
[0034] Figure 12 This is a schematic diagram of the parallelism adjustment system provided in the embodiments of the present invention; and
[0035] Figure 13 This is a schematic diagram of the modules of the electron beam measurement device provided in the embodiment of the present invention.
[0036] Explanation of reference numerals in the attached figures:
[0037] 100. Workbench; 200. Adjustment device;
[0038] 300. Non-contact measuring device; 400. Control module;
[0039] 1000. Parallelism adjustment system; 2000. Electron beam measurement equipment;
[0040] 1001. Electron beam emitting device; 1002. Signal acquisition device;
[0041] 1003. Host computer; 2000. Electron beam measurement equipment. Detailed Implementation
[0042] To make the above and other features and advantages of this application clearer, the application is further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explanation to those skilled in the art, and are exemplary only, not restrictive.
[0043] In the following description, numerous specific details are set forth to provide a thorough understanding of this application. However, it will be apparent to those skilled in the art that the specific details are not required to practice this application. In other instances, well-known steps or operations have not been described in detail to avoid obscuring this application.
[0044] See Figure 1 , Figure 1 This is a flowchart of a method for adjusting the parallelism of a worktable according to an embodiment of the present invention; the parallelism adjustment method includes:
[0045] Step S1: Obtain the reference coordinates of the reference position on the worktable;
[0046] Step S2: Obtain the calibration coordinates of multiple calibration positions on the worktable;
[0047] Step S3: Perform circle center fitting calculation on the reference coordinates and multiple calibration coordinates to obtain the leveling target value that needs to be adjusted for the calibration position;
[0048] Step S4: Adjust the height of multiple calibration positions on the worktable sequentially according to the corresponding leveling target value;
[0049] In this embodiment of the invention, the shape of the worktable is not limited, but it is preferably circular or rectangular.
[0050] In this application, the "reference coordinates" are preferably located at the center of the worktable surface, which can be used to reference whether the center height of the worktable changes after leveling. The "calibration coordinates" are located on the worktable surface, at multiple edge positions close to the worktable boundary. To ensure measurement accuracy, the calibration positions should cover the worktable as much as possible; at the same time, to ensure the response speed and accuracy of the calculation, the total number of reference coordinates and calibration coordinates is preferably 4 to 6.
[0051] It should be noted that both the reference coordinates and the multiple calibration coordinates are three-dimensional coordinates, including planar coordinates and height coordinates. Furthermore, no three points corresponding to the reference coordinates and the multiple calibration coordinates can be collinear. Additionally, for ease of calculation, the height coordinate at the reference coordinates is set to zero.
[0052] During measurement, the relative positions of the worktable and the measuring device can be changed by controlling the automatic translation of the worktable or by moving the measuring device itself, thus achieving automatic data acquisition. Alternatively, the worktable can be moved manually by disabling its enable function.
[0053] To achieve higher measurement accuracy, when performing steps S1 and S2, the coordinates of multiple measurement points at the reference or calibration position can be obtained, and the average of the coordinates can be used as the reference coordinates and calibration coordinates to reduce random errors.
[0054] After obtaining the reference coordinates and multiple calibration coordinates, the center of the circle is then fitted using the reference coordinates and multiple calibration coordinates to obtain the leveling target value for each calibration position. Finally, the height of multiple calibration positions on the worktable is adjusted sequentially using the leveling target value for the corresponding calibration position.
[0055] Because the workbench surface is rigid, a change in one calibration position will affect the others. Therefore, this application employs a center-fitting calculation method to obtain the leveling target value for each calibration position. Based on the corresponding leveling target value, the height of multiple calibration positions on the workbench is adjusted sequentially. This provides a clear guiding target point when adjusting the height of a single calibration position and minimizes measurement errors caused by changes in the overall height due to adjustments at a single calibration position. This improves the efficiency and accuracy of workbench surface parallelism adjustment. Furthermore, this parallelism adjustment method transforms existing manual positioning into automatic positioning, achieving a more efficient and precise leveling process. In addition, this parallelism adjustment method significantly optimizes the debugging process, reducing inefficiency and time waste caused by repetitive operations. This saves manpower and reduces company operating costs during equipment integration and debugging.
[0056] Please see Figure 2 , Figure 2 This is a schematic diagram of a parallelism adjustment system 1000 for a workbench (i.e., a hardware structure that implements the above-described adjustment method) provided in an embodiment of the present invention, which is adapted to the above-described parallelism adjustment method.
[0057] The parallelism adjustment system 1000 of the present invention includes a worktable 100, an adjustment device 200, and a non-contact measuring device 300. The structure of the adjustment system provided in the embodiments of the present invention is only illustrative and does not specifically limit its structure.
[0058] The worktable 100 is circular and can be a high-precision leveling worktable for semiconductor devices. Its surface is used to support semiconductor devices and to perform processes such as semiconductor defect detection and processing. The aim is to ensure the relative parallelism of the surface of the worktable 100 through the leveling method provided in this embodiment of the invention, which can significantly improve the process yield of semiconductors.
[0059] The adjustment device 200 is located at the bottom of the worktable 100. Specifically, the adjustment device 200 includes a plurality of height-adjustable support columns (not labeled), which are used to support the worktable 100. The adjustment device 200 can level the surface of the worktable 100 by adjusting the height of the support columns.
[0060] Furthermore, the worktable 100 provided in this embodiment of the invention has n protrusions on its surface. This multi-protrusion contact design effectively improves the stability of the semiconductor device on the worktable 100, preventing workpiece displacement or shaking during processing or inspection. It also effectively prevents friction and scratches on the semiconductor device and plays a role in distributing loads during processing. In this application, the protrusions also facilitate more precise positioning by the non-contact measuring device 300.
[0061] A non-contact measuring device 300 is disposed on the surface of the workbench 100, such as a laser rangefinder, electromagnetic rangefinder, or photoelectric rangefinder, to obtain the height of the surface of the workbench 100. In this embodiment of the invention, a laser rangefinder is preferred. The laser rangefinder can obtain the relative distance between itself and the surface of the workbench 100 by emitting and receiving laser light, and the height coordinates of the measured surface of the workbench 100 can be obtained through simplified calculation.
[0062] To improve accuracy, laser rangefinders need to be installed in a vacuum chamber. The vacuum environment can eliminate the influence of air on the transmission of the laser beam, reduce the scattering and absorption of the laser beam, and improve the stability of the optical path.
[0063] Optionally, the control software of the workbench 100 is configured with a positioning memory function. For example, the deployment software of an ACS (Advanced Control System) controller can be used to write corresponding scripts to execute functions for different application scenarios. This enables the workbench 100 to repeatedly move by reading and recording the coordinates of different positions, and then changing the recorded values to target values, thus achieving repeatability of the process.
[0064] The parallelism adjustment method implemented in this application requires simple hardware. Using low-cost hardware can improve maintainability and updability, and help reduce the amortized cost of the product in the process.
[0065] Please continue reading. Figures 3-5 , Figure 3 This is a flowchart illustrating step S1 in the parallelism adjustment method provided in this embodiment of the invention. Figure 4 This is a flowchart illustrating step S2 in the parallelism adjustment method provided in this embodiment of the invention. Figure 5 This is a schematic diagram showing the measurement point positions of the workbench 100 as demonstrated in this embodiment of the invention.
[0066] Regarding the parallelism adjustment method described above, in step S1, the center position of the surface of the worktable 100 is used as the reference position. Obtaining the reference coordinates of the reference position on the worktable 100 includes:
[0067] Step S11: Control the worktable 100 to move so that the measurement signal of the non-contact measuring device 300 is aligned with the reference position;
[0068] Step S12: Read and record the reference coordinates of the reference position.
[0069] Understandably, the worktable 100 is first moved so that the convex point at the center of the worktable 100 is aligned with the laser rangefinder, so that the light spot projected by the laser rangefinder is exactly at the center convex point. At this time, the height coordinate of the reference position can be read through the laser rangefinder, and the horizontal coordinate of the center of the worktable can be read through the worktable 100. Therefore, the reference coordinate A of the worktable 100 is obtained, and the height coordinate of the reference coordinate A is set to zero and recorded.
[0070] In some embodiments, the worktable 100 may not be moved, and the non-contact measuring device 300 may be used to align the protrusion at the reference position, or the worktable 100 and the laser rangefinder may move together.
[0071] Further, in step S2, multiple edge positions near the boundary on the surface of the worktable 100 are used as calibration positions. The calibration coordinates of these multiple calibration positions on the worktable 100 are obtained, including:
[0072] Step S21: Control the worktable 100 to move so that the measurement signal of the non-contact measuring device 300 is sequentially aligned with each edge position;
[0073] Step S22: Read and record the calibration coordinates corresponding to each edge position.
[0074] Combination Figure 5 For example, continue to control the worktable 100 to move to the calibration position, and obtain the calibration coordinates B, C and D at the edge position respectively; still read the height coordinates of calibration coordinates B, C and D through the non-contact measuring device 300, and read their horizontal coordinates through the worktable 100, and obtain each calibration coordinate in sequence.
[0075] The calibration coordinates B, C, and D are taken at several specific locations on the surface of the worktable 100 near the boundary, in three directions surrounding the reference coordinate A. Optionally, they can be located at the corresponding protrusions above the support columns to facilitate concentric circle fitting calculations and subsequent adjustments. The distances of calibration coordinates B, C, and D from the worktable boundary can be inconsistent to improve measurement accuracy. Similarly, reference coordinates A, calibration coordinates B, C, and D can all be measured multiple times and averaged to reduce random errors.
[0076] Based on the above, the embodiments of the present invention can obtain more accurate coordinate parameters through the workbench 100 and the non-contact measuring device 300, and can record the reference coordinates and calibration coordinates, so that the data is referable and repeatable when measuring the parallelism of the workbench 100, thereby improving the accuracy of subsequent leveling.
[0077] Please continue reading. Figure 6 and Figure 7 , Figure 6 This is a flowchart illustrating step S3 in the parallelism adjustment method provided in this embodiment of the invention. Figure 7 This is a schematic diagram illustrating the first and second distances provided on the workbench 100 according to an embodiment of the present invention.
[0078] In step S3, the reference coordinates and multiple calibration coordinates are used to perform circle center fitting calculations to obtain the leveling target value that needs to be adjusted at the calibration position, including:
[0079] Step S31: Based on the reference coordinates and multiple calibration coordinates, fit the center of the fitted circle of the worktable 100 and obtain the center coordinates of the fitted circle.
[0080] Step S32: Calculate the first distance between each calibration coordinate and the center coordinate;
[0081] Step S33: Calculate the offset angle of the worktable 100;
[0082] Step S34: Calculate the leveling target value required to adjust the calibration position based on the first distance and offset angle.
[0083] Can be combined Figure 7 To understand this, we first fit the center coordinates O of the reference coordinates A, calibration coordinates B, calibration coordinates C and calibration coordinates D. These center coordinates O can represent the rotation center of the entire worktable 100.
[0084] Subsequently, the first distance L1 of OB is calculated according to the point-to-point distance calculation formula, and the offset angle θ of the worktable 100 is calculated based on the surfaces where the reference coordinates A, calibration coordinates B, calibration coordinates C, and calibration coordinates D are located. Finally, the vertical height h is calculated using the law of cosines based on the first distance L1 and the offset angle θ. The leveling target value can be obtained based on the height of the calibration coordinates and the vertical height h. Theoretically, the leveling target value is the height coordinate of the center coordinate O. However, this is based on the ideal scenario where the surface of the worktable 100 is completely flat and the collected calibration coordinates are at the same position of the convex point. Therefore, this application uses the first distance L1 and the offset angle θ of the worktable to obtain the vertical height, which is closer to the actual leveling target value that needs to be adjusted for each calibration position.
[0085] For step S3 in this scheme, the center fitting calculation can be performed using the least squares method. This involves using the reference coordinates and calibration coordinates to fit a circle, and then using the least squares method to finally determine the center coordinates of the concentric circle. These center coordinates can provide feedback on the rotation center of the worktable. Other algorithms can also be used for different application scenarios. The specific algorithm selection can be adaptively chosen based on the number of measurement points collected.
[0086] Please see Figure 8 , Figure 8This is a flowchart illustrating step S31 of the parallelism adjustment method provided in this embodiment of the invention. According to the above, in an optional embodiment, step S31 fits the center of the worktable based on the reference coordinates and multiple calibration coordinates, obtaining the center coordinates of the fitted circle.
[0087] Step S311: Substitute the reference coordinates and calibration coordinates into the circle equation to obtain the equation of the approximate concentric circle;
[0088] Step S312: Convert the proposed concentric circles into matrix form and use the least squares method to solve for the coordinates of the circle centers.
[0089] An exemplary approach is as follows: Consider the base coordinates A (x1, y1, z1), calibration coordinates B (x2, y2, z2), calibration coordinates C (x3, y3, z3), and calibration coordinates D (x4, y4, z4). Treat these four points as points on a concentric circle, assuming the center of the circle is (x0, y0, z0) and the radius is r. This yields four equations:
[0090] (x1-x0) 2 +(y1-y0) 2 +(z1-z0)2=r1 2
[0091] (x2-x0) 2 +(y2-y0) 2 +(z2-z0)2=r2 2
[0092] (x3-x0) 2 +(y3-y0) 2 +(z3-z0)2=r3 2
[0093] (x4-x0) 2 +(y4-y0) 2 +(z4-z0)2=r4 2 .
[0094] The above equations are transformed into matrix form: Ax = b, where A is a 4×4 matrix containing information from all input points, and b is a 4×1 matrix containing the right-hand side of all equations. Since the reference coordinates A(x1, y1, z1), calibration coordinates B(x2, y2, z2), calibration coordinates C(x3, y3, z3), and calibration coordinates D(x4, y4, z4) are all known quantities, and r1, r2, r3, and r4 can be determined based on the distances between the collected convex points and the central convex point, the least squares method is used to solve the above linear equations to obtain an estimated value for the center coordinates (x0, y0, z0), which is the center coordinate. Finally, the fitted result of the center coordinates is returned.
[0095] It is understood that the above method for fitting the center coordinates of a circle is only an example and is not intended to be limiting.
[0096] Please continue reading. Figure 9 , Figure 9 This is a flowchart illustrating step S33 of the parallelism adjustment method provided in this embodiment of the invention; in step S33, calculating the offset angle of the worktable includes:
[0097] Step S321: Obtain the normal vector coordinates of the workbench plane;
[0098] Step S332: Obtain the offset angle θ of the calculation table based on the normal vector coordinates.
[0099] It is understandable that a plane can be determined by three points, and the normal vector coordinates can be obtained from the plane and the points on it. In the optional method of this application: three points are randomly selected from four points, namely, reference coordinates A, calibration coordinates B, calibration coordinates C and calibration coordinates D, to determine a plane equation. Then, the normal vector coordinates n1 of the plane equation are obtained. The normal vector coordinates (n1, n2, n3...) are obtained by combining all three points of the four points in an iterative manner. Then, the average value of multiple normal vector coordinates is calculated to improve the accuracy of the result.
[0100] In step S332, an exemplary approach is to assume that the final normal vector of the worktable surface in the reference coordinate system is n = (a, b, c), and the unit vector of the z-axis of the reference coordinate system is v = (0, 0, 1). The angle θ between u and v is calculated, i.e., cosθ = u·v, where · represents the dot product operation of vectors. The value of the offset angle θ can be calculated using the inverse cosine function.
[0101] Finally, the vertical height h can be calculated based on the first distance L1 and the offset angle θ. The leveling target value required for each calibration position can be obtained through simple coordinate calculations.
[0102] The calibration positions are adjusted according to the leveling target value of each calibration position, so that when adjusting the height of a single calibration position, there is a clear guiding target point, no longer relying solely on human experience, thereby improving operational accuracy and optimizing the work process.
[0103] In some embodiments, in step S4, the height of multiple calibration positions of the workbench is adjusted sequentially according to the corresponding leveling target value, including: for each calibration position, adjusting the calibration position according to the difference between the height coordinate of the calibration position and the corresponding leveling target value.
[0104] Please see Figure 10 , Figure 10This is a flowchart illustrating step S4 of the parallelism adjustment method provided in this embodiment of the invention. Multiple calibration positions include a first position, a second position, and a third position, with height-adjusting support columns correspondingly disposed below each of the first, second, and third positions. In step S4, the height of the multiple calibration positions on the worktable is adjusted sequentially according to the corresponding leveling target value, including:
[0105] Step S41: Control the worktable to move so that the first position is located at the corresponding calibration coordinates. Adjust the worktable according to the leveling target value corresponding to the first position and the currently measured first height coordinates.
[0106] Step S42: Control the worktable to move so that the second position is located at the corresponding calibration coordinates. Adjust the worktable according to the leveling target value corresponding to the second position and the currently measured second height coordinates.
[0107] Step S43: Control the worktable to move so that the third position is located at the corresponding calibration coordinates. Adjust the worktable according to the leveling target value corresponding to the third position and the currently measured third height coordinates.
[0108] It can be understood that the "first position", "second position" and "third position" correspond to the protrusions on calibration coordinates B, C and D respectively. Support columns are set on the lower side of the worktable respectively. The worktable is moved to the corresponding coordinate position so that the support columns and the protrusions on the upper side of the worktable are aligned. The first position, second position and third position are adjusted according to the leveling target value calculated in step S34.
[0109] Each time the worktable is moved, the height coordinates of the current position are remeasured. The calibration position is adjusted based on the difference between the height coordinates of the current calibration coordinates and the corresponding leveling target value, thus avoiding repeated adjustments caused by changes in the heights of other calibration positions due to adjustments in the height of a single calibration position.
[0110] Please see Figure 11 , Figure 11 This is another flowchart of the parallelism adjustment method provided in an embodiment of the present invention. The parallelism adjustment method of this application further includes:
[0111] Step S51: Control the worktable to move so that the reference position of the worktable is located at the reference coordinates, and obtain the first verification height coordinates of the reference position after the worktable is adjusted.
[0112] Step S52: Control the worktable to move so that multiple calibration positions of the worktable are sequentially located at the calibration coordinates, and obtain the second verification height coordinates of the multiple calibration positions after the worktable is adjusted.
[0113] Step S53: If the first verification height coordinate of the reference position after the workbench is leveled is consistent with the height coordinate before leveling, calculate the height difference between the second verification height coordinate and the first verification height coordinate of each calibration position after the workbench is adjusted.
[0114] Step S54: If the height difference is not greater than the first threshold, the parallelism adjustment of the worktable is completed.
[0115] It is understandable that after leveling, the control table continues to move the convex point at the center position to the reference coordinates to obtain the current first verification height coordinates. Then, the control table moves, sequentially positioning the convex points corresponding to multiple calibration positions at the calibration coordinates, obtaining the second verification height coordinates of each convex point after adjustment, and calculating the height difference between the second verification height coordinates and the first verification height coordinates of the reference position. This height difference reflects the height deviation of the calibration position relative to the reference position. If the height difference is not greater than a first threshold, the accuracy requirement is met, and the table parallelism adjustment is complete.
[0116] In a further embodiment of this application, the parallelism adjustment method further includes: when the height difference is greater than a first threshold and / or when the first verification height coordinate of the reference position after the workbench is leveled is inconsistent with the height coordinate before leveling, cyclically obtaining the calibration coordinate of the calibration position of the workbench until the height difference is less than or equal to the first threshold.
[0117] Please see Figure 12 , Figure 12 This is a simplified schematic diagram of the parallelism adjustment system 1000 provided in an embodiment of the present invention. The parallelism adjustment system 1000 for a workbench of this application includes:
[0118] Workbench 100;
[0119] The adjustment device 200 is connected to the worktable 100 and is used to adjust the height coordinates of the calibration position on the worktable 100.
[0120] The non-contact measuring device 300 is used to measure the height coordinates of the reference position and calibration position of the worktable 100.
[0121] The control module 400, electrically connected to the non-contact measuring device 300 and the worktable 100, is configured to the parallelism adjustment method described above.
[0122] It can be understood that the above hardware can be combined to form a system that automatically adjusts parallelism, and its working principle is as follows:
[0123] 1. Before adjustment, install the non-contact measuring device 300 on the workbench 100 and connect it to the control module 400.
[0124] 2. Start the control module 400 and allow it to automatically execute the following steps:
[0125] a. The worktable 100 is moved by the control module 400, and the reference coordinates of the reference position and the calibration coordinates of the calibration position of the worktable 100 are obtained by the non-contact measuring device 300.
[0126] b. Calculate the leveling target value using the reference coordinates and calibration coordinates;
[0127] c. The drive adjustment device 200 adjusts the calibration position sequentially;
[0128] d. After leveling, measure the verification coordinates of the reference position and calibration position again, and send the verification coordinates to the control module 400 for threshold judgment to determine whether the leveling is successful. If the leveling is successful, stop; otherwise, repeat steps a to c until the leveling is successful.
[0129] The system can automatically measure and calculate to determine the target leveling value that the workbench 100 needs to be adjusted, and then automatically complete the adjustment in conjunction with the adjustment device 200, thereby improving work efficiency, reducing labor costs, and improving accuracy and stability.
[0130] Please see Figure 13 , Figure 13 This is a schematic diagram of the electron beam measurement device 2000 provided in an embodiment of the present invention; the embodiment of the present invention also provides an electron beam measurement device 2000, which can be applied to the detection of semiconductor devices, such as wafer defect detection.
[0131] Electron beam measurement equipment 2000 includes:
[0132] As described above, in the parallelism adjustment system 1000, semiconductor devices are placed on the worktable;
[0133] An electron beam emitting device 1001 is used to emit an electron beam to a semiconductor device;
[0134] The signal acquisition device 1002 is used to acquire and process electron reflection signals on semiconductor devices.
[0135] The host computer 1003 is electrically connected to the parallelism adjustment system 1000, the electron beam emitting device 1001, and the signal acquisition device 1002.
[0136] It is understood that the electron beam measurement device 2000 can emit an electron beam through the emitting device 1001, which can control parameters such as the direction and energy of the electron beam. The signal acquisition device 1002 performs three-dimensional non-contact acquisition by scanning the surface of the wafer, which can measure electron reflection signals of complex shapes and tiny geometric features, and feeds the acquired electron reflection signals back to the host computer 1003 for processing, thereby obtaining the detection results.
[0137] During the measurement process, the electron beam emitting device 1001 remains stationary and continuously emits an electron beam onto the worktable, while the worktable supports the semiconductor device and moves horizontally and vertically. Therefore, the parallelism adjustment system 1000 can significantly improve the detection accuracy of the electron beam measurement equipment 2000 and increase product yield.
[0138] It should be understood that the specific features, operations, and details described herein with respect to the methods of this application can also be similarly applied to the apparatus and system of this application, or vice versa. Furthermore, each step of the methods of this application described above can be performed by a corresponding component or unit of the apparatus or system of this application.
[0139] This application provides a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the above-described parallelism adjustment method.
[0140] Those skilled in the art will understand that the method steps of this application can be implemented by a computer program instructing related hardware, such as electronic devices or processors. The computer program implementing the above-described parallelism adjustment method can be stored in a non-transitory computer-readable storage medium, and its execution causes the steps of this application to be performed. Depending on the context, any reference herein to memory, storage, or other media may include non-volatile or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.
[0141] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.
[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still adjust the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features; and these adjustments or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A method for adjusting the parallelism of a worktable, characterized in that, include: Obtain the reference coordinates of the reference position on the worktable; Obtain the calibration coordinates of multiple calibration positions on the worktable; Both the reference coordinates and the calibration coordinates are three-dimensional coordinates; The reference coordinates and multiple calibration coordinates are fitted with a circle center to obtain the leveling target value that needs to be adjusted for each calibration position; The height of multiple calibration positions on the workbench is adjusted sequentially according to the corresponding leveling target value; The step of performing circle center fitting calculations on the reference coordinates and multiple calibration coordinates to obtain the leveling target value required for each calibration position includes: Based on the reference coordinates and multiple calibration coordinates, the fitting center of the worktable is fitted, and the center coordinates of the fitting center are obtained; the center coordinates represent the rotation center of the entire worktable. Calculate the first distance between each of the calibration coordinates and the center coordinates of the circle; Calculate the offset angle of the worktable; Based on the first distance and the offset angle, the target leveling value that needs to be adjusted for each calibration position is calculated.
2. The parallelism adjustment method according to claim 1, characterized in that, The center position of the worktable surface is the reference position, and obtaining the reference coordinates of the reference position on the worktable includes: The worktable is moved to align the measurement signal from the non-contact measuring device with the reference position. Read and record the reference coordinates of the reference position.
3. The parallelism adjustment method according to claim 1, characterized in that, Both the reference coordinates and calibration coordinates include planar coordinates and height coordinates. The step of sequentially adjusting the height of multiple calibration positions on the worktable according to the corresponding leveling target values includes: For each calibration position, the calibration position is adjusted based on the difference between the height coordinate of the calibration position and the corresponding leveling target value.
4. The parallelism adjustment method according to claim 1, characterized in that, The calibration positions are located at multiple edge positions on the workbench surface and near the workbench boundary. Obtaining the calibration coordinates of these multiple calibration positions on the workbench includes: The worktable is moved so that the measurement signal of the non-contact measuring device is sequentially aligned with each of the edge positions; Read and record the calibration coordinates corresponding to each edge position.
5. The parallelism adjustment method according to claim 2, characterized in that, The plurality of calibration positions include a first position, a second position, and a third position. The step of sequentially adjusting the height of the plurality of calibration positions of the worktable according to the corresponding leveling target value includes: The worktable is moved to position the first position at the corresponding calibration coordinates, and the worktable is adjusted according to the leveling target value corresponding to the first position. The worktable is moved to position the second position at the corresponding calibration coordinates, and the worktable is adjusted according to the leveling target value corresponding to the second position. The worktable is moved so that the third position is located at the corresponding calibration coordinates, and the worktable is adjusted according to the leveling target value corresponding to the third position.
6. The parallelism adjustment method according to claim 1, characterized in that, The method further includes: Control the worktable to move so that the reference position of the worktable is located at the reference coordinates, and obtain the first verification height coordinates of the reference position after the worktable is adjusted; The worktable is moved so that multiple calibration positions of the worktable are sequentially located at the calibration coordinates, and the second verification height coordinates of the multiple calibration positions after the worktable is adjusted are obtained respectively. If the first verification height coordinate of the reference position after the workbench is leveled is consistent with the height coordinate before leveling, calculate the height difference between the second verification height coordinate and the first verification height coordinate of each calibration position after the workbench is adjusted. If the height difference is not greater than the first threshold, the parallelism adjustment of the worktable is completed.
7. The parallelism adjustment method according to claim 6, characterized in that, The method further includes: If the height difference is greater than the first threshold and / or if the first verification height coordinate of the reference position after the workbench is leveled is inconsistent with the height coordinate before leveling, the calibration coordinate of the calibration position of the workbench is obtained repeatedly until the height difference is less than or equal to the first threshold.
8. A parallelism adjustment system for a worktable, characterized in that, include: Workbench; An adjustment device, connected to the worktable, is used to adjust the height coordinates of the worktable's calibration position. A non-contact measuring device used to measure the height coordinates of the reference position and calibration position of the worktable; A control module is electrically connected to the non-contact measuring device, the adjusting device, and the worktable, and the control module is configured to perform the parallelism adjustment method according to any one of claims 1 to 7.
9. An electron beam measurement device, characterized in that, include: The parallelism adjustment system as described in claim 8, wherein the semiconductor device is placed on the worktable; An electron beam emitting device used to emit an electron beam to a semiconductor device; A signal acquisition device for acquiring and processing electron reflection signals from the semiconductor device; The host computer is electrically connected to the parallelism adjustment system, the electron beam emitting device, and the signal acquisition device.