Stage carrier flatness measurement method and device, storage medium and terminal

Abstract

The application discloses a kind of machine table carrier flatness measurement method and device, storage medium and terminal, wherein the method includes obtaining the focusing data set measured when standard wafer is laid on the machine table carrier to be measured, the focusing data set includes multiple focusing data groups, each focusing data group includes the calibration focusing data of two calibration points in a calibration point pair, the edge of standard wafer is provided with multiple calibration point pairs with different position information, and the two calibration points in each calibration point pair are located on the diameter end of standard wafer;Based on each focusing data group in focusing data set, corresponding height difference data is obtained, and the inclination data of the machine table carrier to be measured is obtained based on the height difference data corresponding to all focusing data groups. Realize accurate and fast flatness measurement process to wafer carrier.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor technology, and in particular to a machine table carrier flatness measurement method and device, a storage medium and a terminal. BACKGROUND

[0002] CDSEM (Critical Dimension Scanning Electron Microscope) is a key tool in semiconductor manufacturing. It measures critical dimensions with high precision, optimizes production processes, detects microscopic defects, and supports research and development innovation, which is essential for ensuring the performance of integrated circuits, improving production efficiency, maintaining product quality, and promoting technological progress. CDSEM scans the sample surface by emitting and focusing high-speed electron beams, collects secondary electron signals to construct high-resolution images, and analyzes these images with advanced software to achieve high-precision measurement of the critical dimensions of semiconductor device microstructures. However, during the measurement process, the tilt of the wafer under test can significantly affect the measurement results; such as image distortion, reduced resolution, measurement position offset, uneven dose distribution, poor repeatability and reproducibility, etc. It seriously affects the accuracy and reliability of critical dimension measurement, so controlling wafer placement to reduce tilt is a key measure to ensure measurement quality.

[0003] Currently, the flatness of the machine table carrier is an important factor affecting the wafer tilt, and it is difficult to find the tilt problem of the machine table carrier flatness control, which is often found after online measurement of the wafer and the impact, so there is a problem of not finding in time. And the current online CDSEM machine mainly measures whether the wafer is tilted by measuring the wafer height using a laser before measurement. This method cannot measure the wafer tilt caused by the unevenness of the machine table carrier, so it is urgent to solve the problem of quickly and accurately measuring the flatness of the machine table carrier. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a machine table carrier flatness measurement method and device, a storage medium and a terminal, which solves the problem of lack of accurate and rapid flatness measurement of the wafer carrier during the measurement of the wafer to obtain high-definition images of the wafer.

[0005] In a first aspect, the present application provides a machine table carrier flatness measurement method, comprising:

[0006] obtaining a set of focus data obtained by measuring when a standard wafer is placed flat on a machine table carrier to be measured, the set of focus data comprising a plurality of focus data groups, each of the focus data groups comprising calibration focus data of two calibration points in a calibration point pair, the standard wafer edge being provided with a plurality of calibration point pairs having different position information, and the two calibration points in each of the calibration point pairs being located at the two ends of a diameter on the standard wafer;

[0007] acquiring corresponding height difference data based on each of the focus data sets, and acquiring inclination data of the measured machine carrier based on the height difference data corresponding to all the focus data sets;

[0008] The standard wafer has an arch variable of zero, and all the calibration focus data are obtained by a preset electron microscope measurement.

[0009] In an embodiment of the present application, the preset electron microscope is a critical dimension scanning electron microscope, and the calibration focus data in the focus data set is voltage data.

[0010] In an embodiment of the present application, acquiring corresponding height difference data based on the focus data set comprises:

[0011] differencing two calibration focus data in the focus data set to obtain voltage difference data;

[0012] multiplying the voltage difference data by a voltage height variation coefficient of the critical dimension scanning electron microscope to obtain the height difference data corresponding to the focus data set.

[0013] In an embodiment of the present application, the process of acquiring the voltage height variation coefficient of the critical dimension scanning electron microscope comprises:

[0014] measuring the focus data of a standard wafer at different preset heights by the critical dimension scanning electron microscope, differencing adjacent two preset heights and corresponding focus data to obtain a plurality of height-focus comparison data, and acquiring the voltage height variation coefficient of the critical dimension scanning electron microscope based on the plurality of height-focus comparison data.

[0015] In an embodiment of the present application, the standard wafer has a plurality of calibration point pairs arranged in the following manner: taking a preset fixed point at the edge of the standard wafer as a zero-angle starting point, sequentially arranging a plurality of calibration points with angle position information along the edge of the standard wafer according to serial numbers, and setting two calibration points located on the same diameter of the standard wafer as a calibration point pair.

[0016] When acquiring the voltage difference data corresponding to the focus data set, the calibration focus data of the calibration point with a relatively small serial number in the corresponding calibration point pair is subtracted from the calibration focus data of the calibration point with a relatively large serial number, and the height difference data obtained at this time is a positive number or a negative number.

[0017] In an embodiment of the present application, acquiring inclination data of the measured machine carrier based on the height difference data corresponding to all the focus data sets comprises:

[0018] a target height difference data in the calibration point position-height difference fitting curve corresponding to the target height difference data is obtained as target position information, and a tilt direction and position information of the machine table carrier to be measured are determined based on a positive and negative attribute of the target height difference data and the target position information.

[0019] In an embodiment of the present application, the machine table carrier flatness measurement method further comprises:

[0020] a target height difference data in the calibration point position-height difference fitting curve corresponding to the target height difference data is obtained as target position information, and a tilt direction and position information of the machine table carrier to be measured are determined based on a positive and negative attribute of the target height difference data and the target position information.

[0021] In an embodiment of the present application, the tilt data calculation formula of the machine table carrier to be measured is:

[0022]

[0023] wherein θ is the tilt data of the machine table carrier to be measured, Δh is the target height difference data, and X is the diameter of the standard wafer.

[0024] In a second aspect, the present application provides a machine table carrier flatness measurement device, comprising a focus data set acquisition module and a tilt data acquisition module.

[0025] The focus data set acquisition module is configured to acquire a focus data set measured when a standard wafer is placed on a machine table carrier to be measured, wherein the focus data set comprises a plurality of focus data groups, each of the focus data groups comprises calibration focus data of two calibration points in a calibration point pair, the standard wafer is provided with a plurality of calibration point pairs having different position information, and the two calibration points in each of the calibration point pairs are located at two ends of a diameter on the standard wafer.

[0026] The tilt data acquisition module is configured to acquire corresponding height difference data based on each of the focus data groups in the focus data set, and to acquire tilt data of the machine table carrier to be measured based on the height difference data corresponding to all the focus data groups.

[0027] Wherein the camber variable of the standard wafer is zero, and all the calibration focus data are acquired by a preset electron microscope measurement.

[0028] In a third aspect, the present application provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the machine table carrier flatness measurement method.

[0029] In a fourth aspect, the present application provides a terminal comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the flatness measurement method of the stage carrier.

[0030] Compared with the prior art, one or more embodiments of the above scheme can have the following advantages or beneficial effects:

[0031] The flatness measurement method of the stage carrier provided by the embodiments of the present application adopts a standard wafer as an auxiliary measurement wafer to avoid the influence of height difference or warping of the wafer itself on the measurement result; a plurality of pairs of calibration points marked at the two ends of the diameter of the edge of the standard wafer are focused to obtain a plurality of focus data sets, the focus data sets are then converted into height difference data, and finally a plurality of sets of height difference data are fitted to obtain a calibration point position-height difference fitting curve, and the inclination of the stage carrier to be measured is obtained based on the maximum height difference data in the calibration point position-height difference fitting curve; the inclination of the stage carrier to be measured is obtained by converting the inclination of the standard wafer, so that an accurate and rapid flatness measurement process of the wafer carrier is realized.

[0032] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and achieved by the structure particularly pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate embodiments of the present application, and are used to explain the present application together with the embodiments of the present application, and do not constitute a limitation on the present application. In the drawings:

[0034] Figure 1 A flowchart of the flatness measurement method of the stage carrier described in the embodiments of the present application is shown.

[0035] Figure 2 A structural schematic diagram of the inclination of the stage carrier in the flatness measurement method of the stage carrier described in the embodiments of the present application is shown.

[0036] Figure 3 A structural schematic diagram of the standard wafer in the flatness measurement method of the stage carrier described in the embodiments of the present application is shown.

[0037] Figure 4 A schematic diagram of the height difference data in the flatness measurement method of the stage carrier described in the embodiments of the present application is shown.

[0038] Figure 5 A structural schematic diagram of the flatness measurement device of the stage carrier described in the embodiments of the present application is shown.

[0039] Figure 6 Fig. 1 shows a schematic diagram of a terminal according to an embodiment of the present application. DETAILED DESCRIPTION

[0040] The embodiments of the present application will be described in detail with reference to the drawings and embodiments below, so that the technical means by which the present application solves the technical problems and achieves the technical effects can be fully understood and implemented. It should be noted that, unless there is a conflict, each embodiment in the present application and each feature in each embodiment can be combined with each other, and the technical solutions formed thereby are within the protection scope of the present application.

[0041] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of the present application, and only the components related to the present application are shown in the diagrams, not the number, shape and size of the components when actually implemented. The actual implementation of each component may be a random change in shape, number and proportion, and the layout pattern of the components may also be more complex.

[0042] The following embodiments of the present application provide a machine carrier flatness measurement method and device, storage medium and terminal, which solve the problem of lacking accurate and fast flatness measurement process for wafer carriers in the process of measuring wafers to obtain high-definition wafer images.

[0043] The principles and implementation modes of the machine carrier flatness measurement method and device, storage medium and terminal of the present embodiment will be described in detail below with reference to the drawings, so that those skilled in the art can understand the machine carrier flatness measurement method and device, storage medium and terminal of the present embodiment without creative labor.

[0044] The machine carrier flatness measurement method of the present application can be applied to the process of obtaining high-resolution wafer images based on CDSEM (critical dimension scanning electron microscope) in the semiconductor industry, and can also be applied to other scenarios in the semiconductor industry that require measurement of the inclination of the machine carrier. The present application does not make too many limitations here.

[0045] As shown in Figure 1 The present embodiment provides a machine carrier flatness measurement method, which includes the following steps.

[0046] Step S101: Obtain a set of focus data measured when a standard wafer is placed flat on the machine carrier to be measured.

[0047] The focusing data set includes a plurality of focusing data groups, each focusing data group includes calibration focusing data of two calibration points in a calibration point pair, the standard wafer edge is provided with a plurality of calibration point pairs with different position information, and the two calibration points in each calibration point pair are located at the two ends of the diameter on the standard wafer. And limit the standard wafer to be the wafer with the arch variable being zero, and meanwhile, it is required to ensure that all the calibration focusing data are obtained by the preset electron microscope measurement in the same measurement state, so as to avoid the error between the data caused by the multi-device measurement, and then affect the acquisition result of the inclination of the measured machine table carrier.

[0048] In step S102, the corresponding height difference data is obtained based on each focusing data group in the focusing data set, and the inclination data of the measured machine table carrier is obtained based on the height difference data corresponding to all the focusing data groups.

[0049] The machine table carrier flatness measurement method provided by the embodiment of the application obtains a plurality of focusing data groups through focusing measurement on the plurality of calibration point pairs marked at the two ends of the diameter on the edge of the standard wafer, converts the focusing data groups into height difference data, and finally obtains the inclination of the measured machine table carrier based on the plurality of height difference data groups. Through the conversion of the inclination of the standard wafer to the inclination of the measured machine table carrier, the accurate and rapid flatness measurement process of the wafer carrier is realized.

[0050] The steps S101 to S102 of the machine table carrier flatness measurement method are described in detail below.

[0051] In step S101, a focusing data set obtained by measurement when the standard wafer is placed on the measured machine table carrier is obtained.

[0052] The wafer with the arch variable being zero or the arch variable being infinitely close to zero and the extremely high surface flatness is selected as the standard wafer, so as to avoid the influence of the measurement result caused by the insufficient surface flatness of the measured wafer or the warping and other factors in the measurement process. Figure 3As shown, a sufficient number of calibration point pairs are arranged on the edge of the standard wafer, and each of the two calibration points in each calibration point pair is located on the standard wafer at the two ends of a diameter. The arrangement of the calibration point pairs on the standard wafer is as follows: a preset fixed point on the standard wafer is set as a zero-angle starting point, then a plurality of calibration points with angle position information are sequentially arranged along the edge of the standard wafer according to the sequence numbers, and the two calibration points on the standard wafer at the same diameter are set as a calibration point pair. For example, assuming that a preset fixed point on the standard wafer is set as a zero-angle starting point, the arranged calibration points sequentially include X1, X2, …, X18, each of the calibration points has corresponding angle position information relative to the zero-angle starting point, and the obtained calibration point pairs can sequentially be (X1, X10), (X2, X11), (X3, X12), (X4, X13), (X5, X14), (X6, X15), (X7, X16), (X8, X17), and (X9, X18). At this time, the angle position information of the calibration point with the earlier sequence number in each calibration point pair can be selected as the position information of the corresponding calibration point pair, or the angle position information of the calibration point with the later sequence number in each calibration point pair can be selected as the position information of the corresponding calibration point pair.

[0053] Preferably, the calibration points on the standard wafer can be uniformly arranged along the edge of the standard wafer. In order to avoid that the number of the arranged calibration point pairs is too small to cause insufficient accuracy of the position-height difference fitting curve, the embodiment further limits that the number of the calibration point pairs arranged on the edge of the standard wafer is not less than 9, for example, a calibration point is arranged at every 20-degree central angle along the edge of the standard wafer.

[0054] The standard wafer is placed flat and seamless on the carrier of the to-be-measured machine platform, and then the preset electron microscope is used to perform focusing measurement on each calibration point in each calibration point pair on the standard wafer to obtain the corresponding calibration focusing data of each calibration point in each calibration point pair. The calibration focusing data of the two calibration points in each calibration point pair constitute a focusing data group of the corresponding calibration point pair. The focusing measurement process of the calibration point is as follows: the preset electron microscope is used to focus on the calibration point on the standard wafer to obtain the corresponding data value as the calibration focusing data. Each calibration point pair on the standard wafer can obtain a focusing data group, and the focusing data groups corresponding to all the calibration point pairs are collected to obtain a focusing data set.

[0055] In an embodiment of the present application, the preset electron microscope can be a critical dimension scanning electron microscope, and the obtained calibration focusing data is voltage data.

[0056] In step S102, the corresponding height difference data is obtained based on each focusing data group in the focusing data set, and the inclination data of the to-be-measured machine platform carrier is obtained based on the height difference data corresponding to all the focusing data groups.

[0057] In the condition that the preset electron microscope is a critical dimension scanning electron microscope, corresponding height difference data is obtained based on each focus data group in the focus data set. The specific process of obtaining the corresponding height difference data based on the focus data group includes: performing difference between two calibration focus data in the focus data group to obtain voltage difference data; and then multiplying the obtained voltage difference data by a voltage height variation coefficient of the critical dimension scanning electron microscope, and thus obtaining the height difference data corresponding to the focus data group. Figure 4 A schematic diagram of height difference data in a flatness measurement method of a machine carrier according to an embodiment of the present application.

[0058] The voltage height variation coefficient of the critical dimension scanning electron microscope is obtained in advance. The specific process of obtaining the voltage height variation coefficient of the critical dimension scanning electron microscope can be set as follows: a wafer with an arch variable of zero or an arch variable infinitely close to zero is selected as a standard wafer, and the standard wafer is placed on a standard machine carrier in a seamless manner (the inclination angle of the standard machine carrier is set to zero). The standard machine carrier is set to different heights so that the standard wafer is located at different preset heights, and the same position of the standard wafer is scanned by the critical dimension scanning electron microscope at each preset height to obtain focus data of the standard wafer at different preset heights. Then, the focus data corresponding to adjacent two preset heights are respectively differentiated to obtain corresponding height difference data and focus difference data, and the height difference data and the focus difference data are taken as height-focus comparison data. Through the above process, a plurality of sets of height-focus comparison data can be obtained. Then, the ratio of the focus difference data to the height difference data in each set of height-focus comparison data is obtained, and the average value of all ratios is obtained to obtain the voltage height variation coefficient of the critical dimension scanning electron microscope.

[0059] In an embodiment of the present application, after obtaining the height difference data corresponding to all focus data groups, the maximum height difference data can be selected from the height difference data corresponding to all focus data groups as target height difference data, and the target height difference data is brought into the inclination data calculation formula to obtain the inclination data of the standard wafer, which is the inclination data of the machine carrier to be measured. The inclination data calculation formula can be expressed as:

[0060]

[0061] Wherein, θ is the inclination data of the machine carrier to be measured, Δh is the target height difference data, and X is the diameter of the standard wafer.

[0062] The inclination data acquisition method of the machine carrier to be measured is simple and direct, and can achieve the purpose of obtaining the inclination data of the machine carrier to be measured with fewer processes.

[0063] In an embodiment of the present application, since each focus data set has its corresponding mark point pair, each mark point pair has its corresponding position information, each focus data set has its corresponding height difference data and position information, and then the position-height difference fitting curve formed by the height difference data and position information corresponding to all focus data sets is obtained by taking the position information as the horizontal coordinate and the height difference data as the vertical coordinate. The maximum height difference data in the position-height difference fitting curve is obtained as the target height difference data, and the target height difference data is brought into the slope data calculation formula to obtain the slope data of the standard wafer, which is the slope data of the measured machine carrier. The slope data calculation formula can be expressed as:

[0064]

[0065] Wherein, θ is the slope data of the measured machine carrier, Δh is the target height difference data, and X is the diameter of the standard wafer.

[0066] Since in the process of obtaining the target height difference data, the maximum height difference data may not be directly in the height difference data corresponding to all focus data sets, but may exist between two adjacent mark point pairs, the actual value of the obtained target height difference data should be greater than the height difference data corresponding to all focus data sets. The position-height difference fitting curve method can obtain the height difference data outside the mark point pair, so the slope data acquisition method of the measured machine carrier can make the obtained slope data of the measured machine carrier have higher precision compared with the above-mentioned slope data acquisition method of the measured machine carrier. In an embodiment of the present application, based on the position-height difference fitting curve method for obtaining the slope data of the measured machine carrier, the machine carrier flatness measurement method can further include the following step S103.

[0067] Step S103: obtaining the position information corresponding to the target height difference data in the mark point position-height difference fitting curve as the target position information, and determining the slope direction and position information of the measured machine carrier based on the positive and negative properties of the target height difference data and the target position information.

[0068] Reference Figure 2As shown, since the machine carrier can tilt to one side or the other side, the tilt direction of the machine carrier cannot be determined only by the tilt data. At this time, the embodiment can also set that, in step S102, when the voltage difference data corresponding to the focus data set is obtained, the calibration focus data of the calibration point with the relatively small serial number is subtracted from the calibration focus data of the calibration point with the relatively large serial number in each calibration point pair. At this time, the height difference data obtained can be positive or negative. Similarly, the target height difference data obtained can also be positive or negative. At this time, the position information corresponding to the target height difference data in the position-height difference fitting curve can be used as the target position information, and then the tilt direction and position information of the machine carrier to be measured can be determined by the positive and negative properties of the target height difference data and the target position, and in combination with the preset fixed point position information.

[0069] For example, when a standard wafer is measured, the position directly below the top view circumference of the standard wafer is set as the zero angle starting point, and a calibration point is set every 20 degrees of the central angle in the counterclockwise direction along the edge of the standard wafer. At this time, the calibration point pairs (X1, X10), (X2, X11), (X3, X12), (X4, X13), (X5, X14), (X6, X15), (X7, X16), (X8, X17), and (X9, X18) can be obtained. If it is assumed that the height difference data corresponding to the calibration point pair (X1, X10) is the target height difference data, and the target height difference data obtained is positive, it indicates that the standard wafer is currently in a tilt state of high front and low back, and the tilt position is tilted from the calibration point X1 to the calibration point X10. Further, it indicates that the machine carrier to be measured is currently in a tilt state of high front and low back, and the tilt position is tilted from the calibration point X1 to the calibration point X10.

[0070] The machine carrier flatness measurement method provided by the embodiment of the application uses a standard wafer as an auxiliary measurement wafer to avoid the influence of the height difference or warping of the wafer itself on the measurement result. A plurality of focus data sets are obtained by performing focus measurement on a plurality of pairs of calibration points marked on the diameter ends of the edge of the standard wafer, the focus data sets are converted into height difference data, a plurality of sets of height difference data are fitted to obtain a calibration point position-height difference fitting curve, and the tilt of the machine carrier to be measured is obtained based on the maximum height difference data in the calibration point position-height difference fitting curve. The tilt of the machine carrier to be measured is obtained by converting the tilt of the standard wafer, and the flatness measurement process of the wafer carrier is accurate and fast.

[0071] As shown in the figure, Figure 5 The embodiment provides a machine carrier flatness measurement device, which comprises a focus data set acquisition module and a tilt data acquisition module.

[0072] The focus data set acquisition module is configured to acquire a focus data set obtained by measuring when the standard wafer is placed horizontally on the carrier of the machine to be measured, the focus data set comprising a plurality of focus data groups, each of the focus data groups comprising calibration focus data of two calibration points in a calibration point pair, the edge of the standard wafer being provided with a plurality of calibration point pairs having different position information, and the two calibration points in each of the calibration point pairs being located at two ends of a diameter on the standard wafer.

[0073] The inclination data acquisition module is configured to acquire corresponding height difference data based on each of the focus data groups in the focus data set, and to acquire inclination data of the carrier of the machine to be measured based on the height difference data corresponding to all the focus data groups.

[0074] In the embodiment, the arch variable of the standard wafer is zero, and all the calibration focus data is obtained by a preset electron microscope measurement.

[0075] The machine carrier flatness measurement device provided by the embodiment of the application adopts a standard wafer as an auxiliary measurement wafer to avoid the influence of the height difference or warping of the wafer itself on the measurement result, acquires a plurality of focus data groups by performing focus measurement on a plurality of calibration point pairs marked at two ends of a diameter on the edge of the standard wafer, converts the focus data groups into height difference data, and finally acquires the inclination of the carrier of the machine to be measured based on the maximum height difference data. The inclination of the standard wafer is converted into the inclination of the carrier of the machine to be measured, so that the flatness measurement process of the wafer carrier is accurate and fast.

[0076] The embodiment of the application further provides a computer readable storage medium. Those skilled in the art can understand that all or part of the steps of the above-mentioned embodiment method can be completed by a program instructing a processor, and the program can be stored in a computer readable storage medium. The storage medium is a non-transitory medium, for example, a random access memory, a read-only memory, a flash memory, a hard disk, a solid state disk, a magnetic tape, a floppy disk, an optical disc and any combination thereof. The storage medium can be any available medium accessible by a computer or a data storage device such as a server, a data center and the like integrated with one or more available medium sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a digital video disc (DVD)) or a semiconductor medium (for example, a solid state disk (SSD)) and the like.

[0077] As shown in Figure 6 the embodiment of the application provides a terminal.

[0078] The terminal of the embodiment comprises a processor and a memory connected with each other; the memory is configured to store a computer program, and the processor is configured to execute the computer program stored in the memory, so that the terminal can implement all or part of the steps of the method of the above embodiment when executed.

[0079] The beneficial effects of all or part of the steps of the above embodiment method are the same as the beneficial effects of the terminal provided by the embodiment of the present application, and will not be described here.

[0080] It should be noted that the memory can include a random access memory (RAM) and can also include a non-volatile memory, such as at least one disk memory. Similarly, the processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component.

[0081] Although the disclosed embodiments of the present application are as above, the content described is only for the purpose of facilitating understanding of the embodiments adopted by the present application, and is not intended to limit the present application. Any person skilled in the art of the present application can make any modification and change in the form and details without departing from the spirit and scope of the present application, but the protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A method for measuring flatness of a machine carrier, comprising: obtaining a set of focus data measured when a standard wafer is placed on a machine carrier to be measured, the set of focus data comprising a plurality of focus data groups, each of the focus data groups comprising calibration focus data of two calibration points in a calibration point pair, the standard wafer having a plurality of calibration point pairs with different position information arranged on the edge of the standard wafer, and each of the two calibration points in the calibration point pair being located at the two ends of a same diameter on the standard wafer; obtaining corresponding height difference data of each of the focus data groups based on the set of focus data, and obtaining inclination data of the machine carrier to be measured based on the height difference data corresponding to all the focus data groups; wherein the camber variable of the standard wafer is zero, and all the calibration focus data is obtained by a preset electron microscope measurement; obtaining the inclination data of the machine carrier to be measured based on the height difference data corresponding to all the focus data groups comprises: obtaining a calibration point position-height difference fitting curve based on the height difference data corresponding to all the focus data groups and the position information of the calibration point pairs, obtaining maximum height difference data in the calibration point position-height difference fitting curve as target height difference data, and obtaining the inclination data of the machine carrier to be measured based on the target height difference data; obtaining position information corresponding to the target height difference data in the calibration point position-height difference fitting curve as target position information, and determining the inclination direction and position information of the machine carrier to be measured based on the positive and negative attributes of the target height difference data and the target position information.

2. The metrology method of claim 1, wherein, The preset electron microscope is a critical dimension scanning electron microscope, and the calibration focus data in the focus data group is voltage data.

3. The metrology method of claim 2, wherein, Obtaining corresponding height difference data of each of the focus data groups based on the set of focus data comprises: obtaining voltage difference data by subtracting two calibration focus data in the focus data group; multiplying the voltage difference data by a voltage-height variation coefficient of the critical dimension scanning electron microscope to obtain the height difference data corresponding to the focus data group.

4. The metrology method of claim 3, wherein, The voltage-height variation coefficient of the critical dimension scanning electron microscope comprises: obtaining a plurality of height-focus comparison data by subtracting adjacent two preset heights and corresponding focus data of the critical dimension scanning electron microscope measured on a standard wafer at different preset heights, and obtaining the voltage-height variation coefficient of the critical dimension scanning electron microscope based on the plurality of height-focus comparison data.

5. The metrology method of claim 3, wherein, The calibration point pairs on the standard wafer are arranged in the following manner: taking a preset fixed point on the edge of the standard wafer as a zero-angle starting point, sequentially arranging a plurality of calibration points with angle position information along the edge of the standard wafer according to the serial numbers, and setting two calibration points on the same diameter of the standard wafer as a calibration point pair. When obtaining the voltage difference data corresponding to the focus data group, the calibration focus data of the calibration point pair with a smaller serial number is subtracted from the calibration focus data of the calibration point pair with a larger serial number, and the obtained height difference data is positive or negative.

6. The metrology method of claim 1, wherein, The tilt data of the machine carrier to be measured is calculated by the following formula: ； Wherein, θ is the tilt data of the machine carrier to be measured, Δh is the target height difference data, and X is the diameter of the standard wafer.

7. A stage carrier flatness measuring device, comprising: The method comprises a focus data set acquisition module and a tilt data acquisition module. The focus data set acquisition module is configured to acquire a focus data set measured when the standard wafer is placed on the machine carrier to be measured. The focus data set comprises a plurality of focus data groups, each of which comprises calibration focus data of two calibration points in a calibration point pair. The standard wafer is provided with a plurality of calibration point pairs having different position information, and the two calibration points in each calibration point pair are located at the two ends of a diameter on the standard wafer. The tilt data acquisition module is configured to acquire corresponding height difference data based on each focus data group in the focus data set, and acquire the tilt data of the machine carrier to be measured based on the height difference data corresponding to all the focus data groups. Wherein, the arch variable of the standard wafer is zero, and all the calibration focus data are acquired by a preset electron microscope measurement. Acquiring the tilt data of the machine carrier to be measured based on the height difference data corresponding to all the focus data groups comprises: Acquiring a calibration point position-height difference fitting curve based on the height difference data corresponding to all the focus data groups and the position information of the calibration point pairs, acquiring the maximum height difference data in the calibration point position-height difference fitting curve as target height difference data, and acquiring the tilt data of the machine carrier to be measured based on the target height difference data. Acquiring the position information corresponding to the target height difference data in the calibration point position-height difference fitting curve as target position information, and determining the tilt direction and position information of the machine carrier to be measured based on the positive and negative attributes of the target height difference data and the target position information.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the machine carrier flatness measurement method of any one of claims 1 to 6.

9. A terminal comprising a memory, a processor, and a computer program stored on the memory, wherein the computer program, when executed by the processor, causes the terminal to perform the method of any one of claims 1 to 8. The processor executes the computer program to implement the machine carrier flatness measurement method of any one of claims 1 to 6.

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