Silicon wafer surface shape scanning method and device and electronic equipment

Abstract

The invention relates to the technical field of photoetching, in particular to a silicon wafer surface shape scanning method and device and electronic equipment.The method comprises the steps that the edge of a silicon wafer is scanned according to a preset scanning path, and discrete height information of the edge of the silicon wafer is obtained; curved surface fitting is carried out on the discrete height information of the silicon wafer edge to obtain a fitting model of the height and the position of the silicon wafer edge, and the fitting model can obtain the accurate height of the silicon wafer edge; according to the fitting model, resolving the position corresponding to the entrance point on the preset global scanning path to obtain an estimated attitude value of the entrance point; and controlling the silicon wafer stage to move until the silicon wafer is in the effective measurement interval of the horizontal sensor according to the estimated attitude value before entering the silicon wafer from the entrance point, so that the situation that capturing operation is needed when the scanning light spot of the horizontal sensor enters the field in the global scanning process is avoided. Therefore, the global scanning efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of lithography technology, and in particular, to a method, device and electronic device for scanning the surface shape of a silicon wafer. Background Art

[0002] The full-surface shape scanning of a silicon wafer is the measurement and evaluation of the surface topography of the silicon wafer by a lithography machine to ensure the transfer accuracy and quality of the lithography machine image. Before the silicon wafer is exposed, by globally scanning the upper surface of the silicon wafer, the surface shape characteristics of the silicon wafer surface are obtained to evaluate the quality and applicability of the silicon wafer.

[0003] With the development of lithography technology and the gradual improvement of lithography process requirements, its depth of focus range has also been sharply reduced. To avoid incorrect measurement data of the level sensor, it is necessary to keep the distance between the level sensor and the silicon wafer surface within the effective measurement range of the level sensor at all times; currently, the measurement range of the level sensor on the lithography machine is only a few micrometers. If no capture operation is performed at the global scan entry point, the change range of the silicon wafer surface shape may exceed the sensor range, resulting in inaccurate measurement data. And after deviating from the best measurement interval, it will lead to a height data calculation problem, which will then reduce the scanning accuracy. Therefore, since a capture operation needs to be performed every time the scanning spot enters during the global scan process, the global scan efficiency is reduced. Summary of the Invention

[0004] The purpose of the present invention is to provide a method, device and electronic device for scanning the surface shape of a silicon wafer to solve the problem that a capture operation needs to be performed every time the scanning spot enters during the global scan process, resulting in a reduction in the global scan efficiency.

[0005] An embodiment of the present invention provides a method for scanning the surface shape of a silicon wafer. The method includes: scanning the edge of the silicon wafer according to a preset scanning path to obtain discrete height information of the silicon wafer edge; performing surface fitting on the discrete height information of the silicon wafer edge to obtain a fitting model of the silicon wafer edge height and position; calculating the corresponding position of the entry point on the preset full-surface shape scanning path according to the fitting model to obtain an estimated attitude value of the entry point; performing a global scan on the silicon wafer, and controlling the silicon wafer stage to move to an area where the silicon wafer is within the effective measurement range of the level sensor according to the estimated attitude value before entering the silicon wafer from the entry point.

[0006] Optionally, scanning the edge of the wafer according to a preset scanning path to obtain discrete height information of the wafer edge includes: controlling the wafer stage to complete a first step movement from a scanning starting point, and measuring, through the horizontal sensor, the discrete difference between the upper surface of the wafer edge and the zero plane of the horizontal sensor, where the discrete difference is the discrete height information; controlling the wafer stage according to the discrete difference to reposition the upper surface of the wafer edge at the zero plane of the horizontal sensor; controlling the wafer stage to complete subsequent one-week step scanning along the preset scanning path to obtain all the discrete height information.

[0007] Optionally, performing surface fitting on the discrete height information of the wafer edge to obtain a fitting model of the wafer edge height and position includes: obtaining a fitting surface of the wafer edge height and position according to the discrete difference; calculating the residual of the fitting surface; determining whether the residual is less than or equal to a preset value. If so, the fitting surface meets the requirements; if not, the fitting surface does not meet the requirements, and the surface fitting is performed again.

[0008] Optionally, resolving the position corresponding to the entry point on the preset full-surface profile scanning path according to the fitting model to obtain an estimated attitude value of the entry point includes: determining the height and inclination angle of each point on the upper surface of the wafer edge according to the fitting model; the inclination angle is the angle between the upper surface of the wafer edge and the zero plane of the horizontal sensor; determining the coordinates of the entry point on the preset full-surface profile scanning path according to the preset full-surface profile scanning path and the wafer edge information; calculating the estimated attitude value of the entry point according to the height and inclination angle of each point on the upper surface of the wafer edge and the coordinates of the entry point.

[0009] Optionally, before the step of scanning the wafer edge according to a preset scanning path, it includes: moving the upper surface of the wafer edge to the zero plane of the horizontal sensor through the wafer stage to determine the scanning starting point.

[0010] Optionally, for the global scanning of the wafer, it further includes: controlling the wafer stage according to the discrete difference to reposition the upper surface of the wafer edge at the zero plane of the horizontal sensor; controlling the wafer stage to complete subsequent step scanning along the preset full-surface profile scanning path to obtain all the surface profile information of the wafer surface.

[0011] Optionally, the method further includes: the preset scanning path is a circular ring non-concentric with the center of the wafer, the radius of the circular ring is smaller than the radius of the wafer, and the circular ring covers the edge of the wafer.

[0012] Compared with the prior art, the beneficial effects of the wafer surface profile scanning method provided by the present invention are as follows:

[0013] The silicon wafer surface scanning method provided by an embodiment of the present invention scans the edge of the silicon wafer according to a preset scanning path to obtain discrete height information of the silicon wafer edge; performs surface fitting on the discrete height information of the silicon wafer edge to obtain a fitting model of the silicon wafer edge height and position, and this fitting model can obtain the accurate height of the silicon wafer edge; calculates the corresponding position of the entry point on the preset full surface scanning path according to the fitting model to obtain an estimated attitude value of the entry point, that is, the pose adjustment information of the silicon wafer stage; performs global scanning on the silicon wafer, and controls the silicon wafer stage to move to an effective measurement range of the horizontal sensor when entering the silicon wafer from the above entry point, that is, each time the scanning spot of the horizontal sensor enters the silicon wafer from the entry point, controls the pose adjustment of the silicon wafer stage according to the above estimated attitude value to make the silicon wafer in the effective measurement range of the horizontal sensor, without performing a capture operation on the silicon wafer again, realizing that the scanning spot of the horizontal sensor does not need to perform a capture operation when entering during the global scanning process, thereby improving the global scanning efficiency.

[0014] An embodiment of the present invention further provides a silicon wafer surface scanning device, and the device includes: a first scanning module: used to scan the edge of the silicon wafer according to a preset scanning path to obtain discrete height information of the silicon wafer edge; a fitting module: used to perform surface fitting on the discrete height information of the silicon wafer edge to obtain a fitting model of the silicon wafer edge height and position; a calculation module: used to calculate the corresponding position of the entry point on the preset full surface scanning path according to the fitting model to obtain the estimated attitude value of the entry point; a second scanning module: used to perform global scanning on the silicon wafer, and control the silicon wafer stage to move to an effective measurement range of the horizontal sensor when entering the silicon wafer from the entry point according to the estimated attitude value.

[0015] The beneficial effect of the silicon wafer surface scanning device provided by the present invention is that it can achieve the same technical effect as the above silicon wafer surface scanning method. To avoid repetition, it will not be elaborated here.

[0016] An embodiment of the present invention further provides an electronic device, and the electronic device includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the computer program, the above method is implemented.

[0017] The beneficial effect of the electronic device provided by the present invention is that it can achieve the same technical effect as the above silicon wafer surface scanning method. To avoid repetition, it will not be elaborated here.

[0018] An embodiment of the present invention further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program is read and run by a processor, the above method is implemented.

[0019] The beneficial effects of the computer-readable storage medium provided by the present invention are as follows: It can achieve the same technical effects as the above-mentioned silicon wafer surface scanning method. To avoid repetition, it will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0021] Figure 1 Schematic diagram of the return signal of the horizontal sensor in the embodiment of the present invention;

[0022] Figure 2 Schematic diagram of the step scanning trajectory in the embodiment of the present invention;

[0023] Figure 3 Schematic flowchart of a silicon wafer surface scanning method provided by the embodiment of the present invention;

[0024] Figure 4 Schematic diagram of the scanning path of the silicon wafer edge in the embodiment of the present invention;

[0025] Figure 5 Schematic diagram of the scanning data of the silicon wafer edge light spot in the embodiment of the present invention;

[0026] Figure 6 Schematic flowchart of another silicon wafer surface scanning method provided by the embodiment of the present invention;

[0027] Figure 7 Schematic diagram of the three-dimensional image of the measurement result in the embodiment of the present invention;

[0028] Figure 8 Schematic diagram of the structure of a silicon wafer surface scanning device in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will provide a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings.

[0030] In order to be able to measure the height Z and the inclination angle Ry of the silicon wafer simultaneously in the embodiment of the present invention, the horizontal sensor used in the embodiment of the present invention includes n measurement light spots, where n is an odd number; among them, the central detection light spot is used to measure the height Z, and multiple light spots are combined for measurement and the inclination angle Ry is obtained by linearly fitting the measurement data. The horizontal sensor used in the embodiment of the present invention will obtain the detection signals L l and Lr , convert the height information of the surface to be measured into L l and L r In the form of, during the process of scanning the silicon wafer, L l and L r will appear as a periodic signal. To avoid the height of the silicon wafer to be measured being outside the effective detection area, usually the silicon wafer needs to be initially moved into the effective measurement area first, and the measurement signal of the horizontal sensor is used as the height feedback for the closed-loop control of the silicon wafer stage's own measurement system. The above-mentioned silicon wafer stage's own measurement system checks the movement data of the silicon wafer stage according to the height information measured by the horizontal sensor, and controls the silicon wafer stage to keep the silicon wafer surface at the zero plane of the horizontal sensor during the step scanning process. At this time, the height displacement change information of the silicon wafer stage recorded by the silicon wafer stage's own measurement system represents the difference between the silicon wafer surface shape and the zero plane of the horizontal sensor, that is, it represents the surface shape change.

[0031] See Figure 1 The schematic diagram of the return signal of the horizontal sensor shown, the detection signal L l and L r changes periodically. The interval along the Z-axis direction (-σ, σ) is determined as the best measurement interval; due to the edge protrusion, depression, burrs, etc. of the silicon wafer, which cause changes in the silicon wafer edge, resulting in a periodic jump when the horizontal sensor enters the measurement from the entry point, thus getting out of the best measurement interval and causing a deviation between the measurement result and the silicon wafer stage displacement, and then leading to an error in the height data calculation, and then reducing the scanning accuracy. It should be noted that when the silicon wafer surface does not get out of the best measurement interval, the height information measured by the horizontal sensor is consistent with the height displacement change information of the silicon wafer stage; among them, the best measurement interval is the effective measurement interval of the horizontal sensor.

[0032] See Figure 2 The schematic diagram of the step scanning trajectory shown, where the scanning trajectory is a preset full-surface shape scanning path, point A is the scanning starting point, and point B is an entry point in the preset full-surface shape scanning path; when step scanning the silicon wafer surface shape, the detection spot of the horizontal sensor will enter the silicon wafer at different positions. In order to avoid the need for a capture operation every time it enters the silicon wafer, the embodiment of the present invention proposes a silicon wafer surface shape scanning method based on the silicon wafer edge, and obtains the silicon wafer surface shape by fitting the edge surface shape, thereby avoiding measuring the entry attitude of the silicon wafer using the capture function and improving the measurement efficiency.

[0033] The embodiment of the present invention provides a silicon wafer surface shape scanning method. See Figure 3 The schematic flow chart of the silicon wafer surface shape scanning method shown, this method includes:

[0034] S310, scan the silicon wafer edge according to the preset scanning path to obtain the discrete height information of the silicon wafer edge;

[0035] Optionally, in this embodiment, the wafer stage is controlled to complete the first step movement from the scanning starting point. Through the horizontal sensor, the discrete difference between the upper surface of the wafer edge and the zero plane of the horizontal sensor is measured, and the above discrete difference is the discrete height information. According to the above discrete difference, the wafer stage is controlled to reposition the upper surface of the wafer edge at the zero plane of the horizontal sensor. The wafer stage is controlled to complete the subsequent one-week step scanning along the preset scanning path to obtain all the discrete height information. Among them, according to the above discrete difference, the wafer stage is controlled to reposition the upper surface of the wafer edge at the zero plane of the horizontal sensor, so as to avoid the upper surface of the wafer edge from departing from the effective measurement range of the horizontal sensor during the subsequent step scanning, and improve the accuracy of the measurement data.

[0036] By controlling the wafer stage to complete the subsequent one-week step scanning along the preset scanning path to obtain all the discrete height information, that is, the wafer stage returns to the scanning starting point, then it is not necessary to perform the wafer capture operation again to determine the scanning starting point for the subsequent global scanning.

[0037] Exemplarily, as Figure 2 shown in the scanning starting point, in the Cartesian coordinate system, the coordinates of the scanning starting point are (-r, 0), where r is the radius of the scanning path of the wafer edge. Starting from this scanning starting point along the scanning path of the wafer edge, after scanning one week, it returns to the above scanning starting point again, and then starts the subsequent global scanning with this scanning starting point as the starting point.

[0038] It should be noted that the step movement of the wafer stage is the displacement movement of the wafer stage along the X direction or the Y direction in the XY plane of the three-dimensional coordinate system according to the parameters set by the control system.

[0039] S320. Perform surface fitting on the discrete height information of the wafer edge to obtain a fitting model of the height and position of the wafer edge. In this way, the height information corresponding to each point position on the wafer edge can be obtained from the above fitting model.

[0040] S330. Solve the corresponding position of the entry point on the preset full-surface type scanning path according to the fitting model to obtain the estimated attitude value of the entry point.

[0041] Optionally, according to the fitting model, determine the height and inclination angle of each point on the upper surface of the wafer edge. The above inclination angle is the angle between the upper surface of the wafer edge and the zero plane of the horizontal sensor. According to the preset full-surface type scanning path and the wafer edge information, determine the coordinates of the entry point on the preset full-surface type scanning path. According to the above height and inclination angle of each point on the upper surface of the wafer edge and the coordinates of the entry point, calculate the estimated attitude value of the entry point.

[0042] S340, perform a global scan of the silicon wafer, and control the movement of the wafer stage to place the silicon wafer within the effective measurement range of the level sensor according to the estimated attitude value before entering the silicon wafer from the above-mentioned entry point.

[0043] Optionally, control the wafer stage according to the above-mentioned discrete difference to reposition the upper surface of the silicon wafer edge at the zero plane of the level sensor; control the wafer stage to complete subsequent step-by-step scans along the global surface profile scan path to obtain all the surface profile information of the silicon wafer.

[0044] The silicon wafer surface profile scanning method provided by the embodiments of the present invention scans the edge of the silicon wafer according to a preset scan path to obtain discrete height information of the silicon wafer edge; performs surface fitting on the discrete height information of the silicon wafer edge to obtain a fitting model of the height and position of the silicon wafer edge, and this fitting model can obtain the accurate height of the silicon wafer edge; calculates the corresponding position of the entry point on the preset global surface profile scan path according to the fitting model to obtain the estimated attitude value of the entry point, that is, the posture adjustment information of the wafer stage; performs a global scan of the silicon wafer, and controls the movement of the wafer stage to place the silicon wafer within the effective measurement range of the level sensor according to the above-mentioned estimated attitude value before entering the silicon wafer from the above-mentioned entry point, that is, each time the scanning spot of the level sensor enters the silicon wafer from the entry point, controls the posture adjustment of the wafer stage according to the above-mentioned estimated attitude value to make the silicon wafer within the effective measurement range of the level sensor, without the need to perform a capture operation on the silicon wafer again, realizing that the scanning spot of the level sensor does not need to perform a capture operation when entering during the global scan, thereby improving the global scan efficiency.

[0045] In one embodiment, the embodiments of the present invention provide an implementation manner of performing surface fitting on the discrete height information of the silicon wafer edge to obtain a fitting model of the height and position of the silicon wafer edge.

[0046] Optionally, according to the above-mentioned discrete difference, obtain the fitting surface of the height and position of the silicon wafer edge; calculate the residual of the fitting surface; determine whether the residual is less than or equal to a preset value. If so, the above-mentioned fitting surface meets the requirements; if not, the above-mentioned fitting surface does not meet the requirements, and perform surface fitting again.

[0047] Exemplarily, when measuring the surface profile of the silicon wafer edge, first use the capture function at the capture point to move the silicon wafer surface profile to the zero plane of the level sensor to determine the scan starting point; then perform a uniform scan according to the edge scan trajectory, that is, the above-mentioned preset scan path, to obtain the discrete silicon wafer edge height information obtained by photoelectric conversion. The embodiments of the present invention design a height data fitting model for silicon wafer edge scanning. When performing a global surface profile scan of the silicon wafer, based on the positions (X scanin , Y scanin ) coordinates of each entry point, quickly calculate the Z value of the entry point scanin and Ry scaninInformation. The fitting formula used by the above model is a fourth-order surface formula, which performs surface fitting based on the Z-direction coordinate position information corresponding to the coordinate position points of X and Y. The target surface formula is as follows:

[0048]

[0049] In the above formula, Z i is the height information, P is the surface fitting coefficient, and based on the sampling point coordinates (X i , Y i ) and the actual sampling height Z of the sensor i , the surface model is solved through a fitting algorithm, and the fitting algorithm can adopt a conventional mathematical fitting algorithm. After fitting, the fitting height value corresponding to each sampling point is obtained according to the surface formula , and the fitting residual σ is calculated, and the fitting effect of the fitting model is evaluated according to the fitting residual σ to determine whether it meets the actual requirements. After the above silicon wafer edge scanning is completed, the complete edge height of the silicon wafer can be determined and the fitting model between X i and Y i .

[0050] In one embodiment, before step S110 of the embodiment of the present invention, the above method further includes an implementation manner in which the wafer stage captures the wafer.

[0051] Optionally, the upper surface of the edge of the wafer is moved to the zero plane of the horizontal sensor through the above wafer stage; thus, the capture operation of the wafer is completed, and the scanning starting point is determined; in the embodiment of the present invention, only the above-mentioned one capture operation of the wafer is required, and subsequent steps do not require any capture operation of the wafer to determine the attitude of the wafer stage.

[0052] In one embodiment, the embodiment of the present invention includes a method for determining a preset scanning path.

[0053] Optionally, in the embodiment of the present invention, the above-mentioned wafer surface scanning method further includes: the above-mentioned preset scanning path is a circular ring that is not concentric with the center of the above-mentioned wafer, the radius of the above-mentioned circular ring is smaller than the radius of the above-mentioned wafer, and the above-mentioned circular ring covers the edge of the above-mentioned wafer; thus, the edge surface information of the above-mentioned wafer can be obtained by scanning the scanning spot along the above-mentioned circular ring.

[0054] It should be noted that, refer to Figure 4Schematic diagram of the scanning path of the silicon wafer edge. The radius of the silicon wafer edge is R, and the radius of the silicon wafer edge scanning path is r. During the scanning of the silicon wafer edge, the central scanning spot needs to always be within a specific distance from the center M of the circle pointed by the silicon wafer edge. The specific distance includes but is not limited to the edge safety scanning distance and the distance from the central spot to the edge safety scanning distance. The function of the edge safety scanning distance is to prevent the sensor from exceeding the silicon wafer edge. However, during the moving scan along the edge, since there is a region V for silicon wafer identification and robotic arm grasping at the bottom edge of the silicon wafer, this region V is used for the pre-alignment operation of the silicon wafer and the machine during wafer loading. Therefore, the overall scanning range is defined within a circular ring zone at a specific distance from the edge, and the center of the inner circle of the circular ring zone will be offset along the Y direction due to the functional area of the lower edge of the silicon wafer, with an offset of H. Among them, the inner circle of the circular ring zone is the silicon wafer edge scanning path. See Figure 5 Schematic diagram of the scanning data of the silicon wafer edge spot. When performing trajectory planning, ensure that the central detection spot is always inside the silicon wafer. The other detection spots except the central detection spot will enter / exit the silicon wafer with the change of sampling points. During the scanning of n spots around the edge, the signals of the measurement spots outside the silicon wafer edge are ignored, and the effective measurement points inside the silicon wafer form a spindle pattern when viewed from above.

[0055] As a feasible implementation, see Figure 6 Schematic flowchart of another silicon wafer surface scanning method shown. The above method includes the following steps: S602 Capture the silicon wafer, S604 Obtain the discrete height information of the silicon wafer edge, S606 Construct a surface fitting model, S608 Solve and estimate the attitude value based on the surface fitting model, S610 Initialize the global scan, S612 Complete the full surface scanning.

[0056] Step S602: Control the silicon wafer to move to the capture position, and use the capture function to move the upper surface of the silicon wafer at this point to the horizontal sensor zero plane.

[0057] Step S604: In the silicon wafer edge scan, take the zero measurement height of the horizontal sensor as the control target for the silicon wafer stage height servo control, and scan clockwise along Figure 4 the silicon wafer edge scanning path shown, and stop after scanning one full circle. The measurement spot information exceeding the silicon wafer edge spacing will be invalidated. See Figure 7 Schematic diagram of the three-dimensional image of the measurement result shown. The scanning result is a three-dimensional discrete ring data, and the height change information recorded by the silicon wafer stage position measurement system is used as the silicon wafer surface type data.

[0058] Step S606: Perform surface fitting on the sampled data and calculate the residual between the fitting result and the discrete scanning result, denoted as σ.

[0059] Step S608: Enter the coordinate pair (X scanin , Y scanin ) corresponding to the entry point on the pre-planned full-surface scanning trajectory, the entry point attitude height Z scanin and the inclination angle Ry scanin for fitting and solving to obtain the estimated attitude value of the entry point.

[0060] Step S610: Control the wafer to move to the effective measurement position for full-surface scanning, and move the upper surface of the wafer at this point to the zero plane of the level sensor through this step.

[0061] Step S612: Perform a step-by-step scanning test on the full surface of the wafer according to the trajectory, still using the zero measurement height of the level sensor as the target for controlling the height of the wafer stage.

[0062] Specifically, before the detection light re-enters the wafer, use the estimated entry attitude obtained in Step S608 to move the wafer stage to the zero plane of the level sensor, ensuring that when the detection light spot enters the wafer, the wafer surface is within the effective measurement range of the level sensor.

[0063] Optionally, first use the estimated entry attitude obtained in Step S608 to move the wafer stage to a height Z and a rotation angle Ry that meet the working range of the level sensor, that is, other positions including the zero plane of the level sensor, and then move the wafer stage to the zero plane of the level sensor for subsequent step-by-step scanning.

[0064] Before the global scanning of the wafer in the embodiment of the present invention, the edge of the wafer is scanned, and the scanning results are processed according to the algorithm for wafer edge scanning to calculate the entry attitude during the global scanning of the wafer, so as to improve the joint measurement accuracy of the moving stage and the sensor, where the moving stage is the wafer stage.

[0065] The embodiment of the present invention also provides a wafer surface scanning device, which includes:

[0066] The first scanning module 802: used to scan the edge of the wafer according to a preset scanning path to obtain the discrete height information of the wafer edge;

[0067] The fitting module 804: used to perform surface fitting on the discrete height information of the wafer edge to obtain the fitting model of the wafer edge height and position;

[0068] The solving module 806: used to solve the corresponding position of the entry point on the preset full-surface scanning path according to the fitting model to obtain the estimated attitude value of the entry point;

[0069] Second scanning module 808: used to perform a global scan on the silicon wafer, and control the movement of the wafer stage to make the silicon wafer within the effective measurement range of the horizontal sensor according to the estimated attitude value before entering the silicon wafer from the above-mentioned entry point.

[0070] An embodiment of the present invention also provides an electronic device, which includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the computer program, the steps of the above-mentioned silicon wafer surface type scanning method are implemented.

[0071] An embodiment of the present invention also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program is read and run by a processor, the above-mentioned silicon wafer surface type scanning method is implemented and can achieve the same technical effect. To avoid repetition, it will not be elaborated here. Among them, the computer-readable storage medium, such as a read-only memory (ROM for short), a random access memory (RAM for short), a magnetic disk or an optical disc, etc.

[0072] Of course, those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing a control device. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above-mentioned method embodiments. Among them, the storage medium can be a memory, a magnetic disk, an optical disc, etc.

[0073] Finally, it should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of another identical element in the process, method, article or device including the element.

[0074] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0075] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A silicon wafer surface scanning method, characterized in that, The method includes: Scanning the edge of the silicon wafer according to a preset scanning path to obtain discrete height information of the edge of the silicon wafer; Performing surface fitting on the discrete height information of the edge of the silicon wafer to obtain a fitting model of the height and position of the edge of the silicon wafer; Calculating the corresponding position of the entry point on the preset full-surface profile scanning path according to the fitting model to obtain an estimated attitude value of the entry point; Performing global scanning on the silicon wafer, and before entering the silicon wafer from the entry point, controlling the movement of the silicon wafer stage according to the estimated attitude value so that the silicon wafer is within the effective measurement range of the horizontal sensor.

2. The silicon wafer surface scanning method according to claim 1, characterized in that The step of scanning the edge of the silicon wafer according to a preset scanning path to obtain discrete height information of the edge of the silicon wafer includes: Controlling the silicon wafer stage to complete a first step movement from the scanning starting point, and measuring, through the horizontal sensor, the discrete difference between the upper surface of the edge of the silicon wafer and the zero plane of the horizontal sensor, where the discrete difference is the discrete height information; Controlling the silicon wafer stage according to the discrete difference to reposition the upper surface of the edge of the silicon wafer at the zero plane of the horizontal sensor; Controlling the silicon wafer stage to complete subsequent one-week step scanning along the preset scanning path to obtain all the discrete height information.

3. The silicon wafer surface scanning method according to claim 2, wherein The step of performing surface fitting on the discrete height information of the edge of the silicon wafer to obtain a fitting model of the height and position of the edge of the silicon wafer includes: Obtaining a fitting surface of the height and position of the edge of the silicon wafer according to the discrete difference; Calculating the residual of the fitting surface; Judging whether the residual is less than or equal to a preset value. If so, the fitting surface meets the requirements; if not, the fitting surface does not meet the requirements, and the surface fitting is performed again.

4. The silicon wafer surface scanning method according to claim 2, characterized in that, The step of calculating the corresponding position of the entry point on the preset full-surface profile scanning path according to the fitting model to obtain an estimated attitude value of the entry point includes: Determining the height and inclination angle of each point on the upper surface of the edge of the silicon wafer according to the fitting model; the inclination angle is the angle between the upper surface of the edge of the silicon wafer and the zero plane of the horizontal sensor; Determining the coordinates of the entry point on the preset full-surface profile scanning path according to the preset full-surface profile scanning path and the edge information of the silicon wafer; Calculating the estimated attitude value of the entry point according to the height and inclination angle of each point on the upper surface of the edge of the silicon wafer and the coordinates of the entry point.

5. The silicon wafer surface scanning method according to claim 2, wherein Before the step of scanning the edge of the silicon wafer according to a preset scanning path, it includes: Moving the upper surface of the edge of the silicon wafer to the zero plane of the horizontal sensor through the silicon wafer stage to determine the scanning starting point.

6. The silicon wafer surface scanning method according to claim 2, wherein The global scanning of the silicon wafer further includes: Controlling the silicon wafer stage according to the discrete difference to reposition the upper surface of the edge of the silicon wafer at the zero plane of the horizontal sensor; Controlling the silicon wafer stage to complete subsequent step scanning along the preset full-surface profile scanning path to obtain all the surface profile information of the silicon wafer surface.

7. The silicon wafer surface scanning method according to claim 1, characterized in that, The method further includes: The preset scanning path is a circular ring non-concentric with the center of the silicon wafer, the radius of the circular ring is smaller than the radius of the silicon wafer, and the circular ring covers the edge of the silicon wafer.

8. A silicon wafer surface scanning device, characterized in that, The device includes: A first scanning module: used for scanning the edge of the silicon wafer according to a preset scanning path to obtain discrete height information of the edge of the silicon wafer; Fitting module: used to perform surface fitting on the discrete height information of the wafer edge to obtain a fitting model of the wafer edge height and position; Solving module: used to solve the corresponding position of the entry point on the preset full-surface scanning path according to the fitting model to obtain the estimated attitude value of the entry point; Second scanning module: used to perform global scanning on the wafer, and control the wafer stage to move the wafer into the effective measurement range of the horizontal sensor according to the estimated attitude value before entering the wafer from the entry point.

9. An electronic device, the electronic device includes a memory and a processor, the memory stores a computer program that can run on the processor, characterized in that, When the processor executes the computer program, the method described in any one of claims 1-7 is implemented.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and when the computer program is read and run by the processor, the method described in any one of claims 1-7 is implemented.

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