Wafer processing system and method, electronic equipment and computer medium

Abstract

The invention provides a wafer processing system and method, electronic equipment and a computer medium, and the wafer processing system comprises a wafer polishing assembly which comprises a polishing disc; the eddy current sensor is arranged on the polishing disc, in the wafer polishing process, the eddy current sensor rotates along with the polishing disc to form a circular track, and a first connecting line of the horizontal projection of the center of the polishing disc and the horizontal projection of the center of the wafer intersects with the horizontal projection of the circular track; the horizontal projection of the preset marker intersects with the horizontal projection of the circular track, the position of the marker is kept unchanged, and the marker is used for collecting an eddy current signal in the wafer polishing process; the controller is used for determining a signal included angle of the marker based on the marker signal; determining an angle deviation value between the signal included angle and an actual included angle of the marker; calibrating the wafer morphology characteristic signal according to the angle deviation value; and the control module is used for controlling the wafer polishing assembly to polish the wafer. The accuracy of determining the thickness of the wafer film can be improved.

Description

Technical Field

[0001] This application belongs to the field of semiconductor manufacturing technology, and more specifically, relates to a wafer processing system, method, electronic device and computer medium. Background Technology

[0002] In the integrated circuit manufacturing process, a conductive layer is deposited on a silicon wafer, and CMP (chemical mechanical polishing) is used to planarize the wafer surface. During CMP, eddy current signals and corresponding position signals from eddy current sensors need to be acquired in real time. Based on the eddy current signals acquired by the eddy current sensors and their position signals, the film thickness on the wafer is determined. The measured film thickness is then used to detect the polishing endpoint or to adjust the polishing parameters.

[0003] In related technologies, the eddy current signal and the position signal of the eddy current sensor are prone to being out of sync, resulting in low accuracy in determining the thickness of the wafer thin film. Summary of the Invention

[0004] The purpose of this application is to provide a wafer processing system, method, electronic device, and computer medium to solve or at least alleviate one or more of the above-mentioned and other problems existing in the prior art.

[0005] A first aspect of this application provides a wafer fabrication system, comprising: Wafer polishing assembly, including a polishing disk for use as a wafer polishing base; An eddy current sensor is mounted on a polishing pad. During wafer polishing, the eddy current sensor forms a circular trajectory as the polishing pad rotates. The first line connecting the horizontal projection of the polishing pad center and the horizontal projection of the wafer center intersects with the horizontal projection of the circular trajectory. The horizontal projection of a preset marker also intersects with the horizontal projection of the circular trajectory. The position of the marker remains unchanged. The eddy current sensor is used to collect eddy current signals during wafer polishing. The eddy current signals include: marker signals and wafer morphology feature signals. The controller is used to determine the signal angle of the marker based on the marker signal, wherein the signal angle is the angle between the first line and the second line, and the second line is the line connecting the intersection of the horizontal projection of the polishing disk center and the horizontal projection of the marker determined based on the marker signal and the horizontal projection of the circular trajectory; determine the angular deviation value between the signal angle and the actual angle of the marker; calibrate the wafer morphology feature signal according to the angular deviation value; and control the wafer polishing assembly to polish the wafer.

[0006] In an embodiment, the controller, when determining the signal angle of the marker based on the marker signal, specifically determines: a distance between the intersection point and the horizontal projection of the wafer center based on a signal amplitude peak value in the marker signal; a distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center; a distance between the horizontal projection of the polishing disc center and the intersection point; the signal angle of the marker based on the distance between the intersection point and the horizontal projection of the wafer center, the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center, and the distance between the horizontal projection of the polishing disc center and the intersection point.

[0007] In an embodiment, the controller, when determining the signal angle of the marker based on the marker signal, specifically determines: an average value of signal amplitudes in the marker signal; the signal angle of the marker based on the average value of the signal amplitudes in the rising stage and the average value of the signal amplitudes in the falling stage; the average value of the signal angle corresponding to the average value of the signal amplitudes in the rising stage and the signal angle corresponding to the average value of the signal amplitudes in the falling stage as the signal angle of the marker.

[0008] In an embodiment, the controller, when calibrating the wafer topography characteristic signal based on the angle deviation value, specifically determines: a deviation distance of the wafer topography characteristic signal based on the angle deviation value; calibrating the wafer topography characteristic signal based on the deviation distance.

[0009] In a second aspect, the embodiment of the present application provides a wafer processing method, comprising: controlling a wafer polishing assembly to polish a wafer; acquiring an eddy current signal collected by an eddy current sensor during wafer polishing, the eddy current signal comprising a marker signal and a wafer topography characteristic signal; determining a signal angle of the marker based on the marker signal, the signal angle being an angle between a first line connecting a horizontal projection of a polishing disc center and a horizontal projection of a wafer center and a second line connecting the horizontal projection of the polishing disc center and an intersection point between a horizontal projection of the marker and a horizontal projection of a circular track determined based on the marker signal; determining an angle deviation value between the signal angle and an actual angle of the marker; calibrating the wafer topography characteristic signal based on the angle deviation value; The eddy current sensor is arranged on the polishing disc, and forms a circular track during the polishing of the wafer. The first line intersects with the horizontal projection of the circular track, and the horizontal projection of the marker intersects with the horizontal projection of the circular track. The position of the marker remains unchanged.

[0010] In an embodiment, the signal included in the marker signal is used to determine the signal included in the wafer topography feature signal. The distance between the intersection point and the horizontal projection of the wafer center is determined based on the signal amplitude peak value included in the marker signal. The distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center is obtained. The distance between the horizontal projection of the polishing disc center and the intersection point is obtained. The signal included in the marker is calculated based on the distance between the intersection point and the horizontal projection of the wafer center, the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center, and the distance between the horizontal projection of the polishing disc center and the intersection point.

[0011] In an embodiment, the method further comprises: When it is detected that the eddy current sensor does not detect the marker signal within a preset time length, or the angle deviation value is greater than a preset deviation value range, the position of the marker is calibrated.

[0012] In a third aspect, the embodiments of the present application provide an eddy current monitoring method, comprising: Controlling the relative movement between the wafer and the polishing pad; During the relative movement between the wafer and the polishing pad, the eddy current signal is monitored by the eddy current sensor arranged on the polishing disc. The eddy current signal includes the marker signal and the wafer topography feature signal. The signal included in the marker is determined based on the marker signal, and the angle deviation value between the signal and the actual angle of the marker is determined. The wafer topography feature signal is calibrated according to the angle deviation value. During the polishing of the wafer, the eddy current sensor rotates with the polishing disc to form a circular track. The first line between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center intersects with the horizontal projection of the circular track. The horizontal projection of the preset marker intersects with the horizontal projection of the circular track. The position of the marker remains unchanged.

[0013] In a fourth aspect, the embodiments of the present application provide a chemical mechanical polishing device, comprising: a polishing head, a polishing disc, and a liquid supply module. The eddy current sensor is arranged on the polishing disc. The marker is arranged on the liquid supply arm of the liquid supply module. The marker is used to make the eddy current sensor collect the marker signal. The marker signal is used to calibrate the wafer topography feature signal collected by the eddy current sensor.

[0014] In one embodiment, the surface of the marker is smooth; the marker is connected to the liquid supply arm and the connection is smooth.

[0015] In a fifth aspect, the embodiments of the present application provide an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements the steps of the above methods when executing the computer program.

[0016] In a sixth aspect, the embodiments of the present application provide a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the above methods.

[0017] In a seventh aspect, the embodiments of the present application provide a computer program product, which includes a computer program or computer executable instructions, and the computer program or computer executable instructions are executed by a processor to implement the steps of the above methods.

[0018] The embodiments of the present application have the beneficial effects that: in the scheme of the present application, the wafer topography feature signal is calibrated by adding the marker and using the marker signal contained in the eddy current signal, and then the alignment of the position signal of the eddy current sensor and the eddy current signal is realized, the synchronization of the position signal of the eddy current sensor and the collected eddy current signal is improved, and then the accuracy of the wafer film thickness determined based on the synchronization of the position signal and the eddy current signal is higher, and the determination of the polishing endpoint and the dynamic adjustment of the process parameters are more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 The schematic diagram of the delay of the eddy current signal and the position signal before the wafer topography feature signal is calibrated is provided for an embodiment of the present application; Figure 2 The schematic diagram of the eddy current signal is provided for an embodiment of the present application; Figure 3 The schematic diagram of the influence of the offset of the eddy current signal and the position signal on the compensation accuracy of the wafer edge region is provided for an embodiment of the present application; Figure 4 The schematic diagram of the delay of the eddy current signal and the position signal after the wafer topography feature signal is calibrated is provided for an embodiment of the present application; Figure 5A schematic structural view of a wafer polishing system according to an embodiment of the present application is provided; Figure 6 A top view of a wafer polishing system when a wafer is located at one position during a wafer polishing process according to an embodiment of the present application is provided; Figure 7 A top view of a wafer polishing system according to an embodiment of the present application is provided; Figure 8 A top view of a wafer polishing system when a position of a marker is deviated according to an embodiment of the present application is provided; Figure 9 A schematic view of an eddy current signal according to an embodiment of the present application is provided; Figure 10 A schematic view of an angle between a marker signal and a position signal according to an embodiment of the present application is provided; Figure 11 A schematic view of a marker signal according to an embodiment of the present application is provided; Figure 12 A schematic view of an eddy current signal before calibration of a wafer topography feature signal according to an embodiment of the present application is provided; Figure 13 A schematic view of an eddy current signal after calibration of a wafer topography feature signal according to an embodiment of the present application is provided; Figure 14 A schematic view of a change in a deviation degree between an eddy current signal and a position signal before and after calibration of a wafer topography feature signal according to an embodiment of the present application is provided; Figure 15 A flowchart of a wafer processing method according to an embodiment of the present application is provided; Figure 16 A flowchart of an eddy current monitoring method according to an embodiment of the present application is provided; Figure 17 A schematic block diagram of an electronic device according to an embodiment of the present application is provided. DETAILED DESCRIPTION

[0021] In the following description, specific details are set forth, such as a particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. However, persons skilled in the art will understand that the present application can be practiced without these specific details. In other instances, well-known structures, devices, circuits, and methods have not been described in detail in order to avoid obscuring the present application.

[0022] In a data transmission process, transmission of an eddy current signal and a position signal can be affected by transmission delay and polishing head swing, etc., resulting in jitter of collected data. Even if a software synchronization method is used, a deviation can be introduced due to inconsistent transmission time (for example,Figure 1 D1 / D2 time in FIG. 1).

[0023] Using hardware position calibration (such as Hall sensors) will also introduce uncertain delay in the process of hardware triggering and signal transmission (for example Figure 1 D3 / D4 time in FIG. 1). The transmission delay of the eddy current signal and the position signal will cause them to be unable to be accurately synchronized, especially in the wafer edge area, due to the polishing head swing and process dynamics, the delay effect is significantly amplified, and finally appears as a 2-3mm horizontal jitter on the wafer topography map as shown in Figure 2 . This jitter will directly interfere with the real-time measurement accuracy of the wafer film thickness, and then affect the determination of the polishing endpoint and the dynamic adjustment of the process parameters. It will also affect the edge compensation accuracy, which can be shown as Figure 3 . The offset of the eddy current signal and the position signal has a greater impact on the compensation accuracy of the wafer edge area.

[0024] Therefore, a solution is needed to solve the problem that the eddy current signal and the position signal of the eddy current sensor are prone to being out of synchronization, so that the accuracy of the wafer film thickness determined based on the synchronization of the position signal and the eddy current signal is higher, and the determination of the polishing endpoint and the dynamic adjustment of the process parameters are more accurate.

[0025] The present application mainly increases the marker, finds the corresponding relationship between the position signal and the eddy current signal through the marker, corrects the offset problem caused by the communication transmission delay, improves the accuracy of the endpoint detection, and then can improve the edge compensation accuracy and the stability of the pressure regulation. Through the solution of the present application, the jitter of the position signal and the eddy current signal can be reduced to below 1mm. After the wafer topography characteristic signal is calibrated by the solution of the present application, the delay of the eddy current signal and the position signal can be shown as Figure 4 . Through the solution of the present application, the out-of-synchronization problem of the eddy current signal and the position signal is effectively improved.

[0026] In order to make the purpose, technical scheme and advantages of the present application clearer, specific embodiments will be described below with reference to the accompanying drawings.

[0027] Figure 5 A structure schematic diagram of a wafer polishing system provided by an embodiment of the present application is shown in the figure. The wafer processing system includes a wafer polishing assembly 110, an eddy current sensor 116, and a controller (not shown in the figure). The wafer polishing assembly 110 includes a polishing disc 111 used as a wafer polishing base. The wafer polishing assembly 110 further includes a polishing pad 112, a polishing head 113, and a liquid supply module 114, Figure 5 the arrows in the figure are used to represent the corresponding rotation direction during the wafer polishing process; The polishing disc 111 is used to provide mechanical movement power and stability support for the wafer polishing process, drive the polishing pad 112 to rotate at high speed, and achieve wafer polishing through friction.

[0028] The polishing pad 112 is used as a working surface of mechanical polishing, directly contacts the wafer, and is used to ensure that the wafer surface is uniformly stressed.

[0029] The polishing head 113 is used to fix the wafer and accurately control the polishing pressure and movement.

[0030] The liquid supply module 114 is used to continuously supply polishing liquid and maintain a chemical reaction environment during the wafer polishing process.

[0031] The eddy current sensor 116 is arranged on the polishing disc 111, and further, refer to Figure 6 During the wafer polishing process, the eddy current sensor 116 rotates with the polishing disc 111 to form a circular trajectory, the first line of the horizontal projection O of the center of the polishing disc and the horizontal projection of the center P of the wafer intersects with the horizontal projection of the circular trajectory, and the horizontal projection of the preset marker 115 intersects with the horizontal projection of the circular trajectory, and the intersection point is Figure 6 B in FIG. 1, and the position of the marker 115 remains unchanged. The eddy current sensor 116 is used to collect an eddy current signal during the wafer polishing process, and the eddy current signal includes a marker signal and a wafer topography feature signal.

[0032] Specifically, the intersection point of the horizontal projection of the marker 115 and the horizontal projection of the circular trajectory refers to the center point of the intersection line of the horizontal projection of the marker 115 and the circular trajectory.

[0033] Further, refer to Figure 7 During the wafer polishing process, the wafer 117 moves on the first line while rotating, Figure 6 is a top view of the wafer polishing system when the wafer 117 is located at one of the positions during the wafer polishing process.

[0034] In an embodiment, the first line of the horizontal projection of the center of the polishing disc and the horizontal projection of the center of the wafer can refer to a ray from the horizontal projection of the center of the polishing disc to the direction of the horizontal projection of the center of the wafer.

[0035] In an embodiment, the point where the first line of the horizontal projection of the center of the polishing disc and the horizontal projection of the center of the wafer intersects with the horizontal projection of the circular trajectory coincides with the horizontal projection of the center of the wafer.

[0036] Before polishing the wafer, the position of the marker 115 needs to be calibrated to ensure that the actual angle of the marker 115 is known and stable. During the polishing process of the wafer, if the position of the marker 115 is offset due to the shaking of the wafer polishing system or other reasons, the actual angle of the marker 115 will change. For example Figure 8 As shown, the offset of the position of the marker 115 causes the offset of the actual angle of the marker 115, such as the offset angle e. This further causes the poor accuracy of the calibration of the wafer topography feature signal and the low reliability.

[0037] Therefore, when it is detected that the eddy current sensor does not detect the marker signal within a preset time length, or the angle deviation value is greater than a preset deviation value range, the position of the marker 115 needs to be calibrated. The position of the marker 115 can be calibrated by first controlling the marker 115 to move to an initial calibration position, or can be calibrated at the current position or a new position, and the actual angle of the marker 115 is updated accordingly. This can ensure that the calibration of the wafer topography feature signal always maintains high accuracy during the polishing process of the wafer, and the reliability of the wafer processing system is improved. When calibrating the position of the marker 115, a tool can be used for calibration.

[0038] In an embodiment, whether the position of the marker 115 is offset can also be determined by observing the eddy current signal, which is not limited in the present application.

[0039] The set position of the marker 115 is that the eddy current sensor can pass through the marker 115 during rotation, that is, the marker signal can be collected.

[0040] The actual angle of the marker 115 is the angle between the first connecting line and the connecting line between the center of the polishing disc and the intersection of the actual horizontal projection of the marker 115 and the horizontal projection of the circular track.

[0041] In an embodiment, the marker 115 is made of metal, and the marker 115 can be arranged on the liquid supply arm of the liquid supply module 114, and can also be fixed by a support.

[0042] In an embodiment, the marker 115 has a structure of being wide at the top and narrow at the bottom, which can ensure that only one obvious peak signal can be detected when the eddy current sensor 116 passes through the marker 115.

[0043] In an embodiment, the surface of the marker 115 is smooth, and the marker 115 is connected to the liquid supply arm and the connection is smoothly transitioned. In an embodiment, the marker 115 can be embedded in the liquid supply arm.

[0044] In an embodiment, the marker 115 can be wrapped with plastic material to prevent its metal attribute from polluting the chemical environment of wafer polishing. Also, it can prevent the marker 115 itself from being corroded in the chemical environment of wafer polishing to affect the size of the marker signal. The material of the marker is a material with high insulation strength and low dielectric constant, such as Teflon, Perfluorinated C.

[0045] In an embodiment, the eddy current signal of the eddy current sensor 116 during wafer polishing can be the signal collected by the eddy current sensor 116 during one rotation of the polishing disc 111.

[0046] In an embodiment, the eddy current signal can be seen from Figure 9 The horizontal axis is the distance of the corresponding signal point in the eddy current signal from the horizontal projection of the wafer center, and the vertical axis is the amplitude of the eddy current signal. The distance of the signal point from the horizontal projection of the wafer center refers to the distance of the horizontal projection of the eddy current sensor from the horizontal projection of the wafer center when the eddy current sensor collects the amplitude of the signal point.

[0047] The distance and the line in this application refer to the distance and the line on the corresponding horizontal projection.

[0048] When the eddy current sensor 116 rotates into the edge of the wafer, the eddy current signal presents a rising edge, and when it rotates away from the edge of the wafer, the eddy current signal presents a falling edge. In addition to the marker signal and the wafer topography feature signal, the eddy current signal also includes a base value signal. The base value signal refers to the signal collected when the rotation track of the eddy current sensor 116 does not pass through the wafer 117 and does not pass through the marker 115.

[0049] The following steps S101-S104 can be performed by the controller.

[0050] S101, determine the signal angle of the marker based on the marker signal, the signal angle being the angle between the first line and the second line, the second line being the line connecting the horizontal projection of the polishing disc center and the intersection point of the horizontal projection of the marker determined based on the marker signal and the horizontal projection of the circular track.

[0051] As shown in Figure 10 , the signal angle is the angle between the first line and the second line connecting the horizontal projection O of the polishing disc center and the intersection point B of the horizontal projection of the marker 115 determined based on the marker signal and the horizontal projection of the circular track, P being the horizontal projection of the wafer center.

[0052] S102, determine the angle deviation value of the signal angle and the actual angle of the marker; S103, calibrate the wafer topography feature signal according to the angle deviation value; S104, control the wafer polishing assembly 110 to polish the wafer.

[0053] In some embodiments, the controller, when used for performing the aforementioned S101, i.e., for performing the signal included angle of the marker based on the marker signal, is specifically used for performing the following steps S1011-S1014: S1011, determine the distance between the intersection point and the horizontal projection of the wafer center based on the signal amplitude peak value in the marker signal, the distance between the intersection point and the horizontal projection of the wafer center refers to the distance between the eddy current sensor and the horizontal projection of the wafer center when the eddy current sensor passes through the intersection point; the position of the signal amplitude peak value in the marker signal can be seen from Figure 11 .

[0054] Specifically, the amplitude of each signal point included in the eddy current signal corresponds to the distance between the signal point and the horizontal projection of the wafer center.

[0055] Correspondingly, the signal amplitude peak value in the marker signal can be determined according to the amplitude of each signal point included in the eddy current signal; the distance between the signal point corresponding to the signal amplitude peak value and the horizontal projection of the wafer center is taken as the distance between the intersection point and the horizontal projection of the wafer center, Figure 9 L in the formula is the distance between the intersection point and the horizontal projection of the wafer center.

[0056] S1012, obtain the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center; Specifically, the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center is a known value, which can be pre-stored in the memory. Figure 10 The length of op in the formula is the distance between the horizontal projection O of the polishing disc center and the horizontal projection P of the wafer center.

[0057] S1013, obtain the distance between the horizontal projection of the polishing disc center and the intersection point; Figure 10 The length of ob in the formula is the distance between the horizontal projection of the polishing disc center O and the intersection point B.

[0058] S1014, calculate the signal included angle of the marker according to the distance between the intersection point and the horizontal projection of the wafer center, the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center, and the distance between the horizontal projection of the polishing disc center and the intersection point.

[0059] Specifically, each included angle can be determined according to a geometric algorithm, which will not be described here.

[0060] In other embodiments, the controller, when used for performing the aforementioned S101, i.e., for performing the signal included angle of the marker based on the marker signal, is specifically used for performing the following steps S011-S013: S011, determining an average value of signal amplitudes in the marker signal; The average value of signal amplitudes in the marker signal is a ratio of a sum of amplitudes of each signal point to a number of signal points in the marker signal.

[0061] S012, determining an angle corresponding to the average value in the rising stage of signal amplitudes and an angle corresponding to the average value in the falling stage of signal amplitudes in the marker signal; The positions of signal points corresponding to the average value in the rising stage of signal amplitudes and the average value in the falling stage of signal amplitudes in the marker signal can be seen from the following Figure 11

[0062] In an embodiment, the determination of the angle corresponding to the average value in the rising stage of signal amplitudes in the marker signal in the foregoing S012 includes the following steps S121-S122: S121, determining distance information corresponding to the average value in the rising stage of signal amplitudes in the marker signal, the distance information corresponding to the average value being a distance between a signal point with the average value of signal amplitudes and a horizontal projection of the wafer center; Specifically, the distance information corresponding to the average value in the rising stage of signal amplitudes in the marker signal can be determined based on the eddy current signal.

[0063] S122, determining the angle corresponding to the average value in the rising stage of signal amplitudes in the marker signal based on the distance information corresponding to the average value in the rising stage of signal amplitudes.

[0064] In an embodiment, the determination of the angle corresponding to the average value in the rising stage of signal amplitudes in the marker signal based on the distance information corresponding to the average value in the rising stage of signal amplitudes includes: obtaining a distance between a horizontal projection of the polishing disc center and a horizontal projection of the wafer center; obtaining a distance between the horizontal projection of the polishing disc center and the intersection point; and calculating the signal angle of the marker based on the distance information corresponding to the average value in the rising stage of signal amplitudes, the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center, and the distance between the horizontal projection of the polishing disc center and the intersection point.

[0065] In an embodiment, the determination of the angle corresponding to the average value in the falling stage of signal amplitudes in the marker signal in the foregoing S012 includes the following steps S21-S22: S21, determining distance information corresponding to the average value in the falling stage of signal amplitudes in the marker signal; Specifically, the distance information corresponding to the average value in the falling stage of signal amplitudes in the marker signal can be determined based on the eddy current signal.

[0066] ​S22, determine the angle corresponding to the average value in the signal amplitude decreasing stage based on the distance information corresponding to the average value in the signal amplitude decreasing stage.

[0067] In an embodiment, the angle corresponding to the average value in the signal amplitude decreasing stage is determined based on the distance information corresponding to the average value in the signal amplitude decreasing stage, including: obtaining the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center; obtaining the distance between the horizontal projection of the polishing disc center and the intersection; and calculating the signal angle of the marker according to the distance information corresponding to the average value in the signal amplitude decreasing stage, the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center, and the distance between the horizontal projection of the polishing disc center and the intersection.

[0068] S013, take the average of the angle corresponding to the average value in the signal amplitude increasing stage and the angle corresponding to the average value in the signal amplitude decreasing stage as the signal angle of the marker.

[0069] In some embodiments, in S102, the angle deviation value of the signal angle and the actual angle of the marker is determined, including: taking the difference value of the signal angle and the actual angle of the marker as the angle deviation value.

[0070] When the signal angle is greater than the actual angle of the marker, the angle deviation value is positive, and when the signal angle is less than the actual angle of the marker, the angle deviation value is negative.

[0071] In some embodiments, the controller is configured to perform the following steps S1031-S1032 when performing the aforementioned step S103, i.e., calibrating the wafer topography characteristic signal according to the angle deviation value: S1031, determine the deviation distance of the wafer topography characteristic signal according to the angle deviation value; Specifically, determining the deviation distance of the wafer topography characteristic signal according to the angle deviation value can include: determining the deviation value of the distance from the intersection to the horizontal projection of the wafer center according to the angle deviation value; and taking the deviation value of the distance from the intersection to the horizontal projection of the wafer center as the deviation distance of the wafer topography characteristic signal.

[0072] S1032, calibrate the wafer topography characteristic signal according to the deviation distance.

[0073] In an embodiment, calibrating the wafer topography characteristic signal according to the deviation distance includes: making a corresponding translation to the wafer topography characteristic information according to the deviation distance, so as to calibrate the wafer topography characteristic signal.

[0074] The eddy current signal before the wafer topography characteristic signal is calibrated can be seen in Figure 12 The eddy current signal after the wafer topography characteristic signal is calibrated can be seen inFigure 13 as shown.

[0075] Further, the change of the offset degree of the eddy current signal and the position signal before and after the calibration of the wafer topography feature signal can be seen from Figure 14 as shown.

[0076] In the scheme of the present application, the wafer topography feature signal is calibrated by increasing the marker and using the marker signal contained in the eddy current signal, thereby realizing the alignment of the position signal and the eddy current signal of the eddy current sensor, improving the synchronization of the position signal and the collected eddy current signal of the eddy current sensor, and making the signal collected by the eddy current sensor in each rotation more synchronized, thereby making the wafer film thickness determined based on the synchronization of the position signal and the eddy current signal more accurate, and making the polishing endpoint determination and the dynamic adjustment of the process parameters more accurate.

[0077] Please refer to Figure 15 , Figure 15 The flowchart of the wafer processing method provided by an embodiment of the present application can be executed by the foregoing controller, and the method can include the following steps S501-S505: S501, polishing the wafer by the wafer polishing assembly; S502, acquiring the eddy current signal collected by the eddy current sensor in the wafer polishing process, the eddy current signal including the marker signal and the wafer topography feature signal; S503, determining the signal angle of the marker based on the marker signal, the signal angle being the included angle between the first connecting line of the horizontal projection of the polishing disc center and the horizontal projection of the wafer center, and the second connecting line, the second connecting line being the connecting line of the intersection point of the horizontal projection of the polishing disc center and the horizontal projection of the marker determined based on the marker signal and the horizontal projection of the circular track; S504, determining the angle deviation value of the signal angle and the actual angle of the marker; S505, calibrating the wafer topography feature signal according to the angle deviation value; The eddy current sensor is arranged on the polishing disc, rotates along with the polishing disc to form a circular track in the wafer polishing process, the first connecting line intersects with the horizontal projection of the circular track, and the horizontal projection of the marker intersects with the horizontal projection of the circular track, and the position of the marker remains unchanged.

[0078] In some optional embodiments of the present application, the determination of the signal angle of the marker based on the marker signal in the foregoing S503 includes the following steps S51-S54: S51, determine the distance between the intersection point and the horizontal projection of the wafer center based on the signal amplitude peak value in the marker signal, the distance between the intersection point and the horizontal projection of the wafer center refers to the distance between the eddy current sensor and the horizontal projection of the wafer center when the eddy current sensor passes through the intersection point; S52, obtain the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center; S53, obtain the distance between the horizontal projection of the polishing disc center and the intersection point; S54, calculate the signal angle of the marker according to the distance between the intersection point and the horizontal projection of the wafer center, the distance between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center, and the distance between the horizontal projection of the polishing disc center and the intersection point.

[0079] In an embodiment, the method further comprises: When it is detected that the eddy current sensor does not detect the marker signal within a preset time length, or it is detected that the angle deviation value is greater than a preset deviation value range, the position of the marker is calibrated.

[0080] The specific implementation of the embodiment can be referred to the foregoing content, which will not be repeated here.

[0081] Please refer to Figure 16 , Figure 16 The flowchart of the eddy current monitoring method provided by an embodiment of the present application, which can include the following steps S601-S602: S601, control the relative motion between the wafer and the polishing pad; S602, during the relative motion between the wafer and the polishing pad, monitor the eddy current signal through the eddy current sensor arranged on the polishing disc, the eddy current signal includes: the marker signal and the wafer topography feature signal, to determine the signal angle of the marker based on the marker signal, and determine the angle deviation value between the signal angle and the actual angle of the marker; calibrate the wafer topography feature signal according to the angle deviation value; Wherein, during the wafer polishing process, the eddy current sensor forms a circular trajectory with the rotation of the polishing disc, the first connecting line between the horizontal projection of the polishing disc center and the horizontal projection of the wafer center intersects with the horizontal projection of the circular trajectory, and the horizontal projection of the preset marker intersects with the horizontal projection of the circular trajectory, and the position of the marker remains unchanged.

[0082] The specific implementation of the embodiment can be referred to the foregoing content, which will not be repeated here.

[0083] This application also provides a chemical mechanical polishing apparatus, including: a polishing head, a polishing disc, and a liquid supply module, wherein an eddy current sensor is provided on the polishing disc, and a marker is provided on the liquid supply arm of the liquid supply module. The marker is used to enable the eddy current sensor to collect the marker signal, and the marker signal is used to calibrate the wafer morphology feature signal collected by the eddy current sensor.

[0084] In one embodiment, the surface of the marker is smooth; the marker is connected to the liquid supply arm and the connection is smoothly transitioned.

[0085] The specific implementation method in this embodiment can be found in the foregoing content, and will not be repeated here.

[0086] See Figure 17 , Figure 17 This is a schematic block diagram of an electronic device provided according to an embodiment of this application. Figure 17 The electronic device 900 in this embodiment may include one or more processors 901, one or more input devices 902, one or more output devices 903, and one or more memories 904. The processors 901, input devices 902, output devices 903, and memories 904 communicate with each other via a communication bus 905. The memory 904 stores computer programs, including program instructions. The processor 901 executes the program instructions stored in the memory 904. Specifically, the processor 901 is configured to invoke the program instructions to execute the steps in the methods described above.

[0087] It should be understood that, in the embodiments of this application, the processor 901 may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0088] The memory 904 may include read-only memory and random access memory, and provides instructions and data to the processor 901. A portion of the memory 904 may also include non-volatile random access memory.

[0089] In specific implementations, the processor 901, the input device 902, and the output device 903 described in the embodiments of the present application can perform the implementation manners described in the methods provided by the embodiments of the present application, and can also perform the implementation manners of the electronic device described in the embodiments of the present application, which will not be described here.

[0090] In another embodiment of the present application, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program. The computer program includes program instructions, and the program instructions are executed by a processor to implement all or part of the processes of the above-mentioned embodiment methods. The computer program can also be used to instruct related hardware to complete, and the computer program can be stored in a computer readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned method embodiments can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0091] The computer readable storage medium can be an internal storage unit of the electronic device of any of the preceding embodiments, such as a hard disk or a memory of the electronic device. The computer readable storage medium can also be an external storage device of the electronic device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the computer readable storage medium can include both the internal storage unit and the external storage device of the electronic device. The computer readable storage medium is used to store the computer program and other programs and data required by the electronic device. The computer readable storage medium can also be used to temporarily store data that has been output or will be output.

[0092] The embodiments of the present application provide a computer program product, which includes computer executable instructions or a computer program. The computer executable instructions or the computer program are stored in a computer readable storage medium. A processor of an electronic device reads the computer executable instructions from the computer readable storage medium. The processor executes the computer executable instructions, so that the electronic device executes the methods described above in the embodiments of the present application.

[0093] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been described in general terms in the above description. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0094] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the electronic device and the unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0095] In several embodiments provided in the present application, it should be understood that the disclosed electronic device and method can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces or units, and can also be electrical, mechanical or other forms of connection.

[0096] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, i.e. they can be located in one place or distributed on a plurality of network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present application according to actual needs.

[0097] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or software functional unit.

[0098] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A wafer processing system, characterized by, The application relates to a wafer polishing assembly and a wafer polishing method. The wafer polishing assembly comprises a polishing disc used as a wafer polishing base; an eddy current sensor arranged on the polishing disc, wherein, during wafer polishing, the eddy current sensor rotates to form a circular track, a first line connecting the horizontal projection of the center of the polishing disc and the horizontal projection of the center of a wafer intersects with the horizontal projection of the circular track, and the horizontal projection of a preset marker intersects with the horizontal projection of the circular track, the position of the marker remains unchanged, and the eddy current sensor is used for collecting an eddy current signal during wafer polishing, wherein the eddy current signal comprises a marker signal and a wafer topography feature signal; and a controller used for determining the signal included angle of the marker based on the marker signal, the signal included angle being the included angle of the first line and a second line, the second line being the line connecting the horizontal projection of the center of the polishing disc and the intersection point of the horizontal projection of the marker determined based on the marker signal and the horizontal projection of the circular track, determining the angle deviation value of the signal included angle and the actual included angle of the marker, calibrating the wafer topography feature signal according to the angle deviation value, and controlling the wafer polishing assembly to polish a wafer. When the controller is used for determining the signal included angle of the marker based on the marker signal, the controller is specifically used for: determining the distance between the intersection point and the horizontal projection of the center of the wafer based on the signal amplitude peak value in the marker signal; 2. The system of claim 1, wherein, obtaining the distance between the horizontal projection of the center of the polishing disc and the horizontal projection of the center of the wafer; obtaining the distance between the horizontal projection of the center of the polishing disc and the intersection point; calculating the signal included angle of the marker according to the distance between the intersection point and the horizontal projection of the center of the wafer, the distance between the horizontal projection of the center of the polishing disc and the horizontal projection of the center of the wafer, and the distance between the horizontal projection of the center of the polishing disc and the intersection point. When the controller is used for determining the signal included angle of the marker based on the marker signal, the controller is specifically used for: determining the average value of the signal amplitude in the marker signal; 3. The system of claim 1, wherein, determining the included angle corresponding to the average value in the signal amplitude rising stage and the included angle corresponding to the average value in the signal amplitude falling stage in the signal of the marker; taking the average value of the included angle corresponding to the average value in the signal amplitude rising stage and the included angle corresponding to the average value in the signal amplitude falling stage as the signal included angle of the marker. When the controller is used for calibrating the wafer topography feature signal according to the angle deviation value, the controller is specifically used for: determining the deviation distance of the wafer topography feature signal according to the angle deviation value; 4. The system of claim 1, wherein, calibrating the wafer topography feature signal according to the deviation distance. The wafer polishing method comprises the following steps: controlling a wafer polishing assembly to polish a wafer; 5. A wafer processing method characterized by, obtaining the eddy current signal collected by an eddy current sensor during wafer polishing, wherein the eddy current signal comprises a marker signal and a wafer topography feature signal; ​ ​ determining a signal included angle of the marker based on the marker signal, the signal included angle being an included angle between a first line connecting a horizontal projection of a center of the polishing disc and a horizontal projection of a center of the wafer, and a second line connecting the horizontal projection of the center of the polishing disc and a horizontal projection of an intersection point of the horizontal projection of the marker and a horizontal projection of a circular track; determining an angle deviation value of the signal included angle and an actual included angle of the marker; calibrating the wafer topography characteristic signal according to the angle deviation value; wherein the eddy current sensor is arranged on the polishing disc, and in the wafer polishing process, the eddy current sensor rotates with the polishing disc to form the circular track, the first line intersects with the horizontal projection of the circular track, and the horizontal projection of the marker intersects with the horizontal projection of the circular track, and the position of the marker remains unchanged.

6. The method of claim 5, wherein, The method further comprises: when it is detected that the eddy current sensor does not detect the marker signal within a preset time length, or it is detected that the angle deviation value is greater than a preset deviation value range, calibrating the position of the marker. The method comprises: controlling relative movement between the wafer and the polishing pad; during the relative movement between the wafer and the polishing pad, monitoring an eddy current signal by the eddy current sensor arranged on the polishing disc, the eddy current signal comprising a marker signal and a wafer topography characteristic signal, to determine a signal included angle of the marker based on the marker signal, and determine an angle deviation value of the signal included angle and an actual included angle of the marker; and calibrating the wafer topography characteristic signal according to the angle deviation value; 7. The method of claim 5, wherein, wherein in the wafer polishing process, the eddy current sensor rotates with the polishing disc to form a circular track, a first line connecting a horizontal projection of a center of the polishing disc and a horizontal projection of a center of the wafer intersects with the horizontal projection of the circular track, and a horizontal projection of a preset marker intersects with the horizontal projection of the circular track, and the position of the marker remains unchanged. The method comprises:

8. An electrovortex monitoring method, characterized by a polishing head, a polishing disc and a liquid supply module, wherein the polishing disc is provided with an eddy current sensor, and the liquid supply arm of the liquid supply module is provided with a marker, the marker is used to enable the eddy current sensor to collect a marker signal, and the marker signal is used to calibrate a wafer topography characteristic signal collected by the eddy current sensor. The surface of the marker is smooth; the marker is connected to the liquid supply arm and the connection is smoothly transitioned. ​ ​ 9. A chemical mechanical polishing apparatus characterized by comprising: ​ ​ 10. The apparatus of claim 9, wherein, ​ 11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, The processor, when executing the computer program, implements the steps of the method according to any one of claims 5-7, or 8.

12. A computer storage medium, characterized in that A computer program product, comprising a computer readable medium having stored thereon the computer program, the computer program, when executed by a processor, implementing the steps of the method according to any one of claims 5-7, or 8.

13. A computer program product, characterised in that, A computer program product, comprising a computer readable medium having stored thereon the computer program, the computer program, when executed by a processor, implementing the steps of the method according to any one of claims 5-7, or 8.

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