Method for measuring removal width of wafer edge film layer

Abstract

The invention discloses a method for measuring the removal width of a film layer at the edge of a wafer. The measurement method comprises the following steps: providing a wafer on which a liner film layer and a to-be-monitored film layer located on the liner film layer are formed; carrying out edge removal treatment to expose part of the liner film layer; measuring the thickness of the liner film layer at the plurality of measurement points and obtaining the goodness of fit corresponding to each measurement point; when the goodness of fit jumps, determining that the edge of the to-be-monitored thin film layer is between the current measurement point and the previous measurement point; and determining the actual removal width of the to-be-monitored thin film layer based on the position information of the current measurement point and / or the position information of the previous measurement point. The thickness of the liner film layer is measured through the film thickness measuring instrument, the corresponding goodness of fit is obtained, the actual removal width of the to-be-monitored film layer is determined through the goodness of fit and the position of the measuring point, and the method is simple, low in cost and high in accuracy.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a method for measuring the width of a thin film layer removed from an edge of a wafer. Background Art

[0002] During the semiconductor device manufacturing process, a thin film layer is formed on the wafer. For example, after a copper thin film layer is formed by electroless copper plating (ECP), defects may exist on the edge of the wafer. In order to improve the product yield, it is necessary to remove the thin film layer that may cause defects on the edge of the wafer. The edge bevel removal (EBR) method is usually used to effectively remove the thin film layer that causes defects. The accuracy of the wafer edge removal width is directly related to the number of defects and the size of the effective area of ​​the wafer. Therefore, the removal width needs to be measured so that the removal width meets the preset standard, thereby ensuring process stability and further ensuring product quality.

[0003] In the related art, measurement is usually performed using professional optical measuring equipment or through manual visual inspection. When the wafer edge removal width is measured using optical measuring equipment, the measuring equipment is expensive and the cost is high. When the wafer edge removal width is measured using manual visual inspection, the measurement result is easily deviated due to human factors, and its accuracy cannot be guaranteed. The accuracy of manual visual measurement is low. Summary of the invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description of the Invention section. The Summary of the Invention section of this application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0005] In view of the existing problems, an embodiment of the present application provides a method for measuring the width of a wafer edge thin film layer removed, the measuring method comprising: Providing a wafer, on which a liner film layer and a film layer to be monitored located on the liner film layer are formed; Removing part of the film layer to be monitored in the peripheral edge area of ​​the wafer to expose part of the liner film layer; Using a film thickness measuring instrument, from the edge of the wafer to the center of the wafer, or from the center of the wafer to the edge of the wafer, sequentially measuring the thickness of the film layer at a plurality of measuring points at predetermined intervals and obtaining a goodness of fit corresponding to each of the measuring points; When the goodness of fit of the current measurement point changes dramatically compared to the goodness of fit of the previous measurement point, it is determined that the edge of the thin film layer to be monitored is between the current measurement point and the previous measurement point; Based on the position information of the current measuring point and / or the position information of the previous measuring point, the actual removal width of the thin film layer to be monitored is determined.

[0006] In some embodiments of the present application, determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and the position information of the previous measurement point includes: Based on the position information of the current measurement point, determining a first distance from the current measurement point to the center of the wafer; Acquire the radius of the wafer, and determine a first removal width based on a difference between the radius of the wafer and the first distance; Determine a second distance from the previous measurement point to the center of the wafer based on the position information of the previous measurement point; A second removal width is determined based on a difference between a radius of the wafer and the second distance, and the actual removal width is between the first removal width and the second removal width.

[0007] In some embodiments of the present application, determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point includes: Based on the position information of the current measurement point, determining a first distance from the current measurement point to the center of the wafer; The radius of the wafer is obtained, and a first removal width is determined based on a difference between the radius of the wafer and the first distance, wherein the actual removal width is less than or equal to the first removal width when measured from the edge of the wafer to the center area of ​​the wafer, or the actual removal width is greater than or equal to the first removal width when measured from the center area of ​​the wafer to the edge of the wafer.

[0008] In some embodiments of the present application, determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and / or the position information of the previous measurement point includes: Determine a second distance from the previous measurement point to the center of the wafer based on the position information of the previous measurement point; A second removal width is determined based on a difference between a radius of the wafer and the second distance, wherein, when measured from the edge of the wafer to the center area of ​​the wafer, the actual removal width is greater than or equal to the second removal width, or when measured from the center area of ​​the wafer to the edge of the wafer, the actual removal width is less than or equal to the second removal width.

[0009] In some embodiments of the present application, the measuring method further includes: A coordinate system is established with any point on the wafer as the origin, and the plurality of measurement points are arranged at intervals in a measurement direction at an angle of 45° to the coordinate axis of the coordinate system.

[0010] In some embodiments of the present application, the origin is the center of the wafer.

[0011] In some embodiments of the present application, the thin film layer to be monitored is a metal layer, the metal layer includes copper, and the material of the liner thin film layer includes tantalum.

[0012] In some embodiments of the present application, the metal layer is formed by a chemical copper electroplating process.

[0013] In some embodiments of the present application, when the goodness of fit of the current measurement point jumps compared to the goodness of fit of the previous measurement point, the goodness of fit of the current measurement point is less than a predetermined value, and the predetermined value is less than or equal to 0.8.

[0014] In some embodiments of the present application, when the goodness of fit of the current measurement point decreases by at least 0.1 compared with the goodness of fit of the previous measurement point, it means that the goodness of fit of the current measurement point has a jump compared with the goodness of fit of the previous measurement point.

[0015] The present application provides a method for measuring the removal width of a wafer edge thin film layer. The method comprises the following steps: performing edge removal processing on a wafer having a pad film layer and a thin film layer to be monitored to expose a portion of the pad film layer. A film thickness measuring instrument is then used to measure the thickness of the pad film layer and obtain a corresponding goodness of fit. The edge position of the thin film layer to be monitored is determined by the value of the goodness of fit, and the actual removal width of the thin film layer to be monitored is determined by the position information of relevant measuring points. Thus, the purpose of measuring the removal width of the wafer edge can be achieved by only using a film thickness measuring instrument. The measurement method of the present application is simple, low-cost and has relatively accurate measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following drawings of the present application are used as part of the present application for understanding the present application. The drawings show the embodiments of the present application and their descriptions, and are used to explain the principles of the present application. In the drawings: Figure 1 A schematic flow chart showing a method for measuring a wafer edge thin film layer removal width according to a specific embodiment of the present application is shown; Figure 2A-2B A cross-sectional view showing the positional relationship between the liner film layer, the film layer to be monitored and the wafer during the edge removal process in a method for measuring the wafer edge film layer removal width according to a specific embodiment of the present application; Figure 3The method for measuring the width of the wafer edge thin film layer removed according to a specific embodiment of the present application is shown. Figure 2B Schematic diagram of top view; Figure 4 A top view showing the positional relationship between a current measurement point A and a previous measurement point B in a method for measuring a wafer edge thin film layer removal width according to a specific embodiment of the present application is shown; Figure 5 A top view showing another positional relationship between a current measurement point A and a previous measurement point B in a method for measuring a wafer edge thin film layer removal width according to a specific embodiment of the present application is shown. DETAILED DESCRIPTION

[0017] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features well known in the art are not described.

[0018] It should be understood that the present application can be implemented in different forms and should not be construed as being limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present application to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0019] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part.

[0020] Spatially relative terms such as "under," "below," "below," "under," "above," "above," etc., may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatially relative terms are intended to include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "on" the other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0021] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0022] During the manufacturing process of semiconductor devices, a thin film layer is formed on the wafer. For example, after a copper thin film layer is formed by a chemical copper plating process, the edge of the wafer may be uneven, and metal or chemicals may remain on the edge. The subsequent polishing process cannot handle the residual metal or chemicals on the edge and inclined area of ​​the wafer. These residual metal or chemicals may cause pollution to the subsequent processes, thereby affecting the surface quality of the wafer and the performance of the device. In order to improve the yield of the product, it is necessary to remove the thin film layer that may cause defects on the edge of the wafer. Usually, a wafer edge removal method is used to effectively remove the thin film layer that causes defects. The accuracy of the wafer edge removal width is directly related to the number of defects and the size of the effective area of ​​the wafer. Therefore, the removal width needs to be measured so that the removal width meets the preset standard, thereby ensuring process stability and then ensuring product quality.

[0023] In the related art, a method for measuring the wafer edge removal width is to use professional optical AOI (Automated Optical Inspection) measurement equipment, or to install a module for measuring the wafer edge removal width in the ECP host. Specifically, the wafer defects can be captured and identified by the electron beam patterned wafer defect inspection system, and the wafer edge removal width can be visually measured. The equipment used in this method is expensive and costly. In the absence of professional optical measurement equipment, manual visual inspection is usually performed using a scale magnifying glass. Manual visual inspection will produce human deviations, and the accuracy cannot be guaranteed. The accuracy of manual visual measurement is low.

[0024] Therefore, in view of the existence of the above-mentioned technical problems, the present application embodiment proposes a method for measuring the width of the wafer edge thin film layer removal, such as Figure 1 As shown, it mainly includes the following steps: Step S110: providing a wafer, on which a liner film layer and a film layer to be monitored located on the liner film layer are formed; Step S120: removing a portion of the thin film layer to be monitored in the peripheral edge region of the wafer to expose a portion of the liner thin film layer; Step S130: using a film thickness measuring instrument to measure the thickness of the film layer at a plurality of measuring points from the edge of the wafer to the center of the wafer, or from the center of the wafer to the edge of the wafer, in sequence at predetermined intervals and obtaining the goodness of fit corresponding to each of the measuring points; Step S140: when the goodness of fit of the current measurement point jumps compared to the goodness of fit of the previous measurement point, it is determined that the edge of the thin film layer to be monitored is between the current measurement point and the previous measurement point; Step S150: determining the actual removal width of the thin film layer to be monitored based on the position information of the current measuring point and / or the position information of the previous measuring point.

[0025] The embodiment of the present application provides a method for measuring the removal width of a thin film layer at the edge of a wafer. The wafer having a pad film layer and a thin film layer to be monitored is subjected to edge removal processing to expose part of the pad film layer. A film thickness measuring instrument is then used to measure the thickness of the pad film layer and obtain the corresponding goodness of fit. The edge position of the thin film layer to be monitored is determined by the value of the goodness of fit, and the actual removal width of the thin film layer to be monitored is determined by the position information of the relevant measuring points. Thus, the purpose of measuring the removal width of the wafer edge can be achieved by only using a thin film layer thickness measuring instrument. The measurement method of the present application is simple, low-cost and has relatively accurate measurement results.

[0026] Below, reference Figure 1 , Figure 2A, Figure 2B and Figures 3 to 5 The method for measuring the width of the wafer edge thin film layer removed in an embodiment of the present application is described in detail.

[0027] First, if Figure 1 As shown, step S110 is performed to provide a wafer, on which a liner film layer and a film layer to be monitored located on the liner film layer are formed.

[0028] like Figure 2A As shown, a wafer 200 is provided, a pad film layer 201 is formed on the wafer 200, and a film layer 202 to be monitored is formed on the pad film layer 201. It is worth mentioning that the edge of the pad film layer 201 can be located within the edge of the wafer 200, or can be basically aligned with the edge of the wafer. The present application is described by taking the edge of the pad film layer 201 being basically aligned with the edge of the wafer 200 as an example. Exemplarily, the film layer 202 to be monitored is a metal layer, and the metal layer includes but is not limited to copper (Cu), and the material of the pad film layer 201 includes but is not limited to Ta (tantalum). Exemplarily, the metal layer is formed by a chemical copper plating process.

[0029] Then, continue as Figure 1 As shown, step S120 is performed to remove a portion of the film layer 202 to be monitored in the peripheral edge region of the wafer 200 to expose a portion of the liner film layer 201, and obtain the following Figure 2B It is worth mentioning that the subsequent steps of the embodiment of the present application will be as follows Figure 2B is performed on the structure shown.

[0030] Next, step S130 is performed, and the thickness of the thin film layer at a plurality of measuring points is measured in sequence at predetermined intervals from the edge of the wafer 200 to the central area of ​​the wafer 200, or from the central area of ​​the wafer 200 to the edge of the wafer 200, by a thin film thickness measuring instrument, and the goodness of fit corresponding to each of the measuring points is obtained. It is worth mentioning that when the thickness of the thin film layer is measured from the edge of the wafer 200 to the central area of ​​the wafer 200 by a thin film thickness measuring instrument, the thin film layer is the liner thin film layer 201, and when the thickness of the thin film layer is measured from the central area of ​​the wafer (the central area is also the area within the edge of the thin film layer 202 to be monitored) to the edge of the wafer 200 by a thin film thickness measuring instrument, the thin film layer is the thin film layer 202 to be monitored.

[0031] Goodness of fitness (GOF) is the value obtained by comparing the measured spectrum fitting with the actual measurement results. It is worth mentioning that there is a spectrum value in the film thickness measuring instrument, which is multiplied by the gain coefficient in the film thickness measuring instrument to obtain the measured spectrum fitting. The film thickness measuring instrument can automatically calculate the goodness of fit corresponding to the measurement point based on the measured spectrum fitting and the actual measurement results of the measurement point. The goodness of fit can be obtained by any suitable method, which is specifically limited here.

[0032] Next, step S140 is executed, and when the goodness of fit of the current measurement point jumps compared to the goodness of fit of the previous measurement point, it is determined that the edge of the thin film layer to be monitored is between the current measurement point and the previous measurement point. Exemplarily, when the goodness of fit of the current measurement point jumps compared to the goodness of fit of the previous measurement point, the goodness of fit of the current measurement point is less than a predetermined value, and the predetermined value is less than or equal to 0.8, for example, the predetermined value is 0.8, 0.75 or 0.7. Exemplarily, when the thin film thickness measuring instrument performs thin film layer thickness measurement based on the thin film layer to be monitored, when the goodness of fit of the current measurement point jumps compared to the goodness of fit of the previous measurement point, the goodness of fit of the current measurement point is greater than the predetermined value. In a specific example, the pad film layer is a Ta film layer, and the film layer to be monitored is a copper layer. Since the substrate is metal Ta, the process recipe (i.e., measurement parameters) of the film thickness measuring instrument is configured as Ta-related parameters. Starting from the first measurement point on the edge of the wafer 200, the film layer thickness at multiple measurement points is measured in sequence at predetermined intervals. Before the copper layer, the film thickness measuring instrument has been measuring the thickness of the film layer with only the Ta film layer. Since the process recipe of the equipment is Ta-related parameters, when there is only the Ta film layer, the related parameters of the process recipe match the actual film layer, the measured value is accurate, and the goodness of fit is high. When the copper layer is measured, the film thickness measuring instrument should actually use the copper-related parameters for thickness measurement calculation, but in the present application, the Ta-related parameters are still used for calculation. Therefore, the goodness of fit calculated by the film thickness measuring instrument will jump at this time. For example, when the goodness of fit of the current measurement point decreases by at least 0.1 compared with the goodness of fit of the previous measurement point, it means that the goodness of fit of the current measurement point jumps compared with the goodness of fit of the previous measurement point. When the goodness of fit jumps, it means that the device has detected the relevant material of the film layer to be monitored, and there is a film layer to be monitored at this measuring point. Figure 2B and Figure 3 As shown, the current measuring point is A, and the previous measuring point is B. When measuring point B, there is only the liner film layer 201, and when measuring point A, there are both the liner film layer 201 and the film layer to be monitored 202. Therefore, it can be determined that the edge of the film layer to be monitored 202 is between the current measuring point and the previous measuring point.

[0033] Next, step S150 is executed to determine the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and / or the position information of the previous measurement point. In some embodiments, the position information of the measurement point can be represented by a coordinate system and corresponding coordinates. Exemplarily, a coordinate system is established with any point on the wafer as the origin, and a plurality of measurement points are arranged at intervals in the measurement direction at 45° to the coordinate axis of the coordinate system. Exemplarily, the origin is the center of the wafer. Arranging a plurality of measurement points at intervals in the measurement direction at 45° to the coordinate axis of the coordinate system can make the values ​​of the horizontal and vertical coordinates of the measurement points equal, so as to facilitate the determination of the actual removal width.

[0034] In some embodiments, based on the position information of the current measurement point and the position information of the previous measurement point, determining the actual removal width of the thin film layer to be monitored includes: Figure 3 As shown, based on the position information of the current measuring point A, such as the coordinates of point A, a first distance L1 from the current measuring point A to the center C of the wafer is determined; the radius R of the wafer is obtained, and a first removal width R-L1 is determined based on the difference between the radius of the wafer and the first distance L1; based on the position information B of the previous measuring point, a second distance L2 from the previous measuring point B to the center C of the wafer is determined; based on the difference between the radius R of the wafer and the second distance L2, a second removal width R-L2 is determined. Since multiple test points are set at predetermined intervals, when the first test point to be measured is When monitoring the measurement points on the thin film layer, based on the above reasons, GOF will jump. At this time, the current measurement point A is either on the edge of the thin film layer 202 to be monitored or on the side of the thin film layer 202 to be monitored close to the center of the circle. Therefore, the actual removal width L is between the first removal width R-L1 and the second removal width R-L2. The specific position of the current measurement point A is related to the predetermined interval of the measurement points. The smaller the interval, the closer to the edge of the thin film layer 202 to be monitored, and the denser the measurement points, the closer the first removal width R-L1 and the second removal width R-L2 are, and the value of the actual removal width L is more accurate.

[0035] In some embodiments, when a film thickness measuring instrument is used to measure from the edge of the wafer to the center of the wafer, Figure 4As shown, when the predetermined interval is large, the actual removal width L of the film layer 202 to be monitored is determined based on the position information of the current measurement point A, including: determining the first distance L1 from the current measurement point A to the center C of the wafer based on the position information of the current measurement point A; obtaining the radius R of the wafer, and determining the first removal width R-L1 based on the difference between the radius R of the wafer and the first distance L1, then the actual removal width L is less than or equal to the first removal width R-L1, when the current measurement point A is exactly at the edge of the film layer 202 to be monitored, and the previous measurement point B is also exactly at the edge of the liner film layer 201, the actual removal width L is equal to the first removal width R-L1. Similarly to the above calculation method, when the film thickness measuring instrument is used to measure from the center area of ​​the wafer to the edge of the wafer, the current measurement point is outside the film layer to be monitored, the actual removal width is greater than or equal to the first removal width, and when the current measurement point is extremely close to the edge of the film layer to be monitored, it can be considered that the actual removal width is equal to the first removal width, and the specific calculation process is not repeated here.

[0036] In some embodiments, when a film thickness measuring instrument is used to measure from the edge of the wafer to the center of the wafer, Figure 5 As shown, when the predetermined interval is large and the previous measurement point B is close to the thin film layer 202 to be monitored, the actual removal width L of the thin film layer 202 to be monitored is determined based on the position information of the current measurement point A and / or the position information of the previous measurement point B, including: determining a second distance L2 from the previous measurement point B to the center C of the wafer based on the position information of the previous measurement point B, determining a second removal width R-L2 based on the difference between the radius R of the wafer and the second distance L2, the actual removal width L is greater than or equal to the second removal width R-L2, and the closer the previous measurement point B is to the edge of the thin film layer 202 to be monitored, the closer the actual removal width L is to the second removal width R-L2. Similarly to the above calculation method, when measuring from the center area of ​​the wafer to the edge of the wafer using a film thickness measuring instrument, the current measuring point is outside the film layer to be monitored and on the liner film layer, and the previous measuring point is inside the film layer to be monitored. The actual removal width is less than or equal to the second removal width. When the previous measuring point is extremely close to the edge of the film layer to be monitored and the current measuring point is extremely close to the edge of the liner film layer, it can be considered that the actual removal width is equal to the second removal width. The specific calculation process will not be repeated here.

[0037] Generally, when the actual removal width is within the predetermined range of the removal width, it can be determined that the actual removal width meets the standard. For example, if the predetermined range of the removal width is 2.5 mm ± 0.5 mm, then when the actual removal width is between 2.0 mm and 3.0 mm, it is considered that the actual removal width meets the standard.

[0038] In some embodiments, the predetermined value range of the removal width can also correspond to a radial dimension range, that is, the radial dimension range value corresponding to the edge of the thin film layer 202 to be monitored. Then, based on the position information of the current measurement point and / or the position information of the previous measurement point, the radial dimension of the current measurement point (that is, the aforementioned first distance) and the radial dimension of the previous measurement point (that is, the aforementioned second distance) are determined. When the first distance and the second distance are within the radial dimension range, it can be determined that the removal width meets the predetermined standard. If it exceeds the radial dimension range, it does not meet the predetermined standard.

[0039] So far, the description of the measurement method of the wafer edge thin film layer removal width according to an embodiment of the present application is completed. It can be understood that the measurement method of the wafer edge thin film layer removal width of this embodiment not only includes the above steps, but may also include other necessary steps before, during or after the above steps, which are all included in the scope of the measurement method of this embodiment.

[0040] The embodiment of the present application provides a method for measuring the removal width of a thin film layer at the edge of a wafer. The wafer having a cushion film layer and a thin film layer to be monitored is subjected to edge removal processing to expose part of the cushion film layer. A thin film thickness measuring instrument is then used to measure the thickness of the cushion film layer and obtain the corresponding goodness of fit. The edge position of the thin film layer to be monitored is determined by the value of the goodness of fit, and the actual removal width of the thin film layer to be monitored is determined by the position information of the relevant measuring points. Thus, the purpose of measuring the removal width of the wafer edge can be achieved by only using a thin film thickness measuring instrument. The measurement method of the present application is simple, low-cost and has relatively accurate measurement results.

[0041] It should be noted that the above embodiments illustrate the present application rather than limit the present application, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of multiple such elements. The present application may be implemented with the aid of hardware including several different elements and with the aid of appropriately programmed computers. In a unit claim listing several on-board systems, several of these on-board systems may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names.

[0042] The above is only a specific implementation method or description of a specific implementation method of the present application, and the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for measuring the width of a wafer edge thin film layer removed, characterized in that: include: Providing a wafer, on which a liner film layer and a film layer to be monitored located on the liner film layer are formed; Removing part of the film layer to be monitored in the peripheral edge area of ​​the wafer to expose part of the liner film layer; Using a film thickness measuring instrument, measuring the thickness of the film layer at a plurality of measuring points from the edge of the wafer to the center of the wafer, or measuring the thickness of the film layer at a plurality of measuring points from the center of the wafer to the edge of the wafer at predetermined intervals, and obtaining the goodness of fit corresponding to each of the measuring points; When the goodness of fit of the current measurement point changes dramatically compared to the goodness of fit of the previous measurement point, it is determined that the edge of the thin film layer to be monitored is between the current measurement point and the previous measurement point; Based on the position information of the current measuring point and / or the position information of the previous measuring point, the actual removal width of the thin film layer to be monitored is determined.

2. The measuring method according to claim 1, characterized in that: The determining the actual removal width of the thin film layer to be monitored based on the position information of the current measuring point and the position information of the previous measuring point includes: Determine a first distance from the current measurement point to the center of the wafer based on the position information of the current measurement point; Acquire the radius of the wafer, and determine a first removal width based on a difference between the radius of the wafer and the first distance; Determine a second distance from the previous measurement point to the center of the wafer based on the position information of the previous measurement point; A second removal width is determined based on a difference between a radius of the wafer and the second distance, and the actual removal width is between the first removal width and the second removal width.

3. The measuring method according to claim 1, characterized in that: The determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point includes: Determine a first distance from the current measurement point to the center of the wafer based on the position information of the current measurement point; The radius of the wafer is obtained, and a first removal width is determined based on a difference between the radius of the wafer and the first distance, wherein the actual removal width is less than or equal to the first removal width when measured from the edge of the wafer to the center area of ​​the wafer, or the actual removal width is greater than or equal to the first removal width when measured from the center area of ​​the wafer to the edge of the wafer.

4. The measuring method according to claim 1, characterized in that: Determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and / or the position information of the previous measurement point includes: Determine a second distance from the previous measurement point to the center of the wafer based on the position information of the previous measurement point; A second removal width is determined based on a difference between a radius of the wafer and the second distance, wherein the actual removal width is greater than or equal to the second removal width when measured from the edge of the wafer to the center area of ​​the wafer, or the actual removal width is less than or equal to the second removal width when measured from the center area of ​​the wafer to the edge of the wafer.

5. The measuring method according to claim 1, characterized in that: The measuring method further comprises: A coordinate system is established with any point on the wafer as the origin, and the plurality of measurement points are arranged at intervals in a measurement direction at an angle of 45° to the coordinate axis of the coordinate system.

6. The measuring method according to claim 5, characterized in that: The origin is the center of the wafer.

7. The measuring method according to claim 1, characterized in that: The film layer to be monitored is a metal layer, the metal layer includes copper, and the material of the liner film layer includes tantalum.

8. The measuring method according to claim 7, characterized in that: The metal layer is formed by a chemical copper electroplating process.

9. The measuring method according to claim 1, characterized in that: When the goodness of fit of the current measurement point jumps compared to the goodness of fit of the previous measurement point, the goodness of fit of the current measurement point is less than a predetermined value, and the predetermined value is less than or equal to 0.

8.

10. The measuring method according to claim 1, characterized in that: When the goodness of fit of the current measurement point decreases by at least 0.1 compared with the goodness of fit of the previous measurement point, it means that a jump occurs in the goodness of fit of the current measurement point compared with the goodness of fit of the previous measurement point.

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